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downtube shifters on carbon frame w cable stops

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downtube shifters on carbon frame w cable stops

Old 03-14-13, 09:00 PM
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downtube shifters on carbon frame w cable stops

Says it in the title, I know you can buy the reverse of this, STI mounts for cable bosses that turn the cable bosses into cable stops. Is there any thing that is made to turn cable stops into cable bosses and or a way to mount the downtube shifters to the cable stops that anyone has done. I got a new frame and still have my old one I was going to run downtube friction shifts if possible just for a spare bike and wanted to keep it cheap if you must know why I am asking this in the first place.
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Old 03-14-13, 09:18 PM
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You know the answer and the answer is "you can't".

The other option is to use a contraption that moves the down tube shifters to the brake levers. Maybe somebody remember the name of the stuff im talking about.

Maybe there are other solutions like putting a clamp (home made one) like it was done like 30 years ago in some bikes but it will look really dumb looking.

Good luck.
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Old 03-14-13, 09:19 PM
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I suppose you could have the cable stops removed and downtube bosses mounted by a qualified person,...but it won't be the cheapest or easiest option. For that, I'd look at a set of bar end shifter pods to attach your d/t shifters to.
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Old 03-14-13, 10:19 PM
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co-worker has done this

had a special braket fabricated
aluminum halfpipe matching the curvature of the frame downtube
with two pegs perfectly positioned to fit into the existing cable stops
DT mounts on the sides of it

no clamping or modification of the carbon frame; it stays in place via cable tension and the pegs in the cable stops
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Old 03-14-13, 10:29 PM
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There's Paul Thumbies and Retroshift levers.
Both work with friction.
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Old 03-14-13, 10:43 PM
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I might not have the right solution for you but at one point I wanted to put dt shifters on an aluminum frame that had no brazed on bosses. I searched yahoo for "bolt on down tube shifter bosses".

what I found were hundreds of "clamps" which would work fine for a steel bike with a narrow diameter tube, way too small for alum or carbon.

I did find one application where you drill a hole through the tube, insert a stiffening rod, thread the bosses into it, then cover it all with a clamp. It looked like it would work just fine but I didnt want to drill into a new frame. I decided to go a different way. sorry no link, good luck.
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Old 03-14-13, 11:30 PM
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The component market place adopted the Brifter before the sales of carbon fiber went mass production..

not quite like bringing back the buggy whip, for the horses,

but hiring a custom build is always possible ...

.possible just for a spare bike and wanted to keep it cheap if you must know why
you have to look for older frames , used stuff, of metal, to get that combo, realistically.

carbon stuff is too recent to go so retro on your wish list.

Last edited by fietsbob; 03-14-13 at 11:39 PM.
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Old 03-14-13, 11:56 PM
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well, it's possible, but pretty ugly. here's what i'd do...

buy a new or NOS clampon friction shifter set off ebay, you know, the kind they used to put on 70's and early 80's bikes, before they started to braze on the bosses. then mount a third water bottle ferrule under the downtube at the point you want the shifters. this will serve as the plate normally associated with clampon downtube friction shifters that serves to prevent the clamp front sliding down the tube when shifting, although just about anything wrapped around the downtube below the shifter clamp will prevent it from slipping i imagine.

finally, in order to address the too small clamping strap, i would cut the clamp in half and fashion a splint of suitable length and fasten it to the two parts of the strap that were cut with a couple of simple aluminum pop rivets similar to those often used to attach brake cable guides to the toptubes of carbon frames. won't look good, but with a little effort and some imagination it may be passable. good luck.

or you could just slap one of these on there:




Last edited by hueyhoolihan; 03-15-13 at 12:03 AM.
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Old 03-15-13, 12:18 AM
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This is probably your cheapest and least goofy option for running your existing downtube shifters on the new frame.

https://www.rivbike.com/product-p/sh13.htm
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Old 03-15-13, 03:25 AM
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Would epoxy glue hold them in place? I think you are barking up the wrong tree and if you must use your existing shifters (I must, I must!), then bar-end pods are the way to go.
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Old 03-15-13, 06:29 AM
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Originally Posted by fietsbob
you have to look for older frames , used stuff, of metal, to get that combo, realistically.

carbon stuff is too recent to go so retro on your wish list.
Not so retro in fact. Trek Madones up to 2007 still had down-tube shifter mounts - I was riding one of those with a right-hand STI and left-hand down-tube shifter until a couple of years ago. This was the setup that Lance was still using on mountain stages until at least 2004, maybe still in 2005 also (you can see it in some of the old photos).

I still prefer a friction down-tube shifter to an indexed STI to control the front derailleur, but unfortunately don't have the mounts on my current frames. I therefore now have a bar-end shifter or Campagnolo Ergo left-hand lever, which work just as well and are easier to reach than the down-tube mounted version. The right-hand lever is always a Shimano STI though, so everyone thinks I'm a bit odd - and they are right.
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Old 03-19-13, 02:10 PM
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Originally Posted by xenologer
co-worker has done this

had a special braket fabricated
aluminum halfpipe matching the curvature of the frame downtube
with two pegs perfectly positioned to fit into the existing cable stops
DT mounts on the sides of it

no clamping or modification of the carbon frame; it stays in place via cable tension and the pegs in the cable stops
xenologer do you have a picture of this so I can see what I need to make here, I was thinking of something like this and thought it should not be too difficult to make such a device. If not an exact picture a drawing would also help just so I can make sure what I am picturing is what you are talking about
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Old 03-19-13, 02:36 PM
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Allowing for frame modifications..

Run a piece straight through the frame, for the bosses you attach the shift levers onto,
they typically as you see, on the steel braze ons, have 2 flat spots , those flats for the outer friction plates,

those flats could be also keeping the pieces that you bond onto the Frame tube with the lever stops ,
from rotating relative to the outer friction disk

typically fit over a Square base of the Braze on , to
stop the lever from Moving past the forward slack cable .. stop..

The difference between the flat stop which the lever uses for part of its friction
And the round of the Tube can be done in something like Epoxy Putty.

the pins as suggested above would just penetrate enough to keep the plate from rotating.

perhaps just the bonding by the Epoxy would handle the lever and friction shear forces , IDK ,

I'm just working with mechanical practices and thinking of practical Materials, to use..




in addition.. if you can Make it in Wax , you can get it cast in Metal, even Aluminum.

Last edited by fietsbob; 03-19-13 at 02:44 PM.
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Old 03-19-13, 05:04 PM
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You sure your rear wheel is going to fit?

Not sure I'd be up for clamping carbon outright or what the tube diameter is, but this is something- https://problemsolversbike.com/produc...shifter_mounts

Or, if you can convince yourself and the entire BF community that drilling a 1/4" hole in your DT is a good idea, these would do- https://www.cycle-frames.com/bicycle-...-AL-FRAME.html I had to repair mine on my basso. I used 60 minute loctite epoxy as well.
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