Rear wheel not centred

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RobC
Posts: 146
Joined: 5 Feb 2008, 3:27pm

Rear wheel not centred

Post by RobC »

I'm building up an old Lenton Sports frame. When I first put in a rear wheel it was very obviously sat to the non-drive side. Flipping the wheel showed it was still to the left, so I assumed it wasn't a dishing or spacer issue.

So I got out some string, as per Sheldon, and measured the gap between the taut string and the seat tube - slightly out by a couple of mm one side.

Then I noticed that there is a small dent (maybe 10mm) on the drive side chainstay so I guess in the past the frame's taken a little knock, but absolutely no bending of the tube or creasing of the paint or any other noticeable damage.

Cold set the rear and managed to get the difference from one side to the next down to only 0.5mm or so.

However the wheel is still sitting to the left, even when flipped. The rim is about 4-5mm closer to both the seat stay and chain stay on that side, when fully back in the dropouts.

Should I just ignore it? Or space the wheel so it sits centrally? Or redish? It's just going to be a town runabout bike.
pwa
Posts: 17370
Joined: 2 Oct 2011, 8:55pm

Re: Rear wheel not centred

Post by pwa »

Tempting just to go to work on the spokes to put the rim central.
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[XAP]Bob
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Joined: 26 Sep 2008, 4:12pm

Re: Rear wheel not centred

Post by [XAP]Bob »

Dent could just be chainring clearance.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.
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cycleruk
Posts: 6065
Joined: 17 Jan 2009, 9:30pm
Location: Lancashire

Re: Rear wheel not centred

Post by cycleruk »

I can only think that the drop-out slots are out of alignment. ie. one further forward than the other.
Is the wheel central under the brake bridge?

Also upend the bike, (sit it upside down on saddle and bars), now looking from the rear, check to see if the rear wheel lines up with the front one.
You'll never know if you don't try it.
RobC
Posts: 146
Joined: 5 Feb 2008, 3:27pm

Re: Rear wheel not centred

Post by RobC »

Thanks, will check dropout alignment later
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531colin
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Joined: 4 Dec 2009, 6:56pm
Location: North Yorkshire

Re: Rear wheel not centred

Post by 531colin »

https://forum.cyclinguk.org/viewtopic.php?f=1&t=59332&hilit=string........How to check your frame alignment using string.....
My way checks the wheels are in line......I don't understand why people muck about checking against the seat tube?
Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Rear wheel not centred

Post by Brucey »

worth checking that the seat stays are not bent, and that the dropouts have not been filed oddly or something; they may originally have been a little narrower than would accept a modern hub.

If the string-to-seat tube clearance is different by ~2mm side to side, this can indicate that the whole back end is offset by ~4mm. If someone has just widened the rear end spacing by pulling, it isn't uncommon to find that you end up with the wheel doing exactly the things you describe, because the RH chainstay (having a chainring clearance dent) will often move so much more easily than the left.

originally a lenton sports would have had a fairly narrow back end spacing; I'd expect that it isn't like that now....?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
RobC
Posts: 146
Joined: 5 Feb 2008, 3:27pm

Re: Rear wheel not centred

Post by RobC »

The spacing was ok - about 115mm which is roughly what it should be.

I made a little dropout alignment tool which showed they were pretty far out - all brought much more in line now. Wheel still sits a bit to the left but is much improved and I reckon it'll do - don't want to be bending the steel over and over as no doubt that will weaken it.

Thanks for all the advice
gxaustin
Posts: 890
Joined: 23 Sep 2015, 12:07pm

Re: Rear wheel not centred

Post by gxaustin »

Has it got the derailer hanger in? That takes up a couple of mms on my old bike. Can you measure end of dropout to the BB?
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