Ksyrium SSC 'knocking' - help needed

[rustychisel]

Hi all, a vexing issue which someone might be familiar with.

Have changed my Teschner over from Shimano to Campagnolo, running Chorus carbon 10 speed. Changed freehub on Ksyrium SSC wheel (black, milled rim, circa 2003) from Shimano to Campagnolo, lubed pawls etc, installed Campagnolo cassette (12~26 as it happens), all good.

Some months later the wheel has developed a 'knocking' sound which resonates through the bike, generally when pedalling harder, generally in the 3rd/4th/5th cog is worst. Intermittent, but persuasive, and annoying. Anyone have any ideas, please?

Freehub installation?
Cassette: missing a thin spacer behind cassette?
Bearings?

Have pulled apart and checked, there appears to be no wear pattern or markings on freehub to indicate anything amiss, but.... Cassette seems well bedded and locknut tight and not wobbly. Wheel bearing seem as smooth as ever. QR cleaned, checked and reinstalled with a smear of grease.

Note: definitely back wheel. Suspected BB bearings but replaced checked etc, then narrowed the field by swapping in my partners wheels (Eurus '05) one at a time. Frame seems whole and uncracked. The 'knocking' is quite loud, is neither a creak nor click, and the frequency strongly suggests it is not chain related. It also happens with 3 different cassettes installed on the same Ksyrium wheel.

[Fixed]

mavic q.r.' s can make nose check them too imho
cheers replace with a shimano see if that helps
maybe wheel ratchet paws

[DRietz]

Lift your bike up on the top tube by the seat "lug" area and open your brake's quick release. Attempt to move the rim from brake pad to brake pad.

Can you? If so, it's definitely your bearing adjustment. I'm unsure if your Mavic hubs adjust the same way as my Mavic SSC hubs, but I can adjust my bearing with my hands and the wheel mounted in the dropouts.

If it's not that, I know my SSC Classics have a tendency to makes sounds at the spokes if I don't triflow the straight-pull heads, so that could be it as well.

[R2D2]

Lift your bike up on the top tube by the seat "lug" area and open your brake's quick release. Attempt to move the rim from brake pad to brake pad.

Can you? If so, it's definitely your bearing adjustment. I'm unsure if your Mavic hubs adjust the same way as my Mavic SSC hubs, but I can adjust my bearing with my hands and the wheel mounted in the dropouts.

If it's not that, I know my SSC Classics have a tendency to makes sounds at the spokes if I don't triflow the straight-pull heads, so that could be it as well.

+1
The bearing pre-load adjustment is not the best design. It basically just loosens the entire axle and allows the casette to knock about if too loose.

[Stefan]

+1 on the Hub diagnosis. It makes a god awful sound. Put on a different wheel, I bet it's quiet. It took trips to two LBS's to get it diagnosed.

[oldpotatoe]

Hi all, a vexing issue which someone might be familiar with.

Have changed my Teschner over from Shimano to Campagnolo, running Chorus carbon 10 speed. Changed freehub on Ksyrium SSC wheel (black, milled rim, circa 2003) from Shimano to Campagnolo, lubed pawls etc, installed Campagnolo cassette (12~26 as it happens), all good.

Some months later the wheel has developed a 'knocking' sound which resonates through the bike, generally when pedalling harder, generally in the 3rd/4th/5th cog is worst. Intermittent, but persuasive, and annoying. Anyone have any ideas, please?

Freehub installation?
Cassette: missing a thin spacer behind cassette?
Bearings?

Have pulled apart and checked, there appears to be no wear pattern or markings on freehub to indicate anything amiss, but.... Cassette seems well bedded and locknut tight and not wobbly. Wheel bearing seem as smooth as ever. QR cleaned, checked and reinstalled with a smear of grease.

Note: definitely back wheel. Suspected BB bearings but replaced checked etc, then narrowed the field by swapping in my partners wheels (Eurus '05) one at a time. Frame seems whole and uncracked. The 'knocking' is quite loud, is neither a creak nor click, and the frequency strongly suggests it is not chain related. It also happens with 3 different cassettes installed on the same Ksyrium wheel.

Could be bearing adjust, as has been mentioned or the plastic bushing on the bottom of the freehub body is not round, concentric anymore, which will also make that noise. Wobbling on the hub 'stub' where the pawls live.

[AngryScientist]

just so i'm clear, the sound disappeared when you used your buddy's rear wheel, correct?

[DRietz]

+1
The bearing pre-load adjustment is not the best design. It basically just loosens the entire axle and allows the casette to knock about if too loose.

You know, I'm actually a huge fan of their system from a durability and serviceability stand point.

But it does take some vigilance... :D

[rustychisel]

thanks so far,

I will explore further, but pretty confident it is not

QR (see OP)
spokes (well acquainted with Ksyrium spoke issues and noises)

will examine bearing play (seemed tickety-boo at a quick feel this morning. I only have time for a quick feel in the morning, as do most men :cool: )

And nylon bushings etc in freehub will get a disassembly and look see.

Supplementary question[s]: should I clean off the oil etc on freehub body and carrier and just lightly oil the pawls.. ie less is better?

How tight is too tight in torquing on the freehub body?

[Fixed]

one more reason to like a fixed gear
cheers

[rustychisel]

Well, actually, no it's not. But I like them too. :beer:

http://www.dbmagazine.com.au/cyclo/IMG_3977web.jpg

[Ralph]

Quick link in chain? I had one for Campy 10's chain, made by a popular company, that had a sould like that at times. It took me a long time to figure that out. And I took the whole rear apart.

[rustychisel]

Quick link in chain? I had one for Campy 10's chain, made by a popular company, that had a sould like that at times. It took me a long time to figure that out. And I took the whole rear apart.


