Derailleur pull inverters

boxofoilyrags said:

I searched and read a lot of posting here. I haven't found a specific answer to a problem I'm facing with a current bike rebuild though.

The frame is a hybrid made for top pull front mechs. I'm replacing the crankset and rings completely, and putting in a wide 52-38-24 <don't try convincing me out of this arrangement; please, I'll spare you the details>. That said, reading these forums, I've a good idea of the front mech I need...XTR M901, RX100 A553, Sachs Quarz, Suntour XC Pro. I'd rather not go too much earlier than the XTR or RX100, and the Sachs I've found ABSOLUTELY impossible to