orangeology

ugghh.

1. just found crown race interface on the fork got chased a bit too much—the diameter varies from 26.4mm bottom to 26.05 ish around the top. yes, not completely parallel cylindrical but slightly conical.
2. stupid Passage Crown Race got a nice smoothly rounded opening at the bottom vs old school, straight 'cut' opening. this round goes almost half the height of crown race. while it looks nice, don't think it smart engineering at all.

the result of combination of the above, it snuggs "smoothly" with a nice room of play—it actually rotates with no resistance... sigh. it would actually not have happened if either: the crown race interface had been new, un-chased or the crown race opening had not been rounded...

while i don't think i can do much on the metal on the fork side as far as i know, what would be the possible solution other than returning either? don't want to spend another 5 years to find the right fork...

1. any QnD solution like: would Loctite Compound or JB Weld could hold the gap? (which i'd doubt). i'd say max 0.3mm diameter of gap's there.
2. just trying to alter the crown race with more old-school shape? i mean. it wouldn't be the exact-fit bearing surface, but 'could' work out taking advantage of loose-ball bearing surface with a bit of room to play?

Salamandrine 

I'd be inclined to take it to someone that can lay on some silver braze and then recut the crown.

That area is under a lot of stress and is constantly wriggling around. I wouldn't trust loctite or JB weld as a long term solution in this application.

But I guess if you take the first suggestion you almost may as well take it to a framebuilder who can put a longer steer tube on it.

nlerner

I recently shimmed a slightly loose crown race with a section of thin steel feeler gauge, something like this. I had seen that hack on one of the forums, and it's come in quite handy for a number of shim needs.

ljsense

Instead of glue, you might try a shim, if you're looking for a quick and dirty solution, and you really have that loose of a gap. I'd try a soda or beer can. Cut a big section, wrap it around the fork, hammer the crown race on, then trim off the excess. It should be hard to hammer on; if it's still loose at all, forget that approach. You could wrap it with extremely fine wire.

SurferRosa

Take it to the best lbs you have that specializes in vintage bikes. They should have a knurling tool.

Loctite makes special stuff to close bearing interfaces. Check their website. It can be expensive -- $20+.

I have actually used a bit of JB Weld for this application, and it worked beautifully.

dddd

JB weld will easily do this for as long as any headset will last. I would apply a very thin wipe of silicone oil or grease to the steerer and crown before applying it, which will make it not stick well to the steel of the fork.

Red Loctite has worked for me on some really poor headset fits. The parts need to be absolutely stationary while curing occurs. I accelerate curing by heating to 130-140F with a hair drier.

I have a pedal fixed into stripped left crankarm threads on my mtb, I used copious application of Red Loctite, little to no air space where plenty of space existed. Removed it easily enough using a pedal wrench one year, just to service the M520 pedal bearings. Back in with LocTite.

SJX426 

This works if you are willing to take the risk of the crown race breaking. Super Record crown races are notorious for failing.
Personally, I would highly recommend to leave the hammer in the drawer.

orangeology

checked, of course. i do have a nice and proper crown race setting tool—aka 10 lbs steel pipe—from Cyclus. i've ruined quite a few nice vintage parts with hammering when was a real noob.

orangeology

glad to hear that Loctite Red or JB Weld 'could' work out. still the Passage crown race has no chance due to the stupid rounded opening. #whatweretheythinking

unworthy1

LocTite GREEN is what they specify for "sleeves" and gap-filling like this. I have a big bottle of it, if there's no better option MAYBE I could mail you some, but this might fall into the "not allowed to mail" category. I have used the aluminum can or brass shimstock for shimming and worked out fine when the gap was "just right", if it's not a "good-sized gap" or irregular then you may be better off with an adhesive. I use epoxy on many things but never on a crownrace (yet), still no reason that JB Weld couldn't work if you are comfortable with it.

orangeology

(ooohhh i'm all for exploring "don't tell yo USPS what's inside" option if finding a container is not a big hassle for ya. will PM ya on this sir)

yeah. i've used JB Weld on quite a few places where meant-to-be also not-meant-to-be, very familiar with what it is and its capability. that stuff is always, i see, as "the last resort", tho. pro'ly the acme of QnD solution on many occasions yet never become an elegance.

thinking aluminum can shim + glue (LR LG or JBW) as 'combined' on top of an alternative crown-race. the one in the Passage, no way to make it tight unless getting messy. just ordered a good ole' Cane Creek crown race—i've used it for mix-match application with a good result. low enough, and the bearing surface is kinda very receptable/workable even tho its meant to be holding a sealed one.

will update with what and how i've done on this one. thanks for all the inputs, forks!

obrentharris 

Don't discount the knurling tool suggestion by @SurferRosa.
This is a common technique which works well if the gap is not too big.
Brent

gugie 

BITD the caveman LBS solution was to use a punch and make little indentations all around the crown. The indentations make little craters, which rise up higher than the surface. This is what the knurling tool does, and it does it in a more controlled fashion.

I've done the silver filler thing and milled it back down, which is probably the best approach mechanically, but of course you're looking at a repaint.

orangeology

1. great idea. got some stamps for golf club heads. i think i can totally try it!
2. in the silver filler case—cudak888 suggested me to contact you on 'steerer tube extension' in another thread, thanks for visiting!—can chrome plating survive? losing paint is fine, and i wouldn't mind revealing the chrome (under the paint now) if gonna be preserved. if so i could consider both lengthening the tube + redoing the crown.

thanks!

Reynolds 

While indenting with a punch gets you peace of mind because the fit is snug when you assemble it, this fit doesn't last much under stress IME.

gugie 

While you're correct, it's not a disaster if it comes loose. We used to do a lot of things that an LBS wouldn't touch nowadays, like straightening a steel fork, cold setting dropouts wider to accept the "next generation" of wheels. Heck, we even used to assemble bikes with quick release that didn't have lawyer lips...

gugie 

PM me.

scarlson 

I did it to a bearing arbor in a SAAB 900 transmission where a bearing had spun and worn down the shaft. Also used Permatex 20297 bearing mount for worn parts. Lasted 5 years until I sold the car.


Did the same on a crown that the powdercoater sandblasted undersize.

merziac

It will if you stick it together with JB Weld, Super Glue, Permatex or Loctite bearing formula, the indents will center and hold the race firmly in place and minimize the gap for the sticky stuff to really bite and hold for the long haul.

gugie 

Good to know, I'll add that to my bag of tricks!

orangeology

(cavemen knurling aka indenting punching + loctite green) + possible beer can shim if needed more
is my current plan!

3alarmer 

.
...as already stated a couple of times above, the magical space age stuff you want to use is called "Bearing Mount" compound. Loctite makes it in several incarnations, including liquid and stick forms. Once it's on there, it's on there, and the heat needed to remove the race in the future would require a repaint. But it goes on at room temperature, and while you don't require the high heat variety, that's probably the one you see around in auto parts places most frequently.

I have done the aluminum can shim stock thing a couple of times, and it seems to work out OK iff you can manage to get the race on there centered, and don't fold the shim in under it so it prevents full seating. I haven't taken any of them back apart, to inspect for compression of the aluminum. So many bikes here that even if a few of them get ridden hard, it's only on occasion. So probably less of a problem for me, personally. The shimming works more easily if you cut strips, insert them vertically around the interior circumference of the race, tape them somehow around the steerer so you can control the depth, then seat the race with your tools. After you are certain it is fully seated, you cut off the strips above the race with a sacrificial Exacto knife blade, or single edge razor blade if you have a holder for one.

Have the other races mounted already, so you can install and check for alignment, because you want that right before the mounting compound dries, if you use it. I would be reluctant to use both at the same time, because the tech specs on bearing mount compound list it as pretty resistant to compression...possibly more so than aluminum. If you look at the Loctite website, they give the specs for adhesion, compressibility, and the gap sizes for their various formulations. I'm guessing you don't have much of a gap to fill.





I have to do this myself soon, on a Holdsworth that I took apart that has the same issue. Not sure what I'll do at this point, but I might just go with a beer can. That steel shim from a feeler gauge sounds interesting, but it might be overkill in my case.

SurferRosa

I remember when I was a boy our town knurler was indeed called Gappy, but maybe because he was missing his front teeth. His profound lisp was a little hard to understand. And he was often drunk, which compounded it. Helluva knurler, though, Gappy was.

unworthy1

I am sending Hong (orangeology) a small amount of THIS flavor of Loctite Green, it's "high strength" and am glad that this stuff is actually the COLOR green, unlike all the other Loctites that are called "Red" or "Purple" but are the same blue color as the "Blue"!
Must have been invented on St. Patrick's Day!
Cannot guarantee this RC compound will be successful but, when it arrives if it's still in liquid form (should be since all LocTites are anaerobic adhesives), give it a try or...try that JB Weld. In all cases clean the surfaces really well with something like denatured alcohol.

cudak888 

FYI, if you're willing to cover the shipping costs, I'd be glad to run the crown race on my JA Stein knurling tool for good measure.

Mine is the one with the straight cut knurling cylinders.

-Kurt