10inch rims versus 13inch rims

[Kamaz]

Hi everyone,

The whole idea is to build single seater of weight around 200-250kg and with power output of 80-90 bhp. What kind of wheels would be more benficial 10inch or 13inch?
My initial thought is smaller wheels would be lighter, there are tyres with widths of up to 225mm. Smaller wheels would need less torque to spin the wheels resulting in increased acceleration, also uprights and hubs could be made lighter.
Or 10inch wheels are a bit too small for 80-90 bhp? considering that pneumatic and mechanical trail areas can be matched to 13 inch wheel's.

[Richied76]

i know this maybe a silly idea but i'm doing the same sort of thing with my son. the choise i took was based on the cost and availability of street tires. I wanted 10" wheels for all the same reasons you noted above. but getting hold of cheap tires was a bit of a nightmare. There all wear out in the end and if you only take it out once in a while, it could be a year or two down the line when you need to replace them. I settled for 13" aluminium mini wheels. Tires £35 each. new set of wheels if i prang them £300. Plus i had an upright to map out and modify on CAD rearther than start from scratch. Keep in touch if you want to exchange ideas..

[CMSMJ1]

What are you doing about brakes?

[Kamaz]

Uprights and hubs will be designed from scratch - CAD software will play major role tyre cost is not a problem, plus single seater will see only track surface. Regards brakes it is a bit of a problem, because the majority of brakes are designed for vehicles above 200-250 kg, and motorcycle calipers won't be any good - they use huge brake rotors. So the only way to go is to design custom calipers. What are the bad points of smaller wheel instead of bigger one? not counting reduced length of pneumatic trail.

[mx_tifoso]

It seems that packaging is one of the most obvious "bad points" of smaller wheels.

Would it be possible to use rear motorcycle brakes? The rotors are usually way smaller than the fronts.

[fastback33]

There is a whole forum dedicated to this issue. It is called FSAE forums. check it out and do a search there if you want some more info, topic has been discussed to death...