stupid stems, stupid handlebars :(

[Ben M]

Right, now I'm converting a bike (tandem) from flat bars to drop bars.

It has a stem on it (well not on it, it's on my desk) which, I think, is 25.4mm fitting at both ends (steerer and handlebar ends). It's a quill type which opens up, rather than the front coming off.


Now I have some shiny new handlebars, with no amount of coaxing are they going to fit them onto the stem, the radius of the bend looks tight, but the real issue is that they are 3T mutant bars with bumps at the bottom which are tight.

Now, the way that I see it is that I can either get a new set of bars with nice shallow drops, and scratch them to buggery to get them on the existing stem, if they will fit at all. Or I can get a new quill stem which has the front opening up like an A head (i.e. the front coming off) or I can get a quill adapter and fit an A head stem.

What I want to know is what size adapter and A head stem do I want? Can I get a quill which has the front opening up? I think that my bars are 25.8mm and my steerer tube is 25.4mm It's a bit of a mind field and I'm struggling to get my head around it.

 

[MacB]

I'd get the quill to Ahead converter this will give you a steerer tube clamp size of 1 1\8 which is nearly all new ahead stems. Then you buy the stem to match your bars seperately. A quick visit to:-

http://www.sjscycles.co.uk/product-...ll-to-1-1-8-Inch-Threadless-Adaptor-22444.htm

 

[MacB]

here's one that is meant to work with both sizes:-

http://www.halfords.com/webapp/wcs/...6-b2c0-dc36b54a327e&istItemId=lwmwtw&istBid=t

 

[Ben M]

I'd get the quill to Ahead converter this will give you a steerer tube clamp size of 1 1\8 which is nearly all new ahead stems. Then you buy the stem to match your bars seperately. A quick visit to:-

http://www.sjscycles...aptor-22444.htm

Here's where I'm getting confused, is that one the right size for my steerer? It says that it's 1 inch.

That Halfrauds one might be what I'm after if it's universally compatible.

So which A head stem do I want? What size is it? are 25.8mm bars 25.4 compatible?

My brain hurts.

 

[MacB]

Here's where I'm getting confused, is that one the right size for my steerer? It says that it's 1 inch.

That Halfrauds one might be what I'm after if it's universally compatible.

So which A head stem do I want? What size is it? are 25.8mm bars 25.4 compatible?

My brain hurts.

Ah, no you'd want a road stem, I generally follow the rule, 25.4mm is MTB/Upright town bike, 26mm is road bike, 31.8mm oversize is the new across the board. Worth having a read of Sheldon Brown on the subject, though his stuff will becoming more out of date:-

http://www.sheldonbrown.com/gears/

 

[RecordAceFromNew]

A number of different sizes are used for stems/handlebars. For example Cinelli's, which is on many high end older bikes, were different to others. Sheldon's list here is excellent.

In particular NEVER assume the diameter at the grip is the same as where the stem clamps on. As someone on this forum mentioned recently it is worth investing in a vernier caliper. I saw one in Poundland the other day, I was surprised that they could do it for a £.

 

[MartinC]

3T road bars won't fit in a 25.4mm handlebar clamp stem. They'll be 26mm nominal (25.8mm). Quill stems with single piece clamps always needed some judicious wiggling to get the bars through, the steel ones needed the clamp levering open quite a bit first 'cos they were wider.

A quill to ahead converter will allow you to use an ahead stem and bars of your choice. You sound like you need a 1" (25.4mm) one, often they come as 1" with a shims that allow you to fit them to a 1 1/8" steerer and stem.