Can’t get a crown race to set
I have a 1973 Raleigh Comptition that I am restoring. Came to be from the back of a body shop about 3 years ago for $50. Not bad!
Well, didn’t SEEM bad. as I am attempting to seat the crown race (IRD TechnoGlide 1” threaded) and the damn thing won’t set! I have a piece of PVC and have supported the crown with a piece of wood and banged on the PVC with a hammer, I have turned the whole thing upside down and used a bigger hammer, no dice. It seems like the crown seat is not round. As I try to set the race, it can rock side-to-side (see pics) can I just “split” the trace with a Dremel? (Sealed bearing headset) Do I absolutely need to find someone in the DC/Baltimore area who can cut this? What the hell is going on! https://cimg4.ibsrv.net/gimg/bikefor...2c7ca0ef6.jpeg Rocked one way https://cimg5.ibsrv.net/gimg/bikefor...8e577b43b.jpeg And the other way |
The cup is an "interference fit" to the stem shoulder/seat. It has to go on square. If tipped this way or that, it will be tough to fit. It takes patience and practice.
Make sure that the cup and seat are clean. Warm the cup up, in Mom's oven, to about 200 degrees farenheight. Be careful handling it and it should slip right into place. Or... Measure the inside diameter of the cup and the outside diameter of the shoulder seat and compare the difference. Report that difference here, and we might be able to help a bit more. |
Put the fork in a freezer for a couple of hours. Is your PVC pipe square at the race end, I've installed numerous races this way. I recently installed a Velo Orange sealed bearing headset for a friend and the crown race was split just for info. Don't take that as a reason to split, just saying it apparently is done. I would also examine fork seat area closely and maybe take some measurements if you have a caliper to get a feel for what you have.
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the I.D. of the fork crown race is supposed to be .1mm smaller than the O.D. of the seat so that when it is mounted a very tight fit is achieved the more common problem on Raleigh bicycle headsets is that the fork crown race is slightly loose if you have access to a measuring caliper suggest you make measurements prior to doing anything else if need be you can have the fork crown race seat milled by a bicycle shop or framebuilder ----- |
Do you have the original crown race to compare? In my experience Raleigh had some odd proprietary sizing/threading etc bitd
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Is your headset 26.4 or 27.0 ID? Either the fork is cut for 27.0, or it needs to be cleaned up a bit with a crown race face and chase tool. Either way that's not something that all bike shops have nowadays, so check around. Alternately some more "advanced" framebuilders use a lathe.
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...some sealed bearing headsets are designed to operate with an easily installed spit crown race, and some are not.
I would not assume you can split yours and get your headset to still work well. As suggested above, get a decent caliper and measure what you have. Sometimes, if the press fit is especially difficult, PVC wont do the job. It flexes too much when you hit it with your hammer / mallet. |
Measurements:
https://cimg0.ibsrv.net/gimg/bikefor...19fcae735.jpeg Crown Race https://cimg3.ibsrv.net/gimg/bikefor...fccb0637c.jpeg Fork side-to-side https://cimg1.ibsrv.net/gimg/bikefor...1171cf1a5.jpeg Fork front to back I know Raleigh was known to do some crazy stuff, but use a 27mm crown race? Come on... this is a Carlton built Raleigh Competition, not a Nottingham built Sports or something. the VO (and others) is where the idea to just split it came from. I really don’t want to spend MORE money and have a shop face this thing. I looked for the original crown race and couldn’t find it. Also friend the fork in the freezer/race in boiling water trick to no avail. also, sorry for the crappy caliper measurements. Digital is needed. I looked at the photos again and it makes it look like the front to back measurement is 26mm and the side to side is 27. But the theoretically round crown race seems "pivot" or "hinge" on the seat at the front and back. If I didn't like old bikes so much, I would hate them so bad... EDIT: Also, sorry for all the edits. You would think someone at 36 could still work a computer and phone |
You'll want a metal "hammer" to set the crown race, like this one. No way a makeshift PVC pipe hammer will work with the tight interference fit on some combinations of steerer tube and crown race.
