Well yesterday DWB & I Got to spend some time with the new group of belts... we learned a lot, but came away with even more questions... We did find time during the afternoon to install the new Elka front springs on his 700 Prairie...

IMO... I did find a magic belt ... it went fully to the top of the primary sheaves, like I was looking for, then proceaded to disappear... magic right ???... one thing I did learn, is when a belt distructs & the belt shield ( cover ) is not on, it will wreck the speed sensor, & any wiring that gets in the way of the flying pieces...LOL... all the more reason to fully test for function before flying wide open down the road...

I have one more speed run, ( hind site ), to run this morning ( to verify the trend we were noticeing ), then I will post our initial results... look for them soon ...WAM

 

the Belts measured or tested ...
width measurements were taken with a dial caliper, all of the Kawasaki belts were used but in good condition, all others were new

650 belt...1.11" widest width, 0.89" narrowest width X 33.75" O.D., 29.5" I.D.
700 belt...1.12" widest width, 0.89" narrowest width X incomplete
360 belt...1.14" widest width, 0.88" narrowest width X incomplete
Belt A.......1.16" widest width, 1.00" narrowest width X 32.5" O.D., 28.75" I.D.
Belt B.......1.36" widest width, 1.14" narrowest width X 33.0" O.D., incomplete
Belt C.......1.43" widest width, 1.28" narrowest width X 34.2" O.D., 30.2" I.D.

the 650 belt went within 1/2" of the top of the primary, when deflection was set normally...

the 700 belt went within incomplete of the top of the primary, when deflection was set normally...

the 360 belt went within 7/16" of the top of the primary, when deflection was set normally...

the belt A went within 5/16" of the top of the primary, when the deflection was set too tightly ( the quad would walk in idle )...

the belt B went fully to the top of the primary, deflection was definately too tight, the primary clutch would not open wide enough to allow this belt fully to the bottom of the sheaves... the belt destructed before speed testing...

the belt C was too wide to mount, with the stock primary clutch...
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All speeds were recorded with a GPS, all speedometers recorded 4-5 mph more speed than actual, recorded on the GPS's

Mike's 650.............. 1/2 mile GPS Speed

360 belt..................56.8 mph............................................... ..............Shimmed with 1 - .06 mm shim ... .06mm total

Belt A......................56.6 mph............................................... ..............Shimmed with 2 - .06 mm shims... .12mm total

these were shimmed at as close to speck as possible
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Bob's 700................1/2 mile GPS Speed

700 belt...................57.3 mph............................................... ..............Shimmed with

360 belt...................55.5 mph............................................... ..............Shimmed with

Belt A.......................55.5 mph............................................... ..............Shimmed with

the 700 belt was shimmed as close to speck as possible, the 360 belt & belt A were too tight, in fact belt A was so tight & hot after running 4 1/2 mile test runs, that it was smoking, but still in good shape... this could be why the top speeds didn't go up, as the width got wider...

How do you all set your deflection??? anyone have a scientific or technical way to set it, i.e. fish scale etc. to measure the poundage required... It has been suggested by other knowledgable forum users, that for drag racing, or where top speed is the only concern, that a loose belt will result in higher speeds... this appears to be true... I'd also reccomend pulling the K-BEC fuse & running the quad in neutral for a minute or 2 , or ride for 5 minutes & recheck your deflection... it was noticable that just spinning the secondary around a few times did not tighten up the belt to the same level as running it for a few minutes....
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I have some comitments today, so I'll edit this post complete in 2-3 trys... look for much more discussions & some explainations on belt delfections soon...WAM

 

THANKS for the info, I am looking forward to readding what you learned!!

 

where to go from here...???... Belt B's profile ( extra width to length ratio ) is what I'm looking for... I need to find out why it exploded... if I remember corectly ( the belt didn't stick around long enough to measure & look at the fits etc... ), I still had the .12 mm of shim in the secondary ( it should have had much more shim stock ), I need to verify that this width will fit in the primary without extra machining ( I think it did )... I'll have to see what the distributers have in this belt size & similar...

