Bicycle Mechanics - Please comment on this drawing of my proposed set up.

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bryroth
07-08-08, 07:21 AM
I have a 7-speed cyclocross-like bike made by Kona. I'm getting a new 9-speed cassette and bar-end shifters. It currently has Sora everything and a Tiagra rear derailleur.
Here is my plan:
I'm going to remove the drop handlebars and the brifters. In it's place I will put time trial base bar, pursuit bar, or bullhorn bar (whatever you want to call it).
The brake levers will be inserted into the bar-end.
I'd use bar-end shifters, but I'd attach them with Paul's thumbies. Here my question though. I'm thinking of attaching them so that they face down towards my hands. Seems like that's where your thumbs are anyway. Here is a crapulous picture of my idea.
75651
If you know of any reason why this would not work, please let me know. The only thing I can think of is that the shifters would get in the way of my brakes. But perhaps the levers are long enough?
Or if you have any suggestions please let me know.
maddmaxx
07-08-08, 09:22 AM
Instead of buying 2 thumbies and new bar end brake levers, try putting the shifters in the bar ends and buying 24mm clamp on cyclocross/interrupter levers ( to use as standalone levers ) and mounting them just behing the shifters. Rotate the shifters slightly in and the brake levers slightly out so the cables run side by side under the tape. Works fine and has been done by others here.
bryroth
07-08-08, 09:42 AM
But then I'd have to lift my hand to shift, correct?
maddmaxx
07-08-08, 09:49 AM
About 1/2"
the_mac
07-08-08, 02:56 PM
if you really want to do the thumbies, I'd mount them so that the shifters are on the inboard side of the bars. This way the flat tops of the bars are unrestricted and you can more easily manipulate the levers on the shifters (think of how your hands would grip the bars).
BCRider
07-08-08, 03:20 PM
Instead of buying 2 thumbies and new bar end brake levers, try putting the shifters in the bar ends and buying 24mm clamp on cyclocross/interrupter levers ( to use as standalone levers ) and mounting them just behing the shifters. Rotate the shifters slightly in and the brake levers slightly out so the cables run side by side under the tape. Works fine and has been done by others here.
Um... apparently this isn't a good idea. There's a recent thread here where someone was doing this and found that the cables flex due to the type of termination at the lever and the brake cables snapped on him after a while. The proper style of bar end brakes use a different termination for the MTB style barrel end that lets the barrel end pivot to keep the cable running straight so it won't fatigue..... which reminds me that I should squish a little grease into mine that I just installed to help them pivot easier.
Bryroth, I've only just gotten my first bullhorn bar bike but already I've really enjoyed being able to wrap my hands fully around the upcurved portions around the brake levers. I would not want to install any more junk up there since it WOULD get in the way of my grip.
Instead I'd go with mounting them as the_mac suggested and as shown in the Paul website... http://www.paulcomp.com/roadthumbie.jpg
Yes you need to move your hand to shift but so do all the folks running tri bar setups with the brakes on the ends of the bullhorns and the shifters on the aero extensions. I think you'll appreciate the extra comfort when pulling hard on the climbs much as I do.
maddmaxx
07-08-08, 03:49 PM
Um... apparently this isn't a good idea. There's a recent thread here where someone was doing this and found that the cables flex due to the type of termination at the lever and the brake cables snapped on him after a while. The proper style of bar end brakes use a different termination for the MTB style barrel end that lets the barrel end pivot to keep the cable running straight so it won't fatigue..... which reminds me that I should squish a little grease into mine that I just installed to help them pivot easier.
Bryroth, I've only just gotten my first bullhorn bar bike but already I've really enjoyed being able to wrap my hands fully around the upcurved portions around the brake levers. I would not want to install any more junk up there since it WOULD get in the way of my grip.
Instead I'd go with mounting them as the_mac suggested and as shown in the Paul website... http://www.paulcomp.com/roadthumbie.jpg
Yes you need to move your hand to shift but so do all the folks running tri bar setups with the brakes on the ends of the bullhorns and the shifters on the aero extensions. I think you'll appreciate the extra comfort when pulling hard on the climbs much as I do.
I've searched for this thread you mention and although I've found lots of broken brake cables in brifters, I have not found this one. Could you or anyone point me to it. I and several others have been using interrupter brake levers as stand alone for several years without problem and I'd like to read about this one.
