Hubbers with access to CNC

[Spez247]

Hi Gents. Need help with regards converting my Cotic Simple to a Geared bike. A knee op has made standing on the pedals a very uncomfortable proposition.

 

I have achieved this with an aftermarket part, but sadly it doesn't work all the time. It would involve machining a part that slots into the sliding drop out, with very little play. The current part moves out of alignment, as soon as the rear wheel comes close to locking up under braking. So normally what happens is that the wheel starts to rub up against the frame, closest to the BB.

 

It would be a case of making a "negative" to the existing drop out. Hope that makes sense.

 

Any suggestions on who I should approach? Obviously willing to pay for the time and material.

 

Let me know if I can explain further.

 

Attached is the Surly tensioner, just as a reference.

 

Thanks

 

N

 

 

[Pah Bear]

Hi Spez.

 

Had an interesting chat to Kevin at BMC (021 448 4692) in Salt River Cape Town a few days ago. He is a highly qualified bike mech and now starting a business doing specialised engineering projects. I see you are in Gauteng. Know its far from you, but might be worthwhile investigating if it gets you what you need.

Best of luck.

PB

[madbradd]

How about something like this

 

http://www.chainreactioncycles.com/mobile/za/en/dmr-chain-tugs-mech-hanger/rp-prod249

[Spez247]

Thanks Gents for the replies.

Will give him a shout, Pah Bear.

Madbradd - I have something similar, but no matter how tight the QR gets tensioned, it still shifts out under braking. Best case is you get disk rub, worst case is the wheel gets locked up against the chain stay.

[madbradd]

Ah.. OK. I was worried about the same thing with those type actually when I was buying chain tugs for my Inbred. A "solid" one would be better for sure I think you can just mill it though.... don't specifically need it to be CNC machined do you?

[xcd]

Try contacting a guy by the name of Mark. He has a small engineering workshop and does machining,specialized welding and suspension repairs and service all for the bicycle industry. info@cyclesuspension.co.za.

[droo]

Your other option would be to get a bolt on hub, which will tighten up way more than a QR one. Hope and WTB both make them. 

 

Also, if you're currently running anything other that a Shimano skewer, see if fitting one helps. They clamp far tighter than any of the open cam designs.