Wednesday, January 30, 2013

Not weird enough?

If you didn't think the QR15/tapered blade fork I was working on was weird enough, check out how weird it looks with a post-mount brake setup (customer is generously letting me experiment a bit on him, but even after I get it figured out a bit better it's still going to look pretty weird...)

After spending some time messing around, it became clear that due to the high precision required, putting the threaded bit into the posts first wasn't an option (no matter how precisely you miter and join the posts, there's going to be enough distortion to pull the end of the mount out of line, especially the lower one). If you install the posts first, then do the threaded inserts (in this case stainless M6 nuts from the HWS, I think M6 pulley mounts would look nicer though I worry about having enough surface area for the brake to mount to) you can make sure the brake will line up right.

The cool thing about the QR15 dropouts is that they line the blade up much better with a post-mount setup than most standard 9mm dropouts.

Oh, I should also mention this is for 160mm. I would hesitate to do 180 or 200 on this setup (though you could run an adapter) just because the posts get even longer. 140 is obviously no problem.


dicky said...

I can not condone this behavior...

not that it matters.

steve garro said...

How about if you tacked it up with a light web gussett inbetween the posts?
It would keep them from spreading or pulling together - something like 18 gauge or so....

Walt said...

Hey Steve -

Actually, if you tie them together, it makes everything much worse - more ways to pull out of alignment. I figure the caliper will be the bridge, so as long as I get the threads where they need to be, it's good to go.

Anonymous said...

Walt what I usually do is just tack the nuts or fasterners and then weld everything else first then cut the tacks on the fasterners to relieve them. The pulley nuts would be a great choice and maybe the tubing bullets from paragon.