Zipp grinding wheel

okgo

So my bike has been making some horrid noises when pedalling. I withdrew from a race last night as it was sounding like I was ruining something!

Upon switching rear wheels the noise goes. Now I've had a look at the zipp free hub and it does have some large bite marks in it (why they use such soft material I'll never know) could it be this that's causing the noise?

Also what is the consensus with spacers on zipp wheels? I've read that new wheels don't need them, but mine seem to need at least 1...

Does this sound like free hub is knackered? Or is it something else in the rear wheel that can be making this horrid noise...?

Thanks for any help

fish156

First time I rode '404s I'd not removed the Tire Guides from the brake cartridges (the small screw that protrudes below the brake shoe) and with worn rear pads these were touching the widest part of the the deep rim whenever I went near the brakes. :roll: In my defence I bought them 2nd hand so was unable to RTFM.
The noise was horrible - "it was sounding like I was ruining something!" - which I probably was.

Was your noise continuous, when braking, when under power, when honking out of the saddle, etc?

My freehub was also heavily notched (do Zipp make these from cheese?), but with the cassette lock-ring torqued down didn't lead to any noise.

Spacers? Used to run one (Shimano 10 speed), but always required half a turn on the rear mech adjuster when compared with other rear wheels.

napoleond

It'll most likely be a tiny bit of grit that has got in between the hub and preload bearing cap on the non drive side. Loosen it right off and give it a clean out.
I had that issue and it sounded like Armageddon because it was amplified so much through the carbon rim. Easily sorted.

okgo

Thanks guys. Not the brakes, made that mistake on my other rims.

Its only under heavy load when pedaling. Not freewheeling or anything other.

I've since realized that I was using a 11t lock-ring on a 12t cassette, so that didn't help I'm sure. However even swapping this (which now means I only need 1 spacer) but the noise is still there.

Nap, I can't see how I would get it apart, is there a good guide for this?

napoleond

Sounds EXACTLY like my problem!

All you do is loosen off the tiny allen bolt on the none drive side and unscrew the preload adjuster. Really really simple, 2 minute job. I assume it's a 188 hub - explained here -

http://www.zipp.com/support/maintenance ... enance.php

(link to the manual here http://www.zipp.com/support/maintenance/wheel_care.php )

And it was the tiniest piece of grit. It made a shocking racket, when out of the saddle I thought the bike was going to explode apart!

okgo

Having looked I think its actually the 182 hub, which seems slightly different in its assembly... But you think principles could be the same?

napoleond

Doh! The 182 was notoriously crap which is why the older Zipp wheels don't go for much money. The 182 has the carbon end cap.

However, still likely to be a similar grit based problem.

Instructions on how to strip and clean here -

http://www.zipp.com/support/maintenance/model182.php

ugo.santalucia

The freehub has nothing to do with it. Moder freehubs are made of light alloy which is quite soft compared to the sprockets steel.
As Nap says, there is probably too much load on the bearings... it's important you resolve it, otherwise the bearings will go... replacements can be 2 quid for standard bearings or 20 times as much if fancy ceramic ones... replacing them can be a 5 minutes job or a nightmare depending on the hub

okgo

How will I know if they're borked?

And how will I know if they're overloaded?

ugo.santalucia

okgo wrote:

How will I know if they're borked?

And how will I know if they're overloaded?

Take the wheel off the frame, spin the hub in your fingers, it should feel buttery smooth, maybe with a bit of resistance (there are 4 bearings after all), but no grinding... if it's not smooth try to reduce the load on the bearing... if it's still grinding, then one or more have gone...

Resuscitating bearings needs divine intervention... once they've gone there is nothing you can do but replace. They will still be rideable for a long while beofre they collapse, but there is little point in having a 1000 pounds set of wheels with shot bearings

racingcondor

It's often worth backing off the bearing preload a little more than necessary to free them up when the wheel is out of the frame because it will get compressed a little as you tighten up your QR. Looking at the care manual they state that there should be a little side to side play in the wheel when the QR is open.

http://www.zipp.com/_media/pdfs/manuals/wheel_care.pdf

As mentioned though I'd take it all apart, clean, grease and reassemble the lot to be sure that the bearings are fine and nothing is in there that shouldn't be.

I'd be surprised if there is any noise from your freehub body (the bearings in it, quite possibly), it'll get quite a bit of bite in the splines because Alu freehubs are soft but weigh a lot less than steel ones and unfortunately that's where the marketing is.

okgo

Well took it all apart. Cleaned etc and it's still doing it. No grinding or anything when spinning but still same noises under load...

Time to a trip to the shop?

napoleond

Yeah, trip to the shop...

okgo

Bearings were borked. New ones in and it's fine!

£18 while you wait job at Sigma.

napoleond

Sooper!

ugo.santalucia

okgo wrote:

Bearings were borked. New ones in and it's fine!

£18 while you wait job at Sigma.

Very reasonable

okgo

Yeh, the beauty of that shop is that they have enough staff (Evans the same size would have a quarter of the staff I reckon) to be able to fix stuff for you while you wait even on a Sat afternoon. Added to that you can watch the giro while you wait, and being the type of store it is they know about expensive wheels and have all of the stuff in stock. My local admitted to me he'd never trued a deep carbon wheel before....:O

racingcondor

Good to hear. I'm a big fan of Sigma for their attitude to customer service as well, always good to hear of someone getting it right.