Drivetrain noise

[SJG]

2 head scratching creaks my friends had recently, both of which took a while to ID.

1) creaky saddle.

2) rear hub bearings

[XXX-er]

My bike makes creaky sound too when the rear QR is misaligned or not tight enough.

yeah when the QR is maybe half tight the wheel shifts in the frame ever so slightly, so the other shop didn't find it and we spent maybe 3 hrs total

IME fixing computer HW the intermitent bugs are the worst, I had a new bike that would make a click coming from the back wheel, the tech couldn't duplicate it so finaly I rode by the shops back door and called out hey its making the noise and then he could hear it ... tech had to shim the cassette which was sloppy on the hub

[sethschmautz]

IME fixing computer HW the intermitent bugs are the worst

Word. I spent 13 years in IT before switching roles recently. Intermittent issues are the worst.

[creaky fossil]

Hmmm. Went for another ride this morning and the creaking is highly exaggerated in the lowest (largest) gear.

This is a sunrace 11-42 10 speed cassette. Cassette, chain and AB oval have less than 500 miles on them.

Accelerated wear? Chain line issues? I did not install a longer b screw, goat link, or cage. Just running it with a standard XT clutch rear derailleur.

Maybe this is part of the issue? Will have more time to wrench this week.

Seth

cassette torqued snug to spec?

big plate cog on inside has most leverage over cassette/hub interface & lock ring. you might be surprised at how your "this feels tight enough" on the cassette lock ring isn't sufficient once you use a torque wrench to spec.

otherwise, I've had the chainring tooth burr problem someone mentioned above, filed it smooth and found quiet.

over on the Monkey, someone said the SunRace big-range cassettes don't need all that 1-Up / Wolftooth adapter mania, but I can't say myself from experience whether that's true.

[sethschmautz]

Thanks creaky, I'll check. I snugged up the cassette a few days ago and it absolutely helped. I did not have my torque wrench at the time, however, but am heading home today and will check this week.

I appreciate all of the ideas. Lots of things to check.

[creaky fossil]

Thanks creaky, I'll check. I snugged up the cassette a few days ago and it absolutely helped. I did not have my torque wrench at the time, however, but am heading home today and will check this week.

I appreciate all of the ideas. Lots of things to check.

you got it.

burr on chainring should be something you can see pedaling the drivetrain, bike in stand -- chain may make a little hop/hitch on that tooth. pedal slowly, forward and backward, to see it.

I've also had a burr on a cassette cog, 3d cog up the stack, don't ask me how it happened 'cuz I have no clue, and a little filing fixed that tiny chain hop on that cog.

whether this tick/click happens more under heaviest load is something to factor into diagnosis. does it happen equally whether loaded or unloaded? is it biased toward loaded pedaling?

[sethschmautz]

Loaded pedaling for sure. I'm familiar with the symptom (slight hop or click) but never thought it might be a burr. Thanks for the info!

[sethschmautz]

Uggh. This seems to be getting worse. Didn't get a chance to look at it last week, but went out for a short (i.e. 20 minute) ride at lunch today. Out of the saddle peddling created a HUGE cracking noise. After looking for frame cracks, I grabbed my seat stay and the rear wheel at the top of the wheel while standing on the non-drive side. When pushing and pulling, I can see the rear triangle flex and it produces the loud crack. I can't seem to locate where this is coming from. Rim (Enve) doesn't have any obvious cracks that I can see. BB area doesn't seem to have any cracks, can seem to locate any on the chain or seat stays. Linkages don't appear to have any obvious damage. Loosening and retightening the QR doesn't seem to help, but I may try a different QR tonight.

Spokes on the rear wheel could probably use a retensioning. Going to throw a different wheel in there tonight and see if it's the wheel or the frame.

Bike was bought used and I think it's a 2012 TB, so my guess is I have no warranty on either the wheels or frame. Hoping it's (relatively) inexpensive, but it isn't sounding like it thus far.

The good news is that seated, powered climbing in anything but the largest cog is quiet. :-)

Seth

[joetron]

Have you serviced the links/pivots? Sounds like it could be a loose pivot or roached bearing. Maybe just grease and clean.
Or just bring it to a bike shop where people are paid to chase to creaks and pops. A decent shop/mechanic (or 2) can generally isolate and eliminate creaks real quick-like

[SJG]

I'd have a buddy repeat the triangle flexing, while you hold it on the other side to feel for the noise. Possible the carbon is cracking and it's not that visible yet. But also know that Santa Cruz is known for shipping frames with extremely under-lubricated pivots. Maybe they need a servicing.

[sethschmautz]

Well... Mixed results. Pulled everything apart and found what appears to be a small crack in the rear triangle at the lower pivot.



However, I went ahead and serviced the pivots anyway with new grease and tightened everything up. The crack/creak appears to be gone - at least via the hand test described above. I'll probably take it for a mellow test ride to see if the noise comes back.

Am I gonna die?

Seth

[creaky fossil]

Well... Mixed results. Pulled everything apart and found what appears to be a small crack in the rear triangle at the lower pivot. * * * Am I gonna die?

Seth

I know someone who has that happen on almost every frame he rides.

Looks like you load the bike in turns and the frame had some tolerance issues going along with that. Is it young enough to be warrantied?

Maybe that's just paint, though. If it's just paint it means some flex is going on underneath, which isn't a good sign anyway.

