Belt driven compared to driveshaft...

[Motomike122]

Hello all, I new hear..I have a B44 and I love it. I also really like to looks of the new Tamiya TRF511...Why is it belt driven and not shaft? What is the advantage of belt or disadvantage of it? Thanks for the insight....Mike..USA..

[sosidge]

In off-road it's hard to talk about pros and cons - both drivetrains are fast (in onroad it is a different matter, shaft is well out of favour).

Better to talk about characteristics.

Charactersistics of shaft...

- A little easier to seal from the elements
- More direct throttle response
- Setting of bevel gear mesh is crucial for reliability - can wear or strip
- Torque steer due to longitudinal position of motor - however the weight of the wheels and the large suspension travel minimises the effect of this.

Characteristics of belt...

- Can be harder to seal from the elements (Losi and Tamiya DB-01 are sealed, but complete sealed chassis are bulky)
- Softer throttle response (due to taking up slack in belts)
- Belt tension must be right balance between free running and not skipping teeth
- No torque steer

Both win races - the belt Tamiya 511 just won the Euros, the shaft B44 and Yokomo have won BRCA nationals this season.

[Si Coe]

It worth pointing out that the current on road slant is that belts are back in favour, rather than always have been. They went through a spell of shaft drives a while back too.

What is 'in' tends to depend on other factors. For example, the original appeal of shafts was that they are more efficient than belts. Therefore Snoring cars put up with the torque steer problems because they could run a hotter motor and still make 5 mins with the batteries of the day. However, thanks to brushless and much improved cell tech, struggling to last the race is a thing of the past, and we have all the power we need, so running a slightly less efficent but easier to control belt suffers no penalty.

In offroad, where torque steer isn't that major anyway, the drivetrain choice for car designers really comes down to where they want to put stuff.