Urban Velo

Ask B Rose – Thoughts On Road Disc Brakes

brose Industry tech legend B Rose is back with another dose of tech opinions. In this column B Rose lets us know his thoughts on mechanical disc brakes on road and cyclorcross bikes. It may not be what you want to hear.

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

Q:I hear a lot of hub bub about disc brakes on road and cyclocross bikes. People seem to either love it or hate it. What’s the word?

B Rose: The yin and yang of disc brakes; it is not as easy a question as you might think. I love disc brakes on my mountain bike. But there are limits even in love. One thing I can’t abide (get ready to object) is mechanical disc brakes. I know many of you just did a spit and asked, “Who is this joker?” But I have found that mechanical disc brakes have three major flaws (none of which you will admit to). One, they are almost always set up wrong. In all my years specializing in suspension and disc brakes (enough to be way old school) I can count on my fingers all the times someone has put a properly set up set of mechanical disc brakes in front of me.Two, at their worst possible set up, mechanical disc brakes are totally unsafe (it’s a rare situation but I can show you at least 3 examples of ways people roll the dice with their mechanical disc brakes). And finally, and this especially applies to road, touring and cross bikes, they feel like crap. Lets clamp a piece of metal between two more pieces of metal and string a piano wire between them and your hand. Yuck. I hold a pretty high standard and I hate that feeling; it’s bad on a mountain bike but even worse on a road or touring bike (or cyclocross if you are going fast enough). Hydraulic brakes damp the connection and you don’t feel every jerk and ping of the rotor in your lever.

Why did I take you through all that? Because mechanical discs are your main option right now. So for me that is strike one of the “discs on cyclocross” argument.

Strike two? Squeal. Cyclocross, road and touring bikes amplify the biggest issue with disc brakes in two ways. Speed and contamination. I personally feel, with no engineering background, that 700c wheels glaze the current offerings in disc brake pads over very quickly. I say 700c and not 29er because the bikes that refer to their wheel sizes as 700c are faster than your mountain bike or 29er. And contributing to squeal, contamination; you find it so plentifully on pavement. It’s an educated guess that most people use their road, touring and cyclocross bikes on the street. Streets are very oily and that kills disc pads! My favorite bike is now made in a disc version, and everyone I know with one complains about their discs squealing constantly. If your discs squeal until you replace you pads and clean the system then contamination is the issue and that is 100 times more likely on the street.

Strike three? The best thing about about disc 700c bikes is also the third strike for me. Wheel interchangeability. It’s really a terrible reason to do anything on a bike, but it is a total myth with discs. Fits fine, still needs adjusted every swap. Show me a mechanic whose heart doesn’t feel like it is being squeezed every time someone wants to non-permanently swap their disc wheels. So when it comes to swapping out your wheels; you know they are going to need to be readjusted, you know they are probably gonna squeal and in your heart you know the correct answer is just to, “run what you brung.” Wheel swapping is an idealistic idea that always ends in a set of unused wheels.

It’s fashion, and there is nothing wrong with that, but it is the wrong idea. Sorry. Commence fling of slings and arrows now.

Submit your question for a future Ask B Rose column:




Name

Email

Brief description of tech question (required)

Ask B Rose a question.(required)

Maybe a picture will help. 2 megabyte limit.


Sorry for the captcha, we hate these things too but we hate spam more.
captcha
Enter the above text in the box below.

Ask B Rose 3 – More Torque Wrench Wisdom, Old Elastomers, Tight Rim and Tire Combos

brose Industry tech legend B Rose is back with another dose of tech answers. In this column we cover torque wrench choices, ancient elastomer suspension replacements, tight tire and rim combinations and some gripping feedback from another wrench. You ask, B Rose answers.

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

Q: In an effort to completely befuddle your doubt’s that I won’t use a torque wrench (Ask B Rose 1), I would like to know what torque wrench to purchase. Mi amigo Julio has one from Ritchey, but is there one from Park or maybe Craftsman….Snap-On Tool? Which one is the most simple to use? Is there a general rule of thumb or some resource you can think of regarding the torque I should apply to my bike?

B Rose:There are many torque wrenches on the market. And there are none that cover every range, torque requirements run from units of mouse fart force to metric elephant shit foot tons. But I will do my best to save you some coin, here is my theory… Most people over torque bolts rather than under torque bolts. So things like 4 mm stem bolts (average 4-6 nm) get way over tightened till they break and 8 mm crank arm fixing bolts (39-49 nm) get under torqued. I think the more important end of this spectrum is the smaller bolts, the ones that get over torqued. Face plat bolts, seatpost mast fixing bolts, ect. So if you can buy only one torque wrench get a small one. The small Park TW-1 is cheap and easy to maintain. Most of my torque needs are met with a Syntace TT 1-20 (there are a million branded versions of this including the Ritchey.). It is not cheap and you must remember to dial it down after every use but the easily impressed will go gaga at the sight of it.
As I get old I use the Barnett Manual or this page to remind me of the numbers everyone thinks I already know.
Read more →

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?
Read more →

Ask B Rose 1 – Torque Wrenches, Sticky Grips and Popped Saddle Rails

brose Welcome to the first 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 if you should use a torque wrench even without carbon parts, how B Rose makes grips stick and how to replace a saddle rail that has come loose. You ask, B Rose answers.

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

Q: I don’t have any carbon parts, should I use a torque wrench anyway?
Read more →

News & Views

City Reports