Urban Velo

Ask B Rose 2 – Flat Bar Brake Levers, Cartridge Bearing Service, Tire Sizes and Rim Brake Refresh

brose Welcome to the second installment of our new Q/A tech column, Ask B Rose. Industry tech legend and long time friend of Urban Velo, we are proud to be able to bring you his wisdom of all things bike tech. In this column we touch on flat bar brake levers, cartridge bearing service, tire size designations and why your rim brakes suck this time of year. You ask, B Rose answers.

Submit your own questions in the form at the end of the column.

Q: What kind of brake lever should I use to put a flat bar on my road bike with road style caliper brakes?

B Rose: I really like cyclocross interrupter style levers for this. They look good, they have a short enough cable pull to work with the brakes and they come in a wide selection of sizes and shim-able sizes; this means you can find one to fit just about any style of bar and placement on said bars. You should avoid linear pull brake levers (v-brake levers) because they will make your brake feel powerful but actually they make the brake weak. Long pull levers pull too much cable to allow the lever to generate any real leverage. I would also avoid old top access road levers on a flat bar, these can in cases look really nice but as the brake wears the lever will start to hit the bar before it puts any power to the brake.

Q: Should I service or replace cartridge bearings?

B Rose: The joy of cartridge bearings is their replace-ability and their ease of adjustment. Cartridge bearings are made in a giant machine that uses Unicorn gears, pixie pulleys and forbidden magic to assemble them; you are probably not able to make them any better but you can replace them easy enough. Bearings are cheap an plentiful, the tools to install and remove them are not. Wheels Mfg makes some great kits to help you but this can be a tough job. On a scale of 1 to 10, this is a 5 job that can turn to an 11 in the twist of a wrench.

Q: What do the numbers on a tire mean? 700×25? 650b?

B Rose: 28″ is smaller than 27″, there is nothing seven hundred about a 700c, 29 is the same size as 28 but they are both still smaller than 27. 26″ is about the same size as 650c, but both are smaller than 650b and no one remembers 700D. So I am pretty sure the numbers mean nothing.
The truth is the numbers are “nominal” sizes. Nominal sizes are simplified so it is easy to find what you need. Many of these sizes were named by the companies that originally created them to identify their own particular sizes. S6 and S7 are Schwinn sizes and nominal names. 650B is a nominal name for a tire with a bead seat diameter of 584 mm and is known to help people feel creative and special. (It’s an old French size, I will say no more.)
In the case of 700×28, 700 or 700c is a nominal size for a bead seat diameter of 622 mm and 25 is the width of the tire at it widest point in millimeters. The BSD, is generally pretty accurate, the reason is if you put a tire on the market marked 622 and it is 626; then it will blow off the rim and maybe kill someone; that won’t fly so everyone keeps that number accurate. The 25 mm width, is not so important in the governing forces of bicycles (possible liability governs most of bicycles). So that number can give you very different results. Here is a secret, if I take a 700×23 tire and hot patch it 700×25 (a hotpatch is the current style of label used on most tires) then I have created the lightest 25 mm tire on the market and the world is my oyster; keep that in mind when shopping tires by width.

Q: My rim brakes suck now that I’ve been riding in the slop for a few weeks. How do I make them work better?

B Rose: Rubber pads will harden when exposed to moisture. Your rims corrode on the surface when exposed to moisture and salt. There are a lot of things going on to diminish your braking power but focusing on these two will make the biggest differences for you. I recommend two tools for this, a scotch brite pad and a flat file. Some dish detergent, water and elbow grease applied to a Scotch Brite pad will clean the corrosion and built up of material off your rims. STOP! You don’t need to sand your rims or boil them or ride around with sand paper under your pads; just scrub them. Now take the flat file and file the surface of your brake pads… easy tiger. Just a light filing to remove the glazed material from the face of the pad. Rinse and repeat as needed. I recommend dish detergent, I don’t recommend alcohol, citrus crap or any other solvents, just Dawn. (If you have steel rims, there is no safe reliable way to make steel rims brake well. Replacing them is the best, safest idea).

Submit your question for a future Ask B Rose column:




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About B Rose

B Rose: Industry tech misfit legend and excellent cook. B Rose has been in the bike industry since 1989 as courier and shop rat, spending half a decade at QBP before running suspension and hydraulic specialist shop Shockspital from 2007-2011. "I have argued over sausage with Sheldon Brown and argued with many more besides, I am immune to marketing and I cry when I watch Monk. I like to think of myself as the biggest outsider of the bicycle insiders and am proud to add my name to the b-list of bicycle celebrities."

View all posts by B Rose →

4 Comments

  1. Car Less OhioJanuary 17, 2013 at 9:53 am

    See this article for a more complete discussion of tire sizes:

    Tech Talk: Know Your Tire Size from Century Cycles
    http://bit.ly/U3J1L9

  2. Pablo MoneyJanuary 17, 2013 at 10:12 am

    Smart writing and bike geekery….I LOVE THIS COLUMN!!!

  3. icyclebayJanuary 17, 2013 at 12:27 pm

    The Shimano BR-550 levers are an awesome flat bar lever. They retail for $35 for a pair, come with a full cable set, and have the correct pull for a standard road caliper. They have a 22.2 clamp diameter for mountain bike bars.

    For older bikes with steel rims, using a quality pad with an iron oxide compound (the red ones usually have this) will help you stop quicker. Also make sure your cables are properly lubricated. If there is too much corrosion or friction in the cable housing you lose a lot of stopping power. Something like Triflow works well, but Rock n’ Roll Cable Magic is the best.

    More tire sizing info: http://sheldonbrown.com/tire-sizing.html

  4. Doug M.January 17, 2013 at 5:09 pm

    loving this column so far. keep it up!

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