Tapp blowing belts compared to stock primary

[KillerBee]

Thanks for those updates. My offset is just shy of 60. I put the stock 35 helix back in and installed the dalton b/o wrapped to 90 as suggested by Knapp. So far have not blown another belt but have by no means pounded on it….

 

[max rolph]

Hey Knapp, my buddy is just putting his tapp on his winder, where are you measuring the stationary offset from point A -B.... is it from upper edge of face of inside sheave of TAPP to the outer machined surface of factory secondary? like what STM shows in their measureing points. Mine being a cat with STM i self aligned at 60mph on stand and then float it .050 after finding its own alignment.... mine is spot one for XS829 belt,

 

[KnappAttack]

Hey Knapp, my buddy is just putting his tapp on his winder, where are you measuring the stationary offset from point A -B.... is it from upper edge of face of inside sheave of TAPP to the outer machined surface of factory secondary? like what STM shows in their measureing points. Mine being a cat with STM i self aligned at 60mph on stand and then float it .050 after finding its own alignment.... mine is spot one for XS829 belt,

Back of primary with a flat straight edge to the front of the secondary, just like Yamaha does it with the stock measurements.

I also run locked secondaries. Every time I try to float it will blow belts after a while. What I find floating is the thing is floated out and when you grab a handful of throttle the secondary refuses to float inward and is stuck outward where it wont line up at his speed. You can test this but grabbing a handful on the stand with just a little bit of brake and see the secondary wont float inward. So, no more floating whatsoever is what I'd recommend. Floating might be fine for easy trail riding where one is not always on the throttle, but not for hard performance riding IMO.

 

[max rolph]

soo your just using their method... but not their measurement cuz the sheave is diff thickness on tapp, have you done that Thunder cat with the TAPP and STM with xs829 belt or 827 to see what it measures when you do your straight edge on belt and then see what outside to outside measures. IT would be alot easier if Tapp would make an alignment tool for the 4 common combinations with XS825 for yam and XS827/829
1. TAPP vs YAMAHA SEC = 59.1mm
2. TAPP vs YAMAHA STM SEC =
3.TAPP vs AC BOSSS SEC =
4. TAPP vs AC STM SEC = 61.0 mm/2.400
This being from the flat back of TAPP to the flat front edge of secondary.... NOT FROM FACE of sheave.


sooo what i should do it run it up to top of primary floating... mark where it is and lock0 in there. i see what your saying about it is outwards slightly when at slow speeds then it does float in about .050 when running higher speed on the stand, soo i might just lock in in there.

 

[KnappAttack]

soo your just using their method... but not their measurement cuz the sheave is diff thickness on tapp, have you done that Thunder cat with the TAPP and STM with xs829 belt or 827 to see what it measures when you do your straight edge on belt and then see what outside to outside measures. IT would be alot easier if Tapp would make an alignment tool for the 4 common combinations with XS825 for yam and XS827/829
1. TAPP vs YAMAHA SEC = 59.1mm
2. TAPP vs YAMAHA STM SEC =
3.TAPP vs AC BOSSS SEC =
4. TAPP vs AC STM SEC = 61.0 mm/2.400
This being from the flat back of TAPP to the flat front edge of secondary.... NOT FROM FACE of sheave.


sooo what i should do it run it up to top of primary floating... mark where it is and lock0 in there. i see what your saying about it is outwards slightly when at slow speeds then it does float in about .050 when running higher speed on the stand, soo i might just lock in in there.

Correct, that 59.1mm measurement is on my sled with a XS825 belt TAPP primary using my straight edge measuring the way Yamaha would, it aligns with clutches at full shift perfectly, then I lock down at that measurement. I take great care to get it perfect so I have a good measurement. Even changing belt brands can and will change this number depending on belt length and width obviously.

No, I have not done a TAPP and STM combo.

 

[Hammer70]

Correct, that 59.1mm measurement is on my sled with a XS825 belt TAPP primary using my straight edge measuring the way Yamaha would, it aligns with clutches at full shift perfectly, then I lock down at that measurement. I take great care to get it perfect so I have a good measurement. Even changing belt brands can and will change this number depending on belt length and width obviously.

No, I have not done a TAPP and STM combo.

Hi knapp just curious what shims are being used to get it perfect.Do you make them or can you buy different thicknesses yamaha only offers 1mm and 2 mm.
Thanks Pan

 

[KnappAttack]

Hi knapp just curious what shims are being used to get it perfect.Do you make them or can you buy different thicknesses yamaha only offers 1mm and 2 mm.
Thanks Pan

You are correct Pan, I use the Yamaha shims and other various hardware shims I have to get things real close, sometimes its not exact, but a few thousands not a big thing.

 

[Hammer70]

You are correct Pan, I use the Yamaha shims and other various hardware shims I have to get things real close, sometimes its not exact, but a few thousands not a big thing.

Ok thanks Knapp I thought someone made various shims that’s what I do as well.
Thanks Pan

 

[SideHogger]

I align the straight edge to the belt with a caliper when its close to full shift with tension on it in the clutches. So the straight edge is on the same plane as the belt and can be measured properly. I spend a great amount of effort to verify my alignment on my clutches overtime I make a change.

