Head tube replacement - 1" to 1 ⅛"

[Hat]

I've got a frame on which I'm planning on having the brake bridge moved up a bit for increased tire clearance and I figured I might as well have the head tube replaced at the same time. My reasoning is that I'll need a longer fork anyway (way more options for 1 ⅛" obviously), and since the new fork will have a longer axle to crown, the head tube should be shifted up slightly to maintain the geometry of the frame. I suppose facing the bottom of the current headtube could also accomplish the same result though.

Is it all more trouble that it's worth? I'd have the work done by the builder and the cost would be very reasonable. The frame is TIG welded which should make things much simpler I presume. And paint damage is not an issue.

[David Kirk]

The amount of "protrusion" you have on the bottom of the head tube will be the limiting factor. "Protrusion" is the amount of head tube that hangs below the lowest point if where the down tube attaches to the head tube. Typically this will be in the 10 mm range or something like that.

So say the protrusion was 10 mm and you wanted to use a fork that was 5 mm longer you could then face off 5 mm and be OK. But if you have 5 mm of protrusion and you want to use a fork that is 10 mm longer you will of course have issues.

dave

[sandyrs]

If you're anticipating future fork swaps, I'd go for the replacement. If you're getting a new fork built that you anticipate keeping for the life of the frame, just get it built for 1" and it should be fine. No point in having work done that you'll never take advantage of.

[batman1425]

I've got a frame on which I'm planning on having the brake bridge moved up a bit for increased tire clearance and I figured I might as well have the head tube replaced at the same time. My reasoning is that I'll need a longer fork anyway (way more options for 1 ⅛" obviously), and since the new fork will have a longer axle to crown, the head tube should be shifted up slightly to maintain the geometry of the frame. I suppose facing the bottom of the current headtube could also accomplish the same result though.

Is it all more trouble that it's worth? I'd have the work done by the builder and the cost would be very reasonable. The frame is TIG welded which should make things much simpler I presume. And paint damage is not an issue.

Facing might rectify the geometry issues (provided there is space) but won't fix the lack of options in the 1" steerer fork market. If it is a forever frame, replace the head tube and make it as future proof as possible. I'd actually go one step further and do the replacement with a 44mm HT if the frame allows. That opens you up to tapered options as well.

[David Kirk]

I guess my larger, and less well made point, is that if the lower protrusion isn't enough to make the 1" fork work it won't be any better when swapping out the head tube and going to 1 1/8". The down tube is where it is and you can't bring the bottom of the head tube up further than you have room.

You'll need to see how much taller your fork will be and then measure the protrusion to see if you have the room to make it right.

dave

[Erik_A]

I vote to keep your current bike as is; then buy brand new bike for larger tires... doesn't everyone see how logical this is, because then you have 2 bikes!

[pbarry]

What kind of tubing was the frame built with?