Got a tight fit beween a crown race and crown, the difference in diameters being 0.15-0.20mm. I had a go with the race setting tool but wasn’t making any progress - I wasn’t game to hit it too hard given the last line of the quote below. I’ve been told heating up the race should work - that putting it in the oven should be sufficient.
Does that seem reasonable or should I get the crown cut?
dont hit the race setting tool. wang the thing against the ground. it does less damage to forks, and applies more force.
it should go on, but yeah, heat it if you have to.
you can also get the race milled.
Not a major process.
There are 2 different sizes…
yeah but its pretty obvious. a 26.4 is NEVER going to go onto a 27.0 race, and its painfully clear.
By the sounds of things we are talking about much smaller differences here.
my crown race snapped because the dude at bike shop smashed it on. id even tried filing back the crown.
I had the same problem a while back and I used a small flap wheel (80 grit) in the drill press to take just a bee’s dick off the ID of the crown race.
Then I heated the race in the oven and put the fork into the freezer while the missus was out of the house.
ended up with a good interference fit. YMMV
Thanks guys, I’ll give the oven/freezer combination a go.
a.davis12, it shouldn’t take that much force to get it on so I’ll stick with moderate hammering, I want to avoid what happened to 2joes.
Failing that, does anyone know a shop in Sydney with a crown race cutter?
The right store might have a 27.0 crown race laying about that they’d swap you for. Its worth getting on that fits right instead of macgyvering the wrong size on.
Yeah but the wrong size here is 27.0.
That’d make your fork crown a 26.4?? Whichever, you could probably get a swap.
There’s a whole lot of either miscomprehension or plain not reading going on in this thread.
+1
For clarity, the race is ~26.3 and the fork crown is ~26.5.
Your crown is slightly oversize.
1" ISO is 26.4mm (you), 1" JIS is 27.0mm
As mentioned already, just take the fork to a good shop and they can mill it to 26.4 in a jiffy.
If it still doesn’t fit, buy a new bike headset.
Yep, and the crown race is slightly undersized, as both parts have been chromed - though the problem is the crown because I’ve tried other headsets.
I’ll get the crown cut.
Erk. That makes the milling more difficult.
Good luck.
If it is chrome would you be better to sand it? also is there any meat on the race to take away?I know it will be long and laborious but so will getting the chrome fixed up. because of the tight fit it may not be as crucial to have it to have it exactly round if you know what i mean?