I just stretched my Attak to 144 and was thinking maybe I should gear down a little to help pull the 1-1/2 track. What gearing has anyone tried or should I leave it, also thinking I could pull some rivits out of the weights. Any thoughts and options would be great!
680
680
LazyBastard
TY 4 Stroke God
- Joined
- Apr 13, 2003
- Messages
- 5,276
- Reaction score
- 5
- Points
- 1,216
Well, I run an 03 with 144", so I should be able to help.
My gearing is right now at 23/42. Yes, thats geared WAY down from the stock 24/38 (yours is stock at 23/38), but my clutches are modified for overdrive. Your engine likes to spin a couple hundred rpm higher, but your PTO shaft is already geared down more, so gearing should be about the same.
My gearing is set at the absolute edge, where it will precisely fully shift out, but won't run out of gearing and overrev.
Now what it comes down to is this; overdrive is worth about 2 teeth on the bottom, or 1 tooth on the top, so if you do NOT overdrive your clutches, AND you do NOT want to overrev on the top end, then you won't want to go any higher than 40 on the bottom. This will give you the best top speed possible. If you DO overdrive (note that overdrive looses some efficiency), then you can go as far as 42 (note that 42 requires slight modification to the reverse gear if so equipped) or 22/40 if you don't want to modify. The way I see it is that bottom end is more important than top end, so I'm willing to sacrifice a fraction of 1 mph to increase the bottom end grunt by 5% (2 teeth on the bottom = about 5% more torque) -- personal preference.
Also note; bigger gears are more efficient and last longer, so its better to go bigger on the bottom than smaller on the top.
Regarding clutching. I do NOT recommend removing weight. If you're adding stress to the drive system, you want HIGH clutch forces to prevent belt burning. If you decide to gear down, you will DEFINITELY need to ADD weight.
Final important point;
The lower the gearing, the less engagement stress and the longer the belt life. If you're doing a lot of off-trail riding (which I suspect given 144/1.5), then gearing down from 23/38 to 23/42 or 22/40 will mean 10% more pull on the bottom end, which is REALLY going to help in deep snow.
My gearing is right now at 23/42. Yes, thats geared WAY down from the stock 24/38 (yours is stock at 23/38), but my clutches are modified for overdrive. Your engine likes to spin a couple hundred rpm higher, but your PTO shaft is already geared down more, so gearing should be about the same.
My gearing is set at the absolute edge, where it will precisely fully shift out, but won't run out of gearing and overrev.
Now what it comes down to is this; overdrive is worth about 2 teeth on the bottom, or 1 tooth on the top, so if you do NOT overdrive your clutches, AND you do NOT want to overrev on the top end, then you won't want to go any higher than 40 on the bottom. This will give you the best top speed possible. If you DO overdrive (note that overdrive looses some efficiency), then you can go as far as 42 (note that 42 requires slight modification to the reverse gear if so equipped) or 22/40 if you don't want to modify. The way I see it is that bottom end is more important than top end, so I'm willing to sacrifice a fraction of 1 mph to increase the bottom end grunt by 5% (2 teeth on the bottom = about 5% more torque) -- personal preference.
Also note; bigger gears are more efficient and last longer, so its better to go bigger on the bottom than smaller on the top.
Regarding clutching. I do NOT recommend removing weight. If you're adding stress to the drive system, you want HIGH clutch forces to prevent belt burning. If you decide to gear down, you will DEFINITELY need to ADD weight.
Final important point;
The lower the gearing, the less engagement stress and the longer the belt life. If you're doing a lot of off-trail riding (which I suspect given 144/1.5), then gearing down from 23/38 to 23/42 or 22/40 will mean 10% more pull on the bottom end, which is REALLY going to help in deep snow.
Thanks a lot! It looks like 22/40 should be about right. You figure I will have to throw weight at it to make it pull? Also what weights are you running , I ran heavy hitters on my RX-1.
Thanks
Jeff
Thanks
Jeff
LazyBastard
TY 4 Stroke God
- Joined
- Apr 13, 2003
- Messages
- 5,276
- Reaction score
- 5
- Points
- 1,216
If you don't add a whole lot of weight, it will spin the engine too fast and suck back a lot of gas. Regarding the weights, I'm running 48.5g HH's with ALL the weight they came with.
