Question: fixing misaligned rear DOs on Ti frame

[mikemowbz]

I do most of my hanging out on another forum (which correlates to a 1990 frame being, until recently, a 'newish' bike in my stable) - but I thought this question might get more traction and speak more to folks' experience here.

I have a modern Ti frame that turns out to show some misalignment of the rear dropouts; the wheel, while centred between the chain stays and snugly tucked into the vertical DOs, is visibly a few mm off centre relative to the chain stays (the wheel is out of alignment vertically).

It's not massively out, but it is quite noticeable sighting the file tread down the centre patch of the tire relative to the centre of the rear brake bridge (now that it's caught my attention). And it's a new-to-me and not-so-cheap frame, so I'd kind of like to get this sorted out.

Looking around the internets, I've found surprisingly little consistent info about the ease/risk/effectiveness of taking what would otherwise be the typical course for correcting such a problem. If it were steel, no problem, of course. I've got a great LBS with the proper tools.

But some opinions I've encountered suggest that re-aligning Ti drops is difficult, and potentially problematic.

I guess my question is: just how simple/routine would this be? Should I be worried?

Should I make sure anyone doing this work is well-experienced with Ti (I'm considering taking it to a local high zoot frame builder with extensive experience and tools…who will do it, but not cheap), or could any good, experienced wrench who has done their share of alignment work be entrusted with the task?

Any knowledge, experience, or opinions you could share would be much appreciated.

[Ken Robb]

I wouldn't judge alignment based on the center line of a tire.

[ultraman6970]

1 - be sure the rear wheel you are using to measure is dead center.
2- the frame pulls to the left or right? (probably not)
3- Verify that the drop outs are non alligned as you think using the tools or maybe two rods and some bolts.
4- Ive read the same thing you had (not good to play with Ti frames)... if the dropouts are ok then probably you can file the drop outs a little bit?
5- honestly the most issue you might encounter with misaligned drop outs is that the rear hub axle will bent and finally crack, no idea if you are having that problem lately or at some point, if not there is a slight chance that the problem is the brake bridge and not the rear end itself.
6- Did you check the alligment of the whole rear related to the frame using the string technique? is quite simple to do at home.

Hope this helps.

[mikemowbz]

I wouldn't judge alignment based on the center line of a tire.

Fair point. That's not really my 'measure' of the apparent misalignment, so much as a quick visual indication (and how I first noticed). Distance between the outside edges of the rim and the seat stays is off by a few mm, though, checked with two different wheels and a steel rule. Both wheels checked are true and appear properly-dished/well-aligned on other similarly spaced (and properly aligned) frames in my possession.

I suppose I may be getting ahead of myself, and I will have the DO alignment checked at the LBS with the proper tools before I get too bent out of shape, but it does seem to be out of whack a bit.

For the moment, the LBS and not me have the tools that would make an incontrovertible case one way or another about whether it's the DOs out of alignment...and it's a statutory holiday in Canada, so they're closed.

Even if I find that all is well with the frame, I'm still interested in the answer to this question - as a couple of quick searches revealed info/opinions that ranged from casual or cavalier (no prob) to somewhat dire (hard to do right; bad things could happen), and I don't have a strong sense of whether realigning DOs on a Ti frame is an especially delicate (if forceful) operation, or no big deal.

[mikemowbz]

1 - be sure the rear wheel you are using to measure is dead center.
2- the frame pulls to the left or right? (probably not)
3- Verify that the drop outs are non alligned as you think using the tools or maybe two rods and some bolts.
4- Ive read the same thing you had (not good to play with Ti frames)... if the dropouts are ok then probably you can file the drop outs a little bit?
5- honestly the most issue you might encounter with misaligned drop outs is that the rear hub axle will bent and finally crack, no idea if you are having that problem lately or at some point, if not there is a slight chance that the problem is the brake bridge and not the rear end itself.
6- Did you check the alligment of the whole rear related to the frame using the string technique? is quite simple to do at home.

