General: replacing handlebars and stem (compatability)

hey I am thinking of changing my stock road handlebars for nitto rb-021s or normal bullhorns and if I can find a deal on some Nitto B123 alloy drop bars, I would like to get those as well. I want to make sure that 1. my stock bowery stem would take these handlebars if I decide to only change the bars (in terms of the diameter of both the clamp on the stem and the bars themselves) and 2. if I do decide to replace my threadless stem setup for a threaded stem setup (thinking of a more track style stem, maybe a nitto jaguar knock off or a less expensive nitto), how complicated is this change if my bowery came stock with everything for a threadless setup? I saw on sheldon browns page that compatability is key here, since the steerer of the fork needs to accept a threaded system, and there are a few different diameters for steerer tubes and what not. I am also not sure if these mass produced bikes are no longer compatible with threaded systems. I have a winwood carbon road fork, and could check the diameter if necessary. Sorry if I am butchering vocabulary or concepts here. I am working my way up from understanding cranksets.

Any advice would be much appreciated. Thanks

Bowery is 1 1/8. It is truly not worth it to thread the fork and replace the headset and stem.

Posted By: LyKqiDBowery is 1 1/8. It is truly not worth it to thread the fork and replace the headset and stem.

Thanks lykqid. but do you think if i upgrade the handlebars I would be fine with my stock road stem (assuming I replace the shim suicide doors is talking about)?

You have a modern bike with big fat tubes and a sloping top tube. Why would you put a quill stem on that? It would look completely out of place. You'd need a Chris King De-evolution headset to do it, and a threaded fork. You couldn't even do that if it has an integrated headset. I don't know why you'd want to give up threadless anyways, it's much easier to adjust and it stays that way.

Here's a shim:


Here's a shim in operation (the red thing):


The shim will wrap around your 25.4 handlebar (B123 for example) and increase the clampable diameter by .6mm to 26.0
You don't have a shim right now, you just have your bars attached directly to your stem (because they're both 26.0).
You could do what quidose is suggesting and not use a shim, but it's not wonderful for your stem or bars, and yes, you will probably have your bars slipping down after a while. If you can't find a handlebar shim, you can use a slice of a beer can, cut to the correct width and folded two or three times. I would really go for a real shim if you plan to use the B123 or anything else of reasonable quality.

If you want to swap your stem for a Nitto track stem (yes, they do make them, but they're not especially easy to find), you can do so easily. Make sure it is 1 1/8" (steerer clamp) and 26.0 (bar clamp). Note that a 25.4 stem

will not

accept 26.0 bars like the RB-021's.

Ok the shim makes sense now. I have seen handlebars with those in the past. I imagine one of the bike shops in Mexico city should sell these in the size I need, even if something simply basic. I think since I am considering getting a nicer bike in the near future, I should just wait on the stem for a separate project. But for now, if I do end up getting the nitto b123s in addition to the rb 021s, given the road geometry and the sloping tob tube, is it kind of stupid to get steep drops like these on this bike? I really enjoy riding in drops but its not as quite a nice experience with the road drops that came with my bowery. I think the stock bars are more for aesthetics than anything else. I have found some good deals on nitto drops (around 50 dollars new on ebay) so it would be a good investment and I would plan on using them on a EIA godzilla or something with more track geometry in the future anyway. Thoughts? Thanks again to both of you this has been quite helpful