oxcart2006

I appear to have a bit of an issue with my steed. I bought a new Nitto B115 handlebar and it does not seem to fit my SR Custom (circa 1986). I can get the stem around the bar, but it's hanging up on the center sleeve of the Nitto. I tried using some dish soap to massage the stem on, but it still felt like I was going to jamb it onto the new bar. I measured both the stem and handlebar, and they're both 25.4 mm. The handlebars that came off have no manufacturer or measurement markings.

Do I need to ream the stem, get a replacement, or is there something else I'm missing? Can I use a set of ring pliers to spread the quill, or am I risking crushing the handlebar?

ThermionicScott 

I would make sure there aren't any burrs inside the stem. You might need to gently pry the clamp open a little to get the bars in and out. The tight fit is a feature, to make sure the clamping force is spread evenly.

JohnDThompson 

Your best option is to buy a stem with the proper diameter opening for the bar. If the bar/stem discrepancy is small, reaming is feasible *IF* you have the proper reamer. A typical adjustable reamer is not ideal, as the blades tend to hang up in the slot of the stem opening. You'll want a helical blade reamer of the proper diameter, which won't be cheap. Simply buying the right stem would be far less expensive. I wouldn't advise trying to spread the stem opening unless the discrepancy is very slight, as this could lead to catastrophic failure. If the stem and bar appear to be the same diameter but simply won't go together, putting a coin in the slot for the binder to push against can open the stem enough to insert the bar.

oxcart2006

Thanks both for the assistance. All the stem needed was a little spread, and the handle bars slid right it!