Hub Noise (Clunk), Pawls

[HLaB]

Its probably nigh impossible to diagnose on line but the hub on my campag Khasim's has always been noisy I think the pawl's engage to sharply or off square sometimes causing a 'clunk'. In the past its encouraged me to pedal in a higher gear (probably too high tbh) but I'm concentrating on pedaling at a higher cadence and its more noisy then. Its hard to describe but it sounds/ feels like the hub is being thrown forward and there's a clunk as it engages. Has anybody any ideas ?

I had the bike in at the shop at the start of July and they never considered it a problem when I specifically mentioned it but it was probably unnoticeable to them, as it only really occurs when pedaling at a high cadence at speed or honking up a hill.

 

[ianrauk]

I used to have the same thing with a pair of Easton's.
A loud clunk when pushing from off or suddenly hard.
I took the hub apart, pawls, springs, everything but just couldn't find a fault

 

[HLaB]

I used to have the same thing with a pair of Easton's.
A loud clunk when pushing from off or suddenly hard.
I took the hub apart, pawls, springs, everything but just couldn't find a fault

Thats what I am thinking too, having took it apart a few times!

 

[accountantpete]

Probably sticky pawls.

The hub has backwards facing teeth and the pawls point forward. When you freewheel the pawls are forced down by the teeth in the hub and can simply get stuck in the down position due to muck around the pawls.

As the pawls are on a spring there is a tug of war between muck and the spring - and if the muck wins then you get no forward power and the pawls stay down. On the other hand the spring can win but only after a bit of a struggle and delay - which you are experiencing.

You need to take the freehub off and clean the area around the pawls - also make sure the spring is working correctly.

 

[HLaB]

Probably sticky pawls.

The hub has backwards facing teeth and the pawls point forward. When you freewheel the pawls are forced down by the teeth in the hub and can simply get stuck in the down position due to muck around the pawls.

As the pawls are on a spring there is a tug of war between muck and the spring - and if the muck wins then you get no forward power and the pawls stay down. On the other hand the spring can win but only after a bit of a struggle and delay - which you are experiencing.

You need to take the freehub off and clean the area around the pawls - also make sure the spring is working correctly.

Did that a few weeks ago when replacing the spring but I might try again the last time I left the spring/pawls in place and only cleaned and greased the ratchet and pawl tips, maybe I need to look at the base again or try a different brand of grease.

 

[lpretro1]

Some hubs are just clunky like that - if you have a carbon frame it also echoes through the frame and makes it sound worse!!

 

[ianrauk]

Probably sticky pawls.

The hub has backwards facing teeth and the pawls point forward. When you freewheel the pawls are forced down by the teeth in the hub and can simply get stuck in the down position due to muck around the pawls.

As the pawls are on a spring there is a tug of war between muck and the spring - and if the muck wins then you get no forward power and the pawls stay down. On the other hand the spring can win but only after a bit of a struggle and delay - which you are experiencing.

You need to take the freehub off and clean the area around the pawls - also make sure the spring is working correctly.

I did all this with my hub. It was spotless inside. Really clean. The spring was fine, nothing wrong with the pawls, tried with no oil, tried with the tiniest amount of 3in1. They opened and shut easily and properly. What ever I did I still got that clunk. Not always mind, Just now and again. Just one of those mysterious things.

 

[HLaB]

I did all this with my hub. It was spotless inside. Really clean. The spring was fine, nothing wrong with the pawls, tried with no oil, tried with the tiniest amount of 3in1. They opened and shut easily and properly. What ever I did I still got that clunk. Not always mind, Just now and again. Just one of those mysterious things.

I had similarily really cleaned and then lightly greased (that what guides, etc reccommend) my freehub in an attempt to solve the problem and similary the pawls seemed to open and shut properly and easily but no success tried delicately lubing pawl pivot bases and tips and the ratchet, still no success. So this time, I've tried switching grease (I was using TF2 Lithium White grease and bought Hellfrauds Teflon Red last night, the lbs had ran out of grease). Maybe (probably ) overdid the grease, however; it seemed OK on the rollers for a quick mile/ 2 foot before bed but I've not had the wheel on the road yet, I'll see tonight! I maybe need to find that right balance of greasing