chrisboyne

I just bought a pair of Tektro RL520 brake levers (https://www.amazon.com/Shimano-BL-R40.../dp/B000F5LLWG) from craigslist and now that I have them I realize they are designed for use with linear pull brakes. I didn't even think about these while I was purchasing them because the seller said they were from a Kona ***** Tonk which for sure would not have had linear brakes.

Anyway I just wonder what actually makes these levers different from other drop bar levers? What is special about them that makes them for use only with linear pull brakes?

And lastly, of course, can I use these levers on my light touring frame with cantilever brakes.



Thanks,




chris

fietsbob

Well they do pull a lot of cable, but you might use that extra cable pull to leave a wide gap
between the pads and the rims,
and use some of that extra pull , bring the pads to the rims.

long leverage on the V brake end at the wheel demands a lot of cable pull
because of their High Leverage.


You Do understand the basic leverage principles don't you?

Work, Fulcrum, Effort.

[force vs speed ,.. crow bar or catapult.]

Airburst

Long story short, linear-pull levers and brakes are designed to work with the cable being pulled more distance, but with less force, and only work with each other. Linear-pull levers won't let you apply much force to push the brake pads against the rim if you use them with conventional cantilevers.

chrisboyne

Yes I understand the differences to a certain point but I just couldn't wrap my head around how/why the levers themselves would be so different. But you are saying that the linear pull levers pull substantially more cable.

I will re-sell these levers and find something different. I don't want to compromise anything or dick-around too much when I don't have to.

Thanks.

Airburst

The actual mechanical difference is in the distance between the pivot for the lever and the point where the cable attaches to it. I believe linear-pull brake levers pull roughly twice as much cable, half as hard, as conventional ones, although I've never measured it.

As for why, the whole system can be made to feel stiffer, because the cable and housing only deal with half the force of a conventional system, so they deform less. Some people would say you get better modulation of the braking that way, but I can't claim to have ridden any two bikes that were otherwise identical, so I don't know how big the effect is.

gyozadude

I stock an extra pair of these (in black/silver) for drop bar bikes that want to retrofit V-brakes/Linear pull where there used to be traditional cantilever brakes. I'm using them right now on my MTB commuter with drop bars and Suntour barcons where I've replaced old cantilevers with Linear Puls brakes. The design of the lever puts the lever outward 3mm more than my Dia Compe BRS series reference standard aero lever, and the lever pivot axis is about 6mm further down from the brake cable anchor. So it pulls significantly more cable. More metal on the top section of the housing body to support the long distances means less curvature than my reference levers and so it has a flatter profile for riding on the hoods. If you have small hands, I would imagine that these levers will feel a bit bulkier in the hand than previous levers. But for bigger hands, the flatter tops makes it feel more roomy. With my old levers, the Linear Pulls had to be set with brake shoes really close and still I'd bottom out the levers against the drop bars on panic stop tests. These behave as normal and I can lock the wheels without the levers bottoming out, and I still get powerful braking.

Retro Grouch 

I've done it and I didn't feel like it was a dangerous combination.

My general philosophy is, if I'm buying components I'll hold out for parts that match. If I already own parts, I'll bolt them up and see if I can get them to work to my satisfaction.

The leverage factors of linear pull brake levers is different so you'll have to squeeze harder with your hands to get the same brakeing effort at your wheel. When I tried doing it, I didn't think it was that bad. Since you already have the levers, why not try them for yourself and test under some controlled conditions?

Dan Burkhart 

+1. I have used the wrong levers in a couple of applications with no problems. Helps to have substantial hand strength.

reptilezs

if you want less than optimal power, sure

IthaDan 

To echo previous posts, the answer to the question in the thread title is: Yes, but with poor results.

Retro Grouch 

Have you tried it or is that your opinion from reading the book?

I have no problem with engineering but I also think that having enough personal experience to put a perspective on the numbers is important. The OP already owns the parts. That's why I suggested a no out-of-pocket cost controlled experiment.

FastJake

I tried it once (by accident.) V-brake levers and cantis on a MTB. Braking wasn't great, and it was better after I swapped the levers out, but all you need to do is pull harder.

Cantis are pretty adjustable, and depending on how you have them setup you might actually prefer the V-brake levers. On one bike right now I have some old Shimano cantis and Shimano aero brake levers and they feel a bit mushy. I think a little extra cable pull would really firm them up.

Retro Grouch 

Try fiddling with your straddle cable. Sometimes a longer, narrower triangle will really firm up the brake lever feel.

IthaDan 

[QUOTE=Retro Grouch;15534681]Have you tried it or is that your opinion from reading the book?
/QUOTE]

I've done it. Took me a couple rides with cramped hands after riding on hilly terrain to figure what was up.

Not worth the pain when $15 can buy the right levers.

Retro Grouch 

I'd go with that. Any problem that you can solve for $15.00 isn't worth living with.

sreten

Hi,

But not the actual braking. Long pull levers on short pull brakes
will feel firm, which is bad, you want squidgy for progressive
braking and more maximum force at the brake pads.

Lengthening the straddle cable will only make things worse
with long pull levers regarding not being able to squeeze
the levers hard enough, conversely a short shallow straddle
cable can be made to suit a long pull lever, as the straddle
length changes the mechanical advantage of the brake.

Cantilever brakes can be adjusted to suit the levers.

rgds, sreten.

FastJake

Retro Grouch was replying to my comment about my cantis with Shimano aero levers (caliper/canti pull) feeling mushy.

I am using a rather shallow/short straddle cable with those, but the braking is good enough that I haven't bothered to mess with it.

fietsbob

The Brake lever cable pull ratio in the middle, between V and road Aero types,
is the cable out the top road brakes from the 70's~80's .. Modolo and Campag are my favorites

the Modolo Anatomic Hoods on both FTW.


Compact cantilevers are a Class 2 lever , the pivot on the end, 'work' above it,
'effort' further away ... V brakes fall in that category too..

L shaped cantilevers are class 1, .. pivot at a point between.

reptilezs

yea i have done it. on a seven actually per request of the customer. avid ultimate cantis and speed dial levers(these are v brake levers), yes the one with the leverage ratio adjuster. lets just say the customer brought it back to have v brakes put on

reptilezs

seven frame. was a hybridish build with flat bars.