Simple things like belt selection, length & width make small changes to the offset as well. What is not taken into consideration the way I measure is chassis flex and motor mount flex, but the 998 is pretty stout in that regard, so one of those things you can kinda overlook and not worry about.

If you have a straight 35 try that in there with a Dalton B/O set at 90. I had one I setup for my friend last week with a 39-35 also set at 90. I wouldn't be using using that reverse helix like you are trying to do there if your using a Hurricane 270 tune. Use at least a straight helix like the 35 at a min.

Knapp, I gotta ask, why not use the reverse helix? I’ve gone to a 35/39 and tried the 35 straight with black/orange Dalton and it was very lazy back shifting on the trails. Also tried TP orange with 35 and same results. 270 Hurricane tune….btw

 

[KnappAttack]

Knapp, I gotta ask, why not use the reverse helix? I’ve gone to a 35/39 and tried the 35 straight with black/orange Dalton and it was very lazy back shifting on the trails. Also tried TP orange with 35 and same results. 270 Hurricane tune….btw

Because that would be backwards of what I want. I want them to work harder down low accelerating hard early, not just rev and not accelerate. It all depends on what you are trying to achieve and how much push you have on the front and the spring used in the rear. My sled hits about 8900 and climbs to 9000, about a 100 RPM increase. If I was to use a reverse helix that would go backwards having RPM fall, and If I feed it any more helix up top, it will have belt slippage upstairs where the belt is working on a smaller diameter on the secondary. Revy and responsive is not the fast way. Some guys think that quick reving equals fast, and quite the opposite is what I've found. You want backshift, but not at the expense of acceleration. Reverse helix may work in certain situations I suppose for different primary arms or different spring setups, but Ive never run across the need for a reverse helix in all my years.

 

[SideHogger]

I agree Knapp….. I’ve never used reverse angle either and I know a 1 to 1 ratio will accelerate faster but I just couldn’t get the 35 or the 33/35 Thunder products to back shift for that snappy acceleration from corner to corner. This combination also ran 132 mph for me in a little under 1/2 mile run ( yes, gps, not dream meter) with snotrackers, half a tank of gas, and my 225lb fully dressed big butt on it. Maybe it’s the curvature of the D&D weights I’m running and not the Daltons but I wouldn’t think there would be much of a difference. Oh, and Apex primary thanks to you! Lol

 

[Turboflash]

Granted I am on Cat but I had same basic experience with reverse angle setup "someone" recommended. It would rev quickly but not pull.
Changed to compound cut setup. Cut 60' times about .3 secs. and 330' times by 2 secs. A big difference.

 

[max rolph]

can anyone measure their peek to peek measurements.... this eliminates the sheave thickness and all that comes into play is belt width now and all we have to do is adjust for that. i know peek to peek for a xs827 belt is 53.5mm and an xs825 is 52mm, would others mind chking?? thats peek of inner primary sheave where belt runs to peek of outter sec sheave where belt sits.

 

[Trailleader]

18 sidewinder ltx le. 3500+ miles on stock primary and never blew a belt.Many high speed runs, drags etc. Changed belt once as a precaution. Installed Tapp primary last year and with few miles never had a problem. This year I’ve blown two belts in two days last weekend. Both belts broken in, etc. Drag race on both occasions blew belt (snapped), one from a standstill the other from 30 up. Original offset 59. Stock secondary with thunders 33/35 helix and orange spring wrapped at 6-1. Is the suggested 57.5 offset really that big of a difference??
Thanks in advance for any suggestions!

Have you tried 35 or 39 35
Just curious
Just read rest
Nevermind
33/35 makes no sense to me

 

[KnappAttack]

can anyone measure their peek to peek measurements.... this eliminates the sheave thickness and all that comes into play is belt width now and all we have to do is adjust for that. i know peek to peek for a xs827 belt is 53.5mm and an xs825 is 52mm, would others mind chking?? thats peek of inner primary sheave where belt runs to peek of outter sec sheave where belt sits.

Too many variables trying to get a measurement that way IMO. You could easily be off a couple mm depending on if you count the chamfer, along with it being offset so much. There is a reason you go from back of sheave to front of sheave.

If you can't line it up, put a real soft spring in the secondary, put a belt in and use a compressor in the primary or find a way to clamp it to full shift and use a straight edge along the belt and measure the alignment. Get it perfect. This is the best way to do it.

If you idle it and let it come to rest, the belt will only align at an idle, not full shift. If you want the belt to align at full shift this is the only way to do it is manually checking it like that. The belt never lines up at idle and full shift, and thats the reason some people think floating the secondary is fine, which it may be for slow trail use without applying big power, but when you apply the power at slower speeds, the secondary stays stuck outward and the belt no longer lines up at full shift when under power. Typical movement is quite a bit when they float, like 1.5mm or so from idle to full shift.

For me on my sled with the XS825 and the TAPP/Winder secondary clutch. The perfect alignment measuring things the Yamaha way. That measurement is exactly 59.1mm. I have great belt wear and have never blown a belt in 1800 miles on this setup on 300HP tune. Its been run in loose snow and hard pack and run very hard!