Frame respace

[rich100]

I have a randonneur I've restored and modernized, the project is not far off being finished now.

One major problem I had was that the rear frame spacing was at about 121mm, with a hub of 126mm but springs open easily to get in. The frame should be about c1988 and pretty sure it should have been 126mm.

Last night I started to try and resize to 130mm for a new set of wheels I'm building, I put the string between the dropouts and around the headtube as described by Sheldon, and found a good 10mm difference between right and left measurements between the seat tube and the string, the right side being further out.

I started respacing using the threaded rod method, turning the left hand nut and holding the rod with grips, after a couple of goes i expanded it as far as 150mm, when undone the spacing had set to about 126 now.

I'm thinking of using the block of wood method, I'm nervous of stretching too far with the rod to gain the 130mm (how far does it need to stretch to settle back to 130mm??) and also the main thing is I cant see how to control the spread to just one side with the rod, I'm guessing the block of wood is the only way to acheive this??? As even if I get 130mm spacing the ends are still going to be misaligned.

Any thoughts or tips?

thank you

[JamesH30]

My advice would be to get a frame builder or competent bike shop to re-space your rear end. The last thing you want to do is to take it too far!

[meic]

One thought.

IF you build your own wheels (or can true them at least) and the wheel will be used for this bike only.
Then why not take advantage of the offset and build the wheel to suit the offset frame? This will give you a stronger rear wheel and (to my mind) better chainline set up.

I am not sure about the Randoneur but my similar aged Raleigh was 130 OLN ( 6 speed Uniglide cassette).

[breakwellmz]

Hi.
I would take out the bottom bracket,and hold it across the BB shell in a bench mounted vice.
Only then can you pull on the side that needs pulling out,without affecting the other.
If you don`t have access to these things,and you are not confident about doing it,let a bike shop do it.

[Brucey]

I have respaced and re-tracked frames by laying them down on pieces of wood so that the dropouts are clear of the floor, then standing on the frame, and pushing or pulling the rear dropouts one at a time.

If pushing down, you can limit the movement by putting a 'stopper' block on the floor, or nuts/studding in the relevant dropout. It can be a bit hit and miss otherwise.

Check truth by eye to start with, and finally using string.

BTW if taking a frame out 10mm, it isn't a bad idea to check that the dropouts are true afterwards.

cheers

[531colin]

2 ways* let you re-set one dropout at a time, Sheldon's way and the hold the BB in a bench vise way, as somebody mentioned.
Before you decide what to do about the "bent" back end I think you need to check the frame over carefully for straightness..http://forum.ctc.org.uk/viewtopic.php?f=1&t=59332&hilit=+string
You can correct dropouts by bending them (gently!) with a big adjustable.
I'm also a big fan of (deliberately) offset back ends, for all the reasons mentioned.
If you go with the offset, bear in mind that you may have to file the dropouts a bit to get the wheel to line up with the seatpost (or even the downtube). Of course if you move the axle a millimeter, the rim moves a lot more. This probably works best with vertical dropouts, but I have filed the slot of horizontal dropouts wider before now!

3 with Brucey's!

[rich100]

Thanks for the replies.

Hmmm, I think I'd rather not offset. lately i seem to always have a couple of project bikes on the go, and I'd like to be able to swap and change bit without any faffing later, so might as well have it 'correct' now, even if not necessarily the best option.

I do have a bench vise but only a black and decker workmate to bolt it to so it probably wouldn't stay still with me pulling on the frame. I've been to B&Q and got a length of 4x2 so will give the Sheldon method a go, I like Bruceys idea but its just had a respray and I dont really want to stand on it! Although I'll wrap it cardboard on any contact points.

Colin, thanks for the link that looks really useful.

Thanks

[JohnW]

My advice would be to get a frame builder or competent bike shop to re-space your rear end. The last thing you want to do is to take it too far!

+1 - that's sound advice - especially since your rear triangle was eccentric to start with.

[531colin]

hmmmm...."just had a respray".....

Best to bend the frame before you get it resprayed, really.

hmmmmm....."take it to a bike shop".......

