I noticed play in my cranks, so I tightened the preload ring (+ direction) on my crank, now I hear cracking (I mean cracking not creaking!) sounds from my BB area, I loosened a bit bit still hear cracking
Any ideas on what is causing this, do I need to worry, how to fix?
Press fit BB + carbon + cracking sound??
Yes. You need to worry. Take it to a doctor.
Good luck.
The preload ring is probably cracked.
yes :(, is there a spare part?
Yes. The SRAM part is somewhere around $10. I’d look for aftermarket (metal) replacements - looks like CeramicSpeed, Kogel, and Muc-Off have options - those seem to be around $50.
thanks I see they are fortunately easy to find. I was afraid my red crank was toast
It is weak on purpose. It is supposed to break rather than let you kill your bearings. Metal is fine, but it broke because you used too much preload or something went out of plane.
Yes I did use a lot of preload because the preload kept getting undone and the crank kept getting wobbly. After the preload ring broke I had to limp home being very care not to strike the front derailleur: (
it kept getting undone because you were overloading it! You probably damaged the threads the first time it was over loaded. It just needs to close the gap.
There is an beautifully simple order with DUB. 8mm bolt can’t be touched until you back out the preload ring on the non-drive side.
And the preload ring can be touched until the 2mm pinch bolt is loosened.
The most common thing is people overtighten the pinch bolt. This is what cracks the preload ring. It’s a bad idea to make these out of metal and truly i’d recommend plastic so you stay in the range of loads intended on the threads and the bearings. (Same reason Shimano made their Hollowtech crank bolts tools out of plastic…hand tight only).
In any case, get a new preload ring. Then take it to the shop. And sell your tools.
I’ve cancelled my order for an aluminium ring and having looked at the various videos of people trying to undo the 8mm allen bolt had already convinced me to take it to the shop…
What’s the deal with the 8mm? I’ve never had a problem pulling my Sram cranks at home.
from what I saw on youtube the 54 Nm torque spec requires a lot of leverage to undo the bolt (and without damaging it)
Why are you undoing the 8mm bolt? Pretty sure on my sram cranks you just need to undo pinch bolt and preload. That bolt only needs undoing to change chainring.
In this case, pull the crank to replace the broken pre-load ring.
In my case, it’s pulling the crank to clean/service the BB (gravel and mountain bikes). 40ft/lb isn’t all that much torque - that’s about half a typical auto lug nut. Thus my question about why it’s a problem that needs the LBS to resolve.
I’m still confused. To remove the crank and access BB, you loosen pinch bolt, loosen preload, remove non drive side crank arm, then slide the drive side put (which will have the spindle on it. Then you have access to the BB. You only need to remove that 8mm bolt to change chainring or spindle. (I haven’t don’t this in a while and only on sram eagle, so I could be out to lunch).
That being said, removing that bolt is a pain. It’s just a hard place to get the torque needed. It helps a lot if you can get the spindle secure in a soft jawed vice. I have a super long automotive ratchet that makes short work of it.
I think you’re confusing crank designs…
My Sram Force AXS cranks require loosening the 8mm on the drive side to remove the crank. The non-drive has the spindle attached permanently.
Like this…
Default the bolt is aluminium and threads into steel threads. That combined with non-greased threads (also default), 54nm and galvanic corrosion over time can lead to stuck bolts.
I have seen pictures of snapped 8mm allen keys after failing to loosen the bolt with a 2 meter leverage arm.
Grease those threads, people!