SRAM Wavy Washer Or Not?

[love2fly]

Hope someone can provide me with a definitive answer.

My mtb frame has a 68mm bb.

I'm running an OEM Sram external threaded GXP bb with Eagle GX cranks.

I've had ongoing issues where particularly the ND side bearing doesn't last and I tend to get the dreaded ticking sound which is solved when I service or replace bearings. I read somewhere and it appears borne out in Sam's service manual that you only need the wavy washer in PF BBs and not my Sram threaded one. Is this true and could this be the reason for my issues in that the thrust is too high? I run one spacer ( think it'd 2.5mm)and the wavy washer on the Drive side. Should I remove the Wavy Washer and just add a 2.5mm spacer plus perhaps another to the ND side until the space is closed? I had the same ticking on my roadbike bb when I stupidly overtightend the plastic crank cap (Shimano Ultegra 10sp) way beyond the hand tight they specify...

[Butterbean]

The wavy washer is necessary... The cranks won't overtighten as they tighten to the end of the thread - the wavy washer is there to take up any slack in that arrangement.

[David Marshall]

For 68 mm shell you use a 2.5 mm spacer between each threaded cup and the frame.  In the box you get these and the non drive side seal.  That should be all you need.  If you torque the crank and there is play you can think about spacers.

[love2fly]

For 68 mm shell you use a 2.5 mm spacer between each threaded cup and the frame. In the box you get these and the non drive side seal. That should be all you need. If you torque the crank and there is play you can think about spacers.

You're saying no wavy washer? The Sram instructions agree with what

you're saying and only show the wavy washer with the PF BB...

[Barry]

The wavy washer is a variable lift washer can be used on GXP cranks PF or external BB. The spacers are a more accurate way of getting correct preload.

[Barry]

For 68 mm shell you use a 2.5 mm spacer between each threaded cup and the frame. In the box you get these and the non drive side seal. That should be all you need. If you torque the crank and there is play you can think about spacers.

Correct a 68mm should have a 2.5mm each side.then use spacers on the 24mm spindle for correct preload.

[DieselnDust]

Hope someone can provide me with a definitive answer.

My mtb frame has a 68mm bb.

I'm running an OEM Sram external threaded GXP bb with Eagle GX cranks.

I've had ongoing issues where particularly the ND side bearing doesn't last and I tend to get the dreaded ticking sound which is solved when I service or replace bearings. I read somewhere and it appears borne out in Sam's service manual that you only need the wavy washer in PF BBs and not my Sram threaded one. Is this true and could this be the reason for my issues in that the thrust is too high? I run one spacer ( think it'd 2.5mm)and the wavy washer on the Drive side. Should I remove the Wavy Washer and just add a 2.5mm spacer plus perhaps another to the ND side until the space is closed? I had the same ticking on my roadbike bb when I stupidly overtightend the plastic crank cap (Shimano Ultegra 10sp) way beyond the hand tight they specify...

 

 

You need the wavy washer on the GXP cranks as well. The reason for this is that the non drive side bearing is 22mm internal diameter and it buts up against a step in the crank axle. When the system is tightened up the drive side bearing is free floating while the non drive side is captive. This results in that bearing not being pre-loaded and it runs out, causing excessive and premature wear.

 

The wavy washer allows the ND bearing to be pre-loaded.

The best solution is a Chris King GXP to 24mm adaptor kit and an external threaded BB for 24mm axles. The CK adaptor kit uses a sleeve to bring the 22mm axle diameter to 24mm and then provides two spring washers for the non drive and drive side bearings. The washers are needed to take up the play anyway. Its a pricey kit but it works beautifully. Round it of with a CK external cup bb and never look back

[love2fly]

You need the wavy washer on the GXP cranks as well. The reason for this is that the non drive side bearing is 22mm internal diameter and it buts up against a step in the crank axle. When the system is tightened up the drive side bearing is free floating while the non drive side is captive. This results in that bearing not being pre-loaded and it runs out, causing excessive and premature wear.

 

The wavy washer allows the ND bearing to be pre-loaded.

The best solution is a Chris King GXP to 24mm adaptor kit and an external threaded BB for 24mm axles. The CK adaptor kit uses a sleeve to bring the 22mm axle diameter to 24mm and then provides two spring washers for the non drive and drive side bearings. The washers are needed to take up the play anyway. Its a pricey kit but it works beautifully. Round it of with a CK external cup bb and never look back

That sounds like it would be a good option but quite hectic cost.

