MAITOY up…

MAITOY can be found at http://www.circleacycles.com/cantilevers/.

The supporting paper in draft form is available here.

Advertisements

11 Responses to “MAITOY up…”


  1. 1 Federico Cozzi June 24, 2010 at 10:04 am

    Hey,
    your paper is great!
    You won’t believe, but I had those same questions you answered in your paper. Figure 3 is icing on the cake.
    Now I will to back to my cantilevers to tune like your paper suggests. (I switched the front brake from medium profile to wide profile a while back, was disappointed with the switch and now I can really understand why)
    I will try medium profile brakes with as-low-as-possible yokes (no Shimano-fixed-length straddle cable any more) since they have good MA and almost-flat MA curve.
    Thanks!

  2. 3 tavis November 23, 2010 at 7:17 pm

    This is a seriously great little program. I’ve been thinking about how to do something similar for a while but never quite figured it out.

    Have you thought about putting together a database of arm lengths for different cantis?

    • 4 bennobelhumeur November 23, 2010 at 9:11 pm

      Thanks for the props. I hadn’t thought about a database, I guess because there are so many variables that affect what the alpha will be for any given brake that I am unsure how useful it would be. I was thinking more about illustrating guiding principals than I was about trying to compare specific real world brakes.

  3. 5 Jim H March 26, 2011 at 7:31 am

    On my tourer/commuter I have a disc on the front and canti on the rear, I’d gotten so fed up of the canti that I pretty much gave up braking on the rear!

    But now I can see taht for about three years I’ve been setting my low-profile cantis up completely wrong! Thanks for showing me the way! Ok, not completely wrong, I had the yoke nice and low for a higher mechanical advantage but the less obvious thing I was doing wrong is I had the pads all the way out on the ends of the studs, with the spacers on the pad side of the arms.

    This brings the arms lower, which I thought was a good thing. Now I can see that by making this change, putting the thinnest dome washers I can find on the pad side and chunky ones on the outside (plus lowering the yoke a little bit) the arms go higher and the MA is almost doubled – good stuff!

    Just one thing I would change – you take the cable pull as being from the centre of the yoke, but in reality the yoke has a non-zero width that makes a difference since the cable pulls the left/right edges of the yoke. For example, Shimano used to make an extra-wide yoke for the purpose of lowering the MA of canti brakes.

    • 6 Johan January 2, 2012 at 6:48 am

      Jim H – the cable height is virtual: you measure the height on the point where the straddle wires would meet if you extended them. The effects of an actual cable hanger height could be incorporated into the program, but at this point it isn’t.

  4. 7 Johan Larsson January 2, 2012 at 7:53 am

    Thanks for this program! it’s very interesting an useful, and have answered some questions I’ve pondered on quite some time!

    Here’s some feedback: I just discovered that you can’t increase the distance OD for centerpulls more than 45 mm, however there are many centerpulls that have arms longer than that. Dia Compe/Weinmann 750 have that measurement as 57 mm, and I think there are some even longer.

    Also – could you make it possible to specify the angle at P (APR) together with the (1/2) width of the rim (best option – alternatively the length PR) also? That would make the calculator more intuitive and much easier to use when you’re trying to figure out the brakes on an actual bike, as you can measure on the parts directly. What Jim H is thinking of in the comment above would be an interesting addition too, since the virtual yoke height changes rather much depending on the width of the cable hanger, especially with wider ones.

    • 8 bennobelhumeur January 2, 2012 at 11:21 am

      Thanks for the thoughtful suggestions. I hadn’t realized that OD can in fact get much longer. I will fix this if I ever get the chance to get back on this. There are a couple of things I wanted to fix as well, but you know how it goes.

      As far as specifying PR or APR, I agree that it would make it easier to use as a calculator. In my paper (link in post above) I discuss why I chose to use the other values for the purpose of analyzing the problem. Insofar as the applet is an extension of the paper, it makes sense to use the constants that I did.

      With regard to the width of the yoke, I just didn’t have the energy to analyze the effect of a wider yoke and incorporate it into the applet. It would be useful, but perhaps it would make the applet a little too confusing. There are already a lot of adjustments and I think it is perhaps not as clear as I would like for someone new to brakes.

      • 9 Justin January 1, 2015 at 8:57 pm

        I just realized the same thing as Johan Larsson when attempting to compare mechanical advantage of centerpull Mafac Racer and Dia Compe 750, both of which have an OD measurement > -45. It would be very interesting to be able to use the calculator for these common centerpull brake models.

  5. 10 Johan Larsson September 27, 2014 at 10:51 am

    The maitoy page seems broken for some reason? Have some internal links changed maybe?


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s




Categories


%d bloggers like this: