TRX250r.org

Author Topic: Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy  (Read 12312 times)

Offline PNWrider

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #15 on: March 02, 2014, 12:47:26 PM »
Quote from: Allison#51;27376
Why can't I find that thrust washer on the schematic? Is it included with the lifter rod needle bearing?

I've never noticed that before...good question though. I think My extra thrust washer came on the inside of my pressure plates. But sounds like Pumashine will be solving our problems again!

Offline PNWrider

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #16 on: March 02, 2014, 12:56:27 PM »
Here is a before and after measurement of adjusting the clutch arm using the clutch cable adjustments on the left side of the cylinder.

First one is with what my previous clutch arm adjustment was set at for the stock clutch plate and spring setup



This is after adjusting the clutch arm, unfortunately the adjuster is on its last thread so I will be using either a thicker washer or two washers so I dont have to use the last threads of my clutch cable adjustments



And again here is what my clutch cable adjuster looks like


Offline PNWrider

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #17 on: March 02, 2014, 01:00:27 PM »
Here is a before and after measurement of adjusting the clutch arm using the clutch cable adjustments on the left side of the cylinder.

First one is with what my previous clutch arm adjustment was set at for the stock clutch plate and spring setup



This is after adjusting the clutch arm, unfortunately the adjuster is on its last thread so I will be using either a thicker washer or two washers so I dont have to use the last threads of my clutch cable adjustments



And again here is what my clutch cable adjuster looks like





Here are some measurements of the washers I used

The first is the '89 washer that came with my Hinson pressure plate



The second is one that came off one of the older year pressure plates...not sure which, It is a little bit bigger


I'm going to find a washer the same size as the '89 so it doesn't sit off-center of the clutch lifter because its so much bigger.

Offline KASEY

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #18 on: March 02, 2014, 01:11:26 PM »
one thing I see not addressed .. spring wire size,, since these springs are not progressive the spring rate does not increase as they get compressed more,  the thicker the wire size on the spring the higher the spring rate , since a cr500 uses 6 springs and a 250r has 5 there isn't much difference in a single spring as far as spring rate goes ,
I WANT ANIMATED GIF\'S FOR MY SIGNATURE PLEASE.....

Offline mx250r91

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #19 on: March 02, 2014, 01:25:37 PM »
Quote from: Allison#51;27376
Why can't I find that thrust washer on the schematic? Is it included with the lifter rod needle bearing?

http://trx250r.org/showthread.php?2489-89-clutch-upgrade

PN. 90608-072-000

Offline rsss396

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #20 on: March 02, 2014, 01:48:59 PM »
Quote from: kasey;27398
one thing I see not addressed .. spring wire size,, since these springs are not progressive the spring rate does not increase as they get compressed more,  the thicker the wire size on the spring the higher the spring rate , since a cr500 uses 6 springs and a 250r has 5 there isn't much difference in a single spring as far as spring rate goes ,

the more you compress them the more lbs you will see on a scale ( I have tested this ) and this is with no coil bind so if you shim them they will produce more clamping pressure.
now the the untested thing here is a 250r spring compressed to the installed height and a cr500 that is shimmed the thickness of a oil drain washer and another .025" for the extra thickness of the 400EX plate since the cr500 is 2mm shorter you probably need to shim it just to equal or increase the clamping pressure
Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.

Offline 4WHLr

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #21 on: March 02, 2014, 02:43:14 PM »
That second washer pictured looks like the one that goes behind the locking/tab washer that holds the inner hub on. Its way to wide to go in the pressure plate for the lifter bearing.
1986 TRX275R PC2000

Offline mx250r91

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #22 on: March 02, 2014, 02:47:29 PM »
Applied spring force can be calculated pretty easily. Measure the wire diameter, spring OD, and count the number of coils and enter into here:
 http://www.maultechatv.com/techguides/spring%20rate%20calculator/index.php

This gives the rate in lb/in then multiply this by the distance the spring is compressed by the bolt (preloaded) and you get the force in lbs.

I remember Jason (ALL250R) tested a whole bunch of clutch springs a while ago on his site and the results were from weakest to strongest CR500<86-87<88-89

Offline Allison#51

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #23 on: March 02, 2014, 03:47:21 PM »
Quote from: mx250r91;27399
http://trx250r.org/showthread.php?2489-89-clutch-upgrade

PN. 90608-072-000


Cool thanks!

