Primary Spring Binding - Revisited

[gman086]

Do the new sleds ship with delrin washers for the primary spring to prevent the binding/breaking issues that were prevalent on the '11 and '12 models? I haven't seen any posts about this in a while, thus the question. Did the delrins solve the problem? Anyone have a spare washer they can sell me at a decent cost (still unemployed)? I've got the problem now (just replaced bent spring) and it will only get worse without a washer! Also, as I understand it, the washers will increase engagement rpm by about 50. I'm already running a little too aggro of a starting rate with spring at 140/330 so should I be going with a 120/340 for 4-7,000 feet?

Thanks!

G MAN

 

[Teth-Air]

Do the new sleds ship with delrin washers for the primary spring to prevent the binding/breaking issues that were prevalent on the '11 and '12 models? I haven't seen any posts about this in a while, thus the question. Did the delrins solve the problem? Anyone have a spare washer they can sell me at a decent cost (still unemployed)? I've got the problem now (just replaced bent spring) and it will only get worse without a washer! Also, as I understand it, the washers will increase engagement rpm by about 50. I'm already running a little too aggro of a starting rate with spring at 140/330 so should I be going with a 120/340 for 4-7,000 feet?

Thanks!

G MAN

My 14 did not come with any Delrin washers. I tried them but they were not great. Then I tried the Carl's roller bearing in the secondary and it was incredible how easy the sheave rotated. I liked it so much that I sell them now. They are about $25 in the USA and about $30 in Canada.

 

[gman086]

My 14 did not come with any Delrin washers. I tried them but they were not great. Then I tried the Carl's roller bearing in the secondary and it was incredible how easy the sheave rotated. I liked it so much that I sell them now. They are about $25 in the USA and about $30 in Canada.

I use those from McMaster Carr for my rear shock spring of my DH mountain bike - works great to prevent binding! Anyone try them in a primary? Thanks for the idea.
http://www.mcmaster.com/#needle-roller-thrust-bearings/=rybquc

G

 

[FCR112]

Been using these for years in the primary, work well...

http://www.thunderproducts.com/glide_washer.htm

 

[sled_guy]

If you have spring binding already, adding a washer in there is going to make it worse.

I would look closely at your spider jam nut. They can have a sharp edge on them where the little half moon openings are cut for the jam nut tool. Touch those up with a file/grinder so that everything is smooth.

Delrin washers are used in the secondary clutch.

sled_guy

 

[gman086]

I would look closely at your spider jam nut. They can have a sharp edge on them where the little half moon openings are cut for the jam nut tool. Touch those up with a file/grinder so that everything is smooth.

Delrin washers are used in the secondary clutch.

sled_guy

That was the original thought and many of us did grind down with no improvement (this is well documented in the original 7 page thread on the subject). The steel spring eventually galls into the alloy cup and doesn't move when compressing. In fact mine distorted/bent and didn't break which further proves my point. Indy Dan caught the issue as did Thunder Products - both their "slippery" washers have cured the problem allowing the spring to move without binding at full compression. The exact same reason they add a delrin to the secondary as you mention.

I still need a primary delrin if anyone has extras! I'm thinking the needle bearing will be too thick and affect clutching too much?

Thanks,

G

 

[mountainhorse]

Not at all the exact same thing as the secondary.

The secondary sheaves twist in relation to each other... the primary sheaves do not.

The reason the primary spring binds a bit is that the aluminum of the spider seems to be softer than before and/or the spring tail has a sharp edge on it.

Some add a washer to the "spring cup" of the spider so that the spring-tail cannot dig into the aluminum of the spider and cause the spring to hit the nut etc.

Yes, as sled-guy said... make sure you have no sharp edges on spider nut. (dremel works well for this).

A hard steel/stainless washer or the delrin or anything else that keeps the tail from tail from digging into the spider will cure the problem.

Needle rollers are susceptible to dirt and grit as they are unshielded...especially so on the primary and can stop working.... also... I've yet to see a stainless steel one ... so they rust.









.

 

[Wheel House Motorsports]

Just pulled apart a turbo pro with a broken pink spring....

nice goove cut into the clutch cover from the spring tail. looks like why shes breaking! and once thats cut in, gonna keep snapping them fast if its not washered!

 

[LoudHandle]

Not at all the exact same thing as the secondary.

The secondary sheaves twist in relation to each other... the primary sheaves do not.

The reason that the they bind a bit is that the aluminum of the spider seems to be softer than before and/or the spring tail has a sharp edge on it.

The washer is there so that the spring tail cannot dig into the aluminum of the spider and cause the spring to hit the nut etc.

Yes, as sled-guy said... make sure you have no sharp edges on spider nut. (dremel works well for this).

A hard steel/stainless washer or the delrin or anything else that keeps the tail from tail from digging into the spider will cure the problem.

Needle rollers are susceptible to dirt and grit as they are unshielded...especially so on the primary and can stop working.... also... I've yet to see a stainless steel one ... so they rust.

Just thought I'd add a little to this; While the Primary and Tied clutch sheaves do not rotate in relation to each other, the spring ends do (or try to) twist slightly as you change the length (compress and relax it). This is due to their helical contruction and this slight twist is what causes the issues with the non-deburred spring ends digging into the unprotected aluminum spring pocket. If this slight twist is not allowed, the spring deforms / fails prematurely.

A good practice is to debur the spring before installing and protect both of the spring pockets with the washer of choice. Then adjust the spring rates to compensate for the new stack height as needed.

 

[gman086]

Just pulled apart a turbo pro with a broken pink spring....

nice goove cut into the clutch cover from the spring tail. looks like why shes breaking! and once thats cut in, gonna keep snapping them fast if its not washered!

Exactly!

