Bicycle Mechanics - Swapping a crown race...

Is this a DIY job or should I take it to the LBS?

i wouldn't do it without a suitable press to install the new one. a pipe is ok, otherwise park make a good tool.

i've had bike shops mess this up quite a lot though (not set it fully or scrached the paint) so i always do it myself.

Usually DIY just fine. Use a flathead screwdriver and a hammer - turn the fork upside down (so that the end of the steerer tube is sitting on the floor) and place the screwdriver's flat head against the underside of the crown race, and tap the screwdriver with the hammer. Alternate taps between the front-of-the-fork and the rear-of-the-fork sides of the crown race.

It's easy enough to tap a new crown race onto the fork in the same fashion, except with the fork right-side-up this time, and you can tap all around the crown race (not just front and back) to ensure that it's evenly seated on there. Just be careful not to hit the screwdriver's head against the bearing surface of the race. The screwdriver should contact the inner edge of the crown race, directly next to the fork's steerer tube.

I've found it can be useful to set a block of wood on the floor, and set the fork on top of the block of wood (for either operation).

Also, make sure the replacement crown race is the same size as the previous one. There are two main standards for 1" steerer tubes - JIS (27.0mm) and ISO (26.4mm). ISO is more common, JIS is still on some cheaper bikes, and was on lots of cheap asian bikes and some good asian-made bikes (e.g., Centurion Ironmans) in the 80's. Sheldon Brown has a page on headset sizing standards (http://www.sheldonbrown.com/cribsheet-headsets.html).

Geez, a piece of pipe costs about $2 and will save a lot of time and hot air.

Geez, a piece of pipe costs about $2 and will save a lot of time and hot air.

Use copper drain pipe. It's soft and you can sweat a cap onto the top to give you something to pound on if you need to. Plus the cap provides some heft to drive the race into place.

For removing the race, the slickest thing I seen in a very long time (I used to do the screw driver thing) is a bearing splitter (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=7343). Simply put it around the race so that the bevel contacts the bottom and tap on it with a hammer, it slips them right off. Bike Tools Etc (http://www.biketoolsetc.com/index.cgi?id=472057412849&d=single&c=Tools&sc=Headset&tc=Crown-Race-Removers&item_id=CV-501). sells a very nice one for $40

I have a pair of brand new Coppi forks I want to put onto my old bike as the original forks are bent. I have a brand new Dura Ace cartridge headset, but when I tried to fit the crown race onto the forks (using the screwdriver and hammer method as described earlier in this thread) it won't go all the way down to the flat on the top of the crown. Is it likely that the forks are actually 'unfinished' and I need to get them faced down to the correct diameter, or do I just need to get some suitable pipe and use a bit more brute force? I've already chewed the inside of the crown race a bit, and I'm nervous about doing any damage that might turn it into a write off.

I used to take mine to LBS thinking that they had a CR puller. Turns out he uses a screwdriver, so I figure i can do that on my own.

Another way of removing a crown race is to open a bench vise and slide the fork legs over the center bar so the edges of the race sit on top of the vise jaws. Soft jaw inserts are highly recommended. Close the vise to just barely touch the fork crown so the race overlaps the jaws as far as possible. Place a block of wood over the steerer top to protect it and use a mallet or light hammer to pound on the wood block. The race usually pops right off.

This technique assumes the race's outer diameter is large enough to overhang the fork crown. Some aren't and some forks are so wide it doesn't work either. For these you need a "bearing splitter" type of race remover.

To the Coppi guy: I've had this problem, and you will either have to take it to the LBS to file down some of the fork crown, or file it yourself. I took mine to the LBS to watch them do filing I could have easily done at home.

To Taken 67: I'm in favor of the PVC tube to press the new crown race vs. any metal tube. It's definitely softer than the crown race and you can always file it down after hammering to make a new, flat surface. Works like a charm for me.

Some crown races will come off without any tools. I have a Giant TCR, and the crown race has a gap in it that allows you to pull it off.

Some crown races will come off without any tools. I have a Giant TCR, and the crown race has a gap in it that allows you to pull it off.

My FSA Orbit XL also has a split crown race that requires no tools to install or remove. This type, of course, requires the use of cartridge bearings but I'm surprised it isn't universal with cartridge bearing headsets.