A very common source of noise is the clamping of the handlebars. With anti-slip carbon mounting paste, carbon handlebars in particular can be mounted without cracking. Observe the tightening torques on the stem. Use a torque spanner! Light carbon parts are very sensitive to excessive clamping forces.
It grinds on the handlebars
Check the screw connection of the stem on the steerer tube. First check whether the headset bearing has play: Pull the front brake, rock the bike forwards and backwards. If there is play, open the stem screw connection (as shown in the picture), tighten the cover screw, then tighten the stem again.
By the way: You need 40 % less torque for secure clamping with carbon assembly paste. This applies to both stem/handlebars and seat clamps.
Remove the stem cover. Apply a thin coat of carbon assembly paste to the handlebars. Fit the cover, tighten the screws lubricated with assembly grease crosswise. Observe the torques. Ensure that the clamping slot is even all round.
You can find more articles on the subject of eliminating noise on MTBs here:
The seat post emits unknown noises
Apply a thin layer of carbon assembly paste to the carbon seat post. It should slide smoothly into the cleaned, grease-free seat tube. Treat the clamp and its screw - thread and head - with assembly grease. Prepared in this way, a few Newton metres are often enough to clamp the seat post securely. Observe the manufacturer's torque specification as the upper limit. For aluminium seat posts, assembly grease can also be used as an option, in which case higher clamping forces are required.
What is wrong with the sound of the steering bearing?
With integrated bearings, the bearing units are sometimes placed directly in the frame. Regardless of the design, always treat the contact area with assembly grease. Don't worry: carbon does NOT react with mineral oil products - it neither dissolves nor swells.
The saddle: hullabaloo under the bum
Saddles tend to creak. If you spray penetrating oil or silicone oil on the saddle frame/saddle connection, this will often help. If this does not help: Dismantle and clean the saddle clamp. Tighten the bolts with assembly grease.
Localising noises on the MTB
Is the cracking coming from the bottom bracket or rather from the derailleur hanger? Is the saddle frame creaking or is the carbon frame crackling? Our short guide will help you narrow down the source.
1 - Noise only occurs when pedalling
If the noise only occurs when pedalling, all parts of the drive system are possible, but also the wheels, frame, seat post, saddle and handlebars - all connections through which power flows.
- Drive standing up. Once the noise is gone, concentrate on the saddle and seat post.
- Test the handlebars and stem when stationary. Stand over the bike and put alternating pressure on the handlebars. If the noise increases, concentrate on the handlebar/stem/fork steerer connection. The steering head bearing is also a possibility.
- Test the chainring bolts. Are all screws tight? If not - retighten.
- Pedal check. Lubricate and tighten the thread. Does it keep cracking? Then change pedals and shoes.
- Exclude the rear wheel as a source of noise. Replace the rear wheel. Grease the axle/quick release and tighten firmly.
- Is it still cracking? Then inspect the thoroughly cleaned frame for cracks. For aluminium frames: Check the weld seams.
- Now it's time for the details. Shift eyes like to crack - but they are also quickly greased.
- Pull off the cranks. This is usually done using a hexagon socket. Also check the bearings: Does everything turn easily and smoothly?
- Remove the bolted bearing shells. Then clean, lubricate, reinsert and tighten properly (requires special tools).
- Remove the chainring bolts. Clean and grease the screws and threads, then reinsert them. Direct mount blades (Sram) should also be removed, cleaned and greased.
2 - Noise also occurs when rolling quietly
You have worked through the checklist above, nothing has helped and you realise: Even if I sit on the saddle and my MTB rolls along smoothly, the annoying noise continues to occur! Then we have the following 4 points to tick off.
Ride standing up again. If the cracking then stops, check the saddle and seat post.
Brakes squeal. Apply the brakes lightly alternately at the front and rear. If the squealing is then gone, the pads are rubbing.
Check the rear triangle. Joints and damper mountings are sources of noise during compression. Roll slowly while stationary, consciously and clearly compress and listen. Test the joints individually.
Does it only creak when steering? Then check the shift cable sheaths.
