Hi,
I bought an old rigid mtn bike with the intent of converting it to drop bars for a tourer. I like the Nitton 25.4 Randonneur handlebars, but I'm a little perplexed when it comes to the stem. I've ridden the bike maybe 10 miles and I feel like the straight handlebars on it now are in a good position for the flats of the drop bars. I measured the OD of the handlebars right beside the stem clamp, and it measures just a hair over 25mm. So it seems like I could pop those new handlebars right in. However from an aesthetics standpoint, I would really like to get a classic road quill stem like the Nitto Technomic, but that opens up a whole host of issues about rise, reach, etc. I don't know the specs on the current stem (are they stamped on it somewhere?) and it seems a little tricky to try to measure the reach and rise. But I do know this, I think I would need the longer Technomic stem to get the handlebars as high as they are now, especially since those stems have negative rise while the current stem has positive rise.
Furthermore, I know I need about 2 inches of stem inside the headset, but I don't know how much I can actually raise or lower the stem within the headset. I suppose I could test that out with the current stem and see how much vertical space there is.
Also I'm perplexed as to why Nitto does not seem to offer 25.4 clamp stems, you have to get the 26 with shims, although they offer handlebars in 25.4.
Does it seem reasonable based on my measurement that an old mountain handlebar would be 25.4?

Thanks,
Jon

Can you measure it? Only then can I, or anyone for that matter, say that it is likely to be 25.4mm.

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