Member8 March 2009 at 5:17 pm
Another lesson needed by old ba5tard! 😳
OK, I’ve figured how to fit it – piece of cake! Now, FWICS, you can adjust this with screwing in the head cap and also by turning the Allen screw on the Diatech collar between the top cup and the stem. Then presumably you tighten the two stem bolts on the steerer to lock it all into place.
Now, when I tighten the screw on the head cap, it’s fine …. until I tighten the collar, which tightens it too much …. and vice versa 😳
Is it just a question of tightening both a nip at a time with trial and error or am I missing something? 😯
Member8 March 2009 at 5:34 pm
well if were on about the same thing i tightened mine up on my road bike yesterday….
i tighten up the headset nut as tight as you think… then tighten up the stem…
are we on about the same thing 😕
Member8 March 2009 at 5:42 pm
Almost, but I also have a clamping collar between the stem and top race. It’s threadless, of course.
So, two things that tighten to adjust and the stem itself to lock it.
Member8 March 2009 at 5:44 pm
They aren’t normally that sensitive.
Make sure the top cap is not sitting on the actual steerer tube when tightened.
Other than that. Load the top cap and check tightness by putting the front brake on and rocking it. Once done tighten the stem bolts and er that’s it.
The top cap is only for setting the preload it has nothing to do with keeping it tight. The stem does that.
It sounds like that’s what your doing though.
Member8 March 2009 at 7:00 pm
Yes, sure, I’ve worked that out but where does the Diatech collar come into it?
This has a conical washer under it that when you tighten the collar against it, it forces the washer downwards, thus tightening the assembly. So, in effect, you can get the headset assembly tightened without even a stem on and don’t actually need to even have the use the top cap to tighten off the headset. The Marin actually came with just a pop-in top cap …. old skool?
Should I just nip the top cap up or try for half and half between the top top and the collar …. or doesn’t it matter?
Or as I’ve now got a screw-in top cap, should I chuck the Diatech collar and just get some standard 1 1/8-inch spacers and rely on the top nut?
Member9 March 2009 at 4:40 pm
From what I can see, the Diatech is an early attempt at clamping a threadless headset. This is confirmed by the fact that the cap on top of the steerer is a push-in one, just like a handlebar plug and as such, plays no part in clamping the headset. When I first got this bike, I used to clamp by loosening the Diatech clamp and the two bolts on the stem and gently tapping down the stem with a rubber mallet until it was almost tight. Then I tightened the A/K on the Diatech collar and this pushed down the cone-shaped washer until headset was tight (no rocking, but no indexing). Then, of course, just aligned and tightened the stem.
I didn’t know that these are so rare but in any event, have ordered a couple of 1 1/8-inch 5mm spacers so that I can remove the Diatech collar and tighten with the top cap, as now seems to be the norm. 😀
Handy Tips Department for headsets
When removing the headset cups from inside the headtube, Sheldon Brown suggests tapping these out with a screwdriver. I myself have found that the easiest way is to use a 1/2-inch socket and an extension bar.
To remove the first cup, you’ll need to find a socket just big enough to fit through the other cup, about a 22mm one. Fit the socket to the bar backwards, so that the rear of the socket touches the inner edge of the cup. Then hold the extension bar hard against the inside edge of the other cup and give two firm taps before moving the extension bar to the opposite side for another two taps. Keep repeating this until the cup pops out – if doing this in the living room or a china shop, just tape a plastic bag over the cup you’re removing, as a grease-sodden piece of metal flying across the room will pi55 off the wife and scare the crap out of the moggy!
Other side is even easier – with no cup there, you can use a bigger 24(?)mm socket.
To fit the bottom race to the fork crown, I use an adjustable spanner opened to 1-1/8-inch and use a hammer to tap this down on opposite sides so that it fits flush.
If you find that the bottom race is too loose and that it just slides onto the fork crown too easily, just run around the contact surface of the fork crown with a hole punch and hammer and put about 12 slight dimples on this. This should enable you to get a tighter fit.
Member10 March 2009 at 2:54 pm
Heh I use the following.
Install crown race
Like the idea on loose crown races although shouldn’t really happen on modern forks now. I’d be a bit miffed if I bought something that undersized.
Member10 March 2009 at 4:19 pm
Tom, truly you are a God amongst we mere mortals! 😀
As regards the crown, I’ve only ever seen this problem twice, both times after an over-enthusiastic removal of excess paint after a respray. 😕
Member10 March 2009 at 4:24 pm
It’d probably be cheaper if I took everything to the bike shop though.
I’ve done DIY headset installations and using a proper press is so much nicer.
Member10 March 2009 at 4:33 pm
Yeah, but getting medieval with a club hammer and block of wood is a bit theraputic for me! 😉 😀
Member10 March 2009 at 5:12 pm
i must agree steve 😈 😛
Member10 March 2009 at 5:41 pm
I’ve got a big axe and a chopping block for that.
Member10 March 2009 at 6:57 pm
I’ve got a big axe and a chopping block for that.
Pagan!! 😉 😀