Weight distribution on adjustable weights

[BADSLED]

Lets' use Super tips as an example. There are 3 place to add weight to. Heel, mid and tip. We know adding weight in heel helps with lowering engagment rpm and improves holeshots by increasing belt pressure due to least belt/sheave contact area, too much will backshift lazy. Mid is used for controllinng mid range. Tip weight is adjusted for full shift rpm, usually dependent on weight of rider, more tip weight added starts to engage rpm as well.

My question is: Can too much heel weight hurt your top end performance by having too many washers by shifting the center of gravity closer to the pin?

 

[Len Todd]

I believe you are correct. Adding weight on the heel can have an effect on the Top End, because of the change in CG.

From what I have experienced, if the engine has the power to still get to optimum top end RPM, with the added heel weight, then you are still O.K. (e.g. Adding a turbo would give you more power. Therefore it makes sense you could add heel weight to increase grip on the belt, etc..)

But if you add the extra heel weight and then can't get to optimum top end RPMs, then you may have to back off on the heel a bit. Especially, if you have nothing left on the tip to take off, or no more power to add.

But, I warn you, I am just starting to play with the Supertips. But, I have found that there is a limit to what you can put on the heel w/o beefing up the HP. 

The real one to ask is Allen Ulmer. Hopefully, he may chime in here and set us up on a straight & narrow path.

 

[spray25]

I am have some of the same questions.

I am still trying to clutch my stage 2 SC'ed FX Nytro MTX. I have been quite disapointed with my track speed when climbing. I am using 60 gram Super Tips. Most everyone has been telling me to load the heck out of the heel because of the strong bottom end of the SC.

I was running 14.5 mm rollers, the 60's with 8 grams in the heel and just over 2 grams in the tip, Silver secondary at 70, with a straight rate shockwave at 42. The belt was slipping in the secondary REALLY bad. The bottom of the sheaves was black with rubber.

I then changed to a white secondary at 70. I left everything else the same, but thinking I was not getting full shift out in the primary I marked both sets of the sheaves with a black marker. There is no evidence of the black rubber in the bottom of the secondary, but it is still slipping. The secondary is so hot you can't touch it. The marker lines are gone from the secondary meaning it is fully shifting in the secondary, however there is over an inch of marker line still at the top of the primary. So the secondary is shifting fully but the primary is not. BTW with the primary spring removed if I close the primary with the belt installed the belt rides within about 1/8 of an inch of the top of the sheave. My RPMS are good when clutches are cold, but drop dramaticly when the clutches heat up.

This leads me to believe that the high heel weight and light tip weight is not allowing the primary to shift out fully. This would seem to go along with what you to are thinking about where weight is placed in the primary weights.

I also have 50 gram super tips that I have not used. at this point I am trying to decide if I should redistribute the weight in the 60's or start over with the 50's knowing that I will have more room to relocate where the weight is located?

 

[Turk]

I allways tune heel to tip. After doing a few kazillion times you get a "feel" of what your clutches are doing. Your helix can & does make a difference on mass placement also.It is tuff to get the same top end with any weight with that profile. If you compare a stock 4 stroke weight it is relatively flat compared to the "polaris/AC" profile of the aftermarket weights. Your secondary stayed hot after using the white spring cus it was too tight not allowing the secondary to upshift. Somewhere between a silver at 70 & white at 70 is a happy medium. That is a big jump between the 2 of em.

 

[BADSLED]

My question is: Can too much heel weight hurt your top end performance by having too many washers by shifting the center of gravity closer to the pin?

 

[spray25]

So turk are you saying to junk the super tips and return to the OEM weights? Somewhere between the silver at 70 and the white at 70 would be a pink at 70 wouldn't it? I am not really qualified to argue with you, but why are many people saying that even the white is not stiff enough for boost and going to stiffer AC springs in their secondaries? I think Ulmer is even including a white secondary spring in their stock Nytro clutch kit?

Badsled, I think the answer to your question is yes, but would rather let some one with more clutching knowledge like Turk or Allen Ulmer answer that.

 

[Turk]

The supertips are a very good product. You just gotta mes around with them. I have used them on a few sleds & allways got them to work well. As for secondary wrap try the silver at 80 or 90 or the white at 60. I used a silver at 80 in my nytro with good results.

 

[Len Todd]

Last week I put in a Stage II. With the SuperTip setup from Allen, It would hit 10,500 and then drop back to 9900 at top end. Guess I lied too much about my weight. I took off the one tip washer. Now it hits 10,800 and drops back to 10,500 almost immediately. Then at top end it is at 10,200. Darned thing goes like a streak. But, ... I have given up top end to get this. 110 mph tops. But, it revs quick and gets to 100 right now. (One tooth ground out) I am thinking, I may install the screws in the SuperTip's tip w/o the washer or maybe add some center weight or maybe just drop the Pink Secondary back from 70 degrees to 60 to get the revs down just a bit. Probably will try all three, only one at a time. Kinda fun tinkering, when you can undo it!

 

[Turk]

You have too much inner weight & not enuff secondary tension len. You gotta lighten up the inside hole & probably add 10 degrees of wrap to the secondary but just lightening up the inner hole might get you there.

 

[Len Todd]

If I lighten the weight at the pin or increase secondary twist, I think it will rev higher. I was thinking that I want it to rev a bit lower. Or, are you talking about making the increased twist and/or lower pin weight, with the tip washer back in? Right now the tip washer is out. With tip washer in, the Rs dropped back to 9900 at Top End. I could see that taking out Pin weight could eventually lighten the wieght enough to bring the top end Rs back up. But, the tip seems to be the place to affect top end Rs.

Right now there are 5 grams near the Pin, 0 in the mid and 0 in the Tip.

Secondary = Pink at 70 degrees.

Primary = OPO

 

[Turk]

Your probably running the 60 gram supertips. You want to be low 10k rpm,s & climbing to 10,700. Lightening the inner more by 3-2 grams will get you close & also loosening the secondary to 60. The inner will affect the top end rpm,s if it is loaded too much. You should be running the o-p-o primary spring with those weights & it looks to me like your using the stock y-s-y. With the o-p-o you can add more weight & balance the rpm,s better or get the lighter supertips & use those with the stock primary spring.

 

[Len Todd]

Looks like our posts got flipped in sequence.

Given what you have said, I think I am back to setting the Secondary back to 60 degrees. I'll give that a try first.