swapped fork, unsightly gap @ lower-HT/fork-crown

[wallymann]

new fork on my allroad. it's a tapered integrated deal.

with the new fork and lower bearing fitted, the gap is a bit bigger than the original. in the workstand at eye-level it looks terrible, but down on the ground in riding mode you don't even notice it.

is this just something that happens these days and your just live with it? seems like a great place for grime and water infiltration.

[Vientomas]

Would a generic O ring from the hardware store fill the gap?

[stev0]

It could also be, like in my case, that there's a specific part made just to fill that gap! It bugged me too much not to do it.

https://forums.thepaceline.net/showthread.php?t=234647 (https://forums.thepaceline.net/showthread.php?t=234647)

[gintas_ce]

Hmm..try using some ring. Otherwise it will gunk up after a while

[JSL]

Is the bearing sitting correctly on the fork crown? Looks like there could be a separate issue there.

[oldpotatoe]

Is the bearing sitting correctly on the fork crown? Looks like there could be a separate issue there.

Yup, is there no fork crown race?

[wallymann]

Would a generic O ring from the hardware store fill the gap?

i considered that, but the o-ring would tend to ride up the slope of the bearing seat. so i guess it maybe-could work.

Is the bearing sitting correctly on the fork crown? Looks like there could be a separate issue there.

Yup, is there no fork crown race?

nope. bearing sourced from the fork mfg, so OEM. and the bearing seat is molded into the fork crown. lots of designs work this way nowadays, yes?

[Big Dan]

Did you ride it at all?
Does it have any play if you pull the handlebars?

[wallymann]

Did you ride it at all?
Does it have any play if you pull the handlebars?

not yet. wanted to get this sorted, or at least investigated, before going further with the build.

[oldpotatoe]

i considered that, but the o-ring would tend to ride up the slope of the bearing seat. so i guess it maybe-could work.





nope. bearing sourced from the fork mfg, so OEM. and the bearing seat is molded into the fork crown. lots of designs work this way nowadays, yes?

Yes, lotsa forks w/o a FCR but....didja ask the manufacturer?

[fmradio516]

is the bearing upside down?

[Matthew]

To me that does not look right. Appears something should be on top of the fork.

[oldpotatoe]

is the bearing upside down?

ooo, good call....:)

[ultraman6970]

Maybe upside down bearing, but I was thinking if the manufacturer is using the same design at the crown/bearing area between their 1 1/8 and 1 1/4 forks, just because the bearings use the same angles?

[billspreston]

is the bearing upside down?

Would bet money on it.

[rePhil]

I once bought a closeout TST ti frame with a Ouzo Pro Integrated fork from Colorado Cyclist that looked like that. There were no issues other than that gap which in my case was caused by the integrated fork. CC assured me it was cosmetic. They were right, it was a nice riding bike that I rode for several years and thousands of miles issue free.

[wallymann]

Would bet money on it.

you'd lose! ;-)

here's the as-installed lower HS bearing for the new fork...and the bearing itself is actually shorter than the original lower-bearing used with the original fork.

fwiw...i think integrated headsets are stupid.

To me that does not look right. Appears something should be on top of the fork.

nope. neither original fork nor the replacement have anything there. the bearing rests on the integrated "crown race" area.

[ColonelJLloyd]

FWIW, that's exactly what it looks like when the wrong bearing is used on a fork with an integrated crown race. What fork is it and what do the markings on the bearings indicate? It'll work, but the bearing will not fully seat if the angle isn't correct. You're saying the fork manufacturer supplied you with that actual bearing?

[ColonelJLloyd]

fwiw...i think integrated headsets are stupid.

The issue looks to be the result of an integrated crown race rather than the integrated "cup".

[wallymann]

you're saying the fork manufacturer supplied you with that actual bearing?

exactly. i'm messaging with the maker right now. they're talking about making a ~2mm shorter bearing.

[ultraman6970]

Isnt better make the integrated crownrace lower? if somebody needs more room they can use shims... find a shorter/less taller bearing does look like a lot of a problem.

[wallymann]

Isnt better make the integrated crownrace lower? if somebody needs more room they can use shims... find a shorter/less taller bearing does look like a lot of a problem.

shorter as in thinner bearing, top to bottom that's what i need -- more space for the crown race area to nestle into the lower HT.

whats strange is that this new bearing is actually shorter/thinner than the original...the original ends up basically flush with the lower surface of the HT. this one nestles 1-2mm inside -- and i need even more space to work with this fork!

did i say i think integrated headsets are dumb?!

[rePhil]

In my case it was purely cosmetic. CC said they had run out of regular Ouzo and were substituting it with the Integrated version.
I was using a CK headset and the lower bearing was seated on the crown race correctly.

[slambers3]

Are the top and bottom bearings the same? Also, are you certain that the lower taper diameter of the new fork is the correct fit for that frame?

[wallymann]

Are the top and bottom bearings the same?

no.

it's a tapered setup, so top is smaller -- i forget the exact spec. doesnt really matter, as i'm retaining the OEM bearing there -- not changing the top-side setup.

changing the fork is forcing the low-side bearing situation to change.

[billspreston]

Any chance you can take a picture of the crown race and bearing interface outside of the head tube so we can get a better look? It looks like the bearing isn't resting on the crown race at all. I'm not sure the height of the bearing is the issue.

