Wheel-building – replacing a hub

[Samuel D]

I wish to replace the (ruined) hub of a rear wheel with an identical new hub. Are there any gotchas or shortcuts I should be aware of?

For example, when replacing a rim, it’s possible to tape the new rim to the old one and swap the spokes over one by one to avoid lacing from scratch.

Thought I’d ask before getting myself in a pickle this time!

Thanks as always.

[Brucey]

it is possible to replace the 'cup' bearing inserts in some hubs, if that is the problem. However if you have a new hub and the spokes are not seized it is, at best, only a bit faster to replace the cups than to rebuild the wheel. However I have replaced the cups in some cases, for example when I had a large-flange hub which I wanted to keep, but could only find SF hubs (with identical bearing inserts) as replacements. If the old hub is to be used for spare parts (eg freehub body, freewheel) it is best to remove these parts before dismantling the wheel; it is not always a major problem once the hub is out, but it is always more difficult and it is sometimes not possible.

The top tips I have for replacing the hub are that you should take the wheel apart in a specific fashion. It is easiest to dismantle 'symmetric' built wheels, since you can remove all the outside spokes without great difficulty, leaving the 'inside spokes' all slack; in this state you can unscrew the inside nipples with your fingers, no tools required.

So...

1) remove the freewheel, brake disc, freehub body, w.h.y.

2) back all the spokes off ~2 turns using a spoke key, starting with the NDS spokes in a rear wheel (*)

3) using a convenient tool of some kind, unscrew all the 'outside spoke' nipples completely.

4) remove all the outside spokes, keeping them in separate heaps if it is a dished rear wheel

5) unscrew all the inside spoke nipples and remove those spokes, again keeping them in separate heaps. This is easiest if the wheel was built symmetric. If the wheel was built skew, then only the last 1/4 of the spokes will be slack enough to unscrew the nipples using your fingers.

(*) if the nipples seem very tight to turn, it may be in part because of the tension in the spokes. As one spoke is slackened, its neighbours may become tighter than normal and become very difficult to undo. If you want to make life a bit easier, you can rest the horizontal wheel rim on some pieces of timber, and apply bending stress to the rim such that the tension in the spoke you are trying to undo is reduced; this can make the difference between shearing the spoke ends off and the nipples coming undone. if you have a chance to, it isn't a bad idea to apply a single drop of penetrating oil to each nipple, spin the wheel for a couple of minutes to drive the oil between the nipple and spoke, then leave it, at least overnight, before dismantling the wheel.

if it is a deep section rim, it is best to use a nipple driver (eg the DIY one I detailed in another thread) to unscrew the nipples; if they get stuck inside the rim they can be reluctant to come out and may (somehow) escape altogether.

In the case of a dished rear wheel you should end up with four heaps of spokes; inside NDS, outside NDS, inside DS and outside DS. These should ideally be re-used in their original positions if you want to do the least amount of stress relief afterwards.

Just now it is very easy to get in a rush and just sling the wheel together. Some things you might want to do when the wheel is apart;

1) clean/polish the rim properly. It is so much easier to do without the spokes in the way, it isn't even funny. You get to check the rim for cracks this way, too.

2) same goes for the hub

3) drilling the hub for a lube port? Much easier to do now.

4) clean and polish the spokes.

5) Apply paste threadlock to the NDS spokes, if you intend to use it.

6) apply grease to the DS spoke ends en masse, if you intend to use it

7) clean the nipples; e.g. put the nipples into a small sealed container ( a 35mm film container used to be handy for this), give them a generous squirt of GT85, and then give the container a good shake. Usually the nipples come out looking like new, if the plating is still intact.

8 ) add spoke washers, if you think there is a benefit in using them

9) corrosion proof the rim eyelets (eg with melted waxoyl)

10) put a small blob of grease on every nipple seat, if you intend to use it.

now you are ready to build the wheel....

It takes about three or four times longer to re-hub a wheel than to re-rim it. Accordingly it is only worth doing if the rim and the spokes are in really good shape; in the normal run of things you would expect those parts to limit the life of the wheel so any deficiency in these parts will directly affect the life expectancy of the wheel. However the finished wheel can (unlike a re-rim, where the hub tends to stay looking grotty if it starts out looking grotty) look like new, if you put the time into it.

hth

cheers

[Gattonero]

I wish to replace the (ruined) hub of a rear wheel with an identical new hub. Are there any gotchas or shortcuts I should be aware of?

