Rear axle DIY advice
 

After noticing a knocking noise from my last couple of rides, I suspected that the rear bearings were on their way out. I decided to look up some videos (and draw on my experience from changing front hub bearings) and took the rear axle apart. Unfortunately, while doing so, I discovered that the non-drive (left) side nut had completely siezed up and while trying to get it loose - which caused me to inadvertently loosen the drive side (which I understand you should avoid). I decided to continue and took it apart from the drive side and found that the bearings had become worn and the cone had signs of pitting on the drive side.

As I didn't have new bearings to hand, I decided to give it a clean, grease and put it all back together to see what happens. In addition to the noise, I found that the rear freewheel suddently developed a "wobble" where it would wobble up and down relative to the rotation of the rear wheel. My first course of action is to replace the bearings on both sides.

I have new bearings on the way, but wanted to see if I'm doing the right thing and if I could get help tracking down the right type of axle and cone nuts. I can't seem to find the cone nuts as the dust cap on the existing ones has a flat profile while the replacement ones on ebay seem to have a significant lip/squared edge (ebay item: 251214868773). My axle is currently a non-quick release axle, so I am happy to look at QR versions too. I have looked on sheldonbrown for some advice but I couldn't find what I needed on there.

Key specs
Hub make: Shunfeng
Existing axle measurements: approx 175mm long and 8.6mm in diameter
Bearings: 5.9mm loose x 9 on each side (ordered 6mm Grade 25)

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This is to help augment the information above - I hope mods don't mind!

Axles are typically 9 or 10mm thread.
Bicycle Bearings are almost universally imperial sized - 5/32", 3/16", 1/4", not metric. Rear hubs are normally 1/4".

The important parts of cones are the bearing race profiles and diameters.

Doesn't really matter what side you take it apart from, just that you leave one side tight to keep the length adjustment. On a solid axle it matters even less as you don't need the length adjust to be so close. YOu may want to work with a shop to match up cones.

https://wheelsmfg.com/products/hub-parts.html?p=2

[QUOTE=dedhed;21851503]Axles are typically 9 or 10mm thread.
Bicycle Bearings are almost universally imperial sized - 5/32", 3/16", 1/4", not metric. Rear hubs are normally 1/4".

The important parts of cones are the bearing race profiles and diameters.

Doesn't really matter what side you take it apart from, just that you leave one side tight to keep the length adjustment. On a solid axle it matters even less as you don't need the length adjust to be so close. YOu may want to work with a shop to match up cones./QUOTE]

Although my current axle diameter is 8.6mm, I measured the diameter of the dropouts and found that it was just slightly bigger than 9mm, so I think I could get away with it without any modifications. I don't have access


I want to go with your advice and switch to hollow axle. However I need help on the following:

Which axle to go for and where from?

• The hub spacing is 129.3mm and the current axle is 8.6mm diameter x 175mm length
• Amazon has lots of hollow axles with poor reviews
• eBay doesn't seem to have the size that I need (I am looking for 10mm longer than my current hub spacing based on a video by RJ the bike guy)
• I also have the problem of not knowing if I need to match the dustcaps as you may have seen from the pictures that the dustcaps I have are flat ended while Amazon/eBay seem to have dustcaps with a "lip"

Could you recommenmd a reliable brand and/or site for the UK?

On a hub that has a freehub you always want to have the drive side tight and put the axle into the hub from that side...and do all of your adjusting from the NDS. Most hubs will not allow adjustment from the DS, the cone is generally too far inside the freehub to get a wrench on it.

If you can find a new axle by Wheels Manufacturing in the right threading dimension, get it. Use a hacksaw if you need to cut it down. Leave a cone and/or nut inside the cut to clean the cut threads afterwards.

According to the op he had already loosened the DS and would need to pull it out that way to unseize the NDS. I agree working from the NDS is the correct way but it can be done the other way, just much more fiddly to keep loosening things up to set the DS for correct length once you've loosened the NDS

One thing that I forgot to mention in my last post above is that where the current axle is 8.6mm in diameter, if I move up to 9mm hollow for QR, that may require downsizing of the current bearings (assuming that the cone nut will increase in size as a result). Is that assumption correct?

An update for anyone who is following this thread as well as for anyone who comes across this in the future.

I bought a hollow QR set with skewers from Amazon. The rear axle was shows as having a 9mm diameter. When I checked the diameter of the part received, it was 8.6mm just as I had measured on my existing one. I followd a video by RJ the buke guy and managed to get everything fitted nicely (I had to reuse the drive side spacer from my previous axle as the new one was slightly smaller). As the dust caps with the new kit didn't match up, I removed the dust caps from the previous cone nuts and checked that they would fit the new cone nuts (which they did).

Something to note, after the first ride, the rear wheel developed major play. Everything was tight, so I can only assume that the bearings had not sat in properly when I tightened the cone nuts. After a quick inspection to make sure the bearings were still arranged properly, I tightened everything again (making sure that the axle protruded evenly on both sides). Hoping that there are no further surprises!

Thanks all for your helpful responses. I'll be swapping out the front axle for a QR one soon :)

Good to see you got there!

With bearings it is a lot down to experience, and checking!