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Custom arm rests
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A few years ago I injured my right forearm.
(Got in an argument with a circular saw; I lost. The saw ended up on a bonfire)

There's still huge sensitivity right at the spot where my arm sits on the arm rest. Road shock hurts like hell.
My thought is to create a custom rest, as long as I can, and shaped specifically to my forearm. Hopefully it would distribute the load and shock.
It will be covered with some sort of foam and I might even cut out the section where the injury is to reduce pressure.

Mounting: It could be glued on top of the existing arm rest or could replace it (if the material is strong enough).

The question is what material(s) to use?

My thoughts are:
- Aluminium: cheap, strong, but tough to custom shape to my arm. Could use lots of padding but its kinda getto. OK as a prototype
- Fibreglass: cheap, plentiful, easy to customize. Stinky process, a bit heavy, not sure if its strong enough to bolt right on, would be tempted to glue it on top of the existing rest
- carbon fibre. Likely the best, but I have no experience with it. Not sure if I could easily mould it to my arm.
- thermoplastic. Should be easy to mould (and remould if needed). Hopefully retain its shape even on hottest days. likely glue it on top of the existing

If anyone has experience, I'd greatly appreciate it.
thanks

Olaf
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Re: Custom arm rests [Shandit66] [ In reply to ]
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I'd look at having an Al base with thermoplastic filler. That way it's strong enough to bolt on and still easy to mould.
Wouldn't have to be too precise with shape of Al. I've started from pipe and flat (bent with a deadblow hammer and curved form) to make armrests.

Speedtheory
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Re: Custom arm rests [cyclenutnz] [ In reply to ]
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cyclenutnz wrote:
I'd look at having an Al base with thermoplastic filler.

Good point. AL is easy to work with. l will give it a try.
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Re: Custom arm rests [Shandit66] [ In reply to ]
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Depending on the area affected by the injury I would lean toward providing support to the area around it. Keeping in-mind safety and control of the bike.

There is no formula out there but I have had success with Alu bases and urethane honeycomb you will need to minimize pressure in the injured area. You need to keep in mind that any small adjustment will exceptionally travel up your body affecting your bike fit. so you will need to compensate both sides and make sure you are properly fitted.


I have had luck with some metal shops, they see it as a mental challenge from their day to day.




Carlos,
adaptive cycling coach and bike fitter.

Carlos,

Live with passion, Ride a bike.
adaptive cycling coach and bike fitter.
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Re: Custom arm rests [carlogarz] [ In reply to ]
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I'm using a HED Corsar aero bar http://www.hedcycling.com/...ms/aero-bars/corsair
The pads are about 3.5" in dia. The forward edge hits my forearm right on the middle of the injury.

The plan (vision) is to lengthen the pad, distribute the load over a wide area. But keep the same height and position.
I like the idea of an AL base. Cut it roughly to shape. Drill the mount holes. Then cover with the thermoplastic and lastly padding.
I do have a source for the honeycombed urethane / latex.

Your point is well taken, I might want to do both sides.

Ideally, I'd like to keep it simple enough to do myself, so I can modify it as I go along and work out the best fit.
Pete Penseyres original bars were similar to that, if I recall correctly.


thanks for the feedback!
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Re: Custom arm rests [Shandit66] [ In reply to ]
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These may be of interest to you: http://carbon armrests
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