Belt A held up well even though it was exposed to much more adverse conditions than normal ( much too tight a belt deflection )... I'm still interested in seeing what this belt is capable of when the deflection can be properly set ???

I need to find a more precise way to set / measure the belt deflection... as the difference between tight, speck, & loose belt deflection could measure up to 2-4 mph difference in top speeds...


what else ??? WAM

 

Very interesting. Nice and informative results. I look forward to the updates as they become available. From the looks so far I see Belt A as being the "most likely to succeed".

As far as checking belt deflection, I used an RCBS trigger pull guage. But, my trouble was it only went to 7lbs and the manual calls for 13lbs. So, taking this into consideration, I just had to develope my own personal "feel" for how much pressure to put on the belt with my finger and relation to the trigger pull gauge. In a nut shell I push down as hard as I can with my left thumb while measuring with my right hand. This seems to work because first time I made a belt adjustment I removed one .024" spacer and the deflection went to 22mm. I had a slight squeel when in a drive gear.

I changed my mind and decided to order a 700 belt. Im glad to see you got better top end times with that belt over the 360 belt.

After seeing where you belt is running on the primary pulley I was curious to see where my belt is running. After measureing, my belt "has" went to within 11mm of the top. This is just a little less than 7/16". BUT, I have a black ring about a 1/16-1/32 just below that mark. That is where I feel the belt could be running at the moment.

My belt deflection is 25mm with my measureing technique.

 

K.O.D.... I was thinking a pocket fish weighing scale may work... idealy I'd think that there must be something that would help get definate repeatable deflection settings ??? I think the 700 belt is more suited for our CVT, because of the wedge shape, rather than the diamond shape ( the sheave contact surface on the sides, is greater with the 700 belt )... however, I'd bet that if the deflection was the same on both belts, the 360 belt would result in higher speeds, because of the increased width...an interesting note; the 360 belt appears to be a heavier duty belt than the 700 belt ( the construction materials may be somewhat different, resulting in the 700 being stronger though )...WAM

 

I have heard the 700 is stronger and since Kaw put it on the 700 I would think it would be. As far as top speed goes Im hoping for more out of the 700 belt but will not find out till I try it. I did have the P360 belt ordered but at the last second called Bob Tracys and changed the order.

The fish scale is a good idea. I have though about it but just never did buy one. If I did invest in one it would be the digital type. If I was doing a formal belt test I would want to have one so I could be more precise with the belt deflection instead of using my finger method. That is the reason for me buying the Digital tach. I need one so I could be more accurate in testing the springs next weekend. I also want to be able to better tune my 650.

 

For what its worth, I use a pocket sized fish scale to measure the deflection of my belt. To get a consistent measurement, I tie a string around the belt (located mid way between the 2 pulleys) and then I attach the end of the fish scale (hook) to the string and pull down on the fish scale.

Mike and DWB, Thanx for all of your efforts in testing these belts!!! I must say that I'm quite surprised your initial testing didn't show an advantage in top-speeds compared to the stock P650/P700 belts. Perhaps having the proper belt deflection will change your results somewhat, but my guess is that it won't change the results much. I plan to test the P700 belt soon and report back with my findings.

Mike, my only other thought regarding your testing was did you measure the degree of the angle on the sides of each belt? [img]i/expressions/face-icon-small-confused.gif[/img] I'm guessing that could have a big impact on your testing results because any variances in angles of these belts should vary the amount of surface area contact that each belt makes with the sheaves.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

Mike aka newbeetle, I was curious about your belt width and thought I would look it up in the service manual. Im not sure how you measured it but if you did it the way the manual states the belt you measured is past its service limit. The manual says to replace the belt at 1.13". The standard is 1.15 to 1.20" for a 650 belt. Im going to check mine tomorrow. If its out of spec I will put the 700 belt on when it comes in.

Its 3:30am,...can you tell Im bored. Im ruining myself, Im gonna die when I go back to work.

 

KOD,

WAM put a micrometer on the belts to measure them directly. No, it wasn't the "proper" way to measure the belts according to the manual. However, it gave us a quick comparison. A new belt will measure out of spec, or almost out of spec, when measured directly.