150 mm crank for Specialized Creo SL-is that possible?
- Thread starter HLM
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HLM
Member
Surly, there are MANY 150mm cranks and very few, if any, that can fit this exact ebike. The Miranda cranks that you recommend are 150 and up, yes, but I'll bet you don't know if they can fit the Specialized Creo SL which has a somewhat unique system.
HLM
Member
It attaches to the bottom bracket based motor. The crank can be moved backwards without engaging anything, moving alone. I'm not sure how it's attached but it probably isn't done in a typical fashion, though I'm not absolutely certain. I was looking for answers from people who know this particular e-bike and its set-up.
PedalUma
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- Region
- USA
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- Petaluma, CA
I have been getting 150's for square taper fat bikes. Splined is a different matter. Machine shopping the existing ones may be the best option in a pinch in that case. But why 150's on a Creo of all beasts?
HLM
Member
The 150mm crank is for a friend who has this e-bike (less than a week old) and due to his physiology and a result of a professional bike fitting the determination of 150's, which he had successfully on an acoustic bicycle for years, was made to eliminate his leg/knee pain which had come back after riding the Creo for a few days. He has very short legs.
rich c
Well-Known Member
Could you give me a link?
I think 160 mm is the shortest you can get for the mahle motor ( m30 spline) - using the praxis mtb version instead of the road ( https://praxiscycles.com/product/carbon-m30-ecranks/ ) . Last time I checked, specialized only went down to 165 mm.
NB I-have a niggling suspicion they use the same crank length but just move the pedal hole, so if your issue is pedal strikes it might not be solved with shorter cranks
NB I-have a niggling suspicion they use the same crank length but just move the pedal hole, so if your issue is pedal strikes it might not be solved with shorter cranks
mschwett
Well-Known Member
- Region
- USA
the crank / drive interface of the cranks for the SL motor is unusual. no standard cranks will fit and I’d be very, very surprised to find someone else making them. the 160mm MTB ones from praxis (see link from @PDoz above) look identical on the drive shaft side, but with an added rubber jacket on the pedal side. that’s probably the closest you’ll get.
HLM
Member
Pedal strikes aren't the issue at all but, rather, it's the rider's physiology where there's a need for a shorter crank to avoid pain. I wonder if it's possible to drill a hole in his current, 165mm, cranks to accommodate his pedals. This would be done by a professional machine shop and I'm assuming that the crank arms are solid. The old hole can be covered up somehow.
HLM
Member
I wonder if it's possible to drill an additional hole in his current, 165mm, cranks to accommodate his pedals. This would be done by a professional machine shop and I'm assuming that the crank arms are solid. The old hole can be covered up somehow.
mschwett
Well-Known Member
- Region
- USA
assuming the aluminum ones are solid (the carbon ones are definitely not!) you’d have to start with a much larger set, since the hole for the pedal spindle would probably be too close to the desired 150mm center to center dimension. if you think about the forces exerted on the pedal, the material on the “outside” of the hole takes a lot of the force.
HLM
Member
My friend found a company in Minnesota that specializes in creating small cranks and can do this by utilizing a long crank and shortening it and, as you stated, he requested that my friend purchase a 175mm crank for the reason you described. The major problem, though, is that this is a one person company, he's 77 years old, was just in a bicycle accident that increasingly threatens his ability to work. We'll see.
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