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Hi all,
I'm new to the forum, I'm into road bikes and am currently building a bike from scratch for the first time (after bending the frame of my old bike!).
I'm building the front fork & handlebars at the moment. It's a Planet X RT-58 frame and fork and I am using a FSA Orbit C-40 No.42 ACB headset (I bought purely as that's what Planet X spec on the RT-58 themselves as I don't really know much about the options when it comes to headsets).
I've cut the fork down following youtube video's and am using a 3mm spacer above the stem to clamp the top nut into the compression plug. I've got a torque wrench and am following the recommended Nm's.
I've got a couple of problems I'm not sure about and was hoping to get some advice:
1) The bearing retainer for the bottom bearing does not slide on to the base of the steerer/fork. Is it a necessary? I was thinking perhaps the design of my fork has an inbuilt taper to hold the bearing in the place. See pics!
Retainer in question:
https://goo.gl/photos/Vg9ytQ1XyhAA3vdg8
Pic of how far it will locate on the fork:
https://goo.gl/photos/Bcqx8pGq3NXPpx2L9
Pic of fork without retainer (should have wiped off the grease, but by design it is tapered like the retainer)
https://goo.gl/photos/AUWTA2qdtbkZ8tXY7
2) I've assembled without the bottom retainer for the time being and even just marginally tightening the top cap makes the steering stiff. If I loosen the top cap the fork is no longer solid. What am I doing wrong here?! More grease?
Here's a pic of the fork and stem in situ - showing just incase the fork isn't cut to the right height:
https://goo.gl/photos/Hy1esoHgHv4J24K38
Many thanks for any help 🙂
Matt
What you're calling the bearing retainer looks like the crown race; it needs to be seated onto the crown of the fork. There's a special tool for seating it although some folk bodge it with a bit of plastic tubing or tap it down gently with a piece of padded rod.
When the headset is correctly preloaded the crown race will be pulled up into the headset and mate with the bottom bearings (probably in a cartridge).
Also the steerer tube looks too close to the top of the stem to preload the headset properly with just the top cap, but it you're going to use your spacer on top of the stem then there should be some steerer above the stem on which to fit it. You'll need 3mm or more space above the end of the steerer for it to be pulled up into when you preload the headset.
There's plenty of useful tutorials out on the net but it's not a bad move to pay a bike shop to do the deed in the first instance rather than risk damaging stuff. You'll soon pick up the skills.
Thank you PJay. That now makes perfect sense.
I don't have the tool so think i'll get the LBS sort it for me.
I did think the steerer was too high for the top cap to bolt on to the stem. I think the gap is meant to be 3mm isn't?
I was thinking that it might not be a bad idea to let the bike shop do the full fork fitting, headset preloading thing for you as a first built and hopefully let you watch and talk you through it if you're not quite sure yourself.
In terms of gap above the steerer you need to make sure that there's enough space above the steerer for it to be pulled up a little without hitting the top cap when preloading it.