I would expect a bike shop to reject a job like this....bending a frame carries a certain degree of risk of things going horribly wrong, and customers (and, for all I know, the sale of goods act) expect and demand that a shop guarantee their work....in a shop, you are on a losing wicket with a job like this, get it spot on, you can charge what, £30?....get it wrong, the customer expects a new frame for free.....spoil the nice new respray, how much did that cost?

Take it to a frame builder, who by definition has the knowledge and experience to do the job, they may say if you want us to guarantee the work, its a new back end (seatstays, chainstays, dropouts...) which makes it uneconomic.

I have bent, cut, and brazed the odd frame, but only for myself and family members, and with the attitude that I don't like it how it is now, I can probably make it better, and if it breaks either now or later, I'll deal with it. (I expect Brucey has the same attitude?) With money already laid out for a respray, expectations are maybe running a little higher than mine would be?

[Brucey]

most times when I've been doing this more than a few mm, I've been trying to salvage frames that have been wrecked, or just helping chums out. It always comes with a healthy warning re. the possibility of subsequent cracking in this locality, and this goes double for CrMo frames over MnMo frames.

If the paint is still soft you might get away with it, but if not the paint may crack wherever the frame moves; if not immediately, later perhaps.

cheers

[rich100]

The respray,whilst it looks great,is only a £35 powder coat rather than a full on proper job. Decals done by me and lacquered by hand. yeah I should have realised the issues with the spacing before but hey ho this is where experience comes from. I'll just have to be as careful about the paint job as I can and hope for the best,if the paint cracks or anything then I'll make a decision about another respray later.

As for taking it to a bike shop,local LBS's aren't really an option round here, there are a couple of options of frame builders but then it comes down to cost and time frame. And to be honest, my main passion with bikes more than riding is the fettling, it's a relatively new hobby for me and I'm still learning. So with things like this I tend to hesitate a bit and then research and ask questions, then just have a go and see what happens. To be fair I maybe wouldn't try this work on my new tourer even though I built it, but with older frames I'll have a bash. That said, if when using the plank of wood method it still feels like I'm pushing it too far I may have to reconsider.

So I'm still a bit unsure, and I realise it'll be different for any given frame, in general how far would a rear stay have to be bent past the desired mark for it to settle in the right place?

Brucey, you mention the frame materials, I also have a Raleigh Wisp that needs the same treatment, it's currently 126mm sprung to 130mm, and his one is much stiffer to spring open, in fact it's outright difficult, it also needs the front stretched from 95 to 100. I'm guessing this one will be much more difficult to do without causing damage so I might instead try to source hubs to match and rebuild the wheels.

[uppadine]

Bob Jackson, easy peasy about £15 or £20

[531colin]

OK, more time than money invested so far.....good...there is always a risk of these things going pear shaped, either at the time or later.
I don't think anybody can tell you how far you will have to take any particular stay in order for it to take a set, I feel it probably varies even between left and right stays of the one frame, at least after a few years abuse. Just take it one step at a time, and keep measuring. I guess the first job is to pull out the left stay to get it symmetrical, unless the dropouts are getting too wide before then.
Is a Raleigh Wisp a ladies step-through? If its the one I'm thinking of its probably just thick-walled tubing, so it will take a bit of grunt to bend.

If you are prepared to stick with say 5 or 6 speed screw on block, and can find the right hub, you can build a 126 wheel thats less dished than a 130 10 speed.
(I have reduced 130 ten speed hubs to 126, but the dish is really, really awful)

[Brucey]

FWIW most powder coats are soft-ish and don't crack/flake too easily provided they are reasonably well adhered. I reckon you should get away with it OK in that respect.

Like Colin says, I think that a Raleigh Wisp would be amenable to being cold-set, even if it is hard work to actually do it.

cheers

[531colin]

.................... I put the string between the dropouts and around the headtube as described by Sheldon, and found a good 10mm difference between right and left measurements between the seat tube and the string, the right side being further out.....................

This number has been roaming around in my head, it being more interesting than cutting the grass.....
A good 10mm difference at the seat tube is say 15 or 20mm difference at the dropout?

sounds like a lot!