Rear OLN spacing

[mickle]

The thing is, the quality of the frame, the method of construction, material and the indivual frame components can differ enormously. I've cold set frames which required two big lads jumping up and down on the rear triangle, and others which could be reset with two bare hands (muddy fox courier). One of the worst things you can do to a hub (particularly an internal geared hub) is bolt it into a pair of dropouts which is not totally parallel. So anyone can cold set a rear triangle to give a different OLND but it's no use if you've not bent both stays equally. Because you've now got a bike that crabs sideways. And if your dropout faces are not parallel you're bending the axle, putting a damaging load on your hub bearings which will shorten its life. Bike shops don't charge 'hundreds' to cold set a frame, and there's more to it than just cranking it open with a car jack.

 

[Salty seadog]

The thing is, the quality of the frame, the method of construction, material and the indivual frame components can differ enormously. I've cold set frames which required two big lads jumping up and down on the rear triangle, and others which could be reset with two bare hands (muddy fox courier). One of the worst things you can do to a hub (particularly an internal geared hub) is bolt it into a pair of dropouts which is not totally parallel. So anyone can cold set a rear triangle to give a different OLND but it's no use if you've not bent both stays equally. Because you've now got a bike that crabs sideways. And if your dropout faces are not parallel you're bending the axle, putting a damaging load on your hub bearings which will shorten its life. Bike shops don't charge 'hundreds' to cold set a frame, and there's more to it than just cranking it open with a car jack.

Surely a thread ban for making too much sense.

 

[Ajax Bay]

As I've implied before (to @tommaguzzi wrt his spare car jack), unless I completely misread the OP, the 'issue' is not spreading the rear dropouts.

I'm looking to put a set of 700c wheels on a build. My current dropout rear wheel hub OLN is 130m. The 700c wheels OLN is 124

there's more to it than just cranking it open with a car jack.

(Besides all the experience based wisdom in your comment) partly because the aim is to reduce the OLN to 124mm (OP-measured).

 

[mickle]

As I've implied before (to @tommaguzzi wrt his spare car jack), unless I completely misread the OP, the 'issue' is not spreading the rear dropouts.


(Besides all the experience based wisdom in your comment) partly because the aim is to reduce the OLN to 124mm (OP-measured).

The direction is immaterial - wider/narrower - the point stands. There's more to respacing a frame than merely bending the rear triangle until its a different width.

 

[Ajax Bay]

We agree (I think). See (my) Post #6.

 

[mickle]

We agree (I think). See (my) Post #6.

Oh no we don't! (he's behind you .. etc)

 

[Johnymak]

Maybe a Silly question but
Are road bike 700c rear wheel hub axles that use qiuck release a standard length or do they vary

 

[Johnymak]

Thanks I'm looking at different options with the rear dropout spacing
I have a steel bike with 130mm dropouts
If i can get a set of wheels with an OLN of 126mm
Would the axle length be the same as a 130mm
So i can just add spacers either side as I won't be changing the wheels very often

 

[bigjim]

I'm wondering why you would want a set of 126mm OLN wheels? It's usually the other way round. Modern wheels in an older frame.

 

[Ajax Bay]

I have a steel bike with 130mm dropouts
If i can get a set of wheels with an OLN of 126mm
Would the axle length be the same as a 130mm

No (but read on - not really the exam question). The 126 OLN axled wheels will be about 4mm shorter (axle), which reads across to 2mm shorter each side.
A 130 OLN hub/axle will offer about 5mm each side to 'slot' into the drop outs. So with a 126 OLN axle you'd have only ~3mm each side to locate the axle correctly before tightening the QR.
But 3mm is enough so with the extra spacers this would work.
As Sheldon says: "In practice, the axle can be quite a bit shorter than this [5.5mm either side of lock nut]...even 1-2 mm protrusion past the lock nuts will suffice to locate the axle properly, so, when converting a hub to the next wider spacing, it is usually unnecessary to replace the axle."
The chain line would be skewed but not by much (2mm).
Rather than adding spacers to each side, a more sophisticated approach would be to add the 4mm of spacers on the left which will allow you to increase the strength of the wheel by moving the rim (relatively) to the left and reduce the dishing. This would maintain a better chainline.
Having said all that, why not get a 130mm OLN hubbed/axled wheel (as @bigjim has implied)? In plentiful supply and the dishing is less (unless you re-dish with spacers on the left) so the wheel, ceteris paribus, would be stronger.

 

[Johnymak]

No (but read on - not really the exam question). The 126 OLN axled wheels will be about 4mm shorter (axle), which reads across to 2mm shorter each side.
A 130 OLN hub/axle will offer about 5mm each side to 'slot' into the drop outs. So with a 126 OLN axle you'd have only ~3mm each side to locate the axle correctly before tightening the QR.
But 3mm is enough so with the extra spacers this would work.
As Sheldon says: "In practice, the axle can be quite a bit shorter than this [5.5mm either side of lock nut]...even 1-2 mm protrusion past the lock nuts will suffice to locate the axle properly, so, when converting a hub to the next wider spacing, it is usually unnecessary to replace the axle."
The chain line would be skewed but not by much (2mm).
Rather than adding spacers to each side, a more sophisticated approach would be to add the 4mm of spacers on the left which will allow you to increase the strength of the wheel by moving the rim (relatively) to the left and reduce the dishing. This would maintain a better chainline.
Having said all that, why not get a 130mm OLN hubbed/axled wheel (as @bigjim has implied)? In plentiful supply and the dishing is less (unless you re-dish with spacers on the left) so the wheel, ceteris paribus, would be stronger.

Thanks for the replys thus far
I got the 70.s frame as frame and fork only the bike previously was cold set to 130 to allow a more modern wheel cassette combo for riding.
My aim is to restore the bike to its original condition with parts
Id like the wheels to be period correct 700c ( probably looking at tubular)
The wheels should have a 5 or 6 speed freewheel and the widest wheel OLN I've found suitable so far have an oln of 126mm

I'm not very knowledgeable on wheel axle replacements I'm just trying to find out different options I can work with
Again thanks for the help so far

 

[Ming the Merciless]

Then you want 27" wheels if you want 70's period wheels not 700c

 

[midlife]

Lots of 70's bikes were made for tubs and sprints (700c)

Might be best to play with a Centaur axle in 70's / 80's hubs with spacers Rather than resetting the frame again?