Narrowing a freehub

[chriscross1966]

Ok folks, this is properly off-piste, but im making plans for a bike i might not build for a while, but im trying to solve perceived problems before i have to deal with them later... The bike will be a heavily modded Brompton, but im looking to use a rather different gearing mechanism.... now I note that a lot of normal 10-speed rear hubs are 130oln... the Brompton is 115... what is to stop me putting the cassette body in my lathe, machining 15mm off the end of it and dealing with what entails as a result... probably losing a bearing and having to remachine the thread for the lockring... there will be some issues with having to convert the axle to work with the Brompton chain tensioner, but it is a cylindrical piece of metal about 150mm long and I have a lathe.... is there anything important to the pawls in the outer 20mm of the body of a normal shimano pattern freehub?

 

[TheDoctor]

 

[Yellow Saddle]

You are in for a hiding. The Shimano freehub body is hardened steel with a thread on the inside for the lockring. Good luck with re-doing that. Other Shimano compatible hubs have aluminium freehub bodies. A narrower body means fewer sprockets and modern cassette sprockets dont' mix and match.
Further, on these hubs (with aluminium bodies) the axle is machined with steps for bearing seats. These steps have to be exact so that the bearing preload is zero. Cartridge bearings dont' like axial pre-load. Get your spacing wrong and your bearings will fail chop-chop.

Just buy a Brompton hub.

 

[chriscross1966]

You are in for a hiding. The Shimano freehub body is hardened steel with a thread on the inside for the lockring. Good luck with re-doing that. Other Shimano compatible hubs have aluminium freehub bodies. A narrower body means fewer sprockets and modern cassette sprockets dont' mix and match.
Further, on these hubs (with aluminium bodies) the axle is machined with steps for bearing seats. These steps have to be exact so that the bearing preload is zero. Cartridge bearings dont' like axial pre-load. Get your spacing wrong and your bearings will fail chop-chop.

Just buy a Brompton hub.

Ok, so looking around Novatec seem to make what I need, alloy body for starters. Brompton hubs are heavy, have the wrong spoke count for what I want and are a PITA to mod for four-speed external shift. Internal threading is easy, I have a lathe. Avoiding excess axial preload is just a precision issue. From the POV of sprockets, Brompton modders have been playing with mismatched Shimano bits for years, they do shift Ok but it isn't as slick as when they're built up in their original cassettes.... partly thats cos the Brompton shift system is even cruder than the old Campag straight parallelogram mechs, it's noisy, but it WILL shift...

 

[Illaveago]

Ok, so looking around Novatec seem to make what I need, alloy body for starters. Brompton hubs are heavy, have the wrong spoke count for what I want and are a PITA to mod for four-speed external shift. Internal threading is easy, I have a lathe. Avoiding excess axial preload is just a precision issue. From the POV of sprockets, Brompton modders have been playing with mismatched Shimano bits for years, they do shift Ok but it isn't as slick as when they're built up in their original cassettes.... partly thats cos the Brompton shift system is even cruder than the old Campag straight parallelogram mechs, it's noisy, but it WILL shift...

It should keep your brain active . Good luck with your experiment .

 

[Yellow Saddle]

Ok, so looking around Novatec seem to make what I need, alloy body for starters. Brompton hubs are heavy, have the wrong spoke count for what I want and are a PITA to mod for four-speed external shift. Internal threading is easy, I have a lathe. Avoiding excess axial preload is just a precision issue. From the POV of sprockets, Brompton modders have been playing with mismatched Shimano bits for years, they do shift Ok but it isn't as slick as when they're built up in their original cassettes.... partly thats cos the Brompton shift system is even cruder than the old Campag straight parallelogram mechs, it's noisy, but it WILL shift...

I hereby declare you the right candidate for this project. Please report back from time to time. It will be interesting.

 

[fossyant]

By a proper bike. Far better.

 

[chriscross1966]

By a proper bike. Far better.

What, some old fashioned penny-penny?

 

[DCBassman]

What, some old fashioned penny-penny?

At least penny-penny is still legal tender...