Edit: I do remember a thread where the user was installing an MTB cable in the adjuster barrel instead of a road cable and having a problem.
Edit 2: I'd have to question the "proper style of bar end lever using MTB cables as a general statement. The following TT bar end brake levers use "road cables, SRAM Force TT, TRP RL920, Tektro TL720, Zipp Speed Weaponary Vuka. However, Cane Creek TT200's, Tektro RX4.1 and 5.0, Possibly ITM levers use MTB cables. It appears to be about a 50/50 split. It doesn't seem to matter if the cable is an internal routing or external routing as the lever attachment point moves about the same distance and through the same arc from the housing end on all of these levers.
BCRider
07-08-08, 05:23 PM
I've searched for this thread you mention ......
Edit: I do remember a thread where the user was installing an MTB cable in the adjuster barrel instead of a road cable and having a problem.
Edit 2: I'd have to question the "proper style of bar end lever using MTB cables as a general statement. The following TT bar end brake levers use "road cables, SRAM Force TT, TRP RL920, Tektro TL720, Zipp Speed Weaponary Vuka. However, Cane Creek TT200's, Tektro RX4.1 and 5.0, Possibly ITM. It appears to be about a 50/50 split. It doesn't seem to matter if the cable is an internal routing or external routing as the lever attachment point moves about the same distance and through the same arc from the housing end on all of these levers.
Took me a little bit to pick the right keywords but I got it....
http://www.bikeforums.net/showthread.php?t=434809&highlight=cable+frayed
The one with the barrel end sitting in the rounded hole was another thread. His only crime was a lack of fashion sense for using the wrong cable.... :D
I'll count myself schooled on the last issue. In looking around at bar end brake levers I only saw a few and they all used the Cane Creek style MTB barrel ends used in a barrel end style lever. Given the small size of the lever design I assumed that they were all like that.
Frankly after seeing what happend to the one in the link I would not want to use a setup where the cable end cannot pivot to line up with the tension forces. The one in the link scared the bejeebus out of me. Now the guy in the link above DID admit that the brakes had long been in need of adjustment and the levers were coming up pretty much all the wan to the bars. That alone would induce a lot of chance for flexing where the cable meets the end swaging or at a sharp edge of the moving lever so that could be a factor. Still I'll take the lever with the better design to start with.
Using the interrupter levers as intended probably isn't so bad since that far along the cable the strands are going to slip on each other rather than bend right at the termination like when you use it as a final lever with the cable end right there. But many folks do it so it may not be as bad as I'm making it out to be but it still doesn't make the design a good one.
The levers I just installed are Cane Creek 200TT's and they use an MTB barrel endd and that is supporte in the online manual... http://www.canecreek.com/images/stories/products/brakes/man_brakes/200TT_instr_04-12-2005c.pdf
maddmaxx
07-08-08, 05:50 PM
Thankyou for the thread id. After reading all the posts I'd have to say that I agree with cyccomute's last statement, that the lever is capable of producing a great deal of force. I know that the setup I use requires very little hand pull to engage the brakes. It actually has the feel of very good hydraulic disc brakes. Even when running this sort of lever as a cyclocross interrupter, it is stronger than the primary brake lever on the brifter that it is attached to. This is a result of running very close tolerances on the brake pads and using very solid cable runs. Because of this I have never encountered this sort of extreme angle cable twist. I also admit to replacing my cables every winter as part of the routine servicing of the bike.
Edit: I made an edit to the previous post that you copied because I left out the last part of the sentence about the second group of levers using MTB ends.........sorry bout that.
Edit 2: Upon reflection I am not prepared to recomend for or against this sort of lever pending further research and evidence. It appears that some of these levers provide support further away from the cable end that others. For example the TRP carbon levers that I have been using have a tightly fitting passage through the bottom of the barrel adjuster in the lever that moves the bending point away from the cable end. If there are other levers that bend the cable right at the end then that might present a larger problem.
Joshua A.C. New
07-09-08, 07:08 AM
My experience with cx levers on bullhorns has been so far very good. I don't feel any of the sponginess I'd expect to feel if wires were breaking one by one. I'm using Tektros from a year or so ago. That said, I see how they induce a tight radius and I think that's good inspiration for replacing brake cables often.
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