Wheel building - radial vs lateral truth

Aunty Rubbish · June 2007

Question:- How do I correct radial truth without screwing up my (almost) perfect lateral truth?

Problem:- I've laced the wheel, tightened the spokes and corrected it for lateral truth. Trouble is, the wheel isn't radially true. It's out by about 1 - 1.5mm. If I correct this, the lateral truth goes horribly wrong.

Background:- I'm basically mixing two old wheels into one. Hub from one and spokes/rim from the other. Hub flanges are the same width, so the spokes are the correct length. The wheel is three cross. I have Gerd Schraner's book at my side, but he doesn't really help with the conflict between the two corrective measures. Or am I doing something really wrong?

Cheers,
chuffy

Chuffy

hubgearfreak · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Aunty Rubbish

Problem:- I've laced the wheel, check for radial and lateral trueness. correct the worst first, then attempt the other. this process will increase the spoke tensions. destress the spokes and re-true

<hr height="1" noshade id="quote"></blockquote id="quote">

is how it should be done. if i was you, i'd undo all my work, loosening all the spokes and start again

Mr Bumble · June 2007

I have just started building my own wheels, and obvious as it sounds have yoy checked to see whether the rim was round before you started?

Much to my great annoyance I have found myself in a similar situation, often due to the above, which can only be corrected to a certain extent. Untension and go though the motions are all I can suggest...

good luck

monty_dogcp · June 2007

Allowable tolerance for hop on bike wheels is 2-3mm, so unless you're really worried about it, maybe you can learn to live with it because when riding it would be practically indeterminable. Always try and align for vertical truth before lateral truth. Also adjust vertical truth with adjascent pairs of spokes to try and retain lateral truth

Aunty Rubbish · June 2007

Cheers all. While I'm inclined to agree with Mr Dog and just ride the damn thing anyway, having fitted it onto the bike it's become obvious that the whole thing is comically off centre...[:o)]

Unlace and redo I guess, but slower and with more wisdom in the mix.

Thanks for the answers,
Chuffy

Chuffy

hubgearfreak · June 2007

no need to unlace /re-lace, just slacken the nipples untill the whole assembly rattles well[:)]

pbiggs · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Aunty Rubbish

Question:- How do I correct radial truth without screwing up my (almost) perfect lateral truth?

Problem:- I've laced the wheel, tightened the spokes and corrected it for lateral truth. Trouble is, the wheel isn't radially true. It's out by about 1 - 1.5mm. If I correct this, the lateral truth goes horribly wrong.<hr height="1" noshade id="quote"></blockquote id="quote">Let that happen, then correct the lateral error. That may in turn interfere with radial trueness, but not so much, because more difference in tension is required to affect the wheel radially than laterally.

Keep switching from radial to lateral corrections and the wheel will gradually go on getting truer and truer. Carry on until bored!

~Pete

rustychisel · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by pbiggs

Carry on until bored!

~Pete
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[:D] Yes, you can get very close to a perfect wheel before boredom sinks in.[:p]

- - - - - - - - - - - - - - - - - - - - - - - - - - - -
I'm only escaping to here because the office is having a conniption

hubgearfreak · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by rustychisel

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by pbiggs

Carry on until bored!
<hr height="1" noshade id="quote"></blockquote id="quote">

[:D] Yes, you can get very close to a perfect wheel before boredom sinks in.[:p]
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hehe...i do them an hour at a time, around once a week for a few weeks. when i need time in the shed with a couple of cans away from my wife....
she's lovely, but an hour alone now and again is needed, none the less.

i wouldn't enjoy building one in one go[:)]

Anonymous · June 2007

I did my first wheel, with the advice of Roger Mussons eBook. Came out pretty good after an hours effort of lacing and truing. However, I didnt have a truing stand, and had to use the frame/brake blocks suspended on a pulley hoist. A real satisfying job, and an extra cool feather in your cap on completion. Will invest in buying/making a proper wheelstand.

Aunty Rubbish · June 2007

Hubgearfreak<blockquote id="quote">quote:<hr height="1" noshade id="quote">i wouldn't enjoy building one in one go[:)]
<hr height="1" noshade id="quote"></blockquote id="quote">
A wheel or a wife? [:0]

Thanks for the advice chaps. Will steel myself for a second thrash at the damn thing in the very near future...
Chuffy

Chuffy

hubgearfreak · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Aunty Rubbish
A wheel or a wife? [:0]
<hr height="1" noshade id="quote"></blockquote id="quote">

a wheels takes a few hours to get right...
a wife takes many decades of training i imagine[:D]

paul_smith_srcc · June 2007

Patience is the golden rule, more haste less speed applies especially to wheel building.

Tighten spokes gradually, half a turn at a time when slack, turning less as wheel gets tighter. Don't rush trying to get the wheel tight, best to get it in track and true when the wheel is quite slack, then gradually tighten. It will all be worth it in the end, a well built finished wheel is very satisfying.

Paul_Smith
www.bikeplus.co.uk

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Aunty Rubbish

Hubgearfreak<blockquote id="quote">quote:<hr height="1" noshade id="quote">i wouldn't enjoy building one in one go[:)]
<hr height="1" noshade id="quote"></blockquote id="quote">
A wheel or a wife? [:0]

Thanks for the advice chaps. Will steel myself for a second thrash at the damn thing in the very near future...
Chuffy

Chuffy
<hr height="1" noshade id="quote"></blockquote id="quote">

Surrey Road CC, articles of my tours; Lejog, North Sea to the Alps, English Channel to the Med', 'End to End' Ireland,London to Paris,Corsica

Tom753 · June 2007

"Allowable tolerance for hop on bike wheels is 2-3mm"

Is that only for factory wheels? I think 2-3mm is unacceptable, I know that rims are not perfectly round but I think up to 1mm is OK. Maybe pro wheelbuilders can't afford the time and 2-3mm tolerance is acceptable but I think most amateur wheelbuilders would aim for a lot less than that.

To correct hop without losing lateral truth, on a dishless wheel you need to adjust the spokes on both sides of the flange equally, so that the rim only moves up or down. With a dished wheel, because of the different angle of the spokes on the two flanges, you need to turn the nipple slightly more on one side to keep lateral truth.

<div align="right"> My fixed bike </div id="right">

Tom753 · June 2007

Sorry, I think I know what you mean, it's allowable in a practical sense, ie whether it's 0.5 mm or 3mm you won't notice it when riding your bike.

<div align="right"> My fixed bike </div id="right">

Wheel building - radial vs lateral truth

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