Rim transplant or new wheel?

[Rhys W]

I hit a pothole today and put a dent in my rim. The sidewall on that side is wearing thin - I was hoping it would get me to the spring (winter bike) but now it's definitely not rideable.

The hubs are a few years old and the innards have been rebuilt a couple of times (including a new pawl spring only last week). I did think of buying a new pair of cheapish wheels and keeping these as spares, but my other option (even cheaper!) is get an Open Sport and do a transplant, spoke-by-spoke. The wheels have been rebuilt once before (with new spokes), I could take it to the shop again for a rebuild but I fancy having a go myself. Any advice?

[LittleWheelsandBig]

Lace a new rim on, it is easy.

[TimO]

If it's an identical rim, then yes as LWaB says, it's relatively easy.

Just loosen up the spokes on the old rim, drop the new on top, and transfer the spokes across.

If you really want to, you can obviously replace the spokes as well, but generally they're likely to be OK (unless you had a bad bash to the previous rim which meant that the spoke tension was unusually asymmetric).

[Rhys W]

OK, sounds like it's worth a try. Do I need new nipples or can I re-use them as well?

I did notice some variability in spoke tension when I rebuilt the hub last week. It was completely true though, so didn't do anything about it. I have two almost-identical wheels I can use to get an idea of the tension needed. It wasn't a really bad bash (I didn't even puncture), I suspect it dented because the sidewall was getting thin anyway.

[LittleWheelsandBig]

If the nipples aren't damaged, reuse them. Make sure you use a good spoke key.

[Biggsy]

Nipples can be re-used, but it's nice to have new ones as old ones can become worse for wear.  Sapim Polyax: recommended.

Tape or tie the rims together.  Swap the spokes over one at a time, in order.  You don't even have to think about the lacing this way.

[Manotea]

Talking about rim transplants...

Do you think this one is due?



This is a standard Mavic Open Pro rim fresh on my front wheel for LEL2009 and has covered circa 7~8k km tops. It doesn't seem a lot. I measured the rim thickness a month back and it was about 0.8mm down from about 1.3mm for a new rim. The main wear appears to be at the inner edge of the braking area where the wheel rim moulds inwards to form the hollow rim 'shell' which suggests the rim is not so thick there. Shame you cannot measure the rim thickness at that point. I noticed some minor, er, 'wear thru'  halfway round a routecheck of the Willy Warmer on Saturday upon which I felt incentivised only to use my front brake on special occaisions. The last build was with new spokes so I'll reuse those.

[Tewdric]

You're welcome to come and do it here Rhys - got a truing stand, variety of spoke keys, dishing tool, tensiometer etc.  Plus a beer fridge!  

[TimO]

... Do you think this one is due?

This is a standard Mavic Open Pro rim fresh on my front wheel for LEL2009 and has covered circa 7~8k km tops. It doesn't seem a lot. I measured the rim thickness a month back and it was about 0.8mm down from about 1.3mm for a new rim. ...

Almost 40% of the rim gone after only 8000 km sounds like a lot.  On a commuter that may be less unexpected, but given this is a bike you used for LEL, I'm guessing that you probably don't use it for commuting, so I'd be a little surprised.  On the other hand, having a rim go when you least expect it, is no fun, so I'd be tempted to replace it anyway.  Rather safe than sorry and so forth.

Since, you used the word "incentivised", I think you should be forced to do vast amounts of unnecessary maintenance as penance anyway.

[border-rider]

Do you think this one is due?

Yes

8k isn't much, but if much of that was grotty/wet/winter roads then it's quite within the usual range for an OP.  I had a phase when i did a lot of winter riding and I found that lightweight rims didn't last very much longer than tyres.   The answer is either a hub brake or more substantial rims.  Or a ceramic rim.

[Manotea]

A feeble attempt at irony on my part! To be clear those aren't wear marks, those are holes!

When I said I felt incentivized to only use my front brake on special occaisions, I meant, very special occaisions. I did consider taking out my front brake blocks to be sure but thought that I might come to regret such an extreme measure.

[border-rider]

Blimey

I thought it was the remains of anodising.  So you've worn off the whole of the milled  braking track; that's impressive.

[Chris N]

A feeble attempt at irony on my part! To be clear those aren't wear marks, those are holes!

Fit a smaller gear, you'll be able to leg brake more effectively instead of wearing out your rims.

[Manotea]

A feeble attempt at irony on my part! To be clear those aren't wear marks, those are holes!

