Cycling UK Forum

Hi all,

After discovering a slight wobble on my rear wheel which has now developed into a significant one, and deciding after much research and experimentation that it's almost certainly down to the need for a change in bearings, I have been wondering/dreading how I go about actually doing this, as in what exactly am I looking to buy, and how straightforward is it to carry the operation out.

(I have successful changed a cassette so I'm hopeful this will be no more challenging.)

This is a link to my bike spec:

https://www.ebay.co.uk/itm/352774153147

Thanks.

Park Tools Repair Help: "Hub Service":
https://www.parktool.com/blog/repair-he ... adjustment
(links to the various different types)

Jonathan

Read this:

https://www.parktool.com/blog/repair-he ... adjustment

If your bike has cup and cone hubs (as opposed to cartridge bearings) then it is also worth reading the thread below in Too Good to Lose, and possibly some of the links it contains to other threads, which cover how to adjust the hubs to remove play and the importance of preventing precession of the right hand cones.

viewtopic.php?f=5&t=143125

A photo of the rear hub would help. It SOUNDS like it is a freehub rather than a freewheel ? Next key question is whether it has loose bearings or sealed bearings...the procedure is completely different depending which of these it is. Is there a manufacturer name /part number on the hub?

Could it be that your hub needs a service? I had the same recently and I serviced my hub by removing the locknuts and cones, cleaning it all out and reassembling with new grease.

Not enough information in your request or in the eBay link you provided to determine if the hub uses cup and cone bearings (which are fairly easily serviced at home) or sealed cartridge bearings (which require specialized tools such as bearing puller and press for replacement).
.

Despite you saying you are sure the cause of the wobble is the bearings, in my experience rear wheel wobbles are more often caused by bent axles, particularly in bikes with a freewheel rather than a bike with a freehub.

My question is, does the wheel wobble when you spin it (more likely a bent axle), or does it rock when you grab the rim & pull it back & forward (more likely bearings)?

geomannie wrote: ↑13 Jul 2021, 7:45am Despite you saying you are sure the cause of the wobble is the bearings, in my experience rear wheel wobbles are more often caused by bent axles, particularly in bikes with a freewheel rather than a bike with a freehub.

My question is, does the wheel wobble when you spin it (more likely a bent axle), or does it rock when you grab the rim & pull it back & forward (more likely bearings)?

The probability at the price point for the bike is that it is a freewheel, as suggested - from experience they are highly prone to "wobble" - and almost certainly cup and cone bearings - easy enough to take apart, re-grease and re-assemble if you have the tools (usually a 13, 14 or 15 cone spanner and a 17mm spanner for the locknuts.
Park Tool has the mehto in one the online technical resources

Examination of that eBay listing shows the bike to have a cassette hub, but I would concur that it is unlikely to have sealed bearings so adjustment of the axle cones and locknuts may be effective if done ASAP. It is very much a job done ‘on feel’ and practice makes perfect but with a few simple tools it is certainly straightforward if done correctly. If you decide to attempt the job I would recommend first removing the axle altogether. This will allow you to inspect the ball bearings (replaceable if damaged) and the surfaces they bear on. These are two cones on the axle (replaceable but specific to the hub) and two faces inside the hub; the drive side, which is part of the (usually replaceable freehub body) and the non-drive side which is integral to the hub. If wear or, more significantly, pitting is present on these four surfaces it is often easier and more cost effective to replace the whole hub and ensure its axle is adjusted correctly when assembled into the wheel.

It's worth checking prices before you start.

In 2008, I bought a pair of new Deore hubs, front and rear, for £5 less than the cost of a new freehub.

Thanks for your replies.

I hope the image attached is useful.

For the record, I have inspected the axle by hand and appeared to be perfectly straight.

Out of interest, what exactly are the safety risks of riding a bike whose bearings haven't been maintained?

doffcocker wrote: ↑14 Jul 2021, 7:30pm Out of interest, what exactly are the safety risks of riding a bike whose bearings haven't been maintained?

Generally speaking poorly maintained bearings degenerate at a slow rate and those owners that are bike-wise can spot the symptoms before they become a safety issue. Beyond the scope of wear and tear degradation however you can suffer sudden mechanical failures and issues due to poor assembly. Either of these can result in sudden and dramatic safety-related problems (as can not noticing or ignoring wear and tear) the most obvious of which will result in the wheel bearings locking up or the wheel itself jamming in the frame or brakes or oscillating enough to make the rider loose control.