I need a little help in attempting to isolate a noise that has started today on my trail bike (FS 150/140).
The noise is a fairly loud creaking, and has an almost crunchy sound to it that appears as if it's coming from the rear end of the frame around the cassette area.
My first instinct was to fettle with the drivetrain but I soon realised that was probaly not the issue.
The noise only happens when I am applying force through the cranks but is not completely consistent. The sound will always happen when I crank in higher gears but it doesn't always sound the exactly same and doesn't always happen at the same time during a stroke. Sometimes it appears to happen when I am powering down through the left foot, other times the right foot.
- The noise appears to come from the rear of the bike
- it sounds quite brittley, almost like crunching plastics
- there is no abormal damage anywhere near the drivetrain, mech hanger or rear pivots
- it only happens when applying power in gears 6-12 (I don't think I can generate the required force in gears 1-5)
Things I've tried so far that have made no difference:
- various adjustment to drivetrain
- remove mech hanger, cleaned and torqued
- cleaned the threads and checked the torque on the rear axle
- greased the frame pivots at the rear end of the triangle (this is where it sounds like the noise is coming from but probaly isn't)
The last ride before this happened was on Thursday morning in the wet and wind and this noise did not occur once during that ride to my knowledge. The bike was washed on Thursday evening using a hose with attachment.
I suspect that it's going to hopefully be the bottom bracket bearings and as soon as I've got my hands on a humongous torque wrench to undo the crank bolt I should be able to rule this in/out. I'd much rather it was this than any issue with the frame.
Has anybody had a similar experiance?
Is there anything I am missing or not udenderstanding about the frame and it's bearings?
Is there anything about a bottom bracket that I need to pay particualr attention to? (Sram DUB 73mm Threaded)
Thanks
Sounds like the creak on my bike. No good answer but at least you've saved me the trouble of checking the hanger.
I was going to unbolt the shock and check how smoothly the suspension bearings move.
Standing or sitting? I had similar problem... turned out to be the seat rails. I put a little drop of chain lube on the 4 points where the rails went into the seat. That cured the problem and it hasn't returned.
I'll plump for rear frame bearings needing replacement (or at least a clean/blast out and regrease). They have very little movement and are prone to seizing.
Check the cassette. Some are known to be creaky if loose or dry
What bike?
My Orbea Occam started like this and it was a seized top shock bolt. Ended up with a new frame under warranty.
Make a list of every component and junction on your bike (down to where each cable tie holds something against something else) and order it by the likelihood of it causing this specific creak. Start at the bottom of the list and work up.
Oh and for the BB I've found it helps to find a rod that you can stick into the axle from the NDS, then use a length of wood braced between that and the pedal to push against as you haul on the crank bolt with the longest lever you can find.
Im going with cracked frame or borked BB.
I've been hunting a similar creak for a few weeks now. Had changed the bb and was still there. Only happened when putting power in the cranks and the noise was in sync with the cranks. Didn't matter if I was in the saddle or out. Turned out to be the bearings in the freehub and the noise went when when I regeased the them. If you have the option of swapping out the wheel that might help you isolate if you have the same problem. I just regreased bearings as had no spare wheel to try
I’m going through something similar only difference being that the noise gets quieter and almost disappears by then end of the ride. It’s not the BB, and the cassette,chainring and chain are all new, so dont think it’s that.
Current rear wheel is a Hunt Trail Wide, and I am suspicious of the free hub. I have a spare wheel to try next.
When I have had creaks one was a crack in the top tube of a steel frame. One was a crack in the down tube of a ti frame. One was cracks in the seat and chain stays of a ti frame. The other was a crack in the non drive side crank at the corner of the square tapper bit.
What cassette? My wife’s gravel bike had a creak we couldn’t find, took the cassette off, cleaned it thoroughly including all the separate sprockets and reassembled. Been fine ever since.
I've had this a fair few times. I suspect that prime suspects are rear axle, seatpost, seat rails, chainrings, BB, crankarm; in that order. After that think about what might be stressed extraordinarilary when you put the power down.
You have I think, identified my method of locating the noise. If you soak individual potential sites with water eg from a bidon, you can hopefully i.d. the problem area. Work from the bottom up but remember that it might take a while for the water to work its way in.
A
I've this morning swapped the rear wheel over for another and I think the noise has gone. I can't be 100% sure about that until I hit the trails but a quick shimmy up and down the road outside suggests that's where the issue is coming from. I'll start next by removing the cassette and freehub to see what's happening in there.
I’ve this morning swapped the rear wheel over for another and I think the noise has gone. I can’t be 100% sure about that until I hit the trails but a quick shimmy up and down the road outside suggests that’s where the issue is coming from. I’ll start next by removing the cassette and freehub to see what’s happening in there
OP your describing my bike! Identical sounding creak (pedalling, only higher gears….), also just tracked it down to the rear wheel, a Race Face arc30, apparently they have a habit of failing
Had exactly this with a cracked feehub shell. Noise got transmitted through the rest of the frame & caused a bit of head scratching trying to track the source down.
Check your mech hanger whilst you have your wheel out. They can come a bit loose and dirt gets in there and can creak.
Freehub shell as above - or I've had some of the pawls/springs fail in a freehub that resulted in something similar.
If you can strip the hub down and clean/check the freehub itself as well as all the pawls, springs (or whatever mechanism your hub uses) and the bearings in the freehub.