I'm keen to learn a bit of bike maintenace and have a few concerns around adjusting threadless headset. I've been flicking through some maintenance manuals in Waterstones (and have a copy of Zinn and the art ... myself).
My main hangup around headsets is that I've picked up the idea somewhere that a loose headset can (or perhaps will) ovalise a headtube potentially ruining the frame, and yet in the manuals I looked through this wasn't even mentions,either as a risk in need of urgent addressing or a consequence; in fact one manual went so far as to reassure people not to worry about whether they got the adjustment "right first time". The only consequence that got a mention was premature bearing wear (from both overly tight or loose headsets).
Am I being needlessly concerned? I've also been told that a loose headset won't harm the frame and at other times that it will.
On a related train of thought I've come across manuals that sugguest adjusting the headset AND testing for play with the stem bolts loose and others (the Park website too I think) that say that the stem clamp bolts must be tightened in order to test for play. I realise that the stem bolts need to be loose to adjust the pre-load but should the be done up or loose when testing for play?
My main hangup around headsets is that I've picked up the idea somewhere that a loose headset can (or perhaps will) ovalise a headtube potentially ruining the frame,
I imagine some would have a concern about poor installation of the headset cups, which at least in theory might damage a frame, but a loose bearing is not going to have any discernible effect on the frame that I can imagine. It certainly could ruin the bearings, but you have the very hard bearing cup between the fork and the frame.
--
David L. Johnson
__o | Accept risk. Accept responsibility. Put a lawyer out of _`\(,_ | business. (_)/ (_) |
On Tue, 11 Apr 2006 20:59:41 +0100, "PJay" <[email hidden]>
Quoted message said:
My main hangup around headsets is that I've picked up the idea somewhere that a loose headset can (or perhaps will) ovalise a headtube potentially ruining the frame, and yet in the manuals I looked through this wasn't even mentions,either as a risk in need of urgent addressing or a consequence; in
Can't happen. All you can ruin is the headset. You can ovalise the headtube by putting a headset that's slightly too small in it (JIS instead of ISO, or vice versa, I forget which), which you'll notice by the cups falling out if you don't hold them in.
You can also ovalise the headtube by doing Bad Stuff while (attempting to) replace the headset, as well, but never by simply misadjusting it. Headset replacement is best left to the LBS with the right equipment.
My main hangup around headsets is that I've picked up the idea somewhere that a loose headset can (or perhaps will) ovalise a headtube potentially ruining the frame
Only with those accursed integrated designs. If the bearings come loose in the frame due to wear (which could be exacerbated by poor adjustment) you are fairly well stuffed. Some shops can now recut *some* head tubes to the required seating angle if there is enough material there, but it's not an option I'd depend on.
With conventional pressed-in cups, the frame doesn't suffer.
My main hangup around headsets is that I've picked up the idea somewhere that a loose headset can (or perhaps will) ovalise a headtube potentially ruining the frame, and yet in the manuals I looked through this wasn't even mentions,either as a risk in need of urgent addressing or a consequence; in
Quoted message said:
Can't happen. All you can ruin is the headset. You can ovalise the headtube by putting a headset that's slightly too small in it (JIS instead of ISO, or vice versa, I forget which), which you'll notice by the cups falling out if you don't hold them in.
Quoted message said:
You can also ovalise the headtube by doing Bad Stuff while (attempting to) replace the headset, as well, but never by simply misadjusting it. Headset replacement is best left to the LBS with the right equipment.
i bought a spare headset! change lube - philwood or finishline trojaneze - and bearings every year: the lube wears out in a year from daily use. if you have an old style headset, filing the thin headnut down to the headset wrench measure - exactly - as a slip ughuhg fit - is a gross improvement over what's normal there. i use vicegrips (carefull on squeezing the nut out of shape) or 12" handle channelocks. total nut torque related to pressure to swing the fork?m without a tire on it? tighten the nuts down so the fork turn pressure gets into the stiff range. Not so you need to force the fork to turn but that you can feel resistance to turning the fork from the nut pressures no bearing rumble! an ideal situation is to get a friend to hold a pipe(stethescope) to the bearing area as you turn the fork back and forth? i haven't done this but its an interesting speculation.
I blue locktite everyhting together in a very warm climate. all tools are in line and everything is production go. when i get to the how much pressure is needed i go to what i wrote and then say the hell with it - works ok!
