Forum menu
So having just built up my new (to me) Genesis Altitude Ti, I've just got round to setting up the brakes (I'm a heathen, I still have IS mount brakes not post) and the brake mount on the frame is out massively... We're talking about 1mm here from end to end!
Anyway, my question is that is it exactly the same process for Ti as it is for an alloy frame? Or is Ti inherently a lot tougher? And 1mm seems a lot to have to remove, is that normal? Or should I just not even bother, and just shim it to suit (with 1mm more on the top hole)?
Just shim it.
ti is hard - shim it as the pixie suggests
Is Ti really THAT hard? How hard is it compared to steel say?
And any way of measuring exactly how many mm the one end of my disc mount is from the other, so at least I could measure out the correct thickness of shims, rather than just guessing?
I have some very fine brass washers that I use for occasions like this. You can have some if you pop over or I'll post you some.
Cheers mate, that would be grand... Either way would be good for me.
How fine we talking? Thinner than the conventional 0.2mm?
Hope do shims, think they come in 3 diff thickness.
So a good LBS who do Hope should have some.
Might get burned at the stake for this one, but Halfords sell a little set of brake shims which is absolutely perfect, comes with a good range of sizes.
Titanium's a bugger to work, never worked with a bike frame but cutting ti exhaust pipes with an angle grinder is pretty hard work. But [i]excellently[/i] sparky.
Hope do shims, think they come in 3 diff thickness.
Already got tonnes of shims, just need to work out how much the top hole is further over than the bottom. And I can't see any way else to do it other than guesswork sadly! Cos it's somewhere near 1mm, but my eyes aren't calibrated to the nearest micron sadly! 😉
Might get burned at the stake for this one, but Halfords sell a little set of brake shims which is absolutely perfect, comes with a good range of sizes.
Cheers, will check out Halfords in the morrow as it's only just down the road, suspect they won't have anything thinner/more accurate than the 0.2mm shims I've already got.
Titanium's a bugger to work, never worked with a bike frame but cutting ti exhaust pipes with an angle grinder is pretty hard work. But excellently sparky.
Oh yes, I remember back in the 90's when guys on sports bikes everywhere started using knee sliders with titanium rods in, just so they could get a photo of themselves with sparks coming off their knee as it dragged along the floor... And don't sparklers (fireworks) contain Titanium Dioxide or something that makes them sparkle in the way they do as they burn? Or have I got that wrong?
mboy - put the bolts inbut don't do them up completely and pull the brake on - then see how many shims / what size you can get in the gap between mount and calliper gives you a start point. you need to end up with the caliper centralised and parallel to the disc
you need to end up with the caliper centralised and parallel to the disc
Yeah I realise this... Sorry if I'm sounding ungrateful (I don't mean to), I've been building my own bikes for about 12 years now but I've never come across a disc mount that is so out from one end to the other, and I've usually just got them faced anyway. But I then remembered hearing something about Ti being a very hard material, so thought I'd ask...
put the bolts inbut don't do them up completely and pull the brake on - then see how many shims / what size you can get in the gap between mount and calliper gives you a start point
Again, sadly my eyes aren't calibrated all that well! 😉
Though you have just given me a thought... Where does one buy a set of feeler gauges from? Local DIY place, or specialist toolshop?
I doubt the STD cutters would do much to ti.
A file ought to do it? Power sander?
😉
I've used a hope facing tool on a soda that was a long way out. It was bloody hard going but I got there in the end. Titanium is hard but not totally unworkable. If it was, how would they make frames?
I've also worked on frames that were as much as 1mm out. Last one was an Orange patriot.
Feeler gauges from any automotive shop halfords etc - but I simply use the shims like feeler gauges seeing how many you can get in the gap
With Onzadog on this one, 1mm out is a regular occurance on new frames(with far worse out there), shimming it's ok as long as it's laterally out, but if it's vertical too, then you'll never get the pads to hit square without facing it.
I use the feeler gauge method for shimming up calipers
[*]Mount the caliper without pads and with the pistons pushed back[/*]
[*]Have a good guess at what's needed and put the shims in, nip it up[/*][*]measure the distance between the caliper body and the rotor at both sides/end[/*][*]Adjust your guess to suit how far out it is and add or remove shims to suit[/*][*]Repeat until central[/*]
It's not as bad as it sounds and only takes a couple of minutes once you get going with it
I have a Hope Spot tool but even with the faces levelled, there's often the need for shimming if you want it perfectly central.
Sometimes I can be bothered, other times I can't, still works OK TBH
Shim for the lazy win.
Might take a couple of goes to get it spot on. Ti will prob be a lot harder than the facing tool is designed to deal with, so may well blunt the tool.
Just bring the bloody thing round to me you muppet!
Talk about over-thinking a simple task.
Just bring the bloody thing round to me you muppet!
LOL