Engine 11 chainring

Engine 11 chainring DEFAULT

Can I switch 44 teeth Chainring to 50 teeth

The answer is maybe. Mostly depending on if you will have enough clearance on your chainstay. According to this chart, a 44 tooth chainring would have a diameter of 184.6mm, while a 50 tooth chainring would have a diameter of 208.8mm, that's an extra 12.1 mm (24.2mm ÷ 2), or just under a half inch of clearance over what you would have already.

If you don't have enough clearance, you could get a bottom bracket with a slightly longer axle. Although you shouldn't push it too far as you will have problems with the chainline if your bottom bracket axle is too long.

See the image below to see how a larger chainstay could have problems with chainstay clearance. Also, as mentioned in the comments, you will need a longer chain.

According to this answer. You should keep about 4mm as minimum clearance between the chainstay and the chainring.

chainstay clearance

Sours: https://bicycles.stackexchange.com/questions/76538/can-i-switch-44-teeth-chainring-to-50-teeth

low price Creative Metal Leather Car Bicycle LED Keychain Key Fob Engine Chainring keyring general high quality

low price Creative Metal Leather Car Bicycle LED Keychain Key Fob Engine Chainring keyring general high quality

the first symptom of a cold is usually a sore throat. this is generally followed by sneezing or a blocked, sore or runny nose. usually, 1 in 3 people with a cold will get a cough and feel unwell.

colds are caused by viruses. antibiotics cannot treat viruses. instead, drink plenty of liquids to replace those lost from sweating and runny noses. get lots of rest and eat healthily. do not ask your gp for antibiotics for a cold.

you will usually feel worse during the first 2 to 3 days before gradually starting to improve. your symptoms will usually last about a week.

cold and flu symptoms are similar but flu tends to be more severe.

cold

  • appears gradually
  • affects mainly your nose and throat
  • makes you feel unwell but you're ok to carry on as normal - for example, go to work

flu

    low price Creative Metal Leather Car Bicycle LED Keychain Key Fob Engine Chainring keyring general high quality
  • appears quickly within a few hours
  • affects more than just your nose and throat
  • makes you feel exhausted and too unwell to carry on as normal

cold symptoms can include:

  • blocked or runny nose
  • sore throat
  • headaches
  • muscle aches
  • coughs
  • sneezing
  • a raised temperature
  • pressure in your ears and face
  • loss of taste and smell

the symptoms are the same in adults and children. sometimes, symptoms last longer in children.

causes of colds

colds are caused by viruses. they can easily spread to other people. you're infectious until all your symptoms have gone. this usually takes about a week.

colds are spread by germs from coughs and sneezes which can live on hands and surfaces for 24 hours.

to reduce the risk of spreading a cold you should:

  • wash your hands often with warm water and soap
  • cough into your elbow to stop germs getting on to your hands and spreading to other people
  • use tissues to trap germs when you cough or sneeze
  • bin used tissues as quickly as possible

how to prevent catching a cold

the best ways to avoid catching a cold are:

  • washing your hands with warm water and soap, especially before eating
  • not sharing towels or household items, like cups, with someone who has a cold
  • not touching your eyes or nose. you can infect your body if you've come into contact with the virus.
  • staying fit and healthy
Sours: https://dermrxpharmacy.com/index.php?brick464/efaded7244.htm
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Review: 3T Strada – The 1x / Single Chainring Road Bike

1x drivetrains are hot, but for road bikes? Earlier in 2018, the 3T Strada raised the eyebrows of the European professional peloton when Irish-registered professional team, Aqua Blue Sport, announced they’d be riding the uber aerodynamic 3T road bike during the 2018 season.

It has disc brakes, nothing new there, we’ve already seen sporadic use of this technology in the pro peloton.

What the eff? No front derailleur?

But, the 3T Strada eschews 2x / two chainrings for a 1x / single chainring – huh? Isn’t this supposed to be a road bike?

3T have made some interesting claims with the Strada. Sure, a lot of work has gone into the aerodynamics of the bike, you’re either going to love or hate how it looks. Credit the Strada’s stealthy lines to Gerard Vroomen, co-founder and former co-owner of Cervelo.

There’s a generous amount of room for tyre clearance, namely 30mm front and rear.

However, the claim of dropping about 400 grams to ditch one chainring, a front derailleur and a further improvement in aerodynamics is a bit questionable in my opinion.

Thus, with a healthy dose of skepticism in mind, I took delivery of the 3T Strada (size medium) early in 2018. You can check out my unboxing video here (so many people love unboxing videos!… or not) and the build video here.

Rolling some of Florida’s historic brick roads.

Much of the time I ride gravel and cyclocross bikes on the funnest roads of all, but I still ride on the road when necessary. I despise doing solo intervals, but with the help of some of my mates in Gainesville, Florida, I knock about on the odd roadie group ride, hoping to maintain and gather some higher end fitness.

The 3T Strada has served as my primary road bike for over eight months for group rides and solo jaunts.

Rather than continuing to ramble on about the 3T Strada in written form, please check out my comprehensive, long-term review of the bike in the video below. Gearing, group rides, rides in the Georgia mountains, all of it is covered.

