Help with drop handlebars oversize or not?

nitesight

I need a new stem cause mine is a tad short and rather ugly. A 100mm will be fine and I know I have a 1" headset but now it gets confusing. I understand metric and I understand imperial but what the hell size drop bars do I have.

I'm looking at a stem that takes 25.8mm bars. What the hell is 25.8mm? 2 and a half centimeters and a bit?! Is it the diameter or the circumference?

Why is the headset in inches and the bars in millimetres. God this is nuts!

Any advice please?

tim_f

see

the info at http://www.sheldonbrown.com/gloss_st-z.html

If you have a 1 inch steerer then the chances are that you have a 25.8 non oversized handelbars. Because 1 1/8 steerers became fashionable before 'oversized' bars became fashionable. Not seen a stem which fits a 1 ich steerer and oversized handlebars.

However you can get shims to fit 1 1/8 inch stems to 1 inch steerers so this is not definative.

You can also get shims for the handlebars ao a 25.8 nhandlebar will fit in a to 31.8 (oversized) but these are not sold by most shops.

what you might what to to avoid is buying a stem designed for 25.4 handlebars (which mountain bikes used to use before they moved to 31.8. You can fit a 25.8 handlebar in these but it is debateable if this will stress the handlebar or stem. Sheldon Brown implises that this may be ok.

Tim.

nitesight

Tim,

Thanks for the pointer. I'll give it a shot.

cheers again. The time you took to reply is appreciated.

maddog 2

if your stem is an aheadstem then you can pretty much make anything work

eg. buy a 1 1/8 inch aheadstem with a 25.8mm or 26.0 clamp (the two sizes are interchangeable and basically the same thing) - often called a 'road' stem, and use a reducer on your stem to go from 1 1/8 down to 1 inch to fit your forks

or, buy a 1 1/8 inch aheadstem with a 31.8mm clamp - an 'oversize' stem, and use a reducer on your stem as above. Ideally you'd run oversized bars too, but not necessarily (see below).

if you run a quill stem then your options are much more limited. You'll have to stay with 25.8/26.0 bars, as I'm not aware there is a oversized quill stem out there.


If you want confusing further, non-oversized MTB stems use 25.4mm clamps (which is exactly 1 inch!). This is smaller than a ‘road’ clamp, and need to be used with 25.4mm MTB bars really, although there are some bodges which work.

So, to recap
Steerers can be 1inch or 1 1/8 inch, and you can reduce a 1 1/8 stem down to fit a 1 inch steerer

Clamps can be:
25.4mm , as used on standard MTB bars
25.8 or 26.0 (basically the same thing), as used on standard road bars
31.8mm as used on oversized mtb and road bars
And if you want, you can run an oversized stem with a 25.4/25.8/26.0 bar by using a shim
And if you run a quill stem you're in trouble :?

All dimension are diameters

Bhima

maddog 2 wrote:

And if you want, you can run an oversized stem with a 25.4/25.8/26.0 bar by using a shim

Who sells these shims? Can't find em anywhere!

maddog 2

26.0 - 31.8

http://cgi.ebay.co.uk/Handlebar-Shim-26 ... 286.c0.m14

25.4 - 26.0

http://cgi.ebay.co.uk/Handlebar-Shim-25 ... 286.c0.m14

Bhima

Expensive! :shock:

I'll go down the LBS and see if they have any going cheaper...

maddog 2

LBS cheaper than Ebay?

:shock:

They're pretty rare online so you'll be doing well to find one in your LBS.

I've got another link somewhere, to a shop, but the price is still about £6ish

maddog 2

here're some more shims

http://www.billys.co.uk/english/product ... 20&group=H