Guys, I need some help getting my clutching dailed in ...
I have a '10 RTX stretched to 136 with the following:
Secondary spring is set at B1, with approximately 30-degrees of twist. New primary spring appears to be a lighter gauge spring, but has about the same number of coils as the OE spring, which is/was black with "Blue-pink-Blue" markings I think. I don't know what the new primary flyweights weigh, but the kit requires drilling out the middle and tip flyweight rivets and replacing them with an aluminum hex head bolt (6mm x 1.0 pitch x .75 inch) and a zinc coated steel hex nut for the middle and tip of the flyweights. Originally, the replacement weights I was given were identical for both the mid and tip. But I found that the RPMs with this set up were too high, and so was given new weights for the tips (a steel button top, socket(or Allen) head screw-6mm x 1.0 pitch x .625 inch) with a thinner zinc coated steel hex nut. Again, I don't know what the weight of these screws and nut are. Was still over revving so it was suggested that I change the thinner nuts on the tips to the thicker ones originally provided. Did that ... has brought the RPMs down slightly but still not where I'd like to be.
Here are some numbers at WOT:
11,900 at 45-60 mph
12,120 at 65-80 mph
80 mph is top end for me with this setup.
I would like to get closer to 11,300 from 45-70 mph at WOT. I know I need to add weight, but how much? Tried calling Schmidt Bros for help, but they are unavailable for a while (on vacation?). Any help is appreciated.
I have a '10 RTX stretched to 136 with the following:
- 136 EZ-Ryde skid
Freeride track
Schmidt Bros Stage II clutch kit (consists of new helix, primary spring and weights)
stock gearing (18/43)
stock drivers
Secondary spring is set at B1, with approximately 30-degrees of twist. New primary spring appears to be a lighter gauge spring, but has about the same number of coils as the OE spring, which is/was black with "Blue-pink-Blue" markings I think. I don't know what the new primary flyweights weigh, but the kit requires drilling out the middle and tip flyweight rivets and replacing them with an aluminum hex head bolt (6mm x 1.0 pitch x .75 inch) and a zinc coated steel hex nut for the middle and tip of the flyweights. Originally, the replacement weights I was given were identical for both the mid and tip. But I found that the RPMs with this set up were too high, and so was given new weights for the tips (a steel button top, socket(or Allen) head screw-6mm x 1.0 pitch x .625 inch) with a thinner zinc coated steel hex nut. Again, I don't know what the weight of these screws and nut are. Was still over revving so it was suggested that I change the thinner nuts on the tips to the thicker ones originally provided. Did that ... has brought the RPMs down slightly but still not where I'd like to be.
Here are some numbers at WOT:
11,900 at 45-60 mph
12,120 at 65-80 mph
80 mph is top end for me with this setup.
I would like to get closer to 11,300 from 45-70 mph at WOT. I know I need to add weight, but how much? Tried calling Schmidt Bros for help, but they are unavailable for a while (on vacation?). Any help is appreciated.
xt_gt
TY 4 Stroke Junkie
i don't have as much clutching done as you do but i'll try & help.
i myself have a 136 but a 1.75 track & ulmer clutching. i messed around with the secondary alot. tried going tighter (more degrees like in b1,b2, & c1) but ended up still hitting the limiter. i went back to stock A1 & don't hit the limiter in fresh powder or at all. also like the backshift better now (less)
i myself have a 136 but a 1.75 track & ulmer clutching. i messed around with the secondary alot. tried going tighter (more degrees like in b1,b2, & c1) but ended up still hitting the limiter. i went back to stock A1 & don't hit the limiter in fresh powder or at all. also like the backshift better now (less)
I too went back to the A1 helix setting, and have noticed slightly lower rpms, but still a bit too high. The Schmidt Bros stage II kit comes with a new helix, which is what I'm using now. I might try going back to the stock helix, starting at A1 and go from there. At this point (with my current set up) I am thinking I may just have to bite the bullet and buy heavier flyweights for the primary. Still seeing 11,900 at WOT on hardpack. Correct me if wrong, but I'm told you shouldn't be over 11,400 ... at least not very often.
UP bushman
VIP Member
OVR4D said:
What primary clutch arms do you have and do you have the nut & bolt kit from Schmidt Bros. when purchased. Adding weight to heel will give you better low to midrange and more tip weight will give more top end. Try adding 1.5 grams to each clutch arm and it should put you closer. Lots to be gained on these things in the clutching department good luck.
