So bought a second hand set of kom rims and took them to be built but wheel builder noticed both had opened at the joint and indeed the crack had torn the kom sticker on the rims. Contacted seller he said that they were a budget rim and once the wheel is built with the spoke tension all will be good.

Anyone similar experience or will they fail?

He is BS i know of no rim held together by the spoke tension - its does not even pull in the correct direction
its not the case with the WTB KOM I built up at Xmas

Assuming you can money back Assuing you cant dont ride it

https://dcrwheels.co.uk/custom-wheelsets/which-mtb-rim/

this website says they are a welded rim not a pinned rim WTB website says nothing from a quick search - cannot check mine as tubeless. but i assure you it was one complete circle when i started and the sticker did not hold it together


What sort of idiot/ [swear word goes here] sells rims they know are cracked?

In one of the wheel building books he cut a rim into 6 pieces, taped it together to hold it in the right place then built it back into a rideable wheel in order to prove the joint wasn't what kept the rim together. I'll see if I can find the bit (and indeed which book it was in)

This is from Musson's book:

and page 16

i am notsure that is helping as what can be done and what is done are not the same thing,
Do you know a single rim maker who makes there rim not jointed/welded and just say use the spokes to close the gap?
As I said this was not the case with the KOM rim I used or any other rim I am aware of
It has come apart at the joint/weld-it was not designed like this or to do this so it has failed.
Will it kill you - no would I accept this or use it -NO
YMMV

Cheers have contacted seller for a refund but no word yet.

Mactheknife68 wrote: ↑Sat May 02, 2020 3:16 pm Cheers have contacted seller for a refund but no word yet.

Could you please post up a pic

Would surely but how do I do that

https://www.flickr.com/photos/74866179 ... ted-public https://www.flickr.com/photos/74866179 ... ted-public

https://www.flickr.com/photos/74866179 ... ted-public

Just looked at em. In my opinion (there are others) and probably a fair few others, theres no problem with that joint. Perfeclty normal and usually you'd be careful at that joint during the build process...

Mac, get it build mate

Just to add... under the tape/logo there should not be any jagged edges and it should be smooth enough to the touch. Can't tell from that 3rd pic if the actual alu is non jagged where the joint meets. If that makes sense

AlexGold wrote: ↑Sat May 02, 2020 2:17 pm built it back into a rideable wheel

The extract doesn't say he rode it, only it would take his weight. Whist I fully understand the theory, it's the same basic maths as keeps the blocks of a stone arch in place, that is a static loading. I'm not sure it would work when ridden and the loads are dynamic.

I've got an old rim in the shed and time on my hands, if only I had some spokes I could try it out, although we're not meant to be going to hospital at the moment so maybe not

As for the original question, my KOM rims are a continuous piece with no crack at the joint. I wouldn't use them if there was. Also, the KOM is tubeless compatible, not sure how airtight it would be with a crack at the joint.

Well, they're not continuous as there's a join

WTB recommend tape 5mm wider than the internal rim measurement. In effect, this means that the join is irrelevant as the tyre seals against the tape only, not the rim.

Based on your replies I’ve had a close look at them under a torch and there are no jagged edges , no gaps where the light of the torch shines through, just the jagged look of the two stickers. Safe or not??

Just to clarify I haven’t had these built up or ridden on by myself but purchased second hand to put on my Vaya

Safe? Yes.
Untidy? A bit.

Let’s put it a different way, if the seller had put those pictures up of the join, would you have bought them?

No not a chance!

thre is no way I would ride them as it has certainly moved hence the crack

Money back and the reason they did not show the crack was because they know no one would buy them and also i assume they have declined to ride them/cary on riding them

Poor form from the seller

Mactheknife68 wrote: ↑Sat May 02, 2020 5:19 pm No not a chance!

If you explain that to the seller any reasonable one would be willing to refund or return... I'd still build and ride em personally but would definitely have a stern word with seller/ebay... hope you got wm cheap enough

I'm not a pro wheel builder but have done dozens over the decades.

This pic shows my current i35 rim. That 'seam' was apparent with the sticker in place but hadn't stretched the sticker. It hasn't changed now fully laced.

If your wheel builder is a professional he's quite understandably covering himself. No point in building a wheel that may be problematic.

It's a secondhand rim of unknown history. Always a slight risk. With your concerns I don't think you'll ever be 100% happy, so return it. If the 'defect' wasn't shown in the advert, the seller has been dishonest. It is expressly stated that listings must describe all defects. ebay generally favour the buyer and will enforce their own policies.

Cheers for that , yes I don’t think I’d have 100% confidence in the and as they are going on a gravel bike with rigid fork for doing some local trails and singletrack I’d Ned them to be as bombproof as possible.

Measure the rim dia accurately in a few places to see if it is round. Tensioning the spokes should pull the joint together but the question is how it got sprung in the first place. If its been sat on then this would bend the rim slightly and spring the pinned joint. If this has permanently deformed the rim it will be nigh on impossible to true to a round rim...

I’ve been refunded for them so not taking a chance on them.
Cheers