I just went through this with my early 1990s Trek 5900. I need to send the original Chris King headset off for servicing. Meanwhile I'm temporarily using an inexpensive but functional Origin8 headset. The crown races and bearing angles weren't compatible, otherwise I'd have left the original crown race in place. But the fit was so incredibly tight I couldn't budge the CK crown race with any makeshift removal method, so I took it to the LBS where they used the very elaborate, pricey and effective Park tool. They got it off in less than a minute. I knew the PVC pipe trick wouldn't work so I bought the most affordable setter/hammer I could find online. There are a few similar designs. This one uses separate piece with bevels to match most common crown races. Others with similar designs use grub screws to fasten the two pieces together. The separate design seems simpler. It looks and feels kinda crude, with a coarse "blued" finish to minimize rusting, but it's heavy, solid, not cheap pot metal and does the job. I've heard complaints about other similar hammers claiming they were pot metal. This one rings like steel when smacked so it's probably durable enough for repeated use. Even as heavy as this thing is, it took about 30 smacks to fully set the crown race, using the safer method of handholding the fork without allowing the fork ends/dropouts to touch anything. Some folks will set the fork ends against a block of wood or something similar but I didn't want to risk that. The air-hold method will take a little longer and more strikes, but is less likely to damage anything. I wore work gloves while doing this. The only danger is pinching the web of your hand between thumb and forefinger in the process. And wear safety glasses and hearing protection, of course. https://cimg8.ibsrv.net/gimg/bikefor...8736530a39.jpg "CyclingDeal" crown race setting hammer on Amazon. There are others with similar designs. |
I use a length of heavy steel pipe as a crown race setter, at least for steel races on steel forks (but not for CF forks!). I essentially use it as a slide hammer, and it delivers lots of force. Only once did a crown race brake in half as a result, so be careful out there!
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I just had a Stronglight race I could not set with even my press I use to assemble and disassemble SAAB transmissions. It was on a chromed fork (chromed from factory, which had a steel race happily on it before). I think the copper/nickel/chrome process added a couple thou and the Stronglight race was on the very tight side of the tolerance window, with no chamfers to help it go on, and made of soft aluminum. I ended up reaming the inside of the race with my Chadwick adjustable reamer. Just a tiny bit! Popped right on with a tight but manageable fit, using my standard hammer-and-pipe approach.
I'm wishing I'd done the same with my Trek. That one, I used an arbor press and I'm not confident I wouldn't destroy the race if I ever need to get it off! |
Originally Posted by Splendidtutiona
(Post 21707692)
Measurements:
https://cimg0.ibsrv.net/gimg/bikefor...19fcae735.jpeg Crown Race https://cimg3.ibsrv.net/gimg/bikefor...fccb0637c.jpeg Fork side-to-side https://cimg1.ibsrv.net/gimg/bikefor...1171cf1a5.jpeg Fork front to back I know Raleigh was known to do some crazy stuff, but use a 27mm crown race? Come on... this is a Carlton built Raleigh Competition, not a Nottingham built Sports or something. the VO (and others) is where the idea to just split it came from. I really don’t want to spend MORE money and have a shop face this thing. I looked for the original crown race and couldn’t find it. Also friend the fork in the freezer/race in boiling water trick to no avail. also, sorry for the crappy caliper measurements. Digital is needed. I looked at the photos again and it makes it look like the front to back measurement is 26mm and the side to side is 27. But the theoretically round crown race seems "pivot" or "hinge" on the seat at the front and back. If I didn't like old bikes so much, I would hate them so bad... EDIT: Also, sorry for all the edits. You would think someone at 36 could still work a computer and phone The rocking means there is a high spot, looks like a repair or some such was done, I would try and carefully smooth that out, it can spit a race even if you get it on. I have the Park setter and its not the best but does the job if you bring your A game, took a lot of force. The frame builder said he makes them tight so they stay that way. I would encourage you to get a proper tool, chamfer the race and use plenty of regular thick axle grease with the hot and cold parts method. And yes, you gotta get a digital caliper, that one has more deviation than the amount we're trying to look at. ;) |
I hate digital calipers because the batteries are always going dead on me. And my mind always plays trix on me with those verniers, although they are good for making noobs feel like rubes. But there are plenty of good analog dial calipers available. I use this one, which does metric and inch at the same time, and is available for around $36:
Anytime Tools metric-inch dial caliper If you take care of it, it's as good as a Brown & Sharpe. If you're interested in upping your caliper game... |
Originally Posted by Splendidtutiona
(Post 21707692)
I looked at the photos again and it makes it look like the front to back measurement is 26mm and the side to side is 27.
Don't get hung up on the rocking, it doesn't mean anything important. I think this is a simple case of crown race too small for the fork. If you don't want to mill or lathe-turn the fork, get a larger crown race. @scarlson, interesting dial caliper you linked to. I have always preferred digital for the instant inch - mm conversion at the press of a button, but yours does the same thing in analog – cool! Maybe my next calipers will be that type. I will say, my Mitutoyo digital doesn't go through batteries near as fast as cheap calipers do. I think there must be some drain or inefficiency in the cheap ones. One problem with Mitutoyo is all the cheap fakes out there. I've found it fairly safe to buy old used ones that were owned by machinists or engineers – less likely to be fakes. For installing, I have a Campy that you hammer on with a hammer (because it came with my Campy toolkit), but I never use it. I have a Var slide-hammer, and that is very satisfying to use. Usually about 3-4 whams to set the race, and the last one has a distinctly different sound, so you know when it's "home". Wear ear protection, it's very loud. Mark B in Seattle |
Thanks guys. I found the old crown race, and the measurement looks just like the new one, between 26 and 27mm, so I am assuming 26.4mm, not 27. I know the measurements on the fork look like 27 and that is what was messing with my mind. The crown "race" for the new headset is steel (thank god, i have been whacking at that thing all kinds of ways) so no worries there. Looks like I will be investing in one of these slide hammers I keep hearing so much about. Oh, and the fork will get a few hours in the freezer to go with it.
