ZXLNT
Needs a job
Kawpuke Extraordinare
Posts: 2853
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posted August 27, 2004 08:15 PM
 Edited By: ZXLNT on 27 Aug 2004 21:17
Up on an old thread. My RC's are from 2000. Do the new cush drives install the bearing from the wheel side or the sprocket side??? Mine only has 1 bearing installed from the sprocket side of the cush drive.
Do you think RC would uprgrade my sprocket carrie/cush drive then???
  
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entropy
Moderator
Posts: 8671
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posted August 28, 2004 06:48 AM
and it ain't just RC wheels...
watch out all you Marvic Piuma owners who drag race. grrrrrrrr seems like the cush drive is meant for wimpy hp.
Thanks to Dave Conforti at WWBearings, I MAY (now) have a solution.
I'm going to the Texas Shootout today, let's see if it holds up.
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osti33
Needs a job
Posts: 2973
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posted August 28, 2004 04:00 PM
quote:
and it ain't just RC wheels...
watch out all you Marvic Piuma owners who drag race. grrrrrrrr seems like the cush drive is meant for wimpy hp.
Thanks to Dave Conforti at WWBearings, I MAY (now) have a solution.
I'm going to the Texas Shootout today, let's see if it holds up.
Entropy,
I just got a set of Marvics. Did you have a bearing failure in the cush?
What was your fix and how well did it work today?
Thanks.
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entropy
Moderator
Posts: 8671
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posted August 29, 2004 07:26 AM
Edited By: entropy on 29 Aug 2004 08:45
osti,
I did have a failure in the cush, and and my fix ended up being exteme because i got into a lil development project for Dave Conforti (aka Saint Dave!) of WW Bearings, the ceramic guys.
last nite, i made 6 passes and everything seems fine. I'll pull the wheel and check more carefully this afternoon before claiming 100% victory.
2 basic problems with the rear Marvic for drag racing
1. As delivered, the single row cush drive bearing doesn't seem to support the Marvic cush drive/sprocket well enough under 1/4 mi stress.
- soln: go to double row bearing, modify the cush drive sleeve and collet/spacer to account for add'l bearing width.
- extreme soln: go to MOJO-sized double row ceramic bearing, machine the cush drive to receive it, mod the sleeve & collet to fit.
2. the Marvic comes with aluminum spacers/sleeve; which CANNOT take the 94# torque OEM axle spec. You WILL crush the long spacer between the 2 wheel bearings and a bearing WILL fail.
- soln: do NOT torque the axle over 70# (and that may be too hi), you will crush the long spacer with ONE over-torquing 
- extreme soln: have your local machinist make up a complete set of beefed up custom ss spacers/sleeve. This cost me $420...
Something I didn't know before, but I sure as shit know now:
If you drive the bearings outa the cush drive or the wheel (to get at the long spacer), you really need to replace those bearing with new ones like the manual (and Dave C) says.
Also,
MAKE DAMN SURE the cush drive is aligned with the wheel as you start to tighten on the axle. If you look carefully at the space between the cush drive & the wheel you will see it go wide/narrow as you rotate the wheel. I took a block of wood/hammer and tapped on the cush until the sprocket was running true before torquing down the axle.
Caution #1: all the above is just my experience, surely some errors in it; use the info with an extra large helping of your experience/common sense.  And share your experiences so we all can benefit.
Caution #2: the bove applies to Marvic Piuma for ZX12; I have no idea what the Busa SBS guyd are doing...
Lotta folks having 1/4 mi probs with aftermarket wheels, but they are generally not saying anything (notably excluding the EVER-HELPFUL MM, whose informative thread was just jacked )...
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osti33
Needs a job
Posts: 2973
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posted August 29, 2004 06:01 PM
Dann it!
1. I have the Marvic Piumas on my ZX12.
2. I torqued it down today at the track.
My first pass today it felt like the whole back of the bike was trying to shake apart. I pulled that wheel off and put my stock wheel back on and no problems the rest of the day.
It could be something as simple as a tire balance issue...Not to sure yet.
I will pull the Marvic apart tomorrow and see if I bent that long spacer...
Entropy,
Check your PM's.
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blink
Novice Class
Posts: 48
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posted August 30, 2004 03:53 PM
I had the ceramic bearings fail in my rear wheel. No fault of the bearings though. The person who changed my tire somehow left out the spacer between the cush drive bearing and the wheel bearing. Only the large bearing in the cush drive was intact. The right side bearing was seized up solid and the axle was just sliping inside the inner race. Just lucky I guess. I made my own spacer, like Mike is about to do, and purchased new ceramic bearings but also added another dust seal this time. I just recently changed the front ceramic bearings after 19,000 miles, they were OK just a little gritty feeling so I have the double seals on these too. Nothing wrong with the ceramic bearings if you have the correct spacers.
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