Crank Length on track

[tauruswho]

What length cranks do you use for track at Manchester or Newport?

I have been using 170mm for years, but have been told I must now change to 165mm or I could be sued if there is an Accident!!!!!

[legro]

I would thave thought the BB height is main factor
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[Magnier]

Im 6'2" and i use 165mm cranks.

[Andrew R]

[puma]

[mattr]

[tob]

The keeps coming up every so often.

When the Peugeots were bought for Manchester, the smaller frames (21” and below) had an 11” BB height and were fitted with 165mm cranks. Those above 21” had an 11½” BB height fitted with 170mm cranks to suit longer legs. We have always quoted this as a standard to ensure clearance between the right pedal and the track surface. From memory Peter Jaques (City of Edinburgh) had a Corima with a 12” BB height.

Tony Rominger rode a Colnago with a 10 3/8” BB when he was checking the track out for his attempt on the Hour record. However, it should be said that he would have been on his own throughout and perpendicular to the surface nearly all the time.

What we have now (occasionally) are people bringing none ‘standard’ frames (one in particular) with really low BB height having bought the bike/frame and been told that they are safe on Manchester. Even with 165mm cranks I am fairly certain that the pedals are making contact with the surface and I think I have seen one ridden slowly do just that! Until I have proof I won’t name it but if you look along a string or riders the chain stay angle is steeper than most – which suggests a low BB height. I certainly wouldn’t want to ride below a rider on one of these.

Regardless of whether someone might sue for and accident involving a bike with a low BB height, the mind boggles at the thought of a rider on such a bike making contact and losing the back wheel then sliding into a string below doing 28+ below him / her! A fleet of ambulances arriving comes to mind.

Tony
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[John McC]

170mm, unless you are a short 'rse then 165mm.
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[Adam]

I think I know which bikes you are talking about. They're 'fixed' road bikes, right?
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[mattr]

wouldn't a simple flattened V shaped block long enough for a bike show how much pedal clearance is needed for safety, this would include bottom bracket height, crank length and pedal size/width.

Rather than all this 165/170/175 rubbish.

Shouldn't be too hard to work it out, and 15 minutes to put it together.

[SteveO]

[legro]

Calshot does specify 165's but I know you can get round on 170's np
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NLP Practitioner


Fear leads to anger....Anger leads to Stress......Stress leads to Doobies...and Doobies leads to Twinkies

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[John McC]

Me too.
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John McClelland's victory in the motor paced event with Derek Marloe on the derny was a thing of beauty (Oldmanof)

[tob]

[Adman_Rob]

[tob]

[tob]

[legro]

which is why Calshot specify 165
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www.mastercoach.co.uk
NLP Practitioner


Fear leads to anger....Anger leads to Stress......Stress leads to Doobies...and Doobies leads to Twinkies

The spirit of Brian must live on

[TBK]

165mm, on frames with bb height varying from 10 3/4", 11" and 11 1/4" but I'm a 5'6" midget

As has been said Rominger used 10 3/8", I think this was for the Superdrome meet after he had got the hour record when he had a head to head with Boardman over 5K? What wasn't mentioned was his hour record bike had 175mm cranks even with this low bb. He had tried 177.5mm if I recall and occaisionally grounded those on the turns

I know of others who have used 175mm and 172.5mm cranks on Manchester in bunch races, but both these were on fairly high bb height frames, one a Cannondale and the other a custom frame. Both were road cranks using a narrower than usual bb axle and pedals with lots of cornering clearance so the eventual height and "angle of dangle" of the pedal was the same if not higher than say an 11" bb frame with 165's and more standard pedals.

If you have a lower bb there are ways of getting around it and similarly longer cranks can be used with the same methods, you just won't be able to spin and accelerate as well as others with shorter cranks.
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[tauruswho]