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I have bullhorn bars, with a Tektro cyclocross lever and a TT style bar end lever as well, operating rim brakes. The calipers are Tektro dual pivot. The pads are cartridge style pads (I don't have the exact make and model with me right now).

This is the closest photo to my setup I could find. I have bullhorn bars rather than drop bars, but it shows the way the cyclo levers interact with the bar end levers.

inline brakes

I've been having trouble with braking performance, particularly in the wet. The levers don't bottom out (as I'm careful to keep them adjusted), but even squeezing very hard the bike doesn't pull up very quickly. I should also mention that I've tried removing each lever and haven't noticed any difference (although it can be hard to compare different days and different conditions).

I've had 3 different bike shops tell me that the problem is having both brake levers. They claim that it introduces too much flex into the system and braking power is reduced. I was very skeptical until all 3 people told me the same story independently.

This doesn't make sense to me. The cable is not interrupted and using either lever doesn't seem to compromise the brake line in any way. When you use the bar end lever, the interrupter is closed and I can't see any flex in the lever. When using the interrupter lever I don't see how the bar end lever can be causing any flex either.

Can anyone explain how having both levers would compromise performance?

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1  
It introduces some friction, but probably not a whole lot. And when you squeeze the main lever, the interrupter lever is going to compress slightly against its stop, "eating" a small amount of your brake travel. But what's most unclear is what sort of "performance" problem you have -- brake levers bottoming out, brakes grabbing, brakes fading, what? If it doesn't involve the levers bottoming out, or simply a "feel" that's too spongy, I don't see how the levers are involved. –  Daniel R Hicks Sep 27 '11 at 23:39
    
@DanielRHicks good point, I've edited to specify the performance problem. I assumed the same about losing a small amount of brake travel but the lever is pretty much a solid block when it's closed. –  Mac Sep 27 '11 at 23:58
    
Sounds to me like maybe your brake pads are too hard. –  Daniel R Hicks Sep 28 '11 at 0:27
    
(BTW, rim or disk brakes?) –  Daniel R Hicks Sep 28 '11 at 0:28
    
Added some detail about rim brakes and the brake caliper and pads –  Mac Sep 28 '11 at 1:26

2 Answers 2

up vote 3 down vote accepted

The problem is not to do with the interrupter levers (they are probably the least weak part), the problem is systematic.

Shimano and Campagnolo are known for their bike components, however, they can be seen as companies specializing in cold forged aluminium alloy components and able to churn out the best quality stuff, whether that be fishing reels, wheels for Porsche cars or bike bits. These companies have invested in really big presses for the cold forging process, invested in the finest alloys and invested in the really expensive dies that only make sense to invest in if the sales volume is there.

Only engineers inside the machine tool/cold-forging business or in the cold-forging business can really illuminate to you the science going on at the high end and what the likes of 'Tektro' miss out on. However, 'Tektro' parts are nearer being 'stamped out of cheese' than cold-forged properly. It is unlikely that their parts get put in the press multiple times, this forging process required to give the 'Shimano grade' finish, aligned aluminium alloy grains and consequent strength.

The Tektro brakes are well known for being 'spongy' and, as of yet, no Tour de France teams upgraded their Campagnolo/SRAM/Shimano brakes to 'Tektro' for that special 'spongy' feel. They are OEM parts without much call for them in the aftermarket. The processes used to make all of their parts are cheaper than those used by Shimano/Campagnolo. Hence the problem is systematic.

Given where you are, consider getting a better front brake, e.g. Shimano 105 (or even Sora). Also consider investing in Shimano cables. The back brake is less crucial as you skid on that anyway, but you might want to be on the lookout for a complete brake setup replacement minus the interrupter levers - keep them and swap out the rest as time and effort allows.

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Thanks for the suggestions and I definitely plan to upgrade the brake calipers, levers etc. Maybe the question is too focussed on brake performance, but the question I really want answered is why 3 people independently identified the cyclo levers as the problem. –  Mac Sep 28 '11 at 23:55
    
They do interrupt the cable and you get bit of extra squishiness from the cable outer joins. But I think poor alloys in the system as a whole is the problem here. –  ʍǝɥʇɐɯ Sep 29 '11 at 0:30
1  
This seems like a bit of a non-sense answer. The metals used for things like brake levers don't "sponge". I seriously doubt there is enough flex in those tektro levers to be a problem regardless of manufacturing technique (if the manufacturing is that bad, they'll bend or break). The problem is more likely to be with bad design (incorrect mechanical advantage or pads too hard, as mentioned by Daniel R Hicks in the comments), or incorrect set-up. Even the crappest department store brakes are usually pretty performant when set-up correctly (excluding those pressed-steel kid's bike calipers). –  naught101 Sep 3 '13 at 5:47

The only way that interrupter levers could make much of a difference is if the installation requires extra housing (which would compress under braking, increasing the lever travel for a given braking pressure). If you're not bottoming out the levers, though, that's not the source of your problem (and from the picture I don't see why the interrupters would require additional housing anyway).

I think Daniel R Hicks is correct here--your lever/caliper setup likely isn't giving you enough mechanical advantage. You're squeezing the levers as hard as you can, but you're just not getting enough pad/rim force for decent stopping power. You notice this mostly in wet weather because there's less pad/rim friction when they're wet.

Finger positioning on the levers is one thing that can make a difference--keep them as far away from the pivots as you can. On my drop-bar commuter bike, for example, I need to ride in the drops during wet weather because I just don't get enough mechanical advantage with my hands on the hoods.

You might also see better braking performance if you switch to softer brake pads, or rain-specific pads like Kool-Stop Salmon or similar, though I've read that the Salmons tend to chew up rims pretty quickly when it's dry.

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Thanks for the comment about the installation compression. It's a very relevant answer and I had trouble deciding which answer to choose. –  Mac Oct 17 '11 at 3:45

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