Thanks Ralph,

made by Connex? Yes, I have, both in old old chain and brand new installed chain. Could it be that simple? hmmm

I considered and discounted this earlier as the 'knocking' was not of a frequency I could tie to a particular part. ie not once per chain rotation or once per crank rotation

[Ralph]

I bet it's the link then. It's like a knocking, but not all the time, or every revolution. Maybe not on all cogs. These quick links don't fit chain like a stock link. I'm having better luck with Campy 10's chain and KMC link. That's how I learned what it was. Replaced the quick link.

[rustychisel]

I bet it's the link then. It's like a knocking, but not all the time, or every revolution. Maybe not on all cogs.

correct

These quick links don't fit chain like a stock link. I'm having better luck with Campy 10's chain and KMC link. That's how I learned what it was. Replaced the quick link.

I noticed the plate profile is rather different, but maybe its the incidence/frequency of knocking had me fooled. Tonight that link's a goner. Saturday I ride. I'll report back.

[oliver1850]

.

[rustychisel]

Yes, understand about the width question. Have used mainly but not exclusively Connex on Shimano chains for years and never a problem. Mostly 8 and 9 speed. The supplied link was assuredly correct for Campagnolo 10 speed and has a fish shaped profile. I'll get rid of it in the interests of sorting out this annoying problem.

[oliver1850]

.

[rustychisel]

No, all ideas are gratefully received. Which is why the chain link is going.

So far in attempts to isolate this I've installed and/or pulled

Campagnolo Record crabon sq taper
Campagnolo Chorus sq taper
FSA SLK compact crabon (MegaEXO BB)

12~26 10 speed cassette
11~23 10 speed cassette
13~29 10 speed cassette

old chain (with link)
new chain (new link)

1 x K SSC SL wheel (except when using borrowed Eurus wheels). I'm gonna get to the bottom of this sucker

[R2D2]

You know, I'm actually a huge fan of their system from a durability and serviceability stand point.

But it does take some vigilance... :D

Agreed. The SSC is bomb proof. But I'm not a fan of the cassette carrier.
Don't like the bushing. If the preload is the slightest bit loose the carrier wallows around which casuses the cassette teeth and chain to wear quickly and knock. It is hard to adjust on the road with the pin holes.
I think there are better designs. That's all.
But the rim paved the way for tubeless tires. So pro's and con's.

[Ralph]

No, all ideas are gratefully received. Which is why the chain link is going.

So far in attempts to isolate this I've installed and/or pulled

Campagnolo Record crabon sq taper
Campagnolo Chorus sq taper
FSA SLK compact crabon (MegaEXO BB)

12~26 10 speed cassette
11~23 10 speed cassette
13~29 10 speed cassette

old chain (with link)
new chain (new link)

1 x K SSC SL wheel (except when using borrowed Eurus wheels). I'm gonna get to the bottom of this sucker

If you keep eliminating things, you will figure it out. Knocks/clunks/creaks, etc are hard to spot. I've had noises from old stems creaking I would have sworn came from rear. My Ritchey stems with 4 bolts will make stranges noises if not tightened evenly, stuff like that. You're experienced, you'll get it.

[rustychisel]

road the gears in to the city today. It ain't the quicklink.

///// more to come

[DRietz]

Did you check the bearings? The adjustment is simple enough.

[rustychisel]

finger tested only thus far (I like to go about things from complex to simplest :confused: ).

Seem firm, no slop or obvious movement/notching. Will remove wheel and check thoroughly tonight.

[rustychisel]

Bringing this old dog back to life in the interests of a) finishing it off and b) providing assistance to those who may have a similar problem.

1. The issue. 'Knocking' of rear wheel, as discussed in detail.

2. Specifically. OldPotato got closest (natch) in suggesting concentric wear of nylon bush on freehub inner support. Actually, the bush was fine, virtually new, but where it rests on the hub itself was worn.

Mavic: hubs are machined from an aluminium billet, cleaned up and anodised. The freehub body uses a nylon bush on the inner point which contacts a slightly raised alloy face on the hub itself. In use, eventually the anodising wears out, the alloy itself starts wearing away, and any lube in the freehub (Mavic suggest light machine oil) becomes an abrasive grey sludge, accelerating the wear.

My hub was worn from manufacturing tolerances to well over 0.4 mm. It's poor design is what it is, inbuilt obsolescence. If I didn't like these wheels I would have hung them on the wall, but I think they're robust, capable etc

3. Ideas. There are people in the US and elsewhere who sell rebuild kits for these wheels, mostly new freehub bodies with (I gather) slightly outsized nylon bushes etc.

Obviously, this is not a great engineering solution, the fix is temporary, the root cause not addressed.

A friend of mine is an engineer by trade, specialising in machine tools, metal turning and complex structures, and he developed a fix when his Ksyriums went the same way as mine.

4. Solution. Friend Ian machines back the aluminium shoulder slightly and manufactures a stainless steel collar (shim) to size. It is very thin, machined to original Mavic tolerances for the freehub, and about 4mm wide. This is then bonded onto the hub, after checking the pawls ears will seat and engage correctly. The nylon bush now runs on a stainless steel face.

I rebuilt the wheel last night, lubed it appropriately, and rode in to the city this morning. We have a winner, and all for the price of a slab of pale ale.

Sweet!!!!!! :banana:

[hybridbellbaske]

Well done.

Now about that noise that's coming from the bottom bracket on my Pegoretti....

[rustychisel]

that's easy!

The noise is a little Italian framebuilding gnome screaming "RIDE ME YOU BASTARD, RIDE ME!!!!!"

[thinpin]

Now, I need to add a beer drinking engineer with time to do trick work to my tool box! Will it ever stop?
Chapeau! I'd have bought new wheels.