Strong freewheeling crankset

[DanGT86]

Yeah, a human stood up cranking is a pretty impressive amount of torque.

What happens to these csk units when they are overloaded? Do they just slip or do they gouge the contact surfaces? There is a big difference for me in using a bearing clutch that might slip in some situations vs one that will catastrophically fail requiring replacement the first time I overload it.

 

[Hummina Shadeeba]

Why not use a one way bearing instead of a freewheel type ratchet? Theyre wide so assume able to take off-kilter loading and the clutch mechanism seems fail proof.

https://youtu.be/umZYlF-INjk

Probably not as efficient but a minor loss and people don’t seem to care.

 

[DogDipstick]

Why not use a one way bearing instead of a freewheel type ratchet?

We use a 12mm hardened shaft, and those one way bearings, in the RC Helicopters I fly. they take some 14-15kW pretty easy... but at 1200-2300RPM.... They allow an autorotation moment to develop and the mainshaft / head to freewheel, if needed: without power....and ... and..

I think this is why we dons see much of them i bicycle drives but I dont know. I always thought they make very compact strong one way bearings ( in RC and in automatic transmissions and hydro shifting things like a telehandler hydraulic motor internals ) too.

bearings have to be really big to withstand all the pedal torque a strong rider can develop.

 

[Hummina Shadeeba]

The Amazon freewheeling bottom bracket definitely doesn't contain one that size.

what is this bb?

Where are freewheeling cranks sold that use a thread-on single-speed freewheel and have a square taper?

 

[A-DamW]

what is this bb?

Where are freewheeling cranks sold that use a thread-on single-speed freewheel and have a square taper?

Try the search term "jackshaft kit motorized bike"
https://www.amazon.com/s?k=motorized+bike+jackshaft+kit

 

[Hummina Shadeeba]

Try the search term "jackshaft kit motorized bike"
https://www.amazon.com/s?k=motorized+bike+jackshaft+kit

Thanks. I see the full kit but anyone just seen the cranks for sale?

 

[DanGT86]

Thanks. I see the full kit but anyone just seen the cranks for sale?

I have seen them around on different bike trials vendor sites.

These are available in 140mm and 160mm and are square taper.

Comas JIS cranks for bike trials

Comas JIS bike trials cranks at the best price, ready for immediate delivery. Find the best parts and accessories for bike trials from Comas, Ozonys, Clean, Jitsie, Monty, Hope, Magura, Bonz, Crewkerz and all trials brands at Trial-Bikes.com!

www.trial-bikes.com

Comas Square Taper Cranks

Buy Comas Square Taper Cranks as well as a wide range of Cranks (Pair) and other trials bike products from the world's leading trials bike shop, TartyBikes.

www.tartybikes.co.uk

 

[Hummina Shadeeba]

I have seen them around on different bike trials vendor sites.

These are available in 140mm and 160mm and are square taper.

Comas JIS cranks for bike trials

Comas JIS bike trials cranks at the best price, ready for immediate delivery. Find the best parts and accessories for bike trials from Comas, Ozonys, Clean, Jitsie, Monty, Hope, Magura, Bonz, Crewkerz and all trials brands at Trial-Bikes.com!

www.trial-bikes.com

Comas Square Taper Cranks

Buy Comas Square Taper Cranks as well as a wide range of Cranks (Pair) and other trials bike products from the world's leading trials bike shop, TartyBikes.

www.tartybikes.co.uk

Anything in usa?

 

[DanGT86]

The only ones I know of for sure in the US are on the shelf in my basement. They were used when I got them but I can probably ship them to you for $50

WebCyclery is the only US vendor I can think of that sells trials cranks with freewheel threads but there are no square taper cranks on their site. Maybe worth an email to see if they have any laying around.