Clutch Testing Time

[Cornell Customs LLC]

Time to wake up the H2 from its winter nap and do some more clutch testing

 

[Sand Shark]

So when are you taking the H2 out to test the KWI clutch set up?

 

[Cornell Customs LLC]

So when are you taking the H2 out to test the KWI clutch set up?

I'll have some other components tomorrow to set them up, these clutches have been tested for several weeks in fast desert conditions so I'm working on the other end of the spectrum, slow crawling, I'm working with KWI and setting it up to see just how low of a belt engagement we can get and will be running a longer belt to achieve 15% lower gear reduction on the bottom, the downside I may only be able to run 90 mph instead of 110

 

[Sand Shark]

I'll have some other components tomorrow to set them up, these clutches have been tested for several weeks in fast desert conditions so I'm working on the other end of the spectrum, slow crawling, I'm working with KWI and setting it up to see just how low of a belt engagement we can get and will be running a longer belt to achieve 15% lower gear reduction on the bottom, the downside I may only be able to run 90 mph instead of 110

90mph is way too slow. LOL!!!

 

[Dragoon]

Nice! Those clutches look like a work of art!

 

[AXE]

I'll have some other components tomorrow to set them up, these clutches have been tested for several weeks in fast desert conditions so I'm working on the other end of the spectrum, slow crawling, I'm working with KWI and setting it up to see just how low of a belt engagement we can get and will be running a longer belt to achieve 15% lower gear reduction on the bottom, the downside I may only be able to run 90 mph instead of 110

I've noticed with mine, the longer the belt, the more rpms for engagement, also audible belt slap. Never noticed much difference in top or bottom end with various belt lengths. That was with the OEM clutch and the Tapp clutch.

The OEM clutch engages about 1800 rpm, which I liked better. The Tapp clutch is 2200 or 3000 rpm. I have 2200 and would definitely not like the 3000.

For me, less weight in the Tapp arms and running in L or H would do wheelies and pull like a freight train with the OEM belt. I am now using the G Boost Cross Country belt with the Tapp and it's the best I've felt since the Tapp primary was added. Seems like the right amount of deflection. We'll see about longevity as the miles rack up.

 

[Cornell Customs LLC]

With a center bearing primary the secondary spring should control the belt tension and should really have no or very little deflection, if the secondary reaches full shift
(all the way closed) and doesn't take up all the slack in the belt then it will get loose.
We modify the secondary clutches for more travel on KRX, Ridge and H2s and use a longer belt to let the belt ride higher and provide lower initial gear reduction (Under Drive).
The KWI secondary we are testing is larger in diameter than the factory secondary and has a lot more travel, this lets us run a wider and longer belt for about 15% reduction or run a shorter belt for more top end..
We are testing different springs and arm weights and are getting belt engagement right above idle, I hope to get some crawling testing as well as some WOT runs in this week.
I haven't had the opportunity to test the TAPP to see if it has the capability or how much trave the secondary has.

 

[AXE]

The WBB and the Cross Country belt both sat a tad higher (1 mm above the secondary sheave) as what you show in your photos. The WBB was too sloppy for me, not smooth and some belt slap. The OEM belt was tighter than a banjo string. I ended up snapping an OEM belt hitting some whoops about 30-35 mph, I believe it was shock load when coming off the top of the whoops and then the tires hooked up abruptly. Cleanest belt I've ever seen blown, just pulled right apart in one part. I haven't had many belt issues like others.

What size/weight/brand of lighter spring are you running? Tapp said there wasn't a lighter option, but not sure why one of the lighter aftermarket springs wouldn't work to get a 1800ish engagement.

I haven't done anything with the secondary yet. Just waiting to see if Kawasaki does anything with the secondary for the recall. Then I'll decide what's next. But if they don't do anything, then I'll add the Tapp secondary or if you offer a secondary modification, I might do that.

 

[Cornell Customs LLC]

You would need to measure the spring, Inside and outside diameter, length, and wire diameter and I can calculate the rate and see if we have anything that would work.

 

[Sand Shark]

How is the clutch testing going?

 

[Cornell Customs LLC]

How is the clutch testing going?

We have it all set up and ready to rip, been playing with different belts and springs to get the lowest engagement and most reduction (we are trying to set up the clutching best for crawling as it's already been tested at high speed in the desert) we are currently at over 15% reduction on the low end compared to the factory setup and engagement is just above idle at around 1400 RPM, if the weather straightens up we'll get some riding in on steep terrain and get some dragy data as well, while I expect to lose some top speed it should be quicker with the lower initial gearing if we can get it to hook up and should still run 85-90..
Check out the picture below compared to the one I posted before to see where the belt is now riding, this belt is over 2" longer than the OEM H2 Belt.

 

[AXE]

Have you tried this belt? The Gboost XC recently replaced the EX. I guess this one is made in Japan, but it's knife cut. So I've seen purple recommend a longer break in.

I run this with the Tapp primary and OEM secondary. It rides similar to the one in your picture. I've done about 75 miles on it, including about 15 miles of break in, but only a few good rips in upper rpms up to 70 mph. So far, I really like this belt. I was gonna pull the cover and inspect it soon.

 

[Cornell Customs LLC]

Have you tried this belt? The Gboost XC recently replaced the EX. I guess this one is made in Japan, but it's knife cut. So I've seen purple recommend a longer break in.

I run this with the Tapp primary and OEM secondary. It rides similar to the one in your picture. I've done about 75 miles on it, including about 15 miles of break in, but only a few good rips in upper rpms up to 70 mph. So far, I really like this belt. I was gonna pull the cover and inspect it soon.

Yes, the belt we are now testing is way longer and wider than the GBoost, the KWI secondary is larger in diameter than the OEM secondary so it will allow for a longer belt and therefore more low end reduction

 

[Cornell Customs LLC]

Did some testing with the KWI Clutching setup today and it’s gonna be good news for the rock crawlers!!
Nice smooth low engagement at around 1500 rpm, it can crawl a 25% grade at 1-2 mph.
15% reduction and was still able to hit 96 mph before hitting the limiter!!
But…. We think we can make it even better, even lower engagement!
Stay tuned, the primary is going back to KWI for a couple more modifications and we’ll be doing more testing when we get back from Moab on the 26th.

 

[AXE]

Definitely like a lower engagement for technical stuff.

How is the compression braking in L? I dont use L very often. Mostly higher speeds in dunes and medium to high for desert trails. I do get on some steep trails and use L, but on steep downhill sections the compression braking is very abrupt and constantly came on and off making for a very jerky ride with the stock clutch. Haven't ran that steep stuff with the Tapp, but would expect the same. L is almost unusable for me in most situations.

 

[Cornell Customs LLC]

Definitely like a lower engagement for technical stuff.

How is the compression braking in L? I dont use L very often. Mostly higher speeds in dunes and medium to high for desert trails. I do get on some steep trails and use L, but on steep downhill sections the compression braking is very abrupt and constantly came on and off making for a very jerky ride with the stock clutch. Haven't ran that steep stuff with the Tapp, but would expect the same. L is almost unusable for me in most situations.

Seems to be pretty good and no jerking, more testing yet to come, making a few changes to the setup which should improve it even more.