Is it normal for the brakes to activate upon sharp handlebar turning?
 

I was tuning up my friend's road bike the other day (Felt ZW 95) and after adjusting the rear brakes to where they were tight but didn't rub, I noticed that when I let the handlebars go (they'd fall to the side on my stand) the brakes would be activated, holding the rear wheel in place. Now, this won't be an issue during normal riding, unless you're crashing. You'd never turn your handlebars this far, even when trying to turn around on a small road. The cables have plenty of excess in front of the bars, they're looped around nicely. No more or less than my other bikes. However, this is the only bike I've ever worked on with interrupters on the flats of the bars. Obviously the front brakes don't have this problem.

Is this normal? Should I adjust the brakes looser so this doesn't happen? Cabling is stock from the factory. We've never had a need to change it.

it's not normal. IME, indicates a handlebar tape/housing/length issue. :)

Some of my bikes do that when the handlebars are rotated all the way to one extreme, taking out all slack in the rear brake cable housing. Since as you say it's not an issue for any kind of normal riding, I don't view it as a problem to be fixed. I'd try to avoid it if setting up the bike from scratch, though.

The cables are probably a little short but If it isn't an issue during regular riding I wouldn't worry about it. If you have to turn the bars that far while riding you are crashing anyway.

Just loosen up the brakes. No need to have them adjusted so close to the rim. I usually have at least half a centimeter or more gap between pad and rim.

That's more travel than most brake levers will take up before bottoming out.

Yeah I was going to say, that seemed like a bit much. I generally have to have my pads within a few mm to have adequate stopping ability. Maybe they meant a half centimeter total (for both pads, so ~2mm for each pad?)

Housings too short, but it doesn't matter much. I'd keep the brakes adjusted tight and have no concern about it.

It is not normal. Make sure you have enough slack on the cable so you can turn freely from side to side. If there is enough slack there might be something in the casing catching the cable or the cable it bent too tight some place.

I believe the suggested standard is 2mm per side, 4mm total travel.

Given this is another blind guess , and not a job on the repair stand in front of me in person, another perspective, thrown out... :innocent:

Housing/cable length may be adequate when the bike is in motion, you never turn the bars 90 degrees when moving. other than crashing, out of control ..

but if you want to replace the bar tape and cables , Have At It.

No. It's not normal. Fix it.