Hope this helps.

Thanks, Ultraman. Appreciate that checklist of sound advice.

I checked with two different wheels (and checked the wheels against other frames that I know to be properly aligned), and measured a difference relative to outside edges of the rim and the seat stays...so seems to be something going on here, I think.

I haven't found the bike to track noticeably to either side, though I just assembled it (and no issues with axles...but also no more than 20 miles on the new frame).

I will definitely have the LBS check the DO alignment ASAP. And you're right - I should check the whole rear triangle as well, which I have not done.

[ptourkin]

I got my Seven fixed on eBay. The seller noted that the rear triangle was about a mm off due to a crash. My local ti bike builder had no problem cold setting it back in place, resulting in a steal for me. A few minutes of work and it rides like a dream.

[mikemowbz]

I got my Seven fixed on eBay. The seller noted that the rear triangle was about a mm off due to a crash. My local ti bike builder had no problem cold setting it back in place, resulting in a steal for me. A few minutes of work and it rides like a dream.

Good to hear.

If it comes down to it, I might take this down to Dekerf (local steel and ti builder here in Vancouver).

If there is a problem, though (which it seems to me there is), I'm a little annoyed - as there was no mention of one by the seller, and I paid a good bit for the frame. But that's another can of worms.

Your success with cold setting a Ti frame that had been knocked out alignment is a good data point.

[pbarry]

DO alignment tools will tell you if the faces aren't parallel. Not uncommon with Ti frames/vertical dropouts is one DO being slightly fore or aft of the other. A good builder can take a rat tail file and correct the lagging DO. Not a big deal. :)

[lhuerta]

Ti can be handled like steel....as long as ur mechanic is not ham fisted and has the correct tools (and mad skilzz), the alignment process is no different then working with steel. IME I have encountered some Ti frames that are harder and less maliable then steel, and vice versa. Lou

[oldpotatoe]

I wouldn't judge alignment based on the center line of a tire.

What he said. It could be a lot of things not the least that the RH and LH chainstays are a different length(seen that once).

Has somebody with "H" tools and a frame alignment gauge looked at the frame or is it all based on your rear wheel?

If it is just a dropout, align just like steel.

[malcolm]

Not sure I completely understand exactly what you are talking about, but couldn't it be wheel dish if it's just a few mm's off ? put the wheel in backwards, driveside on the left and see if the offset changes. Seems to me a tweaked frame would be off in the vertical or the wheel would sit at an angle in the dropouts relative to the seat tube, or is that what you are describing ?

[mikemowbz]

Not sure I completely understand exactly what you are talking about, but couldn't it be wheel dish if it's just a few mm's off ? put the wheel in backwards, driveside on the left and see if the offset changes. Seems to me a tweaked frame would be off in the vertical or the wheel would sit at an angle in the dropouts relative to the seat tube, or is that what you are describing ?

Not wheel dish. Tried flipping the wheel, and it's still off in the same direction with the same wheel reversed. Tried with another wheel as well. Checked both wheels relative to other frames in my possession known to be properly aligned.

It could be that the stays are different lengths, potentially; all I'm clear on is that the wheel does not appear to sit straight vertically - i.e. off by ~3mm relative to the chainstrays (easily visible, but also consistently measurable relative to the rim and yielding the same measurements when swapping the wheel as a control). Seemingly not quite in line with the seat tube vertically.

As I said, I'm taking the frame in to someone with proper dropout tools/alignment gauges at first opportunity. That's going to be Wednesday.

One of the key reasons for my question is that I wanted to be sure of whether I ought to just leave it to the LBS that will do the checking to try to adjust the alignment (of DOs or the whole rear triangle) if there is a confirmed issue at that stage - or should I save that job for someone with more experience with Ti, if this is indeed trickier than working with steel (as I've been told).

[David Kirk]

I think the only way to be sure you're not making it worse would be to have the frame on a real alignment plate. You will get real answers there.

dave

[tumbler]

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[Mikej]

Does it shift ok?