Handlebar and stem sizes

Lucky Luke

I built up a bike last year with old bits (including the handlebars) but bought a new stem for the build . Now as I thought that there were only two sizes for handlebars i.e standard and oversize , II bought a standard stem which grips the bars well but there is an amount of creaking when I put the bars under pressure for example when riding out of the saddle on the hoods . This creaking didn't bother me much to begin with but has begun to be increasingly annoying . I've had the bars off , applied a bit of grease between the stem/bar interface in an effort to cure it but without success . Last night I took them off again, degreased the bars and stem then applied some loctite before reassembly. Hopefully this has done the trick (I've not tried it yet) but it did occur to me today that maybe there are possibly more than two handlebar sizes . Can anyone enlighten me , please ?

Uranus

The smaller (non-oversize) handlebars can be 26.0, 26.4, 25.8, 25.4mm

Are you sure the creaking isn't coming from the headset?

Lucky Luke

I don't think so , I suppose it is a possibility but from the array of sizes that the 'standard' bars seem to come in it wouldn't surprise me if my bars and stem aren't as completely compatible as I first thought .

Uranus

What make are the bars/stem? I ask because ITM for example stuck with 25.4 (one inch) long after the other Italian makers had gone to 26 or 26.4 . . it's not an exact science though, as one way or another the stem clamp will be stretching some metal to fit.

Try smearing something greasy on the bars, then clamp them up, then take them off and the marks in the grease will show you how much actual clamping area is in effect. "Engineer's Blue" is ideal for this, but it's only thick oil with blue dye in it.

If you think the bars are too small, cut a piece out of an old aluminium drinks can and wrap it round the bars before clamping. If this works you can trim the aluminium neatly so no-one can see your bodge engineering!

BTW I presume this is a modern "threadless"/Aheadset type of stem?

Monty Dog

It's unlikely that you've mixed them up - an oversized road bar simply wouldn't fit a standard road stem, and you'd probably struggle to fit a standard 25.8/26.0mm road bar to a 25.4 MTB stem. 25.4 drop bars aren't common either. As well as cleaning up the surfaces of the stem and bars, rather than grease, try an assembly compound like Loctite which will stop the micro-movements that cause the creaking.

Uranus

Monty Dog wrote:

rather than grease,

I was only suggesting grease to check the fit, I wasn't suggesting suggesting riding the bike with the bars greased! :shock:

Lucky Luke

Monty Dog wrote:

try an assembly compound like Loctite which will stop the micro-movements that cause the creaking.

Yep that's what I thought would do the trick as I mentioned when I first posted but unfortunately it hasn't .

Lucky Luke

Uranus wrote:

What make are the bars/stem? I ask because ITM for example stuck with 25.4 (one inch) long after the other Italian makers had gone to 26 or 26.4 .


Yes they are ITM and only now on closer inspection have I discovered that the bars are indeed 25.4 .






"If you think the bars are too small, cut a piece out of an old aluminium drinks can and wrap it round the bars before clamping. If this works you can trim the aluminium neatly so no-one can see your bodge engineering!"


This seems worth a go , I will try tonight . Fingers crossed .

Monty Dog

Loctite Bearing Fit is a bit thicker and 'stickier' designed to take up alignment / tolerances in assemblies - try your local engineering suppliers if the normal runny stuff doesn't work.

Uranus

Apart from the headset itself, the other interface to look for movement is between the stem and the steerer tube, even more so between the spacers.

You could try riding with no spacers and no top cap, may not be very comfortable but at least it would remove one possible source of noise.

Creaks like this were very common on older threaded quill stems, usually the quill moving in the steerer tube, rather than the bars moving in the stem clamp in my experience.

Typically the creaking only started when you get out of the saddle and start putting in some big effort, pulling on the bars.

Lucky Luke

Monty Dog wrote:

Loctite Bearing Fit is a bit thicker and 'stickier' designed to take up alignment / tolerances in assemblies - try your local engineering suppliers if the normal runny stuff doesn't work.

OK Monty , cheers . If the shim doesn't work then I'll perhaps give that a go as well .