smaller spur/final drive ratio
 

who makes/sells smaller spur gears for the rat ?
whats the final drive ratio ? as i want to make a gear ratio chart

I've read you can modify a B4 spur (by drilling/reaming out the centre to fit the Rat's layshaft) but that also means buying the slipper pads as well.

Also read that the FDR is the same as the B4 (2.6:1 I think?)

This is correct however you also need to machine down the slipper plates if you do this to fit inside the hex shape of the pads :cry: I think its a 5mm drill bit you use (Measure first I'm not 110% sure)

It's a bit of work with dremel and file but well worth it :thumbsup:

Rhino, Pm me an e-mail address and I will send you a spread sheet over that you can use to do the gear charts. Already set-up for the ansmann just copy the formulas and change to suit.

Ok so I have re-done my gear chart with the original spur gear and associated spur gears on it. I always went crazy on the pinions to cover all bases :woot:

Hopefully this is what you wanted Rhino.

thanks rob, thats excellent.:thumbsup:

I'm in the process of reducing my spur size as i'm now upto the largest pinion I can possibly fit.
Would this be suitable; http://www.modelsport.co.uk/index.php?product_id=35659
Anyone know any alternatives to the B4 spur that fit without modification?