Rail 55s: Behind the music

Rail 55s: Behind the music

Does anyone even remember VH1: Behind the Music? A girl I had a huge crush on during high school became one of the researchers for Pop Up Video. It's no wonder my generation is all messed up. 

Last week, we announced the Rail 55 by sort of not announcing the Rail 55, but we thought a deeper explanation of how and why we came to the decision to do this was merited. 

It's no secret that we've been sour on carbon rim brake clinchers for a while. Ultimately, they're a flawed product. The brake heat issue, though tremendously mitigated, still exists. That's a strange start to an announcement of a new product, to tell you how it's flawed, but there it is and that's how we roll. And bear in mind, this is the whole category - Rail 55s use an up to date resin system and after 3 years (time flies) of working with this rim manufacturer, we have deep trust in their processes and quality. 

First, I'm going to explain the "why" and then I'll go into the "what." Say what you will, the carbon clincher era absolutely set the table for the disc brake era. To say otherwise is just fooling yourself. A whole lot of people switched to disc brakes and aren't looking back, and the industry as a whole sure isn't - it can't push rim brakes into history fast enough. 

Alloy rim brake rims had blossomed through a golden moment, which we've certainly chronicled and been huge advocates and beneficiaries of. Without the emergence of the HED Belgium+ and the Al33 and others, our business would have been in a severe pinch. Carbon clinchers weren't, and aren't, an "everybody, every ride" product, but that's what was being demanded of them. There was also a huge insurance nut with doing our own rims, and that didn't work. But times change, and the alloy rim brake market is tightening up a bunch. The industry's investment level in rim brake stuff has gone to zero, and this creates a self-fulfilling prophecy - you push disc brake disc brake disc brake, to the point where that's all you sell, and you can't make any money selling rim brake stuff because you've pushed all the customers to disc, and so there's no justification for investing in rim brake stuff. 

But there are still a lot of people who are in no hurry to bail on rim brakes, and a lot of them are our customers. And because of them, we kind of backed into selling what's become the Rail 55. We ran out of Rail 52 rims a few years ago (it's now 4 years since our last shipment was delivered to us, and almost that long since we last sold them - time flies). But people like to crash and run over their wheels with cars and just wear their wheels out. Consider that the average Rail 52 is about 5.5 years old (time flies) and at a typical-ish annual mileage of 4000, they're starting to wear out. And as we developed this relationship with our carbon rim supplier, and gained confidence in their work, we started "sotto voce" offering what we now call the Rail 55 as a really good stand-in replacement rim. All those good Nimbus Ti and T11 hubs out there are nowhere near done yet, so new rims make sense, and we'd done a couple dozen builds on these and finally got to the point of "you know, it's dumb not to just do these as a product."

As to the use case worries, yes we still do counsel against using these as "mountain wheels." They're not for that. As described in the previous announcement, these are the normal places, fast group ride, road and crit race, hammer around and don't put extreme stress on your brakes wheels. They're great at that. And with the user base winnowed down thanks to discs, our logic is that the majority of the people who would have pushed them to where they don't want to go is largely out of the market for these. Also, if you've gotten to the point of wearing out a set of Rails, you've proven yourself to be a completely eligible user of carbon clinchers. 

Why 55? When we did the Rail 52, the 52mm depth was no coincidence. We started with an 18mm inner width, which was then nearly revolutionarily wide, and that got us to 25mm at the brake track. When you put a 23mm tire on it, which would generally measure a shade over 25mm, the 52mm depth put us right at a 3:1 ratio of depth to width. 3:1 is broadly thought to be the ratio where "good aerodynamics" begins, and 52 solved for the minimum depth to achieve that with the intended tire. Minimum depth implied better handling and lighter weight. The weight differences split hairs, but the Rail 52 proved itself to be quite ridiculously good at crosswind handling. 

Despite what I wrote above, we also wanted to stick to 55 because we don't want to create the temptation of a "carbon rim brake climbing wheel." A Rail 55 build comes in just about at weight par with an Al33 or Boyd Altamont build, which is enough to turn off the weight weenies but WAY within bounds for a hammer. 