I wouldn't ride that any more. You have other bikes to ride? If I needed to ride, I'd even ride roadie before riding that any more, unless you want to have full breakage mid-ride and see how that plays out. /sketchy!/

[sethschmautz]

Hmmm. I thinking the warrantee is a long shot but I'm trying. I think I can get a repair for $200-300, but I'm also hoping that I might be able to find a replacement triangle from another crash replacement, but I'm not really sure how to go about that.

If Santa Cruz is keeping track of this, they should have a record of every crash replacement from that model. It would make it relatively easy to contact those individuals to see if they still have their rear triangles. However, I'm sure they can't/won't give that info out. So I may be stuck calling dealerships one by one...

Seth

[sethschmautz]

Update. Santa Cruz did not warranty the frame (and I don't blame them - I am the second owner and this frame is older than their warranty allows).

I contacted a bunch of carbon repair shops including Appleman, Ruckus, Calfee, and others. There were two criteria that I was going for - reputation and cost. Because of the location of the damage, I wasn't concerned about trying to paint match. I figured if I ever sold this bike I would need to disclose this issue anyway, and being able to see it probably wouldn't hurt anything.

Appleman (Minnesota)
- Said he couldn't fix it (and was moving locations which may have been a factor).

Ruckus (Portland)
- Quoted around $500 and offered a $50 discount for no paint match.
- They were the most responsive of the bunch.
- They have an excellent reputation from what I can see, and a close friend had them do some cosmetic work and said they were great.

Calfee (California)
- Quoted around $250 without paint match and without shipping and handling
- Not very responsive.
- They have an excellent reputation from what I can see, but no personal experience.
- Were recommended by Santa Cruz.

At the end of the day, I went with Calfee. I shipped my frame out on 7/27, it was received on 8/3, and I received a call yesterday discussing the price. After inspecting, their quote came out to $200 for the repair, $50 for UV coating (instead of paint), and $35 for shipping ($285 total). I was looking at a frame replacement at ~$1k, so this is going to save me some $$.

There were a few chips on the lower linkage from rock strikes which I asked that they inspect and determine if I should repair while we are at it. They suggested that this was unnecessary - mostly cosmetic. The lowered quote ($200 instead of $250) and recommending NOT fixing the cosmetics is a trust builder.

They suggested that the frame will take 7-10 days in the repair line before being shipped back. :-( I'll post some "after" pictures up in the event that somebody else needs to do this in the future.

Seth

[skaredshtles]

You are one brave dude.

[sethschmautz]

Amigonnadie?

[jono]

Amigonnadie?

Yes. Probably not on that bike. But maybe. Nice that you can watch the fibers now, though.

[radam]

It's not the prettiest thing in the world, but hopefully that holds up. If it does fail though, I think you're only looking at serious body mutilation, not death. Good to go.

[sethschmautz]

It's not the prettiest thing in the world, but hopefully that holds up. If it does fail though, I think you're only looking at serious body mutilation, not death. Good to go.

Ah ha ha. You're probably right.

They have a paint matching option, but it was something like $200. I figured that for the location and the resale hit either way, it probably wasn't worth it.

Seth

[creaky fossil]

Yes. Probably not on that bike. But maybe. Nice that you can watch the fibers now, though.

As long as Calfee waved the Magic Wand over the completed repair, all's good. I'd confirm Magic Wand use.

****

Seth, did SC talk about successful repairs by Calfee? Simply suggested using Calfee? Something else?

How do such cracks get fixed? Repair on mold interior wall as well as exterior wall? Cracks infused w/ epoxy?

The fibermat isn't ugly IMO, and if it holds up then I'd say it looks damned good.

[teledad]

I think they just lay up new carbon over the exterior. I've had several friends get carbon frames repaired (mostly road bikes), never heard of a problem. Calfee has a good reputation.

[creaky fossil]

External wrap reminds me of how lacrosse sticks were fixed, back when they were wood. Wrap cracked area with fiberglass, apply epoxy, let cure. Sometimes, drill hole(s) & use fixing wire(s) prior to 'glass wrap.

[sethschmautz]

I'll give them a call and ask. I think Ruckus suggested that they cut out the cracked piece and put in a new piece.

Didn't die on my first ride but got plenty dirty.

Seth

[creaky fossil]

I hope that wetness means lots of rain up north. We got a little, you can see the ridges around town this AM, which hasn't been typical during the past 6 weeks.

Those tiny center knobs on that rear tire, how will you brake?, you're definitely gonna die! I want one of those in 26 but am too cheap to buy one when I have a pile of others that aren't worn/trashed. DHRII front gives plenty of braking bite to make up for the un-knobs on the back, I'm running a Crossmark back and it really has no braking or cornering knobs to speak of but somehow it works.

"Cut out a part & replaced" sounds interesting since carbon isn't a set-dimension tube of Al or CrMo.

[sethschmautz]

Yeah we received since much needed rain yesterday morning. After building the bike back up I wanted to take it for a test ride before this weekend.

Brake? :-)

I bought that you're from dunfee and that was my first ride on it. I have been running an aggressor back there and a DHF up front. The SS feels a little faster (no surprise) and a little squirrellier when turning without much bike angulation, but seems to corner hard pretty well. Time will tell if I end up putting the aggressor back on or not. Didn't notice any obvious breaking issues, but it was wet so I was probably a little more conservative than normal.

Seth