Hi,

I have a new sram Red Bb30 compact crank with new bearings and it is wobbling after the second ride. I did not notice it the first ride, but the second ride I noticed some chain rub on the front derailleur. I checked it and I saw that the crank is wobbling side to side. Both chainrings move a bit to the side when cycling. Today I also noticed a "clicking" noise with each pedal stroke. I thought that the chainring bolts came loose but that is not the case. I did not fall with the bike or do something out of the ordinary. The crank is brand new.
I took off the crank and checked the bearings but they seem fine with me. They were installed by a good mecanicien of the bike shop where I bought the frame this year. The sram black bearing shields are also fine. On the drive side there is a wavy washer and one plastic o-ring. On the non-drive side there is only one sram bearing shield. Should there also be a plastic o-ring? The wavy washer is not fully compressed but firm against o-ring on one side and the bearing shield on the other side. Is it possible that the crankarm on the non-drive side is the problem? Could there be a problem with the bolt? I put the crank together and in the frame and the wobble is still there. I don't think it is acceptable. The wobble is very obvisous.
Can you give me some advice? Should a contact SRam for a new crank? Could there be a problem with the bearings?
Thanks.

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Specialized Tarmac S-works SL4
http://i891.photobucket.com/albums/ac11 ... 11af34.jpg

The wavy washer should go on the non-drive side along with enough plastic shim washers to nearly fully compress the wavy washer. I'm not sure what the o-ring is that you're talking about, but it shouldn't be in there.

Take a look at the user manual here:
http://www.sram.com/sites/default/files ... sets_3.pdf

also, when "wobbling", do you mean the chainrings or spider is out of round? or can the crank arm be shaken by hand?

What you call O-ring is plastic spacer(s), this is directly added to the side of the bearing shield on NDS, then wave washer directly contact the NDS crankarm. Drive side only should have bearing shield ONLY!

It sounds to me like your wave washer is on the wrong side of the crank.

Your mechanic installed them wrong. Do over. Srams instructions on their site are pretty clear how to install them.

http://www.sram.com/sites/default/files ... sets_3.pdf

Sounds like a wave washer issue but check the manual to make sure it wasn't installed without a spacer.

Thanks for the replies. The problem was indeed wrong installation of the crankset, but after proper installation the crank remains to have a wobble. We checked the chainrings but still a wobble. The crank is send to SRAM. I hope to hear from them asap. If the crank is not the problem, where can we look further? The bearings and/or bracket?

_________________
Specialized Tarmac S-works SL4
http://i891.photobucket.com/albums/ac11 ... 11af34.jpg

SRAM will look after it if there is an issue. In very, very rare cases a crank arm can become separated from the spindle in which case correct bottom bracket assembly won't remove a knock. In this case the spider and chainrings will appear perfectly in plane off the bike, yet still wobble under load. I've only ever seen that on heavily used cranksets.

When it's correctly installed - and as has been said above - the wave washer should be almost completely 'squished'. On my CAAD that means no clear plastic shims, on my BMC it means three of them. One final check for inadequate preload is to line a crank arm up with a chainstay and try to squeeze the arm into the frame. If you get a knock you need to add shims. If the washer is completely flat you need to remove them. There shouldn't be any o-rings in there.

I know... I thought the the spacers were O-rings but I was misinformed. We installed the crank the right way but in our opinion still to much wobble. We have to wait what Sram will say about it. I hope to hear from them asap because I want to cycle

_________________
Specialized Tarmac S-works SL4
http://i891.photobucket.com/albums/ac11 ... 11af34.jpg

To clarify the install:

1) The drive side arm/spider is a solid piece along with the spindle. It sits with no spacer against the bearing and goes all the way through to the other side.
2) The non-drive side gets as many spacers as needed(thin 1/2mm plastic type spacers) along with the final wavy washer, then the crank arm, torqued to spec to remove any play.

When the bolt on the NDS is torqued to spec, it shouldn't flatten the wavy washer, yet, the crank arms will not move about or have any play. The only time I've had play in the crank, or a ticking sound, was when my crank arm bolt came loose. Re-tightened /torqued it, problem went away.

If there is play:

1) Bearings are not seated properly, or bearing is moving around?
2) You need more washers? 2-3-4? It varies based on frames/bearings.
3) You are not torqued to spec?
4) Crank bolt arm/mount is somehow messed up on the NDS arm?

Other than that, there isn't much to this installation, I've done it numerous times.

But I also read, you already took it back off and sent it back? Please report back if SRAM finds the actual bolt/spider on the NDS is somehow messed up or has worked itself loose via some flaw in the process of manufacturing, due to it is a permanent bolt/star carbon arm design.

Good luck!

I will report back what Sram thinks about the crankset. The bolt on the crankarm non-drive side is probably the problem, but the mechanic of my local bike shop thought that the bolt is just fine. Let's wait and see, because I am not surprised when it is the bolt.
Thanks for the good replies everybody!

_________________
Specialized Tarmac S-works SL4
http://i891.photobucket.com/albums/ac11 ... 11af34.jpg

I wondered too why my BMC needed a bit more spacers than usual. It seems like the NDS arm would be spaced out by 1.5 to 2mm.

Maybe the effective distance between bearing is less than other frames, when I looked at it the bearings are recessed in the shell more than my previous BB30 frames. It seems like the crank side go in more than but I was not desperate enough yet to add spacers on drive side.

Hi guys,

I promised to report back. Sram checked my BB30 RED Black crankset and I will get a new crankset. There is indeed a wobble that is not acceptable.
I don't know if it is the crank bolt or a problem with one of the spider arms.
I will first get a temporarely "normal" BB30 red crank and as soon as they have the black edition on stock I will get a new one.
So in the mean time I can cycle my bike.

_________________
Specialized Tarmac S-works SL4
http://i891.photobucket.com/albums/ac11 ... 11af34.jpg

Good news. Glad SRAM is going to honor their warranty, and to go the extra step to ensure you get at least some crank in the meantime and then ship the black later is cool also!

Hey, so I've had the same problem as you (SRAM SRM BB30) and it ended in a warrantied frame. This wobble you're referring to is exactly what I had but it was discovered that the inside shell of the BB was deformed (possibly for a few months of this lingering wobble) and I got a new frame. I had the same wobble when I got it transferred over and then we just went in with some washers until it was fine. I still worry this is going to be an on-going issue and what's worse is the S-Works cranks I have on my Shiv feel so much better. I really wonder what the difference is in the two cranks as the BB standard is the same on both bikes (Specialized OSBB). Could anyone maybe shed some light on this?