Hammerschmidt with Twist Shifter

cw - it will work, but the problem is, is that the shifter innards (the barrel where the cable runs needs to be a smaller (maybe larger?) diameter, or, the barrel could be made elliptical to get the same effect.

The way front derailleurs are set up the ratio must be somewhere around 3:1 for a shift. The grip shift rotates a ton in order to meet that. On the HS, all you need is about 3/8" - the same amount that the shifter would move a front derailleur from the big ring to granny gear, and that's the problem.

There was a thread on this section about grip shifters and the die-hards using them (I'm one of them). I boasted about "going to figure a way out to really use them with HS" but in all practical terms, once I got all the bits and pieces, it's just good piece of mind to use the thumb shifter. It's simpler, faster shifting, is locked in in the shift 1:1, or in overdrive, and you won't accidentally twist it into a position where you knock it into 1:1 and bust yourself up in the middle of a climb or technical section.

Right now (I think I said this already in a different thread), I'm running the HS thumb, and a gripshift *X for the rear. Odd as hell, but I don't have the $ to dump on bike parts right now (plus the wife would be PISSED).

MPB

Thanks for the feedback again Shag.

I'm no stranger to trigger shift. I run both trigger and twist shift on different bikes and love each for their own reasons, but the bike I'm considering converting to HS for is my twist shift bike. I guess I'm not so opposed to running a trigger on the left and twist on the right as you have done. The benefits of twist shift (derailleur trimming) on the left won't be needed on a HS. Just like the consistent look, and it'll suck to have to buy two pairs of lock-on grips when I need grip replacements (one short set one long set).

I'm a little confused on your post here:

shag555 said:

The way front derailleurs are set up the ratio must be somewhere around 3:1 for a shift. The grip shift rotates a ton in order to meet that. On the HS, all you need is about 3/8" - the same amount that the shifter would move a front derailleur from the big ring to granny gear, and that's the problem.

Click to expand...

So you're saying that the amount of cable pull for the hammerschmidt is the same amount as going from big ring to granny gear in a three ring setup? Right now I have a two ring setup in front and rotate the twist shifter about 1/4 to 1/3rd a turn to go from one gear to the other. Will I be twisting the shifter more or less with a HS?

I might be wrong about the amount of travel (IE 2 ring vs 3 ring setup). However, in order for mine to activate the 1:1.6 overdrive, my gripshift needs to go from "granny" to "big ring" in order to fully lock in the HS. My gripshifts are circa 2000, so who knows what the ratio was (I'm just guessing). If I go from the granny to the middle ring setting on the grip shift, the HS is not fully enguaged and the "dog ears" (for a lack of the right term), do not enguage the planetaries fully, and skip. I don't feel like trashing this fine piece of engineering so, I'm not taking the chance of running the shifter.

It would seem to me, that all SRAM would need to do, would be to modify the current production grip shifter barrell to allow a spring return, and incorporate a push-button lock system, so rotating the grip shift would engage the 1:1.6 overdrive and the shifter would then lock itself into that position. Then to get back to 1:1, the spring return would be activated by pushing a button (similar to the return trigger mech) to get out of the overdrive. There and again... Very limited market (HS... at least right now), and an even more limited market (HS with preferred Gripshift).