1. Originally Posted by jhm
mucho appreciate you guys help! When I roll backwards the tops of my wheels angle in and rub hard against my side guards, doesn’t do that when I roll forward. Weird right?
Your wheels are toed out; when you roll forward they want to move away from themselves, and when you go backwards, they move in as far as there's play or compliance to do so. That's also why when you come to a stop, it wants to roll back: it's probable that the wheels deflect and that spring-force wants to relax/return to null, which rolling backwards restores.
So there's a quick way to eyeball the toe: loosen the axle clamps enough to twist it in place, have a buddy move it and you'll see the change in behavior.
If you have a large, level, hard floor, you could experiment with coasting. The best toe is the one that coasts the farthest. I don't know about skinny, radiused wheelchair treads, but with automobiles (race cars) with much camber, -0- toe is not the lowest rolling resistance.
Imagine when you roll one of your wheels across a floor. As it inevitably leans over (gains + camber; our wheelchairs have neg camber; so do cars), it begins to turn into the way it is leaning. Hold it as possibility that to achieve minimum loaded rolling resistance, -0-Toe may not be ideal! A little toe-out may be better! It will compensate for the force that is trying to have the tires turn in? Some one needs to test this!

So, the ball is in your court! Go get some empirical data for us! Do coast-down test with different alignments an let us know if your axle isn't aligned with the framing square when it hits the optimum.

PS: you should check the camber plugs to ensure nothing is rotated. Both have two parallel flats which technically should be 90* to the plane the chair is parked on. If one is twisted, then of course they can't both be right and you'll need to fix this first. If you have an aluminum axle spare, that would be the best fix! CF axles sound like bullshit to me.

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•