Bike Repair – Replacing a Damaged Rim

Bicyle rim without the tyre.

A rim that is beyond repair doesn’t have to mean the end of the wheel. Here’s how to replace the rim while retaining your spikes and hub.

1. Replace rim

It’s best to replace your rim with a matching model. This will make it easier, and your spoke lengths will be unaffected. If you can’t get hold of an identical rim, look for a rim with the same ERD number as your old rim, or one within a couple of mm. If spoke lengths are different, then a straight rim swap won’t work – you’d need to rebuild your wheel from scratch.

2. Remove wheel

Remove the wheel from the bike, making sure it’s clean. Remove the tyre and tube, followed by the rim tape. Clean the rim bed to get rid of any dirt. If you don’t have a tension metre, give a pair of spokes a squeeze in order to gauge the sort of tension you’ll be working towards later.

3. Align rims

Sit the new rim against the old one, lining up each valve hole and rim join, double-checking the spoke holes all line up with each other too. With the two rims aligned, tape them together with four separate lengths of insulating tape. To keep them secure, tape them in the 12, 3, 6 and 9 o’clock positions.

4. Loosen spokes

Put your wheel with the new rim attached into a wheel truing stand. Grab the spoke key and, working from the valve hole (so you know where you started), turn the key anti-clockwise half a turn, loosening each spoke, one at a time, until you’re back to the valve hole where you started.

5. Remove tension

Continue to loosen the spokes half a turn at a time, removing any tension from them until you can see the spoke’s threads, but without removing the nipple. If the nipples are removed it can make the process far more complicated. With the spokes no longer under tension, it’s time to start swapping them to the new rim.

6. Remove nipple

Next up, starting with the spoke next to the valve hole, use the appropriate nipple driver to remove the nipple completely from the end of the spoke and the rim.

7. Move spoke

Move the spoke to the neighbouring/equivalent spoke hole in the new rim, popping it through the rim and into the spoke hole. Use the nipple driver to carefully wind the nipple onto the spoke one turn – just enough to get the threads to catch.

8. Work around wheel

Work around the wheel from your starting point next to the valve, repeating steps 6 and 7 on every spoke, until you’ve stripped all the spokes out of the old rim and switched them over to their adjacent holes in the new rim. Remove the wheel from the truing stand and unwind the insulation tape holding the rims together. Discard the old rim.

9. Tension spokes

Stick the newly rimmed wheel back in the truing stand. It’s time to tension the spokes. Starting with the spoke next to the valve hole, work your way around the wheel using a spoke key or nipple driver to turn the nipples one whole turn clockwise. Do this for each spoke, once around the wheel.

10. Check bagginess

If the spokes are still really baggy, repeat step 9, going around the wheel tightening each nipple by a full turn (roughly until the spoke threads are obscured by the nipples). If the spokes start to feel under tension, work around the wheel again, starting at the valve hole, but only turning the nipples half a turn at a time, this time around.

11. Check tension

Work around the wheel, turning each nipple half a turn at a time until the spokes feel roughly as taught as they did at the start. If you have a tension meter, aim for around 120kg/f on each spoke for a 26in wheel. If you’re below this or the spokes feel baggier than they did, adjust all the nipples by another quarter of a turn before re-checking tension.

12. Even tension

Make sure you’re always applying tension evenly. Small adjustments have a big effect on the other spokes’ tension throughout the wheel so try to keep adjustments as even as possible. Squeeze each pair of spokes to gauge how even the tension is around the wheel. When you’re close to the required tension, it’s time to true the wheel.

13. Check truing

Spin the wheel in the truing stand, and watch for lateral and vertical deflection. Set the truing stand’s arms almost against the rim. Ideally, you’re looking for less than 1mm of side-to-side or up-and-down movement. If the rim is out of true, you’ll need to adjust the tension on the spokes to account for it.

14. Adjust

If the rim deflects to the right, you’ll need to add a small amount of tension (a quarter of a turn) to the closest opposing spoke (or two) that attaches to the left-hand-side hub flange. You then need to remove tension (quarter of a turn) from the spoke (or two) on the right where the rim deflects. The opposite applies if the rim deflects to the left.

15. Re-check tension

With all the adjustments made, re-check the tension in the spokes and remove the wheel from the truing stand. Slot the wheel in the bike. The rim should sit centrally in the fork or between the seatstays. Check the position by measuring either side of the rim. This is the wheel’s dish. If the rim sits too far to the left, you’ll need to add an eighth of a turn to every spoke on the right.

16. Fit new tape

Getting the wheel true and the dish correct takes patience. If in doubt, head to your local bike shop for help! If it looks bang on, re-check the spoke tension before removing the wheel and fit some new rim tape followed by the tyre (and tube if you’re not running tubeless). Fit the wheel back on and go for a quick spin. Then re-check spoke tensions again.

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