Forum menu
I guess few are likely to have much relevant experience but that doesn't usually stop advice being offered 😛
For my latest project I'd like to bend the steel rear triangle of a single pivot bike. I've done similar before with forks and RTs by standing on them (which is how framebuilders do it I am told), but this time I want to introduce an offset into the RT (i.e. bend both dropouts out to the RHS).
I think I'll just stand on each one individually, while it's appropriately supported, but any ideas?
Use a spoon for extra leverage?
If you bend them both to the right side, you'll go round and round in circles!
Called cold setting and covered nicely by Sheldon, Ill go get the link
Ta stoner, I'd not thought of that, nor that SB might have been a like mind 😎
I'm still having that pint off you mind!
I'm still having that pint off you mind!
you'll have to come down here to get it. Cant stand 80 shilling myself.
steve sustin is right tho - you will end up with a rear wheel not parallel to the top tube unless you put a double bend in each side or adjust the dropoouts
sheldon is, of course, way ahead of you TJ
Spreading the frame will cause a slight change in the angles of the fork ends, so they will no longer be exactly parallel to one another (assuming they started that way.)
For higher-quality frames with forged fork ends, this can theoretically lead to problems if the fork ends aren't re-aligned. In the case of older/cheaper frames with thin, stamped dropouts, the dropouts are flexible enough that it's not a problem.Moderate spacing changes make only small changes in the fork-end angles. For instance, spreading a 120 mm frame to 126 mm only changes the angle by half a degree. Spreading a 126 mm frame to 130 only changes the angle by one-third of a degree.
Problems attributed to misaligned fork ends include bent/broken axles. As it happens, the direction that the alignment changes when you spread the rear triangle is such that the alignment error is unlikely to cause this, because the stress it puts on the axle is opposite the stress created by the chain drive. Alignment errors in the opposite direction would be much more likely to cause problems.
There's no easy "home-mechanic" tool for fork end alignment, except for a big adjustable wrench and a good eye. I would advise, if in doubt about the alignment, that you take it to a shop for this purpose, even if you do the frame spreading yourself.
Tools available to adjust. Probably need to phone around a number of shops to do it, or TBH Id build my own tool
[img] 
[/img]
I may be dim but, what is the point of this?
[s]track frames = 120mm OLN
road frames = 130mm OLN
MTB frames = 135mm OLN
sometimes you want to do something with a specific hub for which the frame wasnt designed.
I have a 120mm pelissier hub in a 130mm Falcon.[/s]
Of course Al is actually just raping a perfectly good frame in the name of cuttlery.
TJ & SA I intend to try to put the same bend on both stays - the RT will then be chopped and re-assembled, re-aligned.
Bazz...wait and see!
FS Tricycle or sidecar I reckon
That would be stupid 😛
Is this going to be the albodgetastik fullsuss fatbike with an off seat rear wheel then?