Thanks again. |
bulgie
I don't want to question your wisdom but does it not look like a high spot where it is shiny with less paint in both pics and what looks to be a blob of braze just above it that should lessened a bit? :foo: |
Good ideas about heating and cooling! I've been working on a 1972 Raleigh Competition, and just set the crown race with a section of pipe. Fortunately I had the original headset and it wasn't giving me major trouble. FWIW, I "hammered" by sliding the steerer tube down into the pipe with the dropouts in the air and the pipe on the floor, rather than hammering while supporting on the dropouts, to avoid pressure on the fork tubes.
https://cimg1.ibsrv.net/gimg/bikefor...a8bc63dc9d.jpg https://cimg2.ibsrv.net/gimg/bikefor...d944e419eb.jpg |
Originally Posted by scarlson
(Post 21708075)
I hate digital calipers because the batteries are always going dead on me.
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Originally Posted by bulgie
(Post 21708373)
@scarlson, interesting dial caliper you linked to. I have always preferred digital for the instant inch - mm conversion at the press of a button, but yours does the same thing in analog – cool! Maybe my next calipers will be that type.
I will say, my Mitutoyo digital doesn't go through batteries near as fast as cheap calipers do. I think there must be some drain or inefficiency in the cheap ones. One problem with Mitutoyo is all the cheap fakes out there. I've found it fairly safe to buy old used ones that were owned by machinists or engineers – less likely to be fakes. Anyway sorry for the thread hijack! |
Originally Posted by merziac
(Post 21708444)
I don't want to question your wisdom but does it not look like a high spot where it is shiny with less paint in both pics and what looks to be a blob of braze just above it that should lessened a bit? :foo: I tried the "upside-down" thing, but I only have a PVC. I think I am going to get one of the hammers that CancleCat mentioned and try that. This one has been an adventure for sure! |
PVC is never going to work. Get a piece of heavy steel pipe with the right ID.
The last time I had to do this I took it to the LBS for installation, because, even though I was a pro mechanic and have installed hundreds if not thousands of headsets, they have a crown race facing tool and I don't. (nor did I care to buy one) Not all LBS have the tool or skill to do this anymore. You have to ask. However, if your fork crown already had a headset installed and is properly faced, you should be able to do it at home. This assumes you have the right size crown race. If it's 27.0, get a 27.0 headset. If you can't tell, get better calipers. |
Originally Posted by Splendidtutiona
(Post 21708888)
I was thinking about this. I have been (very lightly) getting at that area with a file and sandpaper. I may be doing to too lightly it do anything, but i also don't want to mangle the race seat area of the fork.
I tried the "upside-down" thing, but I only have a PVC. I think I am going to get one of the hammers that CancleCat mentioned and try that. This one has been an adventure for sure! Sandpaper won't do it so the file is what you should use. Is there a fill or repair and is that braze and from it? |
Originally Posted by Splendidtutiona
(Post 21707692)
Measurements:
I know Raleigh was known to do some crazy stuff, but use a 27mm crown race? Come on... this is a Carlton built Raleigh Competition, not a Nottingham built Sports or something. the VO (and others) is where the idea to just split it came from. I really don’t want to spend MORE money and have a shop face this thing. I looked for the original crown race and couldn’t find it. Also friend the fork in the freezer/race in boiling water trick to no avail. also, sorry for the crappy caliper measurements. Digital is needed. I looked at the photos again and it makes it look like the front to back measurement is 26mm and the side to side is 27. But the theoretically round crown race seems "pivot" or "hinge" on the seat at the front and back. If I didn't like old bikes so much, I would hate them so bad... EDIT: Also, sorry for all the edits. You would think someone at 36 could still work a computer and phone My 75' Carlton built Raleigh Gran Sport has a 27mm crown race. I don't have the original head set, so I've been looking for one that'll fit. |
Originally Posted by merziac
(Post 21709471)
Well it looked like that to me, especially with the rocking at that spot, you should be able to smooth it if you're careful.
Sandpaper won't do it so the file is what you should use. Is there a fill or repair and is that braze and from it? I'm also investing in a proper tool. A place called MTB Tools seems to have one for like $10, so I sent them an email and we'll see what they come back with. |
Campy SR crown races are the ones that split. Try finding a good one! I couldn't.
https://live.staticflickr.com/2875/1...2598c6fd_h.jpgP9201322 on Flickr |
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