For your viewing delight, a few more photos:

Swoopy lines of the seattube hug the rear wheel.

This bike be UCI approved.

The uber aero seatpost clamp has performed flawlessly.

The seatpost head is finicky to setup, but hasn’t budged.

Squaero = Aero.

Pardon the steerer, you don’t cut them short on review bikes.

Final Thoughts

A single chainring road bike may indeed work well for some people. It would be killer in a criterium or in flat parts of the world with the odd overpass or two, but I feel it’s a massive compromise. In my opinion, the small amount of weight saved and claimed aerodynamic advantages just aren’t worth the limitations of highly annoying gearing, especially when the front derailleurs in modern drivetrains shift so well. Why subject myself to annoying gaps on the cassette, where I felt the Strada was dictating my tempo with a 1x drivetrain – and not the other way around – when I can have it all with two chainrings and a much tighter cassette.

I really wish there was an option to retrofit this Strada with a front derailleur mount, because it would make the riding experience so much better for me. With that said, if you can get past the bike’s idiosyncrasies and limitations, the 3T Strada may be the ticket for you. The frame is a rocket and it’s a sharp looker.

Don’t like the idea of 1x on a road bike? 3T released the Due a little while ago, the 2x / double chainring version of the Strada. I would like a 3T Due please… and a 3T Exploro with 2x whilst you’re at it.
Priced at about $US 3,300 for the 3T Strada Team Red/White frame module as seen in this review, or $US 5,900 for the complete Strada Team Force bike, all are available now at 3T’s website. 3T also offers a slighter heavier, Strada Pro model if you don’t to spend quite as much.

3T Cycling


Article and video by Gravel Cyclist. Jayson O’Mahoney is the Gravel Cyclist: A website about the Gravel Cycling Experience.

Sours: https://bikerumor.com/2018/11/29/review-3t-strada-the-1x-single-chainring-road-bike/
FIXED GEAR VLOG #127 / Destroying a Engine 11 frame

2021 Engine11 CritD x Faith Complete Bike

Exclude Sale and Clearance, if for any reason you do not love your items once received, and the condition is still new, with tags, haven't be used, they can be returned at any time! You can exchange or return merchandise through our mail. But return policy is within 30 days. We will not be able to offer you a refund or exchange past 30 days from the date of purchase.

Below are the steps you need to follow for return & refund policy.

1. If you confirmed to make exchange or refund, please attach your purchase invoice got from us and email to [email protected] 

2. Once we confirmed received your requirement, we'll proceed refund process and send back confirmation. To not affect second selling, please ensure your return item with same condition (with tags) as new as you received.

3. Please send your item back with original packing to below our shop address. Shipping fee or any custom fee will be charge by your own side.

Faith Gear Fixie Corp.

No.7, Ln.106, Baojiang Rd., Chonghe Dist., 235 New Taipei City, Taiwan.

+886-2-29405758

4. We'll arrange exchange or refund process once confirmed receiving your item without damage. Exchange will send ASAP if product in stock. If exchange product is out of stock, we'll inform the estimated arrival days to you. Refund may will takes 7~14 days returned to your account depends on each bank. 

Sours: https://www.faithgearfixie.com/product-page/2021-engine11-critd-complete-bike

11 chainring engine

2014 Engine 11 - Sprinter Track Bike

Category: Road Bikes

Frame Size: 60cm
Wheel Size: 700C

Original Post Date: Jan-08-2017 2:39:00
Last Repost Date: May-20-2018 6:41:02
Still For Sale:Sold
View Count: 2,886
Watch Count: 0

Selling my e11 Redhook track bike. [https://redhookcrit.com/]
More info on these bikes here: http://www.engine11bikes.com/

Frame: ENGINE11 “SPRINTER”
Fork/ Headset: Columbus Carbon Fork/ 1 1/8" FSA
Crankset/ Bottom Bracket: Truvativ Omnium/ SRAM BB (167.5)
Pedals: Look
Drivetrain/ Cog/ Chainring/ Chain: Dura Ace/ Izumi
Handlebars/ Stem: Deda RHM 02 / Ritchey
Saddle /Seatpost: Selle Italia Flight/ Thomson
Front Wheel/ Hub/ Tire: Mavic Open Pro/ Dura Ace/ Continental
Rear Wheel/ Hub/ Tire: Mavic Open Pro/ Dura Ace/ Continental
Geometry: http://images.bigcartel.com/product_images/194433097/sprinter_geo.jpg?auto=format&fit=max&w=1500

Saddle is a little chewed up, as it is from the 90s, but works great with no creaks. Bikes solid for the price, get at me if you feel like riding the velodrome (or in traffic) instead of the dirt for a change of pace.

Send Message

Restrictions: Reasonable offers only, No Trades, Will ship within country only

Sours: https://www.pinkbike.com/buysell/2111024
Crankset Reveal for my Engine 11 Crit-D Track Bike

Bicycle gearing

A ShimanoXT rear derailleur on a mountain bike
A bicycle gearbox with chain tensioner

Bicycle gearing is the aspect of a bicycledrivetrain that determines the relation between the cadence, the rate at which the rider pedals, and the rate at which the drive wheel turns.