 

Would another option be to change to Shimano cranks? Probably similar cost?

[Martin PJ]

With GXP cranks I use a ring which you can buy off Aliexpress, look for "GXP adapter", cost is about 1 dollar. You can also make them, a friend made me another one which works equally as well. The Shimano BB's can then be used with the GXP crank, they are much cheaper and seem to last a bit better in the water.

[DieselnDust]

That sounds like it would be a good option but quite hectic cost.

 

Would another option be to change to Shimano cranks? Probably similar cost?

 

 

heres the adaptor kit: https://www.paragontech.co.za/product/chris-king-bottom-bracket-conversion-kit-13-sram-2422mm-pbb050/

Last time I bought a Ck BB it cost me R2200 with adaptor kiit. That was 10 yrs ago.  I still have the BB just waiting for a frame to fit it to. High cost long life. Shimano crank is likely cheaper

Edited April 23, 2021 by DieselnDust

[love2fly]

I chatted to Cape Cycles and apparently the wavy washer isn't required on the threaded GXP BB as the DS bearing has that plastic insert which protects the bearing.

HOWEVER when my bearings wore out (pretty good as I got one year out of them) I replaced with 24x37 bearings and not having that plastic sheield could be the reason.

What I cant remember is if the shield is exactly 24mm or or what that bearing (DS) ID was.

 

Think I'm in for either a new BB, go the CK route with adaptor and new BB or just close the disappointing Sram crank chapter and go with Shimano.

Edited April 23, 2021 by love2fly

[Martin PJ]

I chatted to Cape Cycles and apparently the wavy washer isn't required on the threaded GXP BB as the DS bearing has that plastic insert which protects the bearing.

HOWEVER when my bearings wore out (pretty good as I got one year out of them) I replaced with 24x37 bearings and not having that plastic sheield could be the reason.

What I cant remember is if the shield is exactly 24mm or or what that bearing (DS) ID was.

 

Think I'm in for either a new BB, go the CK route with adaptor and new BB or just close the disappointing Sram crank chapter and go with Shimano.

I actually went Shimano to SRAM because the Shimano crank left crank arrangement is not ideal, The left crank seems to come off too easily. Prefer the Shimano external BB to GXP though, think they are slightly better.

[Eldron]

I actually went Shimano to SRAM because the Shimano crank left crank arrangement is not ideal, The left crank seems to come off too easily. Prefer the Shimano external BB to GXP though, think they are slightly better.

 

That shouldn't happen if torqued correctly. A common Shimano crank mistake is to torque each bolt and call it done. Problem is that when you torque the second bolt the first one gets looser (as the gap narrows).

 

Tighten each one by hand 3 or 4 times then torque both.

 

I have never had a Shimano c´that I have worked on come off (unless there was an actual warranty problem).

[Martin PJ]

That shouldn't happen if torqued correctly. A common Shimano crank mistake is to torque each bolt and call it done. Problem is that when you torque the second bolt the first one gets looser (as the gap narrows).

 

Tighten each one by hand 3 or 4 times then torque both.

 

I have never had a Shimano c´that I have worked on come off (unless there was an actual warranty problem).

My son is a strong rider, broke a lot of things that normal riders would not. I tried everything to get it to stay on. Cleaning with solvent, Loctite, etc, nothing worked. Loctite did make it better, but still didn't solve the problem.

[DieselnDust]

My son is a strong rider, broke a lot of things that normal riders would not. I tried everything to get it to stay on. Cleaning with solvent, Loctite, etc, nothing worked. Loctite did make it better, but still didn't solve the problem.

 

 

Thats weird because the left crank arm has that plastic spacer with the metal hook to prevent the crank falling off. I've also never had the crank losen up on me but I've heard of a few. Often its the incorrect torques on the bolts and the preload adjuster was removed.

[Martin PJ]

Thats weird because the left crank arm has that plastic spacer with the metal hook to prevent the crank falling off. I've also never had the crank losen up on me but I've heard of a few. Often its the incorrect torques on the bolts and the preload adjuster was removed.

Yes, I would say once you have made the mistake of using the crank not properly installed, then you can forget about rehabilitation. I do have a couple of bikes with the Shimano crank design with no problems as yet, but based on experience, slightly biased towards SRAM type crank, seems to be more DIY friendly - by DIY I mean destroy it yourself.