Thread: very hot motor!
View Single Post
  #6  
Old 15-03-2011
Chequered Flag Racing's Avatar
Chequered Flag Racing Chequered Flag Racing is offline
Spends too long on oOple ...
 
Join Date: Feb 2007
Location: In Early Retirment
Posts: 5,993
Default

Quote:
Originally Posted by Martijn View Post
I have a gearing of 22/81,( and drove on grass).
I always used this gearing when I drive on our dirt track.
Which motor wind?

If you use clay tyres on the clay and Schumachers on the grass you should alter the gearing due to the different tyres diameter

So if you take your gear/spur and the tyres as and I'm guessing here on tyre size

Schumacher = 80mm dia = rollout of 26.26mmpr
Clay Tyre = 90mm dis = rollout of 29.54mmpr

So you would need a 25t pinion (29.84mmpr) to get close to the clay tyre rollout, but allowing for the drag of the grass use a 24.

MMPR = Tyre diameter (mm) x PI (3.14) / Number of Spur Teeth x Number of Pinion Teeth / Drive Ratio

if my maths is wrong and the B4.1 internal ratio wrong shoot me down
Attached Images
File Type: jpg mmpr.jpg (55.4 KB, 8 views)
__________________
o0ple Trader Feedback
NE Venue's New & Old
my space on YouTube
CFR RCTV Channel
Glenn Atterton

BRCA 2005 1/10th Off-Road Veterans Champion
LMP12 National Champion 2003/2004 / F3 class
Reply With Quote