Saturday, June 28, 2014

Shimano and Tektro brake comparison ... or what models of v-brakes sit flush with the end of the brake boss stud?

During the process of switching from long pull to short pull v-brakes on a folding bike, I noticed a quirk between the Shimano and Tektro brakes with respect to mounting on the brake bosses.

Long story short, it appears that brake-boss-base -- or where the springs of the v-brakes mount -- is "too long" for the Shimano v-brakes.

Ordinary brake boss.  I'm calling the wider part of the boss
where the brake's spring resides the base.
Black Tektro is flush.  Notice that the entire silver Shimano brake
is moderately wider.  However the spring portion of the Tektro
brake is wider than it's Shimano counterpart. 
Notice the gap between the brake and
the left edge of the brake boss.  The spring end is in
the hole of the brake boss.

A quick comparison between the two brakes reveals the Tektro spring portion of the brake is deeper than it's Shimano counterpart.  In fact, when you take into account that the entire Shimano brake is somewhat wider than the Tektro brake, the brake extends quite a bit past the end of the stud.  

Tektro brake is flush with the stud.
Shimano brake is roughly 5-10 mm past the end of the stud.
I gather from a few online discussions that the gap between the brake-boss-base and the brake is standard for some models and not an issue: The post is more than stiff enough to support the brake and the bearings or whatever that allow the brake to rotate are inside the brake rather than between the stud and brake.   

The sad thing is that after learning all of this, I determined that these Shimano brakes will not work with the folding bike.  The front rack mounts onto the front of the brakes as well as to an eyelet.  Changing brakes would move the mounting points and make it more than a little difficult (impossible?) to fit the rack.  

So does anyone know if a Tektro short pull v-brake -- say the Tektro RX5 -- sits flush with the end of the stud?  Are there other options?  Thanks.  


  1. hi , did you ever get anywhere with this ? i have the same issue , im a mechanical engineer , and this definately isnt right, seems odd shimano would make something thats so different , ive got 3 bikes here and many sets of bosses in my parts box from old bikes and they are all the same , wrong size. regards simon.

  2. Apparently, this is normal. That is, for the same size brake stud, there are different "styles" of brakes that have to do with how the brake arm pivots on the stud. Some have a sleeve on which the lever pivots whereas others pivot on the stud itself.

    It only mattered to me because the folding bike had a custom front rack designed to mate with the stud in a particular manner.