Dual brake levers,will they work?

Discussion in 'Spare Parts, Tools & Product Developement' started by duivendyk, Mar 20, 2008.

  1. duivendyk

    duivendyk Guest

    The answer to that is:possibly on some bikes,but not,or not well on others.
    All bicycle brake setups rely on leverage,that is to say a relatively large movement of the brake lever is translated to a much smaller movement at the brake shoe,but with much larger force.Depending on the type of brake (rim,disk or drum) the leverage ratio required can vary considerably.There is an optimum ration,too much mechanical advantage can result in brakes which are too touchy and can send you over the handlebars,they will also be difficult to keep in adjustment.Not enough mechanical advantage and you will lack stopping power.
    Restricting the discussion to rim brakes,the total leverage is distributed between the brake lever and the brake assembly itself.The mechanical advantage built into the brake assembly proper can be quite different,depending on the type of brake,which means that the brake lever has to be matched to a particular type of brake.For instance a long pull brake lever (low mech. advantage) should be used in conjunction with direct-pull cantilever brakes (similar to the Shimano V brake, with high mech. advantage) and not with other types of brakes (with low mech.advantage, such as center pull cantilever brakes,or older sidepull brakes).You would be lacking in stopping power.Conversely if you mated a shortpull brake lever intended for a centerpull brake to a V brake,you are likely to bottom your brake levers,because you don't have enough reach,or else the shoes will be dragging,if the wheel(s) wobbles just a bit,as most do.It's simply impractical to keep the brakes in adjustment, you have lot's of stopping power in theory only,but you may have none at all, since you bottom your brake lever.If you are confused about the brake terminology I used, go to www.sheldonbrown.com, ,look under drivetrain component/brakes and you will find a wealth of pertinent info, study it, it could save your skin!
    About the dual brake levers such as sold by Pyramid,I contacted a dealer (Eaton bicycles in Key West) and was infirmed as I had expected that this lever was not suitable for V brakes (direct-pull cantilever brakes).I don't know about any other makes.The fact remains also that with a single brake lever,one hand has to do exert the force that was shared between both hands before,so you would appear to need more leverage,with the danger of running out of adjustment,as I discussed previously.
    Another factor is that, compared with motorcyles&most mopeds a bicycle has a much higher center of gravity (mostly determined by the rider), this means that a far more weight transfer takes place during hard braking,80% or more of the braking is attributable to the front brake under those conditions !.So it's easy to lock up the rear brake,which means that you are likely to lose control.It is vital to be able to use your brakes judiciously,so what if an extra cable&lever clutters things up some.Anybody reading this should go to a safe place and practice "really hard braking".It's a useful skill to master esp. for speed demons, JJ
     

  2. azbill

    azbill Active Member

    I use a dual brake lever
    I have a front drum (sturmey-archer X-FD), and the stock v-brakes that come with a Schwinn Jaguar
    my front wheel has been on three different motoredbikes and has more than 2000 miles of wear and it stll stops me easily...I have the back adjusted to pull immediately, and the front just after and never have any prob with either locking or fading under hard braking (I have to confess, I like going into turns hard, braking late :D)
    I can see the benefits of having a coaster as well (a redundant brake for if the handle breaks)

    but..I love my dual lever :D and that's why i am posting (2 different type of brakes and it works great !)
     
  3. duivendyk

    duivendyk Guest

    You seem to have have hit on a fortuitous combination,but I venture to guess that you are relying more on the SA front brake than you probably realize.The drum brake is a "stiff" brake,not much brake lever travel after it takes hold,the V brake has more compliance ( in the brake pads,rim,&cable sheeth) and therefore is spongier ,so with your dual brake lever,you may get the situation that with increasing brake force the front brake starts taking over from the rear,which is fine,but it is difficult to be sure of what's really going on.I can see the advantage in this setup,the drumbrake is durable and is easy to adjust,the rim brake is good for heat dissipation on long hills,which is something I am quite concerned about.Do you have a Pyramid brake?,JJ
     
  4. Scottm

    Scottm Guest

    I have the Pyramid dual pull brake levers on both my bikes, one se up exactly like Bill's. My other one with cantilever front and rear. I have had to bring that bike to skidding stop once. The only thing I worry about with dual pull as it's been posted here before about these setups is that "You have all your eggs in one basket".

    Sheldon Brown's writings are the best info and easy to understand.
     
  5. Alaskavan

    Alaskavan Guest

    I use a dual pull for my front wheels. Properly adjusted, it cuts down on brake steer.
     
  6. duivendyk

    duivendyk Guest

    You must have a recumbent,obviously dual-pull is the way to go for the fronts,you also don't have to cope with nearly as much weight transfer,due to the low CG,altogether a much superior and safer braking environment.My principal concern is with emergency braking,Just last Sunday,on my regular bike I encountered a pickup truck making a U turn & blocking the road, when coming around a blind downhill curve .Somehow I survived it unscathed but concluded that I definitely could use more practice.To cope with these situations you have to be mentally prepared & ready to excecute.What is the best 2 stroke oil for a 43 cc Mitsubishi?.I am getting ready for a trial run on my Staton/NuVinci setup.JJ
     
  7. Alaskavan

    Alaskavan Guest

    I just used Valvoline during break-in, then switched to Royal Purple. I have no idea if these were good choices. From my reading I would say that, if it's available to you, a Castor based oil is probably best for break-in. For me, the shipping charges made it too expensive.
     
  8. sparky

    sparky Active Member

    From what I have read, there are 2 types of 2-stroke oil that could be recommended to anyone after break-in. They are 80% synthetic / 20% castor, which seems about right once you read the properties of these two different types of oils. The best 2-stroke oils seem to be:

    1) Maxima Castor 927
    2) Klotz Super Techniplate

    The cheapest place to order either one is from http://www.rockymountainatv.com

    And of course Royal Purple, RedLine, & Amsoil are great synthetics... but I am not too sure if they have the castor oil mixed in or not.
     
  9. duivendyk

    duivendyk Guest

    Thanks very much for the info, is there a break-in period & break-in oil, or could this be an old wife's tale ?,I ran across the Mitsubishi owner's manual,it had nothing to say on this subject, but did give oil specs. (ISO-L-EGC class,whatever that is). Historically the reason for a break-in has been to seat the piston rings,(and therefore not to over-lubricate the engine initially,I surmise).These micro-engines are fairly highly stressed in operation,so it makes sense to treat them well,JJ
     
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