Mysterious front hub dustcaps (cartridge hub question)

[robjh]

I'm trying to get into a front hub but am being defeated by what appear to be dustcaps, which I can't move at all.

They are the outer parts, in metal and with a serrated surface that sit around the axle. I can turn them (although they're very stiff) by hand but they do not seem to tighten or loosen at all. There's not enough room either to slip a screwdriver or other in to try and prize them off.

Any ideas?

FWIW the hub is running quite badly and I suspect, with its age (10+ years) and poor servicing history that it may be beyond repair, but I'd still like to look inside and check it out before deciding to bin the wheel.

 

[Yellow Saddle]

Have a look inside the axle where the QR skewer goes and see if it isn't shaped for an allen key. Normally they take a 5mm key. It seems to me as if the jamb nut itself screws onto the axle. Alternatively, it is just a press fit. If it isn't screwed on, cup the left hand axle with your left hand and hit the right side with a plastic mallet to see if the axle doesn't pop out the other side.

 

[robjh]

Have a look inside the axle where the QR skewer goes and see if it isn't shaped for an allen key. Normally they take a 5mm key. It seems to me as if the jamb nut itself screws onto the axle. Alternatively, it is just a press fit. If it isn't screwed on, cup the left hand axle with your left hand and hit the right side with a plastic mallet to see if the axle doesn't pop out the other side.

Thanks for those suggestions.
I've tried the mallet on the axle but it doesn't budge, so probably not that.
However, I've discovered that the inside of the axle is threaded so have screwed in a bolt with an allen-key head, as shown :

I can only turn the allen key clockwise in the picture, as anti-clockwise just unscrews the bolt from the axle. However, no combination of turning actions seems to make the dustcap/locknut things move in or out at all - they turn but just stay in place. I've tried it on both sides.

 

[Yellow Saddle]

Thanks for those suggestions.
I've tried the mallet on the axle but it doesn't budge, so probably not that.
However, I've discovered that the inside of the axle is threaded so have screwed in a bolt with an allen-key head, as shown :
View attachment 341240
I can only turn the allen key clockwise in the picture, as anti-clockwise just unscrews the bolt from the axle. However, no combination of turning actions seems to make the dustcap/locknut things move in or out at all - they turn but just stay in place. I've tried it on both sides.

Try holding the jamb nut with a adjustable pliers and turning the bolt clockwise.

 

[robjh]

Try holding the jamb nut with a adjustable pliers and turning the bolt clockwise.

Tried it, no joy.

 

[KnackeredBike]

Thanks for those suggestions.
I've tried the mallet on the axle but it doesn't budge, so probably not that.

You probably need a bigger hammer.

 

[Yellow Saddle]

Tried it, no joy.

Do you have a copper hammer?
I'm convinced it is just a frozen press-fit. Can you do a better photo of the section where the axle exits the jamb nut? Perhaps at a slight angle so we can see in there.
I think the thread is inside the axle so that you can screw a bolt in there and hammer on the bolt instead of directly on the axle.

 

[Ian H]

Are there not flats for a thin cone spanner behind the serrated face?

 

[robjh]

Are there not flats for a thin cone spanner behind the serrated face?

No, there's no flattening at all. The outside edge of the serrated face is grooved, so that I can grip it in a wrench, and the dustcap is completely smooth, but both are round.
At first I thought that the serrated face and the dust caps were a single piece. I'm not so sure now, but the fit is so tight that they still could be.

 

[Ian H]

Do you know the make? There might be something on the web.

 

[robjh]

Do you have a copper hammer?
I'm convinced it is just a frozen press-fit. Can you do a better photo of the section where the axle exits the jamb nut? Perhaps at a slight angle so we can see in there.
I think the thread is inside the axle so that you can screw a bolt in there and hammer on the bolt instead of directly on the axle.

Well I never. Brute force and a bigger whack with a hammer was the answer, but what I found was not at all what I expected.

I'd imagined cup and cone bearings as on all other hubs I've dealt with (including the rear wheel of this same bike), but instead they are in sealed units.

A quick internet search shows loads of models of these available, so I'll tout them round the bike shops of Cambridge tomorrow and see if anyone can sell me a matching replacement. I guess the good news is that I don't have to replace the whole hub (and with it the wheel). The wheel itself may be old but is nearly bombproof and still in good general nick.

 

[robjh]

Do you know the make? There might be something on the web.

No, I can't find any identifying marks on the hub or the rim.

 

[Yellow Saddle]

Well I never. Brute force and a bigger whack with a hammer was the answer, but what I found was not at all what I expected.
View attachment 341301 View attachment 341302

I'd imagined cup and cone bearings as on all other hubs I've dealt with (including the rear wheel of this same bike), but instead they are in sealed units.

A quick internet search shows loads of models of these available, so I'll tout them round the bike shops of Cambridge tomorrow and see if anyone can sell me a matching replacement. I guess the good news is that I don't have to replace the whole hub (and with it the wheel). The wheel itself may be old but is nearly bombproof and still in good general nick.

I love it when a plan comes together. There will be a number on the bearing - something like 6003RS2. That's all you need, no need to go to a bike shop, any bearing shop will do.

The numerical part of the number is all about size and the alpha part all about the seals. RS2 stands for Rubber Seals x 2 (one on each side).

 

[Fab Foodie]

Well I never. Brute force and a bigger whack with a hammer was the answer, but what I found was not at all what I expected.
View attachment 341301 View attachment 341302

I'd imagined cup and cone bearings as on all other hubs I've dealt with (including the rear wheel of this same bike), but instead they are in sealed units.

A quick internet search shows loads of models of these available, so I'll tout them round the bike shops of Cambridge tomorrow and see if anyone can sell me a matching replacement. I guess the good news is that I don't have to replace the whole hub (and with it the wheel). The wheel itself may be old but is nearly bombproof and still in good general nick.

That's a new one on me!

 

[raleighnut]

That explains why the axle is threaded, it's so an extractor/puller can be used to remove it, mind you a big hammer does the trick too.