Offline Fire1

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #24 on: March 02, 2014, 04:33:18 PM »
Quote from: rsss396;27402
the more you compress them the more lbs you will see on a scale ( I have tested this ) and this is with no coil bind so if you shim them they will produce more clamping pressure.
now the the untested thing here is a 250r spring compressed to the installed height and a cr500 that is shimmed the thickness of a oil drain washer and another .025" for the extra thickness of the 400EX plate since the cr500 is 2mm shorter you probably need to shim it just to equal or increase the clamping pressure

So are you saying run stock 250R clutch with CR 500 springs and .025 aluminum washers.

Offline rsss396

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #25 on: March 02, 2014, 06:07:02 PM »
No what I am saying is, it should be no different of a clutch mod if you ran a .025 thicker drain plug washer than what Neil's mod calls for.
the 400ex plate is .025" thicker than a 250r so instead of running out and buying a different plate why not just run thicker washers, obviously this is easier said then done but
if tony can find a sheet of aluminum that gives us that number then it would be much cheaper.

i do not know the thickness of the oil drain plug washer but just as a example if it we're say .080 thick then we want a .105" thick washer to run with the cr500 springs.
or maybe the stock 250r should just be shimmed to make the mod even cheaper, but I will say there is a big difference spring tensions out there so it needs a little experimenting with different springs to find which ones will give the holding power you are looking for.

Barnett springs are normally much stiffer than stock, so taking a stock spring and installing it with washers may just give you exactly what Barnett is already giving you. Without actual testing of the installed heights of the springs you are really just guessing.
My suggestions were based on Neil's example that has worked well for him, I cannot say it's any better than just a good set of stiff springs for a 250r.
I am only pointing out if want to run Neil's mod then it maybe cheaper to just run these extra thick washers
Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.

Offline rablack21

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #26 on: March 03, 2014, 08:03:58 AM »
Quote from: rsss396;27426
No what I am saying is, it should be no different of a clutch mod if you ran a .025 thicker drain plug washer than what Neil's mod calls for.
the 400ex plate is .025" thicker than a 250r so instead of running out and buying a different plate why not just run thicker washers, obviously this is easier said then done but
if tony can find a sheet of aluminum that gives us that number then it would be much cheaper.

i do not know the thickness of the oil drain plug washer but just as a example if it we're say .080 thick then we want a .105" thick washer to run with the cr500 springs.
or maybe the stock 250r should just be shimmed to make the mod even cheaper, but I will say there is a big difference spring tensions out there so it needs a little experimenting with different springs to find which ones will give the holding power you are looking for.

Barnett springs are normally much stiffer than stock, so taking a stock spring and installing it with washers may just give you exactly what Barnett is already giving you. Without actual testing of the installed heights of the springs you are really just guessing.
My suggestions were based on Neil's example that has worked well for him, I cannot say it's any better than just a good set of stiff springs for a 250r.
I am only pointing out if want to run Neil's mod then it maybe cheaper to just run these extra thick washers

I like this approach ^^^. And I agree, this seems like this will be cheaper and easier to do this mod and still get the same great performance. I am eagerly awaiting Tony's response for these requests.

Offline 250Racer

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #27 on: March 03, 2014, 08:22:04 AM »
It worked for me last year when I was in a pinch. My clutch started slipping when heated up and I didnt have the time to get a new one before my next race. Springs and fibers were at their limit. I replaced one 250r plate with a 400ex plate, scuffed up the plates and put the washers on springs and no slipage.

Offline rsss396

Clutch Mod with Pics (Neil aka C-Leigh Racing Mod) - Pic Heavy
« Reply #28 on: March 03, 2014, 09:09:34 AM »
that proves how just a small amount of shim can make a big differance since there is only about .025 differance between the 2 plates so maybe Tony could make up a tuning kit with .025, .050, .075 and .100 kits to try tuning the clamping power and/or adjust for wear in the clutch assembley
Anyone looking for a great builder I highly recommend the following.
For CP products dealers I would recommend:
Arlan at LED(site sponsor), Pete Schemberger at Hybrid Engineering, Mat Shearer at Shearer Custom Pipes, Dennis Packard at Packard Racing, and Nate McCoy of McCoys Peformance.

Other great builders I also would recommend: Neil Prichard, Jerry Hall, Bubba Ramsey and James Dodge.