On some bicycles there is only one gear and, therefore, the gear ratio is fixed, but most modern bicycles have multiple gears and thus multiple gear ratios. A shifting mechanism allows selection of the appropriate gear ratio for efficiency or comfort under the prevailing circumstances: for example, it may be comfortable to use a high gear when cycling downhill, a medium gear when cycling on a flat road, and a low gear when cycling uphill. Different gear ratios and gear ranges are appropriate for different people and styles of cycling.

A cyclist's legs produce power optimally within a narrow pedalling speed range, or cadence. Gearing can be optimized to use this narrow range as efficiently as possible. As in other types of transmissions, the gear ratio is closely related to the mechanical advantage of the drivetrain of the bicycle. On single-speed bicycles and multi-speed bicycles using derailleur gears, the gear ratio depends on the ratio of the number of teeth on the crankset to the number of teeth on the rear sprocket (cogset). For bicycles equipped with hub gears, the gear ratio also depends on the internal planetary gears within the hub. For a shaft-driven bicycle the gear ratio depends on the bevel gears used at each end of the shaft.

For a bicycle to travel at the same speed, using a lower gear (larger mechanical advantage) requires the rider to pedal at a faster cadence, but with less force. Conversely, a higher gear (smaller mechanical advantage) provides a higher speed for a given cadence, but requires the rider to exert greater force. Different cyclists may have different preferences for cadence and pedaling force. Prolonged exertion of too much force in too high a gear at too low a cadence can increase the chance of knee damage;[1] cadence above 100 rpm becomes less effective after short bursts, as during a sprint.[1]

Measuring gear ratios[edit]

Methods[edit]

There are at least four different methods[2] for measuring gear ratios: gear inches, metres of development (roll-out), gain ratio, and quoting the number of teeth on the front and rear sprockets respectively. The first three methods result in each possible gear ratio being represented by a single number which allows the gearing of any bicycles to be compared; the numbers produced by different methods are not comparable, but for each method the larger the number the higher the gear. The fourth method uses two numbers and is only useful in comparing bicycles with the same drive wheel diameter. In the case of road bikes, this is usually around 670 mm. A 700c "standard" wheel has a 622mm rim diameter. The final wheel diameter depends on the specific tire but will be approximately 622mm plus twice the tire width.

Front/rear measurement only considers the sizes of a chainring and a rear sprocket. Gear inches and metres of development also take the size of the rear wheel into account. Gain ratio goes further and also takes the length of a pedal crankarm into account.

Gear inches and metres of development are closely related: to convert from gear inches to metres of development, multiply by 0.08 (more exactly: 0.0798, or precisely: 0.0254π).

The methods of calculation which follow assume that any hub gear is in direct drive. Multiplication by a further factor is needed to allow for any other selected hub gear ratio [3] (many online gear calculators have these factors built in for various popular hub gears).

  • Gear inches = Diameter of drive wheel in inches × (number of teeth in front chainring / number of teeth in rear sprocket). Normally rounded to nearest whole number.
  • Metres of development = Circumference of drive wheel in metres × (number of teeth in front chainring / number of teeth in rear sprocket).
  • Gain ratio = (Radius of drive wheel / length of pedal crank) × (number of teeth in front chainring / number of teeth in rear sprocket). Measure radius and length in same units.
Both metres of development and gain ratios are normally rounded to one decimal place.
Gear inches corresponds to the diameter (in inches) of the main wheel of an old-fashioned penny-farthing bicycle with equivalent gearing. Metres of development corresponds to the distance (in metres) traveled by the bicycle for one rotation of the pedals. Gain ratio is the ratio between the distance travelled by the bicycle and the distance travelled by a pedal, and is a pure number, independent of any units of measurement.
  • Front/rear gear measurement uses two numbers (e.g. 53/19) where the first is the number of teeth in the front chainring and the second is the number of teeth in the rear sprocket. Without doing some arithmetic, it is not immediately obvious that 53/19 and 39/14 represent effectively the same gear ratio.

Examples[edit]

The following table provides some comparison of the various methods of measuring gears (the particular numbers are for bicycles with 170 mm cranks, 700C wheels, and 25 mm tyres). Speeds for several cadences in revolutions per minute are also given. On each row the relative values for gear inches, metres of development, gain ratio, and speed are more or less correct, while the front/rear values are the nearest approximation which can be made using typical chainring and cogset sizes. Note that bicycles intended for racing may have a lowest gear of around 45 gear inches (or 35 if fitted with a compact crankset).

GearGear
inches
Metre
development
Gain
ratio
Front/
rear
60 rpm80 rpm100 rpm120 rpm
mphkm/hmphkm/hmphkm/hmphkm/h
Very high125109.453/1122.33629.747.837.159.744.572
High10087.553/1418292438.63048.33657.9
Medium705.65.253/19 or 39/1412.52016.626.72133.62540
Low403.23.034/237.211.69.615.411.919.214.323
Very low201.61.532/423.55.64.77.65.99.57.111.4

Single speed bicycles[edit]

Main article: Single-speed bicycle

Single-speed mountain bike

A single-speed bicycle is a type of bicycle with a single gear ratio. These bicycles are without derailleur gears, hub gearing or other methods for varying the gear ratio of the bicycle. Adult single-speed bicycles typically have a gear ratio of between 55 and 75 gear inches, depending on the rider and the anticipated usage.