For example, when replacing a rim, it’s possible to tape the new rim to the old one and swap the spokes over one by one to avoid lacing from scratch.

Thought I’d ask before getting myself in a pickle this time!

Thanks as always.

As said above, there's many ways to refurbish a hub without replacing it.
Then the wheelbuild, whether is replacing the hub or the rim, is all related to the skills one has got. An experienced wheelbuilder can lace a wheel in about 5 minutes so it may actually be faster to replace the hub than service it but as said, it all depends on many factors of which I'd include the conditions of the hub flanges (corrosion, too much burrs from the old spokes, etc.) and the conditions of the spokes too, if those show corrosion and/or marks from the chain I'd check how much time vs money is involved and ponder if rebuilding the hub, replace it with existing spokes or replace hub and spokes.
The last two options, involve some wheelbuilding skills and no particular shortcuts: spokes need to be removed, then relaced, if you're planning to reuse the spokes they need to be kept separated the inbounds from the outbound ones.

[Clipper_2018]

It takes about three or four times longer to re-hub a wheel than to re-rim it.

For an inexperienced wheel-builder, moving spokes across one-by-one will almost undoubtedly indeed be quicker than lacing from scratch, which could go horribly wrong again and again.

Wheel-builders with even a modicum of experience will probably choose to lace from scratch even for a re-rim. Reason being, lacing from scratch is a more familiar process. (Just remember to keep left-side and right-side spokes, where they differ in length, separate.)

However, lacing by whatever means is only the first phase of the overall process. The lengthy part is truing, which is identical whether you're re-rimming or re-hubbing.

So the variation in overall build time between the two methods will depend on the builder's experience. A factor of three or four is a bold estimate. I can't say it's wrong but by the same token it's unlikely to be right.

[Brucey]

For an inexperienced wheel-builder, moving spokes across one-by-one will almost undoubtedly indeed be quicker than lacing from scratch, which could go horribly wrong again and again...

I'm not even sure how you would do that when re-hubbing a wheel....?

cheers

[Gattonero]

For an inexperienced wheel-builder, moving spokes across one-by-one will almost undoubtedly indeed be quicker than lacing from scratch, which could go horribly wrong again and again...

I'm not even sure how you would do that when re-hubbing a wheel....?

cheers

Indeed.
Aside from the fact that spokes would be way too short to reach the nipples so won't be able to thread them, there's also 32 (or 36) times the potential to make it wrong and mess with the correct crossing of the spokes: is not that easy to remove and replace in the same position while jostling two hubs side by side.

[pwa]

For me the hub is the heart of the wheel, and a wheel with a terminal hub is dead and only any good for spare parts. So I would get a new wheel and possibly try to make sure that the new wheel's rim is compatible with the old wheel's rim so that when the new rim wears down the old rim can be used as a replacement. So only the old spokes and nipples get wasted.

[Samuel D]

So only the old spokes and nipples get wasted.

But why waste even those if they’re good? That is, if you can find a replacement hub of approximately the same dimensions so don’t need to.

I confess this is my own rear wheel this time. It’s a Shimano 105 FH-5700 hub. For several months there has been a light clicking once per wheel revolution when freewheeling at certain speeds. Having tried other things, I thought I’d replace the freehub body to see if that was the problem. I greased the fixing bolt per Shimano’s instructions, screwed it in, and promptly stripped the female threads off the alloy hub. (I need to get a big torque wrench soon to see what these torques feel like.)

The threads continue for 15 mm inboard of the stripped length, but I don’t know where I’d find a much longer freehub bolt to reach them.

Luckily, I found this hub for sale on eBay, item number 163153219327. So I plan to rebuild the wheel with that and use the old hub parts as spares.

Incidentally, I now think the old freehub was fine and the ticking instead came from a loose piece of broken plastic in the hub shell. I broke the plastic tube inside the hub shell while poking through two balls that had jammed together there. (So far I have learned every imaginable bicycle lesson the hard way.)

Thanks for all the suggestions and especially Brucey’s detailed checklist.

Clipper_2018 and Gattonero, who commented on lacing speed: I am confident I build good wheels but I do it very slowly. In particular, it still takes me longer to lace the wheel than to true it, because I have to follow the steps in Brandt’s book for lacing. I build wheels just seldom enough that I forget the lacing method between builds.

