Is this a BB or rear hub problem?

kingofthetailwind

My winter bike (Felt Z95) has developed a cracking, crunchy noise after Saturday morning's rainy ride. I'm fairly sure it is the BB (possibly some overenthusiastic hosing before I cleaned it) but I find it hard to pinpoint noises.

The noise is only there when the cranks are turning forward, even just turning them gently. There's no noise when turning them backwards. And there's no noise when the rear wheel is freewheeling.

Does this definitely seem like the BB before I change it? Hoping it is as hubs are still a mystery to me.

It's a cartridge FSA 68 x 110.5mm bottom bracket.

arlowood

Sounds pretty much like the BB is shot. However to eliminate one further potential source - were you turning the cranks using the pedals when the noise was evident? If so then I'd remove the pedals and repeat the diagnostic test.

I know from experience that I spent time and cash to get rid of what I thought was a BB failure only to discover that the culprit was a knackered pedal spindle

keezx

KingOfTheTailwind wrote:

My winter bike (Felt Z95) has developed a cracking, crunchy noise after Saturday morning's rainy ride.

Possibly only the chain needs cleaning and lubricating......

wishitwasallflat

As above sounds like BB is to blame but could be pedals or chain.
Easiest way to find out is to slip the chain off rings so it doesn't move and rotate the cranks by pushing the crank arms directly (so the pedals are not turning). Process of elimination should get you the culprit (which will be the BB by the way but at least you will be certain )

kingofthetailwind

The chain was cleaned and lubed after my ride on Saturday , so I can rule that out. I'll try the other suggestions to rule out the pedals. Cheers guys.

kingofthetailwind

Fitted the new BB. It's running much smoother now. But the noise is still there! So it must be the rear hub. I can't tell if the wheel (Giant P Elite C) is cartridge or cup and cone. :oops:

keezx

Most likely cartridge as Shimano is about the only left making cup+cone hubs (apart from some Chinese junk)
Take the wheel out and let it turn withe axle ends holding in your hands you should be able to feel if the hub+ freehub body turns smooth or not.
Most cartridge hubs are easy to take apart and replace the bearings...
Anyway its unusable for hubs to make noise unless the bearings are fallen apart, which doesn't happen after 1 rainy ride....
I still think about the chain (and derailleur jockey wheels!) , what lubrication do you use?

wishitwasallflat

KingOfTheTailwind wrote:

There's no noise when turning them backwards. And there's no noise when the rear is freewheeling.

Don't see how it could be hub then as when freewheeling the hub is still spinning. If the noise is only there when drive train is engaged as above its mor likely to be chain, jockey wheels etc ie soe part of the power transferring system not the hub. If you take wheel out and in it while holding the ends of the axle you will soon feel if the hub s rough or not. Then spin the freewheel body and you can separate the feel of that. Take chain of and feel how jockey wheels run and check chain by flexing one link at a time to see they are all free moving.

kingofthetailwind

The chain, cassette and jockey wheels and clean. I use Muc Off Wet Lube. The jockey wheels seem to be aligned properly too.

Listening to it with the bike on the stand, and with the wheel off holding the axles, there does seem to be a noise from the hub. It's quite quiet, but is much more noticeable with the wheel on the bike and the cranks turning.

So if it's the hub I'll probably get a local mechanic to do it, rather than me ruining it entirely!

keezx

KingOfTheTailwind wrote:

Listening to it with the bike on the stand, and with the wheel off holding the axles, there does seem to be a noise from the hub. It's quite quiet, but is much more noticeable with the wheel on the bike and the cranks turning.

How does it feel is what's interest me....

kingofthetailwind

I'm not sure. :?

Does £30-£40 sound reasonable to supply and fit new bearings?

keezx

Good , new bearings cost £5 a piece from independant supplyers , a bit more when it's bike related so I think it's reasonable.
Possible is that the bearings in the freehub are EOL, that means 2 extra....
(never buy watersportstuff in a yachtstore)

wishitwasallflat

KingOfTheTailwind wrote:

I'm not sure. :?

Does £30-£40 sound reasonable to supply and fit new bearings?

If they are cup and cone hubs then stripping them down, cleaning everything thoroughly and fitting new balls, grease and then adjusting could take an hour maybe so I suppose £30 is reasonable. Make sure they verify that the races on the hubs and the cones are ok otherwise they will just chew up new balls pretty quickly. If its cartridge bearings knocking them out and refitting new ones is more like 15 mons so £30 is steep IMO.

Either type though why not DIY though its a good skill to learn, not too difficult and plenty guides on www and wise heads on here to help if you get stuck?

kingofthetailwind

I think I'd rather see someone do it before attempting it myself. Seems more complicated than changing the BB. Plenty of potential for me to screw it up!

Cheers for the advice guys.

desweller

You can check for rumbly bearings by inverting the bike and giving the wheel a good spin. You'll be able to feel the bearings rumbling by touching the chainstays and seatstays.

cycleclinic

Drop the chain and turn the pedals you will feel roughness imiedatley throught the crank arms. You will know the hub bearing need attention by removing the wheel and rotating the axle by hand. Once you know what the problem is then lets discuss resilution and potential costs. One thing at a time.