Pinions and Spurs and 13.5's oh my!
03-23-2007, 11:55 AM
#1
Pinions and Spurs and 13.5's oh my!
These new 13.5s really require you to gear up. Im finding it difficult to find spur gears small enough and pinion gears big enough to get the proper rollout. On a cyclone with an internal ratio of 2.4375 if I run a 88T spur and 48T pinion then I get a rollout of 38mm on 54mm tires. Ive ran up to a 40mm rollout.
Are these new motors going to force cars to smaller internal ratios and room for the smaller spurs and bigger pinions? My largest pinion would hit the motor screws on my TA05.
Are these new motors going to force cars to smaller internal ratios and room for the smaller spurs and bigger pinions? My largest pinion would hit the motor screws on my TA05.
03-23-2007, 01:30 PM
#3
i got to say it was a little difficult 
to find a spur small enough for my t2 with internal ratio of 1.7 , stock spur 64p is 116 , when down to 100 with a 35 starting pinion with 57mm tires ouch///////// 
with a roll out of 36.87 
to find a spur small enough for my t2 with internal ratio of 1.7 , stock spur 64p is 116 , when down to 100 with a 35 starting pinion with 57mm tires ouch///////// with a roll out of 36.87
03-23-2007, 02:24 PM
#4
tim how much are you having to go up in mod.. or maybe if kevin see sthis he can tell me...
-DC-
-DC-
03-23-2007, 03:02 PM
#6
With the XRAY they have a Triple screw setup. Xenon sells a Center Spur Gear adaptor that will work with "regular" gears as well.
PRS has any size pinion you can imagine. They look like spur gears for the motor.....
PRS has any size pinion you can imagine. They look like spur gears for the motor.....
03-23-2007, 04:10 PM
#7
Originally Posted by or8ital
Are these new motors going to force cars to smaller internal ratios and room for the smaller spurs and bigger pinions? My largest pinion would hit the motor screws on my TA05.
"All pulleys are optionally available in several sizes for optimised internal ratio on long and short tracks with either brushed or brushless motors."
The manufacturers are catching on.
03-24-2007, 02:49 AM
#12
Kimbrough also has spurs.Since I don't use foams and only race outdoors (rubber)my RDX is fine with the gear ratio I'm using.33-34 with the current spur. I've got a smaller Kimbrough spur to install if I needed it (78).Oh yes I also use the Kimbough pinions.
03-24-2007, 04:00 AM
#13
I run rubber tire stock with my jrxs, and was using a CO-27 with a fdr of about 7.50. I wound up so far with 13.5 at a fdr of 6.16. with loads of punch out of the corners, and a temp of only 100-110. this week I am going to try it with the sintered rotor with the same ratio and see how much difference I have. I race on a tight parking lot course.
03-24-2007, 08:06 AM
#14
Originally Posted by losi nut
I run rubber tire stock with my jrxs, and was using a CO-27 with a fdr of about 7.50. I wound up so far with 13.5 at a fdr of 6.16. with loads of punch out of the corners, and a temp of only 100-110. this week I am going to try it with the sintered rotor with the same ratio and see how much difference I have. I race on a tight parking lot course.
With the sintered rotor on a tight carpet track I started 5.50 FDR and ended up at 5.10 FDR with temp. at 100-110F.
03-24-2007, 08:39 PM
#15
Originally Posted by BullFrog
Kimbrough also has spurs.Since I don't use foams and only race outdoors (rubber)my RDX is fine with the gear ratio I'm using.33-34 with the current spur. I've got a smaller Kimbrough spur to install if I needed it (78).Oh yes I also use the Kimbough pinions.