C59 Acros headset bolt
Comments
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looks like a grub screw - have a look on screwfix (the narrow bit on the end looks non standard but if that bit isn't important then a grub screw will be the same - just the threaded part in effect)0
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Yes it is a grub screw, but as you say, that narrow bit could be necessary if what it is going into is narrower, or something else is resting down onto it that requires it to be like that. I will have to take it apart to find out.
Of course, somewhere there is a bit parts drawer with thousands of the actual item in it, it's just finding where.
Canyon run a similarly principled design, maybe their grub screw is the same if I could source it that way.0 -
Can I ask why you need another?
I've got a C59 to build and it too has one of those headsets. I am slightly nervous about in terms of its design because it reminds me of the USE top capless stem designs of yesteryear. It was a split ring thing (with a silly name like ring-go-star or something) and it was completely crap. I can't say I'm delighted about headset preload adjustment via a grub screw.
Hopefully C59 owners will be along to reassure me soon.0 -
Just that the head is a little soft, rounding a bit, probably due to a less than fantastic allen key.
Some alternatives for you...
You can buy the regular style C59 headset they started with. http://www.sigmasport.co.uk/item/Colnago/Integrated-Race-HS01-Headset-for-EPS-and-C59-Frame/RHY (expensive on that link). Comes with 2 conical carbon top caps of different heights and if you use the taller one it just slots over the shorter one.
Or... you can just put the acros stuff on the top, never touch the grub screw to do it up, so you just use it like a regular top cap spacer, then put an expander bung in the fork and adjust like that.0 -
i replaced my headset with a C60 headset. I think those little bolts are Torx 8 or 6 hence get rounded using allan key. You also have to destroy the plastic compression ring to remove the forks, its such a tight fit. A headset that didn't need to be invented.Pegoretti
Colnago
Cervelo
Campagnolo0 -
mfin - thanks for the info and the link. And you're right, that IS and expensive headset!
Yes, I thouht I might just bypass the across headset and bought a Colnago expander bung a week or two ago. It's the longest bung I've ever seen! That is in keeping with their conservative approach to forks, I suppose. Of course, now I'm in "need" of a Colnago top cap. Hmmm.
on-yer-bike - thanks for pointing out that it's a torx. It's so small I might not have spotted that! And agree with your last sentence too.0 -
Well, finally got round to building my C59. (52s KOM from Windwave, BNWT)
I went down the conventional expander plug route, with the acros parts mated, but not tightened/expanded. The plastic ring which fits inside the top bearing is a very tight fit, but doesn't seem to stop fore/aft play. Even when my top cap is deliberately overtightened (i.e. excessive resistance to turning the handebars), the play still exists. The normal headset problems are not the cause: the plug is secure (i.e. it doesn't tend to lift out the fork) and the underside of the conventional top cap does not meet the plug when tightened. I wasn't fully satisfied with the headset adjustment, despite several attempts, but ran out of ideas and/or patience.
About 20 miles into today's 70 mile shakedown ride, the headset works loose. Cue fettling every 15 miles or so, until I revert to the deliberately over-tightening route to get home. I'm actually wondering if the play exists at the bottom of the headtube, as if the crown race isn't fully engaging in the lower bearing. Hmmm.
In a nutshell, my current thoughts are that the C59 frame is absolutely brilliant, but the acros headset is an absolute sac de merde. I'd love to hear what if other C59 owners have encountered this and what they did to fix it.0 -
Should also perhaps say that one thing caught my eye during the build: the split crown race was pressed on (either by Colnago or the UK distributor), so that the split is very close to being straight ahead. It wasn't at 12 noon exactly, more like 12:30, but I thought that was a no-no. Can't see it being the source of my problems right enough...0
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If you're using a conventional expander bung then the Acros parts are doing nothing but acting as a top cap.
I have ended up using the original headset supplied with the early C59's.
http://www.slanecycles.com/colnago-race-hs01-integrated-headset-1-18-1-14-p-25888.html
(I didn't pay that much for it though, so search around).
...I actually have used the two cnc'd acros bits as a topcap, purely because of aesthetics on the colour scheme of my bike.
If you wanna fit one of these headsets you'll wanna pop to a bike shop to get the old headset cups pressed out and the ones from the HS01 headset pressed in.
This headset just works, although I'm not saying you wont be able to suss what is going on with yours and sort it.0 -
mfin - thanks for the reply.
Yes, my acros is not tightened, and is therefore acting conventionally at the moment. It's fully unwound, so has no scope for unwedging/loosening mid ride. I think I will go through the disassembly process and have a closer look at the bottom bearing and crown race. Some of the FAQs on the acros website are crazy (see http://www.acros.de/SERVICE/FAQ/HEADSET:::6_75_169.html ). How they ever thought this system added any value to anything is beyond me.
Regarding the replacement headset you bought: does it use angular contact bearings, so that the top cap compresses an angular split ring down the fork into the upper bearing? That arrangement works, unlike the acros system which has the crappy plasic spacer and non-angled bearings.
In terms of alternative headsets, I was looking at the Slane cycles website earlier as the C60 headset also fits C59s and they are cheaper at £90. I also got a discount code by email from them the other day, so I might take the plunge if no other solutions present themselves.0 -
Yes, angular bearings. That headset is just the same as most headsets you ever see, just with press in cups to complete the headtube.
Fully unwound so there's no forced split is how my Acros pieces are.
Have you tried a shim (one of those thin shiny metal ones) immediately under the acros cnc'd bits? Just making sure you're not pulling the acros stuff down against the edge of the headtube cup instead of that force loading down through the guide that sits in (on top) of the top bearing. I'd have a look at that if you have one of those thin shiny spacers lying around, chuck a couple in even just to see if it all then works sweetly.
The Acros is a shit system really I agree.0 -
That was one of the first things I tried when I wasn't happy with the build. My problem was that the plastic component is "T" shaped in cross section, so when pressed down the fork steerer into the top bearing, half of the top of the "T" sits above the bearing, meaning that none of my thin shiny washers would fit over it.
EDIT: I'm looking forward to getting this fixed, as it's detracting slightly from what otherwise was a thoroughly enjoyable shakedown ride. Lovely bike, the C59.0 -
Even if you have to get the other headset to sort it you will have it running perfectly soon. Enjoy.0
