(Issue Resolved and closed) Gap between fork and head tube

Rpou · #1 07-02-2020, 09:31 PM

Hey all,

I am guessing this is operator error but I recently picked up a 2004 Fondriest Carb Level Plus frameset. When I went to install the fork with the headset it came with the crown race wouldn't seat all the way on the fork. See below.

So I figured it was just the wrong head set so I researched the standards and after measuring the head tube it seems to me the headset is a Internal Headset in the measurements 42/28.6 for upper and 42/30 for the lower. The upper headset fits fine and the bearing for the lower headset fits great too, its just the crown race that is out of place.

I then order a new 30mm crown race and when it came in the ID is not quite 30mm. See below. When I went to install I get the same thing as the first one. Since the crown race to seat all the way down on the fork I end up with this huge space.

Do I have the wrong headset based on my measurement. It seems to me that if the OD of the bottom of fork steerer tube is 30.09mm the ID of the crown race has to be larger than that.

eddief · #2 07-02-2020, 10:27 PM

now maybe your race is too small or fork steerer is too big and out of spec, but maybe you simply need the right whacking tool?

https://www.youtube.com/watch?v=wQQxJfhHLTs

Rpou · #3 07-02-2020, 10:48 PM

I didn't know that but now I do. The one you tube video I watched the crown race didn't have to be pressed on so lesson learned is watch more than one. Thanks for the video.

m_sasso · #4 07-02-2020, 11:10 PM

Here are some numbers for you.

No mallet needed and use some grease, un-like the video above.

Put the fork in the freezer for an hour and put the crown race in some hot water. Pull the fork out of the freezer, lube the fork steerer crown race seat. Pull the race from the hot water, slide the race on the steerer, slide your PVC tube/installer tube over the steerer, invert it along with the fork and tap the installer on the ground allowing the weight/gravity of the fork to do the work of installing the race.

robt57 · #5 07-02-2020, 11:17 PM

fork in freezer, race in hot water. Grease, and get in on fast.

Problem is the race is steel and the crown is alloy, guess which one will win...

Or cut the race. Some headsets actually come with split races.

mjf · #6 07-02-2020, 11:28 PM

Quote:

Originally Posted by robt57

fork in freezer, race in hot water. Grease, and get in on fast.

Problem is the race is steel and the crown is alloy, guess which one will win...

Or cut the race. Some headsets actually come with split races.

Also not the ideal, but occasionally have needed to lightly sand a crown race to take off the tiniest amount to get it on the fork smoothly.

ultraman6970 · #7 07-03-2020, 12:03 AM

I do not think is super off specs, the crownrace needs to fit tight thats why is tad smaller...that crownrace is made of aluminum, is not steel. All crown races are tad smaller so they fit tight.

1s option, put a lot of grease and just pipe it (if you are using a plastic pipe) hard, it will go in...

2nd option... sand the crown race a little bit, put a lot of grease and pipe that thing down. (i would do this)

3rd option, sand the fork... not good idea :P

4th... ad the friend said, cut it and slide that sucker in, put grease obviously. The pressure of the stuff will keep that in place. IMO u shouldnt have any problem because had bikes that came with the crown race split from the factory, actually some headsets new sometimes come like that.

My fabs... 2 and 4.

Rpou · #8 07-03-2020, 12:36 AM

Brilliant stuff all around. I’m gonna try the freezer and hot water trick to start. The thought it needed a little coercion to press on the tube crossed my mind but thought I should make sure before I just start using brute force.

robt57 · #9 07-03-2020, 12:44 AM

I've been known to be brilliant [in my own mind].

Peter P. · #10 07-03-2020, 05:05 AM

All of Rpou's measurements are correct and within tolerance. It's supposed to be an interference/press-fit, not a slip on fit.

No modification of the fork crown O.D. is necessary.

In the absence of the proper tools to install the crown race, if you have an old crown race from removal, you can invert it and place it against the new crown race. They should align. Use your slide hammer of choice to strike the old crown race which will push the new race into position.

The title of Rpou's post is "Gap between fork and headtube" but his question appears to be related to fitting the crown race onto the fork. Is there another problem?

Rpou · #11 07-03-2020, 10:09 AM

Peter P.,

No other problem. Because I didn’t know about the interference fit of the crown race I couldn’t get it to seat properly so that was creating the gap. The real problem was always the lack of knowledge on the crown race and how it is installed so I think I am all set now. I’m gonna tackle that today now that I am all squared away. Thanks all for the help.

Coda1 · #12 07-03-2020, 10:43 AM

Wouldn't putting the race in the oven work better then hot water? Oven could go over 400 degrees.

slambers3 · #13 07-03-2020, 10:54 AM

Quote:

Originally Posted by Coda1

Wouldn't putting the race in the oven work better then hot water? Oven could go over 400 degrees.

Do not put a carbon composite fork in a an oven. There are critical glue bonds between the AL and carbon components that could be damaged with heat. Doing this to install a crown race in the absence of using a crown race setting tool is absurd.

old_fat_and_slow · #14 07-03-2020, 10:56 AM

Quote:

Originally Posted by Coda1

Wouldn't putting the race in the oven work better then hot water? Oven could go over 400 degrees.

Most crown races have rubber seals on them. If you get the temp too high you'll char or burn the rubber, and ruin it.

Rpou · #15 07-03-2020, 12:37 PM

After taking everyone's advice I triumphed this morning.

1st Attempt - I put the fork in the freezer and then put the all metal crown race in boiling water. Ace Hardware didn't have any heavy duty pvc pipe so I found a sink pipe extension that fit perfectly but wasn't very robust. I tried to install the crown but quickly found the sink pipe extension didn't have the strength to transfer the hammer strike to the crown race to fully seat it.

2nd Attempt - I went to Home Depot and got some proper 1 1/4" schedule 40 PVC and a cap. The 1 1/4" pipe fit perfectly around the 30mm crown race. This allowed proper hammer strikes that fully seated the crown race. For $5 bucks I think the ad hoc tool worked pretty well.

Thanks for all the advice.