There are many types of modern single speed bicycles; BMX bicycles, some bicycles designed for (younger) children, cruiser type bicycles, classic commuter bicycles, unicycles, bicycles designed for track racing, fixed-gear road bicycles, and fixed-gear mountain bicycles.

The fixed-gear single-speed bicycle is the most basic type of bicycle. A fixed-gear bike does not have a freewheel mechanism to allow coasting.

[edit]

The gearing supplied by the manufacturer on a new bicycle is selected to be useful to the majority of people. Some cyclists choose to fine-tune the gearing to better suit their strength, level of fitness, and expected use. When buying from specialist cycle shops, it may be less expensive to get the gears altered before delivery rather than at some later date. Modern crankset chainrings can be swapped out, as can cogsets.

While long steep hills and/or heavy loads may indicate a need for lower gearing, this can result in a very low speed. Balancing a bicycle becomes more difficult at lower speeds. For example, a bottom gear around 16 gear inches gives an effective speed of perhaps 3 miles/hour (5 km/hour) or less, at which point it might be quicker to walk (bike shoes permitting).

Relative gearing[edit]

As far as a cyclist's legs are concerned, when changing gears, the relative difference between two gears is more important than the absolute difference between gears.[4] This relative change, from a lower gear to a higher gear, is normally expressed as a percentage, and is independent of what system is used to measure the gears. Cycling tends to feel more comfortable if nearly all gear changes have more or less the same percentage difference.[5] For example, a change from a 13-tooth sprocket to a 15-tooth sprocket (15.4%) feels very similar to a change from a 20-tooth sprocket to a 23-tooth sprocket (15%), even though the latter has a larger absolute difference.

To achieve such consistent relative differences the absolute gear ratios should be in logarithmic progression; most off-the-shelf cogsets do this with small absolute differences between the smaller sprockets and increasingly larger absolute differences as the sprockets get larger. Because sprockets must have a (relatively small) whole number of teeth it is impossible to achieve a perfect progression; for example the seven derailleur sprockets 14-16-18-21-24-28-32 have an average step size of around 15% but with actual steps varying between 12.5% and 16.7%. The epicyclic gears used within hub gears have more scope for varying the number of teeth than do derailleur sprockets, so it may be possible to get much closer to the ideal of consistent relative differences, e.g. the Rohloff Speedhub offers 14 speeds with an average relative difference of 13.6% and individual variations of around 0.1%.

Racing cyclists often have gears with a small relative difference of around 7% to 10%; this allows fine adjustment of gear ratios to suit the conditions and maintain a consistent pedalling speed. Mountain bikes and hybrid bikes often have gears with a moderate relative difference of around 15%; this allows for a much larger gear range while having an acceptable step between gears. 3-speed hub gears may have a relative difference of some 33% to 37%;[5] such big steps require a very substantial change in pedalling speed and often feel excessive.[6] A step of 7% corresponds to a 1-tooth change from a 14-tooth sprocket to a 15-tooth sprocket, while a step of 15% corresponds to a 2-tooth change from a 13-tooth sprocket to a 15-tooth sprocket.

By contrast, car engines deliver power over a much larger range of speeds than cyclists' legs do, so relative differences of 30% or more are common for car gearboxes.

Usable gears[edit]

On a bicycle with only one gear change mechanism (e.g. rear hub only or rear derailleur only), the number of possible gear ratios is the same as the number of usable gear ratios, which is also the same as the number of distinct gear ratios.

On a bicycle with more than one gear change mechanism (e.g. front and rear derailleur), these three numbers can be quite different, depending on the relative gearing steps of the various mechanisms. The number of gears for such a derailleur equipped bike is often stated simplistically, particularly in advertising, and this may be misleading.

Consider a derailleur-equipped bicycle with 3 chainrings and an 8-sprocket cogset:

the number of possible gear ratios is 24 (=3×8, this is the number usually quoted in advertisements);
the number of usable gear ratios is 22;
the number of distinct gear ratios is typically 16 to 18.

The combination of 3 chainrings and an 8-sprocket cogset does not result in 24 usable gear ratios. Instead it provides 3 overlapping ranges of 7, 8, and 7 gear ratios. The outer ranges only have 7 ratios rather than 8 because the extreme combinations (largest chainring to largest rear sprocket, smallest chainring to smallest rear sprocket) result in a very diagonal chain alignment which is inefficient and causes excessive chain wear.[7] Due to the overlap, there will usually be some duplicates or near-duplicates, so that there might only be 16 or 18 distinct gear ratios. It may not be feasible to use these distinct ratios in strict low-high sequence anyway due to the complicated shifting patterns involved (e.g. simultaneous double or triple shift on the rear derailleur and a single shift on the front derailleur). In the worst case there could be only 10 distinct gear ratios, if the percentage step between chainrings is the same as the percentage step between sprockets. However, if the most popular ratio is duplicated then it may be feasible to extend the life of the gear set by using different versions of this popular ratio.