We're into this project, but not into it enough to open our own mold. We don't think we'll sell enough of these to justify our own production and all that that entails (which is a lot), but we think it's a really good product for the time. We also couldn't get production at our rim manufacturer at our production level. If we were going to order 400 at a whack, we probably could, but that doesn't fit our needs. Which meant that we'd be doing an off the shelf product, and they have a great 55. You'd probably have a hard time discerning the difference between a 52 and a 55 with a tape measure much less your eye. 

Mike and I briefly joked about calling the Rail 55 "Point of No Return: The Ultimate Kansas Tribute Band" (you have to say that in the full cheesy classic rock radio announcer's voice to get the full effect) because the shape is like a cover of the Rail 52. Not precise, but pretty darn close. Also, I've now made this whole thing about bygone musical oddities. Sorry.

Some will be skeptical of staying with an 18mm inner width. Wider is better, after all, isn't it? First, the people who are on rim brakes aren't exactly the jump on the latest trend types, and are often perfectly comfortable using the true 25mm tires that these are perfect with. Their not being jump on the latest trend people means a ton of them are riding on bikes that haven't got room for a 28mm tire, and maybe their brakes don't work (or at least work well) with a 28mm or wider rim. If you race crits all day, you might hate the handling slowdown that bigger tires can impart. There are PLENTY of reasons to stick to this width. 

There are a couple of improvements to the Rail 52, the first of which is braking. Rail 55s have a grooved brake track that helps give a bit of bite in braking, and helps prevent the brake pad from hydroplaning on the rim. The tubeless fit is also a bit more evolved on them. The shoulder is a little less high than it was on the tubeless version of the Rail 52, which makes it easier to install and seat tires, but a small bead bump keeps the tire locked on. Of course, tubeless is not mandatory - your tubed tires are more than welcome here. 

Why no pictures? Because I'm a knucklehead about taking pictures, and we're waiting for the first shipment of what will actually be Rail 55s to come in. The graphics will be subtle, and for the first shipment they will be removable. For subsequent shipments (and this will soon apply to all of our carbon rims over 35mm deep) we are doing a stealth November "N" logo, one on each side, opposite the valve hole, and those will be factory applied under clear coat. The time is long since passed for us to start doing that. 

Well that was long enough!

Back to blog


Mark P – Operators are standing by!

JLP – We’re gonna have to disappoint you there. Limiting these to just 55, it makes perfect sense.

Scott – I agree fully

Patrick – There are still a TON of bikes that are somewhat width limited but otherwise good to go for years and years, and there are a ton of people who are going to surrender their 25mm tires through their cold, dead hands.

Kevin – The Corsas are pretty magical. Installed a set for a customer the other day, they’re just really nice tires.

Joe – It is a topic for its own post. That’s on the docket already. For carbon, it’s generally when you start to see the brake track weave switch significantly to a new layer. You can also check the cuppage, just like on an alloy rim. A carbon brake track will cup less, but can generally tolerate less. The good news is that unless you drag a bunch of grit through your pads on the regular, it takes a long long long time to get it to wear down. Carbon is very abrasion resistant stuff.


This might be a topic for a whole ‘nother post but….how many miles do wheels last anyway? It’s never been an issue for me (at least since mountain bikes switched to disk brakes) but now I ride with some retired guys who do 250 miles per week or ~ 10,000 per year. How do you know if your carbon rims are near the end of their lives? Love the idea of the Rail 55, you guys are like retro trend setters with this :)


I still ride my Rail 52s now mounted with 24mm Specialized Turbo tubeless. They aren’t quite as smooth as Corsa G + latex tubes but they are pretty close. I have a lot of rim brake bikes and no intention of moving to disc in the near term so I’m happy to hear you’re standing true. Otherwise I’d have to buy a couple of more wheel sets to keep in reserve for the future.


You make a good case for sticking with the 18mm inner width. When I got my Rails they didn’t fit with my stock brakes. They were crap brakes anyways so I was happy to have an excuse to buy some Ultegras but this is a legit concern. Also, nice to hear these wheels might be easier to get a tire on and off.

Patrick Carlin

Mark P. – the sale page lists the GP5000 25mm at 25.75mm on the Rail 55 rim… Do it!!!


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