[amediasatex]

For me the hub is the heart of the wheel, and a wheel with a terminal hub is dead and only any good for spare parts. So I would get a new wheel and possibly try to make sure that the new wheel's rim is compatible with the old wheel's rim so that when the new rim wears down the old rim can be used as a replacement. So only the old spokes and nipples get wasted.

That’s very wheel dependant, there are many posh racing wheels where the rim and spoke cost can equal or exceed the hub cost and it would be madness to not re-hub.

Likewise in more modest builds it often makes sense to rebuild with a new hub or refurb the hub if you already have a decent rim and spokes, even more so with front wheels where hubs are often inexpensive.

[cycleruk]

Recently replaced the hubs on a pair of wheels with 105 hubs. Originals were Tiagras and cups were shot on the front and the rear starting to rumble.
Used the original rims and spokes but biggest problem I had was starting the first spoke. Making sure it was in the correct orientation with respect to the valve hole.
As mentioned above, and previously on the forum, I replaced the spokes with regard to inside or outside flange positions and trailing or leading. I did have one spoke that snapped when tightened but the rest have been fine in the 400 miles done since.

P.S I had to buy 11 speed (5800) as I couldn't find 5700 now in 32 hole versions.
I also bought the 105's because I think they have better bearings than the Tiagra.
The advert for the 105 say "Cubic Boron Nitride treated cone races" which to me implies that Tiagras aren't ?
Whether that makes any difference I don't know and is it just the cone or is the cup treated as well ?
Mind I have had the Tiagras for some years and where used on my winter/wet weather bike.

[Clipper_2018]

I'm not even sure how you would do that when re-hubbing a wheel....?

Er ..... that's not what I said, which I rather expect, you already know.

[531colin]

……….Clipper_2018 and Gattonero, who commented on lacing speed: I am confident I build good wheels but I do it very slowly. In particular, it still takes me longer to lace the wheel than to true it, because I have to follow the steps in Brandt’s book for lacing. I build wheels just seldom enough that I forget the lacing method between builds.

I think you can either visualise it, or you can't. If you can visualise it, you don't need to remember "the method" by rote.
Try this visualisation....
The "first spoke" is driveside, inbound (ie elbow inside the hub flange). Its inbound because you want to lace all the inbound spokes first, and because its inbound, it isn't "pulling" drive torque, its "pushing" drive torque. So it goes anti-clockwise from the valve hole, and you turn the hub anticlockwise so the spoke goes away from the valve and doesn't cross above the valve. Now you can lace all the inbounds.
(It doesn't matter which hub hole you use, unless you want the stickers on the hub and rim to line up.... )
The outbounds are the same....start at the valve hole
Easy-peasy!

[Clipper_2018]

Aside from the fact that spokes would be way too short to reach the nipples so won't be able to thread them, there's also 32 (or 36) times the potential to make it wrong and mess with the correct crossing of the spokes: is not that easy to remove and replace in the same position while jostling two hubs side by side.

You've clearly never done this. I have.

Approached correctly, the spokes are not too short to reach the nipples on the other rim and there's virtually zero chance of making a mistake. The lacing pattern remains completely undisrupted throughout the transfer process.

[Brucey]

Aside from the fact that spokes would be way too short to reach the nipples so won't be able to thread them, there's also 32 (or 36) times the potential to make it wrong and mess with the correct crossing of the spokes: is not that easy to remove and replace in the same position while jostling two hubs side by side.

You've clearly never done this. I have.

Approached correctly, the spokes are not too short to reach the nipples on the other rim and there's virtually zero chance of making a mistake. The lacing pattern remains completely undisrupted throughout the transfer process.

there is no 'other rim' when you are replacing a hub...?

cheers

[Brucey]

I'm not even sure how you would do that when re-hubbing a wheel....?

Er ..... that's not what I said, which I rather expect, you already know.

this thread is all about re-hubbing a wheel, not re-rimming one. Your comment (presumably, the implication is that it refers to re-hubbing but you don't say) refers to the latter and is somewhat out of place here.

FWIW I've built (and re-rimmed, re-hubbed etc) many hundreds of wheels and Gatto has done many more than I have.

The last time I re-rimmed a wheel it took about twenty minutes and the truing took less than five. All done in half an hour (whilst, er, watching the TV one evening....). BTW I don't consider myself particularly fast at this, and it doesn't always go that smoothly either.

cheers