Gearing range[edit]

The gearing range indicates the difference between bottom gear and top gear, and provides some measure of the range of conditions (high speed versus steep hills) with which the gears can cope; the strength, experience, and fitness level of the cyclist are also significant. A range of 300% or 3:1 means that for the same pedalling speed a cyclist could travel 3 times as fast in top gear as in bottom gear (assuming sufficient strength, etc.). Conversely, for the same pedalling effort, a cyclist could climb a much steeper hill in bottom gear than in top gear.

The overlapping ranges with derailleur gears mean that 24 or 27 speed derailleur gears may only have the same total gear range as a (much more expensive) Rohloff 14-speed hub gear. Internal hub geared bikes typically have a more restricted gear range than comparable derailleur-equipped bikes, and have fewer ratios within that range.

The approximate gear ranges which follow are merely indicative of typical gearing setups, and will vary somewhat from bicycle to bicycle.

rangetransmissionusable gearsmean step
180%3-speed hub gears334.2%
250%5-speed hub gears525.7%
300%7-speed hub gears720.1%
307%8-speed hub gears817.4%
327%typical 1 chainring derailleur setup (1x10, 11-36)1014.1%
327%road 1 chainring derailleur setup (1x11, 11-36)1112.6%
380%NuVinci continuously variable transmission[8]continuousnone
409%11-speed hub gears1115.1%
420%mountain 1 chainring derailleur setup (1x11, 10-42)1115.4%
428%road 2 chainring derailleur setup (2x10, 50-34 x 11-32)1312.9%
441%road 3 chainring derailleur setup (3x10, 52/39/30 x 11-28)1511.2%
500%extreme 1 chainring derailleur setup (1x12, 10-50)1215.8%
518%mountain 2 chainring derailleur setup (2x10, 38-24 x 11-36)1413.5%
526%Rohloff Speedhub 14-speed hub gear1413.6%
630%Mountain 2x11 derailleur setup (24/36 x 10-42)[9]1415.2%
636%18-speed bottom bracket gearbox[10]1811.5%
655%mountain 3 chainring derailleur setup (3x10, 44-33-22 x 11-36)1613.3%
698%touring 3 chainring derailleur setup (3x10, 48-34-20 x 11-32)1514.9%

Gear ranges of almost 700% can be achieved on derailleur setups, though this may result in some rather large steps between gears or some awkward gear changes. However, through the careful choice of chainrings and rear cogsets, e.g. 3 chainrings 48-34-20 and a 10-speed cassette 11–32, one can achieve an extremely wide range of gears that are still well spaced. This sort of setup has proven useful on a multitude of bicycles such as cargo bikes, touring bikes and tandems. Even higher gear ranges can be achieved by using a 2-speed bottom bracket hub gear in conjunction with suitable derailleurs.

Types of gear change mechanisms[edit]

There are two main types of gear change mechanisms, known as derailleurs and hub gears. Both systems have advantages and disadvantages, and which is preferable depends on the particular circumstances. There are a few other relatively uncommon types of gear change mechanism which are briefly mentioned near the end of this section. Derailleur mechanisms can only be used with chain drive transmissions, so bicycles with belt drive or shaft drive transmissions must either be single speed or use hub gears.

External (derailleur)[edit]

Main article: Derailleur gears

External gearing is so called because all the sprockets involved are readily visible. There may be up to 4 chainrings[11] attached to the crankset and pedals, and typically between 5 and 11 sprockets[12] making up the cogset attached to the rear wheel. Modern front and rear derailleurs typically consist of a moveable chain-guide that is operated remotely by a Bowden cable attached to a shifter mounted on the down tube, handlebar stem, or handlebar. A shifter may be a single lever, or a pair of levers, or a twist grip; some shifters may be incorporated with brake levers into a single unit. When a rider operates the shifter while pedalling, the change in cable tension moves the chain-guide from side to side, "derailing" the chain onto different sprockets. The rear derailleur also has spring-mounted jockey wheels which take up any slack in the chain.

Most hybrid, touring, mountain, and racing bicycles are equipped with both front and rear derailleurs. There are a few gear ratios which have a straight chain path, but most of the gear ratios will have the chain running at an angle. The use of two derailleurs generally results in some duplicate or near duplicate gear ratios, so that the number of distinct gear ratios is typically around two-thirds of the number of advertised gear ratios. The more common configurations have specific names[13] which are usually related to the relative step sizes between the front chainrings and the rear cogset.

Crossover gearing[edit]

This style is commonly found on mountain, hybrid, and touring bicycles with three chainrings. The relative step on the chainrings (say 25% to 35%) is typically around twice the relative step on the cogset (say 15%), e.g. chainrings 28-38-48 and cogset 12-14-16-18-21-24-28.

Advantages of this arrangement include:

  • A wide range of gears may be available suitable for touring and for off-road riding.
  • There is seldom any need to change both front and rear derailleurs simultaneously so it is generally more suitable for casual or inexperienced cyclists.

