[Closed] Should I expect my new wheels to be perfectly... round?

Its a symptom of the modern age. Now that Team Sky have got bagseys on 'really round wheels' as part of their marginal gains legislation the law prevents shops and wheel builders from supplying anything other than [i]nearly[/i] round wheels to the rest of us. Its ridiculous. Makes us all look like clowns.

Nothing will be perfect. But a "good few mm" sounds to much. Take them back.

when you say a few mm have you measured it? i ask because with the wheel spinning it can look at lot. but when you measure its a tiny amount. often the stickers can trick the i as well.

often the stickers can trick the i as well.

If it is really a few mm though, I'd take it back. Preferably before riding.

stick the rim in the frame/forks, hold a screw driver or allen key close to the rim as a guide and check how much movement there is when you spin

(don't try it with a tyre on or just holding the axle and looking along the rim)

I'd be ok with 1mm on something I'd built, "a few mm" from a professional isn't on I reckon.

Id take them back and demand a refund. I wouldn't want anyone who thinks 2mm out is OK to work on my wheels.

Don't go in demanding anything. if they're really out by a few mm, then ask if they're able to sort it. No need to be a dick about it.

Should be about 0.2-0.5mm iirc out when freshley built any more is not ideal on my own I allow up to 1mm ish customers should be within tolarance
u will get a slight flatspot whare the rim is pinned sometimes u just can't get it out so check share the dip in the rim is.

When I've had them built I've been quite surprised by how round they are. so it is perfectly possible.

I will go and re-check and measure how much they are out this eve, I could be entirely a case of it appearing worse than it is I suppose, but thanks for giving me an idea of what sort of tolerance I should be looking for.

In this case I really was unsure, if it was to be expected, or I should take action.
Obviously if it goes back to the shop, I will be politely pointing what I have witnessed, and asking if there is anything they can do, not storming in shouting and complaining!

Speshpaul - Member

when you say a few mm have you measured it?...

yes, i'm a measurement geek, i've got my own one of these:

[img] [/img]

and a grade2 (oh-so-close to grade1) measurement lab.

and, as i'm also a total bike-nerd, i've measured a few rims before they got built up.

in terms of the vertical 'wobble' - i've seen circularity of around 0.1mm, which is really rather good (i'm a long way from a full statistical analysis of all bike rims ever made, i don't know how 'round' a typical rim would be).

Could also be a flat spot/high spot by the join, as the vary loads from rim to rim & it isn't always possible to get them as true as you'd like & keep the spoke tension even

A good way of checking [Edit: if you don't have one of those^!] is to hold a match or toothpick against the frame (seatstay or chainstay) or fork if it's the from wheel, and move it closer in towards the rim while the wheel spins. You'll be able to tell whether it's the rim or the wheel, and by how much, if it's the rim.

which rims are these, out of interest?

Like most things if it bothers you enough, then take them back and get them sorted, I'm sure the shop will be more than pleased to help. I'd probably ride them, and mention it at the re-tension

Edit WTB rims, just re-read your OP, sorry 😳

I'd probably ride them, and mention it at the re-tension

I'd probably mention it to them now, and ask if they'd like you to bring them back in before riding or if they'd prefer to sort it at the re-tension. That way there's no chance they can blame you for causing the problem. Not saying they would mind, perish the thought a bike shop would try and pass the blame to a customer, but better not to chance it 😉 .

Should I expect my new wheels to be perfectly... round?. YES. Take them straight back unridden and tell them they are out of round. 2mm is way off for new,secondhand it's bearable. 😕

did you tip the wheelbuilder?

the shop has offered a free "re-tension" in a few weeks after they have bedded in

Apart from a couple of exceptions every custom wheel I've owned has been pretty much perfect until some time during first ride when eccentricities creep in

Some have self-righted after a few rides, some have got worse. In my experience it's to be expected and if the shop is offering to true them when they've bedded in that's fair enough

Frequencies are fine rims but I've read that they are not very round to begin with and allegedly its easy to over-tension them

As has been mentioned, there may be a small hop/flat in the rim at the joint. Other than that, a new build should be dead on.

You'll never get it dead on, so really it's about acceptable tolerances. I'd say 2mm falls outside of that.

This is vertical true you're talking about?

Should be a lot closer than you're describing. As above with using some sort of index marker while you slowly rotate the wheel in a jig of some sort without tyre.

A thought, one of the features of the WTB rims is the '4d drilling' which is meant to fire spokes out at the right angle. For this to work properly the builder will need to have considered where to start, I'd think. Not sure quite what would happen apart from excessive loading if it wasn't right.

I was considering i25's so very interested in this...