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Discussion Starter · #1 ·
I could use a little help with my new SS road bike. I’m new to the SS road bike thing but have been ridding SS Mt. Bikes for several years which is why I went with the SS road bike. My question is… Why did my 57cm bike come with 172.5 cranks??? As do most track bikes in this size come with. I don’t get it :confused: why the shorter crank and should I keep the shorter crank or go with the NORMAL 175?

My intended use for the bike is on use SS road biking only, no track duty. The bike is Jamis Sputnik which I have added brakes to and added a 16t rear cog.

Please enlighten me with your experiences in this matter
 

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I've felt the Felt
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It seems as though many SS bikes come with them because they also come with a flip flop hub if you wanted to try it fixed. Long crank arms on a fixed in a tight corner is disastrous. Just speculation, but I think it has merit.
 

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You have it a bit backwards

onespeedwonder said:
I could use a little help with my new SS road bike. I’m new to the SS road bike thing but have been ridding SS Mt. Bikes for several years which is why I went with the SS road bike. My question is… Why did my 57cm bike come with 172.5 cranks??? As do most track bikes in this size come with. I don’t get it :confused: why the shorter crank and should I keep the shorter crank or go with the NORMAL 175?

My intended use for the bike is on use SS road biking only, no track duty. The bike is Jamis Sputnik which I have added brakes to and added a 16t rear cog.

Please enlighten me with your experiences in this matter
The standard for cranks is 172.5 until the rider gets well over 6 feet. As far as SS bikes goes, as long as you can coast, 172.5 is right on. In regards to track bikes, the standard is somewhere between 165 and 167.5 with 170 being on the long end, mostly because of the danger of pedal strikes.

Brad
 

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Discussion Starter · #4 ·
onespeedbiker

So you are saying the standard crank length for a TRACK bike is 172.5 until the rider is over 6', which is different than the standard road bike or Mt bike which usually come with 175 unless you get into the small sizes 54cm or 15.5" seat tube respectfully.

You mentioned pedal strikes as being a problem on a track bike; do track bikes tend to use lower BB heights? And if so why? Sorry for so many questions but I'm trying to understand the differences between track bikes and road bikes.

Thanks
 

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Some track information.

In general, track bikes have a higher bottom bracket than road bikes. There's really no standard track crank length, but many riders (even tall ones) use a 165 mm crank in match sprints, keirin racing and points races. Many riders and coaches believe that it's easier to spin a shorter crank than a longer one—and on the track, you can easily find yourself spinning at 160 rpm during the last few seconds of a sprint.

The pedal strike thing on the track is often misunderstood as occuring when you "lean into the turn." In a match sprint, you might have to slow down to 2 or 3 mph or even come to a complete stop. If the track curves are steeply banked and you slow or stop on the banked part, you need to lean the bicycle hard into the banking to stay upright. This means that the outside pedal can easily strike the surface. A high bottom bracket and a short crank will make it a little easier to avoid that outside pedal strike.

During steady-speed events like pursuit races or the time trials, pedal strike on the track is not an issue. Also because cadences are also slower, riders often change to slightly longer cranks for those events. I rode track in the 1970s and found that my 6-foot frame did well with 165 mm cranks for sprint events and 170 mm cranks for the kilo and pursuit.
 

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Carbon Fiber = Explode!
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Shorter is better.

When riding fixed, you want all the clearance you can get. Wim is 100% correct.
 

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Would the same logic hold true if one was going to run a SS with a freewheel and not as a fixed?

I'm also in the market for a SS, and I measure my geared road bike, vs. geared MTN and my SS MTN bike:
- 175 on both mtn bikes, one a SS
- 170 on the road bike

I don't plan on running fixed at all, but I plan to get a flip/flop hub in case, at which point I suppose if I really really liked it, I could put on shrter cranks.

Basically I am thinking of getting 175mm cranks with the freewheel for better leverage on climbs, but I don't know if that logic is flawed and could use some feedback.
 
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