One disadvantage is that the overlapping gear ranges result in a lot of duplication or near-duplication of gear ratios.

Multi-range gearing[edit]

This style is commonly found on racing bicycles with two chainrings. The relative step on the chainrings (say 35%) is typically around three or four times the relative step on the cogset (say 8% or 10%), e.g. chainrings 39-53 and close-range cogsets 12-13-14-15-16-17-19-21 or 12-13-15-17-19-21-23-25. This arrangement provides much more scope for adjusting the gear ratio to maintain a constant pedalling speed, but any change of chainring must be accompanied by a simultaneous change of 3 or 4 sprockets on the cogset if the goal is to switch to the next higher or lower gear ratio.

Alpine gearing[edit]

This term has no generally accepted meaning. Originally it referred to a gearing arrangement which had one especially low gear (for climbing Alpine passes); this low gear often had a larger than average jump to the next lowest gear. In the 1960s the term was used by salespeople to refer to then current 10-speed bicycles (2 chainrings, 5-sprocket cogset), without any regard to its original meaning. The nearest current equivalent to the original meaning can be found in the Shimano Megarange cogsets, where most of the sprockets have roughly a 15% relative difference, except for the largest sprocket which has roughly a 30% difference; this provides a much lower gear than normal at the cost of a large gearing jump.

Half-step gearing[edit]

There are two chainrings whose relative difference (say 10%) is about half the relative step on the cogset (say 20%). This was used in the mid-20th century when front derailleurs could only handle a small step between chainrings and when rear cogsets only had a small number of sprockets, e.g. chainrings 44-48 and cogset 14-17-20-24-28. The effect is to provide two interlaced gear ranges without any duplication. However to step sequentially through the gear ratios requires a simultaneous front and rear shift on every other gear change.

Half-step plus granny crankset with 28, 45, and 50 tooth chainrings on a Trek 620 touring bicycle

Half-step plus granny gearing[edit]

There are three chainrings with half-step differences between the larger two and multi-range differences between the smaller two, e.g. chainrings 24-42-46 and cogset 12-14-16-18-21-24-28-32-36.[14] This general arrangement is suitable for touring with most gear changes being made using the rear derailleur and occasional fine tuning using the two large chainrings.[13] The small chainring (granny gear) is a bailout for handling steeper hills, but it requires some anticipation in order to use it effectively.

Internal (hub)[edit]

Main article: Hub gear

Internal gearing is so called because all the gears involved are hidden within a wheel hub. Hub gears work using internal planetary, or epicyclic, gearing which alters the speed of the hub casing and wheel relative to the speed of the drive sprocket. They have just a single chainring and a single rear sprocket, almost always with a straight chain path between the two. Hub gears are available with between 2 and 14 speeds; weight and price tend to increase with the number of gears. All the advertised speeds are available as distinct gear ratios controlled by a single shifter (except for some early 5-speed models which used two shifters). Hub gearing is often used for bicycles intended for city-riding and commuting.

Internal (bottom bracket)[edit]

Main article: gearbox bicycle

Current systems have gears incorporated in the crankset or bottom bracket. Patents for such systems appeared as early as 1890.[15] The Schlumpf Mountain Drive and Speed Drive have been available since 2001.[16] Some systems offer direct drive plus one of three variants (reduction 1:2.5, increase 1.65:1, and increase 2.5:1). Changing gears is accomplished by using your foot to tap a button protruding on each side of the bottom bracket spindle. The effect is that of having a bicycle with twin chainrings with a massive difference in sizes. Pinion GmbH introduced in 2010 an 18 speed gearbox model, offering an evenly spaced 636% range. This gearbox is actuated by traditional twist shifter and uses two cables for gear changing. The Pinion system is well suited for mountain bicycles due to its wide range and low gravity center suitable for full-suspension bikes, but it is still somewhat heavier than derailleur-based drivetrain.[17]

SRAM Dual Drive combination derailleur gears and hub gear

Internal and external combined[edit]

It is sometimes possible to combine a hub gear with deraileur gears. There are several commercially available possibilities:

  • One standard option for the Brompton folding bicycle is to use a 3-speed hub gear (roughly a 30% difference between gear ratios) in combination with a 2-speed deraileur gear (roughly a 15% difference) to give 6 distinct gear ratios; this is an example of half-step gearing. Some Brompton suppliers offer a 2-speed chainring 'Mountain Drive' as well, which results in 12 distinct gear ratios with a range exceeding 5:1; in this case, the change from 6th to 7th gear involves changing all three sets of gears simultaneously.
  • The SRAM DualDrive system uses a standard 8 or 9-speed cogset mounted on a three-speed internally geared hub, offering a similar gear range to a bicycle with a cogset and triple chainrings.
  • Less common is the use of a double or triple chainring in conjunction with an internally geared hub, extending the gear range without having to fit multiple sprockets to the hub. However, this does require a chain tensioner of some sort, negating some of the advantages of hub gears.
  • At an extreme opposite from a single speed bicycle, hub gears can be combined with both front and rear derailleurs, giving a very wide-ranging drivetrain at the expense of weight and complexity of operation- there are a total of three sets of gears. This approach may be suitable for recumbent trikes, where very low gears can be used without balance issues, and the aerodynamic position allows higher gears than normal.

