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-   -   Installing a cheap carbon fork. Is this normal? (https://www.bikeforums.net/showthread.php?t=1263582)

alexk_il 11-22-22 02:48 PM

Installing a cheap carbon fork. Is this normal?
 
Trying to replace an old and heavy suspension fork with a cheap Toseek carbon 27.5 fork.

The steerer has two "ridges" at the bottom, the last one prevents the bottom fork crown race to go all the way down.

Is this normal? Shall I file the ridges off or just force the crown race down?


https://cimg9.ibsrv.net/gimg/bikefor...2d4b3850d2.jpg
https://cimg1.ibsrv.net/gimg/bikefor...439886e7e6.jpg

grumpus 11-22-22 03:24 PM

The race should be a firm press fit. You need to support the race evenly so it's dead square as you press it on - if it tilts as in your picture it can dig in, not go on and damage the fork. It might help to gently smooth the carbon with a fine abrasive, but as I can't see/feel what the fit is like I can't recommend it.

alexk_il 11-22-22 03:42 PM


Originally Posted by grumpus (Post 22718394)
The race should be a firm press fit. You need to support the race evenly so it's dead square as you press it on - if it tilts as in your picture it can dig in, not go on and damage the fork. It might help to gently smooth the carbon with a fine abrasive, but as I can't see/feel what the fit is like I can't recommend it.

Thanks.

I can push it diwn and make it sit square only using my fingers and no tools, though I can't make it go down all the way.

I see youtube videos where they use an extendable race that can be pushed down. Check after 2:40.


Here is mine, still not sure if this is how it is supposed to be or shall I try to get it all the way down.

https://cimg3.ibsrv.net/gimg/bikefor...dee32a2f6f.jpg

Rolla 11-22-22 03:53 PM

I'd use a crown race setter with the appropriate diameter and interface. Not worth buying one, IMO, but your LBS can do it in about a minute. Finger-tight isn't how you want it.

alexk_il 11-22-22 04:01 PM


Originally Posted by Rolla (Post 22718421)
I'd use a crown race setter with the appropriate diameter and interface. Not worth buying one, IMO, but your LBS can do it in about a minute. Finger-tight isn't how you want it.

Used fingers only to avoid unnecessary damage from rushing, smashing or pressing things harder than needed.

Anyway, problem solved now. I figured out that the fork/headset are built to support riders heavier than myself, so I just put the fork into the headset, loaded it with my weight and the race snapped to the bottom of the fork. All is nice and flash now.

Thank you anyway.

FBinNY 11-22-22 05:00 PM

It's an interference fit, so a decent amount of force is called for.

You can use a short length of faced steel pipe as a slide hammer to do the job.

veganbikes 11-22-22 08:42 PM


Originally Posted by alexk_il (Post 22718428)
Used fingers only to avoid unnecessary damage from rushing, smashing or pressing things harder than needed.

Anyway, problem solved now. I figured out that the fork/headset are built to support riders heavier than myself, so I just put the fork into the headset, loaded it with my weight and the race snapped to the bottom of the fork. All is nice and flash now.

Thank you anyway.

That is a bad way of doing it, I would maybe consider have someone double check it all that nothing was damaged. It might not have but generally you are not using bearings as a press. I would not do this sort of thing on any fork but especially a random cheapie carbon fork of unknown quality.

alexk_il 11-22-22 11:36 PM


Originally Posted by veganbikes (Post 22718644)
​​​​​​... generally you are not using bearings as a press...

Agree in general, but in this particular case the crown race is designed to press against the sealed bearings when we cycle, right? The riders's weight is creating this pressure, so it's supposed to withstand a lot of stress.

Or did I get it wrong?

Anyway, all seems to be good in a visual inspection.

Camilo 11-22-22 11:55 PM


Originally Posted by alexk_il (Post 22718719)
Agree in general, but in this particular case the crown race is designed to press against the sealed bearings when we cycle, right? The riders's weight is creating this pressure, so it's supposed to withstand a lot of stress.

Or did I get it wrong?

Anyway, all seems to be good in a visual inspection.

I'm not saying the way you did it won't work, but when you use the proper tool (either purpose-built, or home made) you're tapping it into place with the force between the race and a pipe-like tool. You've essentially used a much more fragile bearing instead of the tool to tap it into place. You'll probably notice if you damaged the bearing (I would guess not) and failure would not likely be catastrophic, just needing a new bearing I would think.

That said, I've installed a few races without a tool. Frankly, I never thought of doing it your way and probably would have tried it if I had. But what I've done is I slide them down the steer tube as far as I can by hand, keeping it squared up to the steer tube. I've then seated it by tapping with a wooden stick or dowel and hammer very carefully and in very small increments, slowly and evenly around the race, keeping it squared up, Tiny taps, very evenly. It's actually not that hard to do it, patience and common sense involved. It's pretty crucial to keep it very squared up, because if it gets angled too much it binds. You just have to work your way around bit by bit. A tool would definitely be more fool proof and easier.

FBinNY 11-23-22 12:27 AM


Originally Posted by alexk_il (Post 22718719)
.....
Or did I get it wrong?

Not at all. The only issue might have been starting it at an angle.

In fact, it's not at all rare for headsets that weren't pressed in all the way, to settle over the first few rides.

veganbikes 11-23-22 10:32 AM


Originally Posted by alexk_il (Post 22718719)
Agree in general, but in this particular case the crown race is designed to press against the sealed bearings when we cycle, right? The riders's weight is creating this pressure, so it's supposed to withstand a lot of stress.

Or did I get it wrong?

Anyway, all seems to be good in a visual inspection.

Not in the same way using bearings as a tool is never a good thing as they aren't really designed to be a hammer. They do sit against the race and in the frame but it is not the same as using them as a hammer. Possibly OK but not something I would want to do with bearings. When you are putting on a crown race like others have said you use a tool or a piece of pipe but at no point do you introduce the bearings into this until finished hammering because you don't want to damage the bearings.


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