Integrated races like this generally (not always) take a 45 degree angle bearing. Possible you were supplied with a 36 degree angle bearing instead?

[wallymann]

bearing resting on crown...

https://forums.thepaceline.net/attachment.php?attachmentid=1697984457&stc=1&d=1567114381
https://forums.thepaceline.net/attachment.php?attachmentid=1697984440&stc=1&d=1567045646

Any chance you can take a picture of the crown race and bearing interface outside of the head tube so we can get a better look? It looks like the bearing isn't resting on the crown race at all. I'm not sure the height of the bearing is the issue.

Integrated races like this generally (not always) take a 45 degree angle bearing. Possible you were supplied with a 36 degree angle bearing instead?

[FlashUNC]

That doesn't look like the right bearing.

[Dave]

Put a thin layer of grease on the bearing so It marks the contact area. While it may look strange, the bearing looks to be about as thin as possible and it fits the frame, so the real problem is the tapered part of the fork being too tall and maybe too large in diameter.

It's probably made to fit a frame that takes a larger diameter bearing.

[blantonator]

bearing resting on crown...

https://forums.thepaceline.net/attachment.php?attachmentid=1697984457&stc=1&d=1567114381
https://forums.thepaceline.net/attachment.php?attachmentid=1697984440&stc=1&d=1567045646

Definitely the wrong bearings for this fork.

[AngryScientist]

that is definitely the wrong ID bearing.

that bearing should sit solid against the flat part of the fork crown, as a shoulder.

dont ride it like that.

[ultraman6970]

Is that a 1 1/4 bearing?

[jtbadge]

Is this frame even designed to fit a tapered fork? The bearings don't match up at all, and the fork barely looks like it would even fit in the headtube, even without a bearing.

Maybe you're using a 1 1/2" tapered fork when you needed 1 1/4", or something?

There certainly shouldn't be that much space between the bottom of the bearing and the fork crown.

[Vientomas]

That ain't right. Looks like that bearing would point load the steerer tube.

[ColonelJLloyd]

that bearing should sit solid against the flat part of the fork crown, as a shoulder.

Well, actually it should not. It should be close, but be entirely supported by the angled race.

That said, what the OP has isn't right.

[Caballero]

Which frame/fork/headset ?

[wallymann]

yes.

Is this frame even designed to fit a tapered fork?

[jtbadge]

This chart is a good start, but you're going to need to add more information.

What is the fork you are trying to use? It looks like it has a 45º crown race built in, and the stock lower bearing with that headset was built for a 36º inner angle. This would make the bearing sit too high, like we are seeing. This would also mean only the very corner edge of the bearing is supporting all of the weight you put onto the bars, instead of the entire bearing surface. This sounds like a recipe for disaster.

What was wrong with the original fork?

[wallymann]

new fork is TA, the reason for the "upgrade". made by hylix out of China.

i was supplied a new 45/45 lower bearing with the fork.


This chart is a good start, but you're going to need to add more information.

What is the fork you are trying to use? It looks like it has a 45º crown race built in, and the stock lower bearing with that headset was built for a 36º inner angle. This would make the bearing sit too high, like we are seeing. This would also mean only the very corner edge of the bearing is supporting all of the weight you put onto the bars, instead of the entire bearing surface. This sounds like a recipe for disaster.

What was wrong with the original fork?

[billspreston]

My initial impression after seeing the bearing + race photo was that bearing has to be wrong but after taking a look at my Parlee with a molded crown race I'm not so sure. The Parlee looks similar to your setup, but with the bearing maybe sitting 1-2mm lower. The gap on my Parlee, however, when everything is mounted up is very tight.

Still thinking maybe the bearing angle is off, but this could very well be correct from a functional perspective. A shorter bearing height (if that exists?) might indeed help to close the gap in this situation.

https://i.imgur.com/3JCwfGf.jpg

https://i.imgur.com/lYAhWYJ.jpg

[billspreston]

Any luck getting that gap reduced? Curious how this ends up.

[zero85ZEN]

I had this issue (excessive gap between frame and fork) with a non integrated crown race on a 3T Funda Team fork mated to a Focus Cayo frame. Drove me absolutely nuts! The problem in my case was that the crown race would not sit absolutely flush to the top of the fork. I went through 3 forks purchased from (and 2 returned to) Nashbar until I got one that allowed the race to sit flush and thus closed the gap.
In your case it almost appears that the integrated crown race is molded too high up onto the steerer and thus the bearing sits too high. May be a manufacturing quality control issue. If you purchased the fork new, I’d recommend exchanging it for another.

[wallymann]

Any luck getting that gap reduced? Curious how this ends up.

still waiting on parts and for some time to free-up to work on it.

[wallymann]

i got my bearings pressed in and everything built up the same as the 1st set and the gap is there, so i'm just moving ahead with the build. its not terrible -- from the saddle or any standing position where your eyes arent peering right at the fork-crown area looking for an issue, the gap is not really visible.

on to more important things...the new fork is a flat-mount disc with T/A, so i'm dialing-in the ISO-to-flat adapter and will be re-lacing the front rim on a T/A hub.

not perfect, but not terrible...ya gotta put your snout down at headset level to see the gap.