Have FUN!

G MAN

 

[gman086]

Just thought I'd add a little to this; While the Primary and Tied clutch sheaves do not rotate in relation to each other, the spring ends do (or try to) twist slightly as you change the length (compress and relax it). This is due to their helical contruction and this slight twist is what causes the issues with the non-deburred spring ends digging into the unprotected aluminum spring pocket. If this slight twist is not allowed, the spring deforms / fails prematurely.

A good practice is to debur the spring before installing and protect both of the spring pockets with the washer of choice. Then adjust the spring rates to compensate for the new stack height as needed.

This is exactly what I was trying to convey, Yes mountainhorse, they obviously twist "more" in a TSS secondary but the washer is doing the SAME FUNCTION - preventing spring binding which is the real problem that is caused by the end of the spring digging in. My jam nut was ground down from day 1; that's not what causes the failure (tho it certainly can exacerbate it).

What are you guys running for primary springs using washers and what elevation? Each washer adds 50 rpm engagement per Thunderproducts. I'm leaning towards buying theirs as it's cheapest.

Have FUN!

G MAN

 

[skibreeze]

I have tried a delrin washer with a pink spring in my turbo and still ended breaking springs. I ended up with really thin steel shims that are used for ring and pinion installs and modified the ID and OD to fit on both sides of the spring and so far so good. Not a ton of miles yet, but more miles will have to wait until next year.

 

[gman086]

I have tried a delrin washer with a pink spring in my turbo and still ended breaking springs. I ended up with really thin steel shims that are used for ring and pinion installs and modified the ID and OD to fit on both sides of the spring and so far so good. Not a ton of miles yet, but more miles will have to wait until next year.

You wouldn't happen to have made any extras, would you skibreeze?

Thanks,

G

 

[Merlin]

I have tried a delrin washer with a pink spring in my turbo and still ended breaking springs. I ended up with really thin steel shims that are used for ring and pinion installs and modified the ID and OD to fit on both sides of the spring and so far so good. Not a ton of miles yet, but more miles will have to wait until next year.

Given that most of us are wanting to install washers in the clutches that are already galled up, I feel that hardened steel washers would be a better solution than the delrin material.

I think if delrin washers were installed in new clutches, or at least ones that had the spring pockets skimmed down in a lathe, they would stand a far better chance of being able to allow the spring to rotate rather than biting into the galled up surfaces.

The thrust bearing idea looks good on paper & would initially provide a fraction of the resistance of any washer option that is available however I just cant see them standing up to the lack of lubrication & exposure to contamination. Perhaps if a sealed arrangement could be developed it would be the answer?

Either way, some type of a hardened washer gets my vote.

 

[diamonddave]

G, I just rounded up a couple of extra of the Thunder product washers. One is coated and the other is zinc coated (the kit has 2 coated and 2 zinc coated washers. Each washer raises engagement by 50 RPM. I believe it's actually higher than that.

I also have some of IndyDan's delrins but can't find them right now.

I can send them to you. If you can replace them by next season great, if not, no big deal. I understand.

PM me your address if you don't have anything yet. I also have a new primary spring.

PS> Pinion shims would work also.

 

[geo]

TP shims are good and Poo used to sell shims (30, 60 and 90 thou). May find some at an older Poo dealer.

I give the steel shim a thin wipe of syn. grease and a light wipe off with a paper towel before install in the spider cup as well as buff the ends of the spring smooth with a belt sander and 400 grit.

FYI. Cat springs are a little larger ID and fit fine (if you find the correct spring). More clearance for the spyder nut.
A D&D white has no coil bind issues (bigger wire, less coils), a little lower start pressure, same finish pressure (in a P85) and slightly higher spring rate (lbs per inch) as a Poo 140/340. It likes heavier weights more than the Poo spring.

 

[skibreeze]

I don't think that the spider nut is the issue. Every spring I have broken, and there are a ton of them (pink spring), has made contact with the outer portion od the spring.

 

[diamonddave]

Given that most of us are wanting to install washers in the clutches that are already galled up, I feel that hardened steel washers would be a better solution than the delrin material.

I think if delrin washers were installed in new clutches, or at least ones that had the spring pockets skimmed down in a lathe, they would stand a far better chance of being able to allow the spring to rotate rather than biting into the galled up surfaces.

The thrust bearing idea looks good on paper & would initially provide a fraction of the resistance of any washer option that is available however I just cant see them standing up to the lack of lubrication & exposure to contamination. Perhaps if a sealed arrangement could be developed it would be the answer?

Either way, some type of a hardened washer gets my vote.

Your opinion in bold above has been my experience with the delrins in the Primary. I've now witnessed 2 sleds where delrins were used in the primary and the end of the springs just dug into the delrin material which then dug into the spider essentially locking the spring into place. Both springs ends were smoothed as well as possible prior to installation.

Both springs were this occurred were the stock Polaris 140/330 springs. Pretty good quality IMO.

 

[Merlin]

Your opinion in bold above has been my experience with the delrins in the Primary. I've now witnessed 2 sleds where delrins were used in the primary and the end of the springs just dug into the delrin material which then dug into the spider essentially locking the spring into place. Both springs ends were smoothed as well as possible prior to installation.

Both springs were this occurred were the stock Polaris 140/330 springs. Pretty good quality IMO.

Yeah, I put the delrin washers in the primaries of 2 of my sleds at the start of season but after thinking about the situation(I hate it when that happens! ) I wish I'd have used steel.

Oh well, there always next year..................

 

[TRS]

I have been installing the Thunder Products washers on both ends also.
I am going to try a combination on one end. A delrin with a steel TP washer on top of it and eliminate the opposite end steel washer. This should have the same affect as a delrin under the cup in the secondary.