Fit a smaller gear, you'll be able to leg brake more effectively instead of wearing out your rims.

The longer gear is a double edged sword because you travel so much faster, especially down hill, and I'm such a wussy descender. I suspect part of the wear problem was caused by being slow to replace my previous set of brake blocks. the tread had gone but there seemed plenty of rubber left. I'm using blingy dual compound koolstops at the moment. They seem a bit softer then the old blocks which should reduce rim wear.

[TimO]

I think you need more smilies in your posts!

I wasn't quite sure what I was seeing on the image, but I assumed it wasn't a hole!

[Hummers]

Braking wears down rims - It's official.

Rim swaps are pretty straight forward.

H


 

[pdm]

Did a rim swap on my pothole damaged dyno-hub front wheel this morning.,,,
Taped the new rim to the old and, working round, swapped the spokes from new to old.
Then screwed in the nipples to the same position on each spoke taking up slack.
Check rim is centered.
Then 3 full turns on each spoke gave the right tension. Release torsional tensions by squeezing spokes.
Check rim is still centered.
Recheck spoke tension all round, release torsion and repeat.
Check still centered.
Minor adjustments to true rim to perfection.
Done - took about 45 minutes.

I really should get a truing stand to make things a little easier....

[mattc]

Blimey

I thought it was the remains of anodising.  So you've worn off the whole of the milled  braking track; that's impressive.

Not really, when you look at all the other stuff he has prematurely worn out / knackered / sheared-in-half ... There is only one Manotea.

[Manotea]

Blimey

I thought it was the remains of anodising.  So you've worn off the whole of the milled  braking track; that's impressive.

Not really, when you look at all the other stuff he has prematurely worn out / knackered / sheared-in-half ... There is only one Manotea.

I'm not sure what Mattc is getting at. Probably best not to mention snapping a 4 month old SRAM PC!N chain whilst route checking the Willy Warmer on Saturday.

[andrew_s]

Tape or tie the rims together.  Swap the spokes over one at a time, in order.  You don't even have to think about the lacing this way.

If the new rim is right of the old rim, transfer all the spokes on the right hub flange first, then do the spokes on the left flange.
If you just work round the wheel, you can find some spokes short enough to be awkward to thread into the nipple by the time you are part way round.

[plum]

I'm in the same situation, except that for the sake of convenience I already replaced the whole wheel. So now I have a wheel with a broken rim sitting about and thought maybe trying to do as suggested above so that I'll have a spare. Something of a learning project as I've never even tried to replace a broken spoke before so not sure of the ins and outs, but one thing is obviously worth asking before I think about it any more; the broken wheel is a rear wheel, will the dishing make it too much more complicated to be worth bothering with?

[Biggsy]

If the new rim is right of the old rim, transfer all the spokes on the right hub flange first, then do the spokes on the left flange.
If you just work round the wheel, you can find some spokes short enough to be awkward to thread into the nipple by the time you are part way round.

That way requires a bit more thought  I haven't found my way too awkward if all the spokes are slackened before beginning the swapping.

I'm in the same situation, except that for the sake of convenience I already replaced the whole wheel. So now I have a wheel with a broken rim sitting about and thought maybe trying to do as suggested above so that I'll have a spare. Something of a learning project as I've never even tried to replace a broken spoke before so not sure of the ins and outs, but one thing is obviously worth asking before I think about it any more; the broken wheel is a rear wheel, will the dishing make it too much more complicated to be worth bothering with?

No.  Just remember that the spokes on the left side are (usually) not tensioned as highly as those on the right side.  You need to check that the rim is centred with a front wheel as well, and make adjustments as necessary, so there's no fundamental difference.

[Rhys W]

Well, the LBS had a rim, so I'll attempt it tomorrow. I have a wheel they built for me a couple of years ago as a reference for the tension. A friend replaced the rim of his Khamsin a while ago and he used a guitar tuner to check the tension!

[iddu]

A feeble attempt at irony on my part! To be clear those aren't wear marks, those are holes!

FFS And you were phoning about the chain If I'd been in it'd been the shotgun to put it out of its misery 

Hope you got round OK

[Manotea]

Bump, bump, bump. The sidewall of my back tyre cover split today, happily close to home. The tyre has mebbe 3k km on it.

So within a week, the front wheel has borked, the back wheel has borked and the transmiassion has borked.

I've come to regard bikes as consumeables.