Others[edit]

There have been, and still are, some quite different methods of selecting a different gear ratio:

  • Retro-direct drivetrains used on some early 20th century bicycles have been resurrected by bicycle hobbyists. These have two possible gear ratios but no gear lever; the operator simply pedals forward for one gear and backward for the other. The chain path is quite complicated, since it effectively has to do a figure of eight as well as follow the normal chain path.
  • Flip-flop hubs have a double-sided rear wheel with a (different sized) sprocket on each side. To change gear: stop, remove the rear wheel, flip it over, replace the wheel, adjust chain tension, resume cycling. Current double sided wheels typically have a fixed sprocket on one side and a freewheel sprocket on the other.
Prior to 1937 this was the only permitted form of gear changing on the Tour de France.[18] Competitors could have 2 sprockets on each side of the rear wheel, but still had to stop to manually move the chain from one sprocket to the other and adjust the position of the rear wheel so as to maintain the correct chain tension.
  • Continuously variable transmissions are a relatively new development in bicycles (though not a new idea). Mechanisms like the NuVinci gearing system use balls connected to two disks by static friction - changing the point of contact changes the gear ratio.
  • Automatic transmissions have been demonstrated and marketed for both derailleur and hub gear mechanisms, often accompanied by a warning to disengage auto-shifting if standing on the pedals. These have met with limited market success.
  • Moving the connection point on a lever changes the mechanical advantage of a drive system in a way analogous to changing gear ratios. Examples include the American Star Bicycle and the Stringbike.

Efficiency[edit]

The numbers in this section apply to the efficiency of the drive-train, including means of transmission and any gearing system. In this context efficiency is concerned with how much power is delivered to the wheel compared with how much power is put into the pedals. For a well-maintained transmission system, efficiency is generally between 86% and 99%, as detailed below.

Factors besides gearing which affect performance include rolling resistance and air resistance:

  • Rolling resistance can vary by a factor of 10 or more depending on type and dimensions of tire and the tire pressure.[19]
  • Air resistance increases greatly as speed increases and is the most significant factor at speeds above 10 to 12 miles (15 to 20 km) per hour (the drag force increases in proportion to the square of the speed, thus the power required to overcome it increases in proportion to the cube of the speed).[20]

Human factors can also be significant. Rohloff argues[21] that overall efficiency can be improved in some cases by using a slightly less efficient gear ratio when this leads to greater human efficiency (in converting food to pedal power) because a more effective pedalling speed is being used.

Overview[edit]

An encyclopedic overview can be found in Chapter 9 of "Bicycling Science"[22] which covers both theory and experimental results. Some details extracted from these and other experiments are provided in the next subsection, with references to the original reports.

Factors which have been shown to affect the drive-train efficiency include the type of transmission system (chain, shaft, belt), the type of gearing system (fixed, derailleur, hub, infinitely variable), the size of the sprockets used, the magnitude of the input power, the pedalling speed, and how rusty the chain is. For a particular gearing system, different gear ratios generally have different efficiencies.

Some experiments have used an electric motor to drive the shaft to which the pedals are attached, while others have used averages of a number of actual cyclists. It is not clear how the steady power delivered by a motor compares with the cyclic power provided by pedals. Rohloff argues[21] that the constant motor power should match the peak pedal power rather than the average (which is half the peak).

There is little independent information available relating to the efficiency of belt drives and infinitely variable gear systems; even the manufacturers/suppliers appear reluctant to provide any numbers.

Details[edit]

Derailleur type mechanisms of a typical mid-range product (of the sort used by serious amateurs) achieve between 88% and 99% mechanical efficiency at 100 W. In derailleur mechanisms the highest efficiency is achieved by the larger sprockets. Efficiency generally decreases with smaller sprocket and chainring sizes.[23] Derailleur efficiency is also compromised with cross-chaining, or running large-ring to large-sprocket or small-ring to small-sprocket. This cross-chaining also results in increased wear because of the lateral deflection of the chain.

Chester Kyle and Frank Berto reported in "Human Power" 52 (Summer 2001)[24] that testing on three derailleur systems (from 4 to 27 gears) and eight gear hub transmissions (from 3 to 14 gears), performed with 80 W, 150 W, 200 W inputs, gave results as follows:

Transmission TypeAverage Efficiency at 150 W
Derailleurs93% - 95%
3 speed gear hubs92% - 95%
7 & 14 speed gear hubs89% - 91%

Efficiency testing of bicycle gearing systems is complicated by a number of factors - in particular, all systems tend to be better at higher power rates. 200 W will drive a typical bicycle at 20 mph, while athletes can achieve 400 W, at which point efficiencies 'approaching 98%' are claimed.[25]

At a more typical 150 W, hub-gears tend to be around 2% less efficient than a derailleur system assuming both systems are well maintained.[26]

See also[edit]

References[edit]

Sours: https://en.wikipedia.org/wiki/Bicycle_gearing

Now discussing:

This post addresses bicycle crankset compatibility in terms of mixing various speed cranksets with other components. For example: an 8 speed crankset on a bicycle with 10 rear sprockets and a 10 speed chain (a), or a triple chainring with a front derailleur (FD) constructed for double chainrings (b). It will also address mixing road cranksets with MTB FDs and vice versa (c).

Before you start, to avoid any misunderstanding:
please take the 5 minutes needed to read the compatibility articles use instructions.

Separate posts explain: standards of bottom bracket (crankset) bearings (and axles), as well as bottom bracket compatibility). That will not be taken into consideration in this post, but when acquiring a crankset, make sure that it’s bottom bracket (BB) standard is one that can be mounted on the bicycle frame.

In the post about FD compatibility, other factors important when matching FD and crankset are described. So, even if number of speeds and type of crankset and FD are the same, those factors should also be matched. In short: FD cage shape and number of large chainring teeth it is designed for should match the teeth number of the largest chainring on the crankset it is combined width. Detailed explanation of things one should pay attention to and try to match are listed in the post:
Compatibility – front derailleurs


1. Different number of speeds for crankset and the bicycle

Typical example: can a crankset for 9 speeds be used with a bicycle that has 11 speeds (rear sprockets) and an 11 speed chain (for 11 sprockets)? Or vice versa: can a 10 speed crankset be used on a bicycle with 8 speeds?

All the “speed” chains have almost the same inner diameter (roller width). Despite the fact that chains for more speeds have thinner plates and are therefore narrower (on the outside) than chains for less speeds, the inner width is the same. For detailed explanation look here: Compatibility – chains.

Because of this, teeth thickness of crankset chainrings doesn’t vary much. Also, adjacent crankset chainrings have great difference in diameter and are not as tightly spaced as rear sprockets. So there is no risk of chain, being to wide, to get stuck between two chainrings.

All this enables crankset chainrings to be freely combined with all kinds of chains (and, over the chain, various numbers of rear sprockets). The only complication is the thinner cage of the FDs designed for more speeds. This means, if using a (wider) chain for less speeds, chain will rub the cage with less cross chaining then if a wider cage FD was used. Cross chaining is not advisable anyway, so one can consider this and early(er) warning. Explanation of gear changing and cross chaining is here:
Bicycle gear ratios

Exceptions to this are single speed chainrings, made for wider, 1/8″ thick chains (they won’t work with multi-speed chains) and Shimano IG chainrings (that work only with chains for up to 8 speeds).


2. Mix-matching various types of cranks (chainrings)

2.1. Combining double chainring cranksets with triple FDs

Explanation of important attributes and differences of FDs can be found in these posts:
Front derailleur
Compatibility – front derailleurs

Triple FD has a longer cage (than a double FD), with inner part of the cage being a bit lower, to catch the chain off the third, smallest chainring. If the two chainrings of a double don’t have a big difference in number of teeth (14 or less), triple FD should work just fine on a double (with correct setup of the limit screws and cable, of course). Typical examples are standard road doubles 53-39 (14 teeth), or 46-36 (10 teeth) – a typical cyclo-cross crankset.

If using a popular “compact” crankset, with a large difference in number of teeth between the big and the small chainring, like 50-34 (16 teeth), or 46-30, shifting will be slower, with more possibility of dropping the chain when shifting onto the smaller chainring.

However, even if chainring difference is large, front shifts are usually quite rare (compared to rear shifts), so even then it might work acceptably well (depending on one’s criteria).

2.2. Combining triple chairing cranksets with double FDs

The biggest problem with this combo is that double FDs don’t have a long enough cage, with inner part lowered enough to catch the chain off the smallest, third chainring.

The quality of this pair functioning is affected by the following two factors:

  • The lower the difference in teeth number between the largest and the smallest chainring, the better.
    For example: 48-38-28 (20 teeth difference) is better than 44-32-22 (22 teeth difference).
    Or: 50-39-30 (20 teeth difference) is better than 53-42-30 (23 teeth difference).
  • The number of large chainring teeth the FD is designed for should match the number of teeth of the largest triple chainring, or be slightly lower.
    For example: FD for 50 tooth chainring on a 50-39-30 triple.
    Or a FD for a 46 tooth chainring on a 48-38-28 double.
    Bad idea is a FD for a 53 tooth chainring on a 44-32-22 triple.

2.3. Combining MTB cranksets with road FDs and vice versa

Road and MTB cranksets have slightly different chainring spacing. Still, this doesn’t cause much problems even to shifters and FDs when mixing them, as is explained in these two posts:
Compatibility – front shifters
Compatibility – front derailleurs

Difference definitely doesn’t bother the FDs. If the shifter, cable and screws for limiting movement are properly set, there won’t be any problems.

Related post – Bottom bracket compatibility:

Bottom bracket compatibility - what can be combined with what


Compatibility posts are also available in eBook (printable and Kindle) and paperback editions on Amazon:

Bicycle drivetrain compatibility book
Categories CompatibilityTags compatibility, front chainringsSours: https://bike.bikegremlin.com/1619/bicycle-crankset-compatibility/


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