Fork steerer alignment. Is there a simple test?
 

I posted this question over on the mechanics forum but thought I'd put it here too, since I don't "know" anybody over there.

I just replaced the head set on a bike I acquired. Head set was and is Campagnolo Nuovo record. I made tools to press in the new cups. Went very well. However, when I installed the new crown race I notice it didn't seat all the way. There is a very small gap, maybe 1/2 mm, on one side between the crown race and fork crown. The rest of the race, about 340 degrees worth, seems to be seated tight. I'm wondering if I could have somehow, inadvertently, tweaked the steerer tube ever so slightly.

I've been looking at fork alignment jigs on Google but would hate to have to go to that extent just to check one fork. Is there a "simple" way to check that the steerer tube is properly aligned with the fork blades? Thanks.

I have no idea about the steerer alignment, but it sounds like it'd be easier just to take into an LBS to have them check?

What about the race itself? I have accidentally a bent race before because I was a little too forceful with it.

EDIT: Forgot a word :)

Possibly the previous race was wedged off with a flat head screwdriver "pushing" that small section of the crown lower?

As far as a test, I'd just assemble and rotate it and look.

Well, I removed the old race with what I think is an inadequate tool. One of those bearing separator-like "crown race removers" like Icetooz offers, because I had it. It worked ok but I marred the old race a bit so have decided not to use it again. I'll try assembling it and trying to look with a straight edge, etc.

As far as taking it to a LBS, P. Pounder, uh .... not sure how to put this but, I don't trust the young turks at my LBS any farther than I can throw them. I would never take a vintage bike there for any reason. That kind of place ...you know. But thanks.

I guess I've got to get that new race off there and re-cjeck everything.

Assuming the frame and fork had a Campagnolo headset installed previously?
If not, time to use the Campagnolo Passa/nopassa gauge to decide if you need to machine the fork.
Or, set it up in a lathe and check for runout. And dimension of 26.6 for a 26.4/26.6 press fit.
Also check the land for squareness.

Personally, I really only like using a headset cup/race press to install those in the machined frame.

Plenty of experience in observing guys who did not have all the tools at their disposal installing a Campagnolo headset themselves and needing another a few months later way back.
Not saying that is the case here, but test, don't guess.

I just put a NR headset on the Junior Moser today,

I think the Campy crown race is slightly tighter,
I had to take it off twice, and clean the seat with a jewelers file untill the race sat without light under it.

Installed with vise and a plastic headed hammer,(steering tube across the vice, race on the side, wacked between the legs :eek: with a plastic hammer - no fuss at all)
removed with piece of oak and a hammer

If the crown race is not both concentric with and perpendicular to the axis of the cups it will be impossible to adjust the headset without either binding in places or being too loose. If this happens, the solution is to mill the race seat on the fork using the proper (expensive) tool to ensure the proper alignment.

Too risky in my book, but I just carry over the mindset of a guy who got paid to do this stuff.

Thanks. Yes, Record head set off and new one on. Well, as far as all the tools, I used my newly made cup press for the cups and it seemed to work like a champ. Very smooth and even. I used this tool I made to press on the race.
http://i1227.photobucket.com/albums/...dsettools1.jpg
Put this tool over the steerer and used my hydraulic press to squeeze it home. At first I thought it might be my tool so checked it and sure enough, the bronze head was just a hair off perpendicular from the aluminum tube. I figured it was because I hadn't faced off the tube in my lathe but just squared it up on my 12 inch disc sander and a 90 degree fence. But when I removed the bronze head the tube was quite square, so I re-pressed it on and mounted the whole thing in my lathe and squared up the head. Tried it again after that and no mas.

It must be the squareness of the land and perhaps I didn't examine the old race in its position closely enough before I removed it.
I'm waiting for a proper race remover to arrive. Tried setting up in my somewhat inaccurate little milling machine to replicate a Campy one but it's turning out to more difficult than I thought.

I'll bet it's the problem. The land/seat didn't look all that great while I was cleaning it. I mean, not bunged up or anything, but just not clean and precise and smooth looking. A chunk of hardwood for remover might get me by until my proper tool arrives, Mike. Thanks! Why didn't I think of that? I've got plenty of very hard hardwoods. I refuse to go after it with a drift. Got to be both sides at once, I figure.

By the way, I should add that I assembled the fork in the head tube with caged bearings, dry, and adjusted it. Spun smoothly all the way around with no binding or sign of roughness. But what I'm worried about is that if that crown race is not seated firmly and properly things will loosen up and cause damage when ridden.

