smd4

How is writing "Just not a fan of silly shortcuts like you're proposing" not articulating my reasoning? Your problem is you can't admit it's a shortcut. And a silly one at that. Yet another reason I wouldn't let you touch my bike.

Why is it so hard for you to come to grips with the idea that not everyone agrees with your "wisdom" when it comes to bike mechanics?

Kontact

Half of what is discussed with bike mechanics on this board are "shortcuts" that allow all sorts of things that the manufacturer didn't design for to work. Shimergo, race fenders, wide rims, respacing dropouts, travel agents, SSCouplers, threadless adapters, zero setback seatposts, drop bar MTBs, clip on aerobars. They are all shortcuts, and you don't seem to hate all of them.

Your problem isn't that you don't like shortcuts, it's that you don't like THIS shortcut. But it is far safer and less stupid than half the stuff that people want to do to their bikes.


Full disclosure: I did this for a friend so she could ride her Vitus with cyclocross tires one autumn. I had never heard of doing this, but it was an obvious and easy solution. When the season was over I popped the spacers off and mounted 25c tires again. It was fast, easy, safe and simple. Unlike buying a bike or a fork.

smd4

I wouldn't consider some of those things shortcuts. Gluing stuff in your fork dropouts is a hack repair--in MY OPINION.

Oh, and one other thing: THIS IS MY OPINION.

Do what you want.

Kontact

Glue is a short or long term solution for attaching things. Cyclists use such 'hacks' to attach things like tubular tires or make composite frames and forks. And those things actually are under stress, unlike a spacer.

But it would be easy enough to drill and pin the dropout if aesthetics are so important.

Another solution is to use tiny rare earth magnets on the axles, if they are steel.

Or you can make a tabbed washer that attaches to the skewer. But that takes fiddling to line up.

smd4

Hack away!

Russ Roth

Maybe try a different brake then? On my old giant that I used to get into cross racing it had just enough space to clear 31c vittorias, the 32c green Michelins were big enough to rub on the crown and brake bridge. But the shimano 6400 dual pivots that I used had more clearance than the frame did. See if you have a pair you can swap on, I think dual pivots have more clearance than single because the pivot points are moved off to the side and allows the brake to sit higher. Otherwise, if there's plenty of clearance like you say, I'd do the 5mm spacer on the brake and that might get the job done.

Duragrouch

"Was it over when the Germans bombed Pearl Harbor? Hell no!"
"Germans?"
"Forget it, he's rolling."

Spacing out the caliper center bolt will do zero, and some harm. Zero because that bolt is pretty close to tangent angle to the tire, so you would need to space it out a lot, and harm because every bit of increase is putting more bending moment on the bolt for the same braking thrust. Spacing the caliper up if they make an offset bolt, or the wheel down if you have plenty of dropout length, would be better solutions.

EDIT: Examine if taking the spacers out from between both pads and the caliper arms, brings the arms up in the center.

downtube42

Tires tend to expand a bit, so I'd be concerned if new tires are that close. I'd probably shop around for tires that are a tad less tall.

ENVE SES 700C at 29mm perhaps.

Kontact

Does the part of the brake that is rubbing look tangent to the tire? (It does not.) Adding spacers will move the caliper even further forward of the tangent point than it currently is.

Duragrouch

Yes but due to the diameter of the tire, I think you wouldn't even make a dent in the clearance until at least an inch or more spaced out. Hard to see, but based on the pic of the rear caliper, I think the arm closest to the fork is closer to the tire, versus the arm farther away. I'll have to do a calc later.

FBinNY 

No need for complicated math. Just some visualization.

The axle is forward of the crown. Ergo, 12 o'clock is likewise forward of the crown by the same amount. So moving the brake out from the crown has it meet the rising tire.

In case you think that the tilted steering axis changes anything, sketch it with a vertical steering axis, then rotate the sketch 17 degrees.

Conclusion, bringing the brake out from the fork is counter-productive.
-------
IMO, close only matters in horseshoes. The OP mentions the molding flash touching, which doesn't matter, so there's nothing to fix. OTOH, if the OP prefers more clearance, the easiest, least consequential fix is to move the wheel down a bit. I'd use body filler in the dropout, then once cured, file it so the wheel pockets squarely. This is easily reversed later, should the OP opt to.

70sSanO

You can always get a duplicate donor caliper and file/grind a bit off that one. No one will ever notice and you keep your original intact.

I’ve read of bending the caliper mounting bolt, but not sure of the ramifications once it is pushed past its yield point.

John

Kontact

Yeah, it may not be practical to get useful clearance by adding spacers - but it won't shrink the clearance as you suggested. I would try two more spacers and see if does anything useful. Otherwise, not much point.

Kontact

You can clearly see in the picture that the tire angles down from the axis of the brake mount. So moving the brake forward along that axis is of course going to make some clearance. You saw the picture, right?

You're making certain assumptions about the angle of the hole in the crown vs the center of the front hub, and they are wrong.

FBinNY 

You're looking ar a photo which wasn't taken directly from the side, so doesn't properly show the reality.


Yes, I'm assuming that this is a halfway decent fork with the brake hole drilled EXACTLY normal to the steering axis, which is SOP and pretty hard to get wrong.

So, feel free to think I'm wrong, but I stand by my post, and choose not to pointlessly argue the point with you.

In any case, the OP has the bike and knows what's what.

Kontact

I looked at 3 of my forks and would agree that the caliper itself is normally tangent. But I think the OPs is not per the photos.

Duragrouch

Let me precede this by a big healthy "I could be wrong...", but I think a combination of tiny-phone-camera-lensing, plus the sideview curvature of the brake arms, could be producing a slight optical delusion. I think looking at the thru-bolt/shaft relative to the tire, helps in perception.

(Cue my father to begin discussion of "The true length of a line".)

rosefarts

So it’s a straight leg fork. I think the dropouts are either straight or just slightly forward. Pretty standard for a straight fork.

That does mean that the crown will tilt out from the steerer tube at a greater angle in order to hit the same rake position as a curved fork. I think it does anyway. I had the fork off a few years ago and I think that’s what I observed.

I’m hoping to mess with it a little bit tomorrow. If for no other reason than to put some of these arguments to rest.

If I can’t get to it tomorrow though, it’ll be Thursday the next time I have a chance. I’ll report back.

Duragrouch

"One valid test is worth a thousand expert opinions." - engineering proverb

FBinNY 

I'll bet you 3 beers* that when you look at it, you'll see that the central part of the crown follows the line of the steerer, with the brake hole straight across.

Then both sides of the crown are "twisted" (in terms of axis, if not obvious fron the outside) so the blades are angled forward to establish the rake.

So everything I said earlier apply the same as it would with curved blades.

*bottled or draft

L134 

A 28 tubular will ride better than a 30 clincher.

easyupbug 

+1, my two Tommasini have 23 up front and 25 in the back and a Litespeed has a 25 front and 28 rear and never an issue.

smd4

Like what? A goat head? Shard of glass? To think something picked up by the tire at road speed will lock up the wheel is delusional. Right up there with thinking that snagging a twig will blow open your quick release.

grumpus

I did know someone whose front wheel locked up because a bit of tar-coated gravel jammed under his mudguard, they were those narrow flat aluminium close clearance guards that were popular in the late 1980s early 1990s, I forget the name. Now clearly a mudguard presents more opportunity for something to wedge, but it does show that road debris can lock a wheel.

Edit: I remember the brand - they were Salmon Profile mudguards, a French product.

JohnDThompson 

Or a wad of tarry gravel. While it may not lock up the wheel completely, it can still be enough to launch a face-plant.