Classic & Vintage - Filing down steer tube under the fork crown?

32c paselas graze the bottom of my fork's steer tube under the crown on my Nishiki Road Compe. Do you think I could file it down a few mm to gain extra clearance?

What an odd bike... With the 27" wheels on there, the bike has ample clearance in the rear, but almost none in the front. I converted to 700c and there is no room for fenders even with 28c for the front. What a strange construction... Anyways I've since decided that it's going to get 32 paselas and be my beater/commuter.

Has anyone had light tire grazing on the steer tube and safely filed it down a bit before?

I would not file down the Fork. Seems like it would weaken it.

I'm thinking more of the steer tube protrusion at the bottom. I don't see anything structural about it, but I guess I am here for your opinions :P

a picture would help, but i would probably recommend a different bike or 650B.

a picture would help, but i would probably recommend a different bike or 650B.

I wouldn't be able to get one until this weekend as it's in storage. I am not attached to this bike really, but it's what I have on hand and it's already half way built up. Has it's fair share of scratches so I don't have to worry about scuffing. I already plan on doing a 650B on another bike, but that's coming down the line :D

I'm no fork structural integrity genius(though I doubt most anyone else here is either. :P), but I'd think that if it were just a small area in the middle and just a tiny bit filed off, it should be fine. The crown shouldn't be so fragile that such a small alteration, at what I would think to be the strongest point, is going to cause it to collapse under you. I do know the weakest part of the crown is typically the section between the steer tube and where the blades go into the crown, so I wouldn't go filing out far enough to reach that area at all.

If it's protruding, it's not doing a darn thing but adding weight and getting in the way. Grind away happily.

I've seen pictures of very tight track frames with the underside of the crowns filed for tire clearance. If you have to get into the crown a bit, it shouldn't make so much of a difference.

If it is a unicrown, should be fine so long as you dont grind/file into the welds attaching the blades to the steer tube. If it is a lugged crown, you dont want to attack the actual crown but it should be OK if the steer tube protrudes a bit to file it flush with the lug.

Another idea- fill the top of the fork-end dropout slots a bit with JB-weld so that the axle is located 1-2mm further down on the fork. 30mm tires would also gain you clearance for very little difference in ride/feel.

I use to do it all the time with something like an 8" half round file. Due to the curvature of the wheel you only need to do the front edge of the crown/steerer and you dont need to file off much.

I don't think it would be an issue. I've seen it done before and the folks are still alive. Does the caliper clear the tire though? I think your caliper would have more of an clearance issue of the tire is grazing the crown? Plus if the steerer tube is being touched by the tire and not the crown it's just excess tubing not serving any additional strength to the fork. I had very tight clearances on my frame/fork when I built it. My caliper needs to have tension on it or just left open it touch the tire. Nothing bigger then a 650-23 tire will fit it. Yes I made it that way when building it. That's weird why you'd lose clearance when using a 700c wheel over a 27"? Any pictures at all?

I used a half round file to keep a 27X1 1/4" tire from rubbing this fork, but I ended up switching to 700c wheels. It's still a close fit with 28s. It has no structural effect. That's ridiculous. The brake clears only because it's a factory slotted MAFAC Competition.

http://inlinethumb12.webshots.com/6667/2788794650068014369S600x600Q85.jpg (http://sports.webshots.com/photo/2788794650068014369BqYPzH)

...What an odd bike... With the 27" wheels on there, the bike has ample clearance in the rear, but almost none in the front. I converted to 700c and there is no room for fenders even with 28c for the front. What a strange construction...

It is not usual to have more clearance on the rear and it is done on purpose to install longer reach brakes. In a braking situation, most of the braking is achieved via the front brake as the load on the rear wheel lessens. This results in a tendency for the rear wheel to lock up and skid. A skid requires a longer distance to stop the bicycle, not to mention the affect on steering. By utilizing a longer reach rear brake, the pressure at the pads is reduced and the rear tire is less likely to skid. Basically, a longer reach rear brake optimizes braking performance for most cyclists.

The Road Compe was a tubular tired competition bicycle and was intended for 700 x 25C tires, so I'm not surprised you're running into these issues. Personally, if the opening in the dropouts has sufficient vertical allowance, I'd opt for filling in the top of the dropouts, as previously suggested.

I don't think it would be an issue. I've seen it done before and the folks are still alive. Does the caliper clear the tire though? I think your caliper would have more of an clearance issue of the tire is grazing the crown? Plus if the steerer tube is being touched by the tire and not the crown it's just excess tubing not serving any additional strength to the fork. I had very tight clearances on my frame/fork when I built it. My caliper needs to have tension on it or just left open it touch the tire. Nothing bigger then a 650-23 tire will fit it. Yes I made it that way when building it. That's weird why you'd lose clearance when using a 700c wheel over a 27"? Any pictures at all?

Sorry, the only reason I lose clearance is because I was using 27" wheels with narrower tires before. I should have made that clear. I thought that going to 700c and popping on some fatter tires would more or less put me at the same spot. The tire grazes the steerer, but there is sufficient room to clear the calipers.

Apart from the paint or chrome you'll lose, it won't be a problem. I sculpt the underside of my fork crowns whenever I build a frame.

Interesting thread. I have the same problem with a Bridgestone RB2 and Pasela 28s. The steerer tube extends below the crown maybe 1/4 inch. I filed it a little, but now I think I will take it down all the way to the crown. Who knows, maybe I can then fit 32s!

It is not usual to have more clearance on the rear and it is done on purpose to install longer reach brakes. In a braking situation, most of the braking is achieved via the front brake as the load on the rear wheel lessens. This results in a tendency for the rear wheel to lock up and skid. A skid requires a longer distance to stop the bicycle, not to mention the affect on steering. By utilizing a longer reach rear brake, the pressure at the pads is reduced and the rear tire is less likely to skid. Basically, a longer reach rear brake optimizes braking performance for most cyclists.

The Road Compe was a tubular tired competition bicycle and was intended for 700 x 25C tires, so I'm not surprised you're running into these issues. Personally, if the opening in the dropouts has sufficient vertical allowance, I'd opt for filling in the top of the dropouts, as previously suggested.

Wow. Thank you for this! I thought everyone at Kawamura was just a little drunk on sake :P