Sunday, September 4, 2011

Center Pulls and Why They Rule/Suck

Depending on who you talk to in the bikey industry, you'll hear a lot of different things about center pull brakes and why they are awesome as fuck or the worst shit ever. I remember the first roadie bike I had was equipped with 2 Weimann center pulls and I hated them more than anything. Fast forward to today, and I love the shit out of them.

Here's ol' Jobsty Brandt's take on centerpulls. He doesn't have too many things to say that are good about them, as you'll read. The old curmudgeon has some interesting things to say about wheels and all sorts of jazz, but I think he is off here dismissing them on the whole. The first bit he starts to dig in to them is their 'large position error'; which is a fancy way of saying the brake design almost never meshes well with the rim and frame design since they were used largely on mass produced bikes. If the rim is too narrow for the center pull, then yes--the brake pads would indeedy make their way into the sidewall of the tire over time. However, if the arms are pointing straight down towards the ground at the point the brake pad hit the rim, then the risk of the pad wearing into the tire sidewall is slim to none. If this is confusing to think about, consider how you would set up cantilever brakes and how the pad should be hitting the rim straight on instead of at an angle.

Jobst then starts dissin' on the 'visual' importance of symmetry that center pulls have... But the symmetry of center pulls goes way beyond asthetics--they modulate far better than most modern dual pivot side pulls and retain there positioning unlike most traditional center-pivot side pulls.

The next thing he rattles on about is the amount of flex most center pulls have due to their long brake arms that are attached to a connection bridge. This is a legit critique for most center pulls out there, including my own. If the mechanic is truly dopey (like me) and puts some big ass brake pads on such as the Kool Stop MTBs (SHELDON SAYZ THEY ARE DAH BEST SO I MUST GET THEM,) then the brake may even run the risk of having the edge of the brake pads rubbing against the tire side wall when the brake is pull at full force due to flexiness. Luckily, those crazy French constricteurs completely minimized this problem. Alex Wetmore demostrates:

Get rid of your ugly bridge! BRAZE THAT SHIT ON.

One legitimate frustration I often hear about center pulls is that they are a headache to set up well. The main culprit of this problem isn't the brake, but this little bastard:

Tiny cable yolk -- aka 'The Finger Bleeder'.

When approaching this thing for the first time, most people will find themselves wanting extra hands to deal with all the shit going on. One to hold the fixed 9mm, a second to hold the adjusting 9mm, a third to hold yolk body, and a forth (maybe fifth as well) to keep the center pull shut. After doing this process a bajillion times, you eventually figure out a few tricks (3rd and 4th Hand tools (that's what they're appropriately named) plus some hand positioning kerfunkage.) But that first time will probably make you cry, or write a pissy internet log about how center pulls are thoroughly moronic. There are also many other yolk designs of different mechanical advantages which are worth looking into, so don't give up on them just yet.

All n' all, the major advantage of center pulls is the maximum amount of brake power well balanced with the amount of control you desire over the brake. Hydraulic lines and disc brakes are great if you want ULTIMATE REAL POWER, but you really don't need that on a road bike... Otherwise all's it takes is a little 'tap' and then 'CURURUGUUNNK!' and something freezes up. [Disc brakes on road bikes on a whole are problematic as someone far more neurosensical pointed out to me once. Maybe I'll write about that later, probably not though. :p] Since center pulls have a nice spongy feel, you can use the full length of brake lever's pull to adapt to the amount of brakage you need. So fuck you dad and yer side pulls, I'm going with g'pas old Mafac shit.