25 January 2008

bikefix Exclusive Review: Paul Neo Retro and Touring cantis

Those of you who started mountain biking after the advent of V-brakes should consider yourselves very, very lucky. Those of us who didn't, and did any service on the damn things, shudder at the memory. Requiring 2-3 tools (and as many hands) to adjust, cantis with post-type pads were a bitch to set up. They regularly squealed, and most home mechanics at the time can remember cutting through a tire sidewall with a poorly-adjusted pad. Thankfully, Shimano chose to use threaded pads with conical (actually spherical) washers in their linear-pull brakes and pretty much everyone saw the light. Linear-pull brakes required more cable pull than cantis, but privided unheard-of power and modulation as mechanical advantage remained constant (cantis' actually decreased) as they went through their travel.

So why are cantis still around? As I mentioned above, linear pull brakes require more cable pull cantilevers. Cantilevers, in turn, require more cable pull than road brakes. Cable pull is the amount of cable pulled by the brake lever as it travels through its stroke. If you have too much (for a given brake), the brake will feel firm, but the lack of mechanical advantage means that they won't stop the bike well- if at all. Conversely, too little cable pull means mushy feeling brakes with frame-spreading power and brake pads that don't really come far off the rim when the brake is released. For this reason, linear pull brakes are all but unusable with road brake levers. So why use canti or v-brakes on a road bike anyways? Well, touring bikes tend to use them for the power (although road dual-pivot calipers have improved road braking immensely) and cyclocross bikes ('cross being a wet, muddy winter sport in which skinny tired bikes are ridden and run with off road) use them for the power and mud clearance. See, if you're riding in a Belgian field in November, you can get all kinds of crap sucked into your fork crown or seatstay bridge. Enough crap, and the wheels don't turn, and you get your ass kicked by some old Belgian lady.

When it comes to 'cross brakes, there are a number of opinions, but the consensus is that Paul's Neo-Retro and Touring cantilevers are pretty damn pimp. CNC machined somewhere in the USA, Paul's brakes are throwbacks to both the '70s and '90s. The Neo Retro cantilevers' L-shaped profile apes old Mafac cantilevers, which are preferred by Euros because of the way in which they fall away from the rim. Because of the way they respond to cable pull, at rest, there are miles between the rim and the brake pad (see top picture). Unfortunately, sticking straight out, they can take a nice chunk out of a misplaced calf or ankle (did I mention that 'crossers jump on their bikes while running?). For this reason, they're often paired with the lower-profile Touring cantis in the rear (see right). These don't come away from the rim as far, but they are less likely to make you bleed. Otherwise, the construction is all but identical.

Thankfully, Paul's brakes use standard V-brake pads, of which there are loads available. Kool Stop come with the set, and their Thinline pads are among my favorites (from before discs). As a result, the Pauls are easy to set up and thanks to fairly solid construction, don't seem prone to squealing. Cool, no? Erm, no, I'm afraid. Sure they look nice and seem well made. The design leaves a bit to be desired, though. The first head-scratcher is the cup in which the spring sits. On the outside of the arms is a little cup where the spring goes. Exposed. These are for mud? The cups are prone to filling with crap and are much less protected than springs on the inside (frame side) of the arms. Meh, OK. No big deal. The use of the o-rings (which 'seal' the aluminum-on-stainless pivot) aren't exactly employed according to best practice, either. These are for mud? OK, whatever. I live in the desert, and they're on my fixed gear.

In practice, the Touring canti felt great. Period. Loads of power with Tektro aero levers. Plenty of modulation and they felt smooth, too. The problem was with the front brake. As folks know, the front wheel handles the majority of the bike's braking. Many mountain bikers prefer a larger (more powerful) disc rotor on the front and a smaller on the rear to balance braking power and modulation. In this case, though, things were precisely opposite. Despite trying a number of setups, with the straddle wire at different heights, neither I nor a local mechanic could get acceptable power out of the Neo Retro. Despite the long-ass arms, there just wasn't enough leverage to slow the bike, let alone nose wheelie (which I can often do with cheap Tektro road calipers). All this for $103 per wheel. Damn.

At least they're light! 100g/wheel (without pads). Of course, forgoing the front brake altogether would save more weight (and money), with only a slight reduction in stopping ability. If I may, I'd like to suggest that anyone considering these brakes look for some cool vintage cantis on eBay or at least buy a set of the Touring model. While I understand Paul for making something that the market seems to want, he could certainly make some improvements that would increase the brakes' function. Avid, Shimano and Cane Creek have done it with their road cantis- Paul should too, even if it costs a bit of mud clearance. As it stands, I consider the Neo Retros' performance simply unacceptable with standard road levers.

Paul Thumbies, though? Really cool...




adrian said...

Thanks for the good review. I've been thinking of setting up touring cantis. Where did you get those sweet peace cable hangers?

bikefix said...

Adrian- thanks! The cable hangers are vintage Ringle Mojos from the mid 1990s... You may be able to find a set on eBay. Mine were buried in a drawer at a local shop that had over invested in high-end CNC'd bits back in the day...

Me said...

I see this post is a few years old, but agree with the lack of power in the design of the Neo Retros. Here's a link to a cool site where you can graph and compare the mechanical advantage of cantilever brakes by changing the parameters. http://www.circleacycles.com/cantilevers/