Use your race install like a slide hammer.....when the race is properly installed you'll know it.

Ting, ting, ting, thud.

If there's a gap there's a gap. The question is why is is there a gap and is it going to bother you?

If your fork spins freely the race is probably squared properly and its just the seat that's not machined 100%. No big deal as I've plenty like this and it poses no problem.

If you have a B&D WorkMate or something similar, this will help to give you a pretty good idea of fork integrity - sort of...

http://bikeforums.net/attachment.php...hmentid=284629

Clamp the fork in the WM and, if you have another fork, clamp it in the other end. Do your best to ensure that they are level, side to side. Run a string through one brake bolt hole and to an axle, or some other tool attached to the drops of the fork you wish to consider...

http://bikeforums.net/attachment.php...hmentid=284632

Now, consider if the string splits the brake bolt hole of the fork under investigation. If not, your stem might be bent or the fork blade might be bent. So...

http://bikeforums.net/attachment.php...hmentid=284631

To check the blades for out of true, install your wheel and see how it splits the space between the tops of the blades. If off, chances are the blades are bent...

http://bikeforums.net/attachment.php...hmentid=284630

Use your imagination to figure out if a fork or frame set is out of true. And, for those who want a quick check (not a perfect works every time method), hang your bicycle upside down by a single strand of string, attached to each wheel...

http://bikeforums.net/attachment.php...hmentid=284633 http://bikeforums.net/attachment.php...hmentid=284634

If the front wheel hangs straight, it is most likely that your frame/fork are true. If the front wheel wants to turn off center, then you probably have an alignment issue.

Hope that is a help.

I like that bit with the string and the workmate.

As far as this goes:

To check the blades for out of true, install your wheel and see how it splits the space between the tops of the blades. If off, chances are the blades are bent...

I would add that you should flip the wheel and check it both ways. I thought my fork was slightly off for years and then one day discovered the front wheel was dished. My bad.

great tip randy!

but please dont try this with plastic workmates,they are not as true as wooden ones!

dont worry about wacking it a bit on both sides with wood,
take the hardened bearings out of a trailer hub, or reset them with steel punch-
come on-you cant hurt that race that easy.
its a bicycle not a turbine engine!



Randy Im getting close to discussing things further regarding our deal..

mike

Good point but I do not try to show and tell all in the forum. Too much information to consider when dealing with frame cavities and frame integrity.

Should have included those links in the first place. Hope it is a help.

All good input. Thanks fellas. By the way, I did mount a known true wheel in the fork while it was mounted and it was dead center.
Your string test is interesting Randy. Wish I had a Workmate, but I'm sure I can rig something. That info is all a good help, thank you.

BTW, why don't they still sell this simple tool? Or do they?
http://i1227.photobucket.com/albums/...7D8C6DE62A.jpg
I can only see that highly complicated Park tool at $150, or the less than satisfying Icetoolz, etc., bearing separator type thing.

Well, I'm not so sure Mike. I removed the old one with a bearing separator, much like the "cheap" ones sold by Icetoolz, etc., and ended up damaging the chrome on the old one. I'm not so worried about damaging the race as I am damaging the land or seat by pounding on it one side then the other. I tend to obsess too much about this stuff, though. ;)

I would be concerned with the 1/2 mm gap on one side. I think you will have trouble in the future keeping the headset adjusted properly. I think you need to recut the race seat. I've been borrowing crown race cutters up till now but ordered one just yesterday on E-bay. If you want your nice bikes to be nice, you need nice tools. I ordered the Ice Toolz cutter for $262. I've not heard any bad reports about it and it's a LOT less than the Park tool.

Yikes. I hope it doesn't come to that, Busdriver, but it might. If it does, I think I might have a fallback method. If I can figure out a way to chuck the whole fork in my metal lathe :eek: I may be able to take a skim cut off the horizontal surface of the race land. But of course, I'm hoping it doesn't come to that. Thanks.

A lot of framebuilders cut their races on the lathe. From the pictures, usually before the legs are brazed on. Probably a balance thing. My lathe is too small but still fun for making small things.

THAT is a problem. No guarantee that when under load that the race may "walk" to fully rest on the fork crown seat, and if it is good with it floating it will not be good when fully seated.

You can still get the VAR version, and for less than the fancy Park:

http://www.biketoolsetc.com/Product_Images/VR-983.jpg

It would be real hairy trying it on my lathe and might not even work. I'd have to spin it REAL slowly, and use a steady rest to hold it. Not sure how I'd chuck it up.

I may be able to do the dressing by hand.

Yes. That is my worry. Got to get to the bottom of this.