Cause of freehub spline damage?

equivariant

I posted in adverts looking for a replacement part but I thought that I might ask for a diagnosis here.

I recently replaced the (Shimano 10sp) cassette on my fulcrum racing quattro wheel. I have replaced the cassette several times without any issue before and as you know it is a straightforward procedure.

However, for various reasons I happened to take off the new cassette after a test ride (I was just messing around with different sprockets) and discovered that the freehub body was damaged (see attached photo).

Basically some of the sprockets have bitten into the splines on the freehub. The freehub was pristine when I replaced the cassette and this damage happened over the course of a 5 minute test ride. The lock ring was tightened properly and all the sprockets and spacers were properly fitted (afaik)

Is this normal? What could be the cause? How do I prevent it from deteriorating/happening again? Do I need to replace the freehub body straight away or can I continue to ride on it?

Raam

Happens to some of my freehubs. Never been bothered by it. Ride on!

Borderfox

Can be caused by the freehub not torqued up correctly, more torque means less radial movement. Can be soft aluminium freehub too for weight saving

easygoing39

Its normal.

nordicb

This is not normal over 5 min test ride. Very odd! You prob need a cassette that is made of bonded groups to share the load.

07Lapierre

your putting too much power thru the pedals! ease off a bit!

equivariant

nordicb wrote: »

This is not normal over 5 min test ride. Very odd! You prob need a cassette that is made of bonded groups to share the load.

Yes - I thought that it seemed odd to happen so quickly. All previous cassettes were just standard Shimano 105 cassettes with the biggest three sprockets bonded and the remaining sprockets all separate - the new cassette was the same. That's what puzzles me - why suddenly (and so quickly) with this cassette? I did not use a torque wrench for the lock ring but it was as tight as I could make it - applying my full body weight to the wrench and bouncing on it to get a bit of extra force. This has worked fine for me in the past.

nordicb

As mentioned earlier, it does look a little like sprockets were able to rotate as if they were not tightened. Perhaps the smallest sprocket doesn't sit properly and the lockring only tightened the smallest one. Also fulcrum wheels, the hub looks very like ones on Campy wheels - no such issue over thousands of km on mine. I have only ever seen hub damage like that on MTB when the sprocket bond works out loose - larger sprockets and more torque to cut in to the freehub...

Wishbone Ash

equivariant wrote: »

.. but it was as tight as I could make it - applying my full body weight to the wrench and bouncing on it to get a bit of extra force....

:eek::eek::eek: It doesn't need to be that tight. You could easily crack the free hub body. It has happened to me twice and I was only applying normal upward one arm pressure.

route66

Wishbone Ash wrote: »

:eek::eek::eek: It doesn't need to be that tight. You could easily crack the free hub body. It has happened to me twice and I was only applying normal upward one arm pressure.

+ 1

On the subject of damage, I've never seen that before and would find it difficult to believe that it is normal. Is the cassette and the freehub compatible - i.e. Shimano / Campagnolo ?

equivariant

Wishbone Ash wrote: »

:eek::eek::eek: It doesn't need to be that tight. You could easily crack the free hub body. It has happened to me twice and I was only applying normal upward one arm pressure.

Point taken - I should really get a torque wrench and do it properly.

I don't doubt your experience but it does surprise me that the free hub would crack with just one arm pressure as you describe, if you think about the force that it must withstand under a full on sprint in 53-11. At a guess the torque on the 11 sprocket should be about 7 times the torque that you are applying to the pedal.

equivariant

route66 wrote: »

+ 1

On the subject of damage, I've never seen that before and would find it difficult to believe that it is normal. Is the cassette and the freehub compatible - i.e. Shimano / Campagnolo ?

Defintely yes - the new cassette was pretty much exactly the same as the old cassette (which did not cause any damage) - both Shimano 105

route66

equivariant wrote: »

Point taken - I should really get a torque wrench and do it properly.

I don't doubt your experience but it does surprise me that the free hub would crack with just one arm pressure as you describe. If you think about the force that it must withstand under a full on sprint in 53-11, the free hub should be getting. At a guess the torque on the 11 sprocket should be about 7 times the torque that you are applying to the pedal.

Different forces in different directions! Tightening the lock ring just forces it against the edge of the freehub. When you are powering along by putting pressure on the pedals, there is a twisting force applied by the inner contact points of the cassette against the splines of the freebub.

Like Wishbone Ash, I cracked the edge of a freehub by excessive tightening. To make it worse, I was using a torque wrench, albeit a cheapo Lidl one :eek: I wasn't able to replace the freehub but did manage to keep the wheels going for a while by using a lock ring with a deeper thread.

07Lapierre

route66 wrote: »

+ 1

On the subject of damage, I've never seen that before and would find it difficult to believe that it is normal. Is the cassette and the freehub compatible - i.e. Shimano / Campagnolo ?

Its normal enough...I've 3 bikes..all 3 are just like the OP's photo.

Wishbone Ash

route66 wrote: »

..Is the cassette and the freehub compatible - i.e. Shimano / Campagnolo ?

A Campy cassette won't slide onto a Shimano free hub and vice versa.

07Lapierre wrote: »

Its normal enough...I've 3 bikes..all 3 are just like the OP's photo.

I've never seen it on any wheels I've had.

07Lapierre

Wishbone Ash wrote: »

I've never seen it on any wheels I've had.

WA, it only happens with good/expensive wheels! :P

Wishbone Ash

07Lapierre wrote: »

WA, it only happens with good/expensive wheels! :P

I was just expecting that response!!!

quozl

Wishbone Ash wrote: »

I was just expecting that response!!!

It's true though; our cheap heavy steel hubs are much too resilient. You have to pay extra for the weak stuff that's easily damaged

equivariant

07Lapierre wrote: »

WA, it only happens with good/expensive wheels! :P

Also I think that it may be more likely for the shall we say 'well endowed' cyclists among us

saccades

Aluminium freehubs are chewed by the splines - happens a lot with hope hubs and anything lower than XT cassettes (spider are different on xt/xtr).

American classic hubs have small steel inserts on the leading edge of the splines to prevent this kinda damage (and you can get steel freehub bodies from hope now too).

minterno

I have had the exact same issue on my last 3 bikes, I just filed the damage carefully with a very fine file and had no problem with any of them, in a perfect world it wouldn't happen but when very hard steel meets very soft aluminium the softy gives, my own was caused by myself being hard on the pedals and if yours happened after a short while well then the cassette or some of the cogs must have moved, no other explanation I think but although its annoying its no biggee

Mech1

I know nothing about bikes, but im a motor mechanic, my view on that picture is that the sprockets turned a bit while locking up whatever nut holds them in place. maybe lube the back of the locking nut before tightening?

cdaly_

Sprockets turning is unlikely since the first couple of sprockets are loose while the rest are bonded together. First sprocket acts like a keyed washer so the remaining sprockets would not turn in the tightening...