Bicycle stems - help!

Elhombremediocre

Hi there,

I am looking to change the stem of my bike but not really sure how I can find out what size I need to replace it.

The bike is a Bianchi Pista 2006. Ideally I would like a Cinelli stem, like the 1/a model, but I understand that Cinelli stems are usally 26mm in size while 'conventional' stems are 25.4mm.

Also, I would like to know if I have a Pop-top stem, which apparently most new bikes come with. Any advice on how I could find out the sizes I need? I am not fixed on using a Cinelli stem, as I have seen some nice ones from Shimano and Nitto - these two be more likely to fall under 'conventional' and hence fit my bike?

Any help appreciated.

Let not trivia dominate our lives.

Garybee

If you remove the front cap of the stem you will often find the clamp size stamped on either the stem or the inner face of the top cap. I have no idea what a 'pop top' stem is though, migh the shop have said flip-flop? This means a stem which can be used either way up to alter the rise angle.

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Hypocrisy is only a bad thing in other people.

Unknown

"'pop top' stem"

Might just mean Ahead?

It's not the stems that vary - bar diameter.

d.j.
"Like a true nature's child,
We were born,
Born to drink mild"

andrew_s

The 2006 Bianchi Pista came with a 1" threadless (ahead) headset and 26.0mm handlebars.

You can't fit a quill stem like the Cinelli 1a, at least without also changing the forks.

You need a 26.0mm Ahead stem, either 1", or 1 1/8" with a shim.
26.0mm is standard for road handlebars these days. 25.4 is MTB and unusual road bars. A lot of road stems don't come on different models for 1" and 1 1/8" steerers - you just get a shim to use with 1".

Mister Paul

I think the Cinelli stems come with a shim.

They do them at www.dotbike.com. Email them. They couldn't be more helpful.

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Elhombremediocre

Hi, thanks for everybody's help. As far as I know, the Bianchi uses a thredless stem, which as I understand, is quite common with bikes nowadays. The pop-top stem is something I read about on Sheldon Brown's homepage and it might well just be American slang. I think I know to what kind of stems I am now limited and have seen a nice one from Nitto I am considering but will continue to do research. I will also check out dotbike.com so thanks for everybody's help and further comments welcome!

Thanks.

Let not trivia dominate our lives.

MrKawamura

When I first read the OP I thought pop-top refered to the way that the stem is attached to the handlebar. A pop-top stem would have a face plate at the end which is attached by two or four bolts - when you undo the bolts the faceplate comes off completely so that the handlebar can simply be lifted free.

A non-pop-top stem has only one pinch bolt - when it is loosened, the handlebar is free to move from side to side, but cannot be lifted straight out of the stem - instead it must be slid off sideways.

That's what I thought it meant anyway.

acorn_user

You could probably get the fork threaded. Some shops might be able to do that. 1/18" stems fit 1" forks with a little shim. Likewise, you can shim 25.4 handlebars to fit 26.0 stems. 26.0 is the standard Italian diameter, 25.4 is more common for mtb stuff. Nitto make both kinds of stems, and bars in 25.4 (don't know about 26.0 bars from Nitto; that's why they make shims).

Cinelli did have an older standard; I forget what. A lot of modern bars have gone to crazy ugly oversizing....

monty_dogcp

The Cinelli stem you refer to is of the older style quill type, which clamps down inside your fork steerer, whereas your bike and vitually all recent ones comes with an ahead type which clamps to the outside of the fork steerer. Both types use different styles of headset bearings too. You'd have to change your forks if you want to use a quill stem. The majority of raod handlebars are either standard 26.0mm or 31.8mm oversize - although the Nitto bars you mention do come in 25.4mm - you can shim them for a 26.0mm stem tho. Older Cinelli stems were for 26.4mm diameter bars too - best avoided unless a classic bike buff. By pop-top I presume you mean open-face - i.e. you can remove the faceplate of the stem to allow removal of the bars easily - thankfull all new stems are of this design. Best bet is to drop into your LBS and they'd be able to advise on what stem suits your needs - prices are from about œ15 upwards.

Elhombremediocre

Thanks again for everybody's help! I have a few stems in mind now that I know what I am after and will probably be the Nitto to be honest. Thanks again and happy riding to everybody.

Let not trivia dominate our lives.