derby car set up advice

[Rocket21]

If you take a wheel with a single axle (not attatched to the car) and run it along the rail in a neg cambered style and then a positive camber, it seems to me that the neg camber is attempting to slice off the edge of rail.....kind of like getting a stick ready for marshmallows with a camping knife as you shave off wood. Two contact points are touching, one- the top edge of the rail, two- the track. With the [junk] camber the contact points change to one- the lower side of the rail almost near the racing surface and two- the racing surface. Not sure about all the physics involved but by simply looking it seems the [junk] camber is a much smoother system vs the neg camber especially if you have an old track like ours with poor joints and small gaps. With this track a neg camber wheel would fall into a small gap and cause a big bounce or definately a big speed loss as the wheel as to blast thru the gap and continue rolling. THe [junk] camber would just roll over it like a small bump in road.

[62vetteefp]

yep!, I would also say that with negative camber there is also the possibility that both the front part of the wheel and the back part could hit the rail while going down the track. This would give two areas of touch with both areas rubbing.

the more I think about it the more I like Positive camber (at least from a theoretical vies).

As a side note I orderd Shortys stuff to polish the wheel bores. Did not do much to that area before.

Also with the cambered wheels is there any advantage to filing out the area of the axle to reduce contact area? Seems like with the 2.5 degrees negative camber (rear) it would only touch in two places:bottom outer and upper inner.

[doct1010]

Also with the cambered wheels is there any advantage to filing out the area of the axle to reduce contact area? Seems like with the 2.5 degrees negative camber (rear) it would only touch in two places:bottom outer and upper inner.

IMO, only if you can reduce bore as well. If you are talking about grooves the jury seems to still be out with cambered wheel. We used grooves with oil with good results. There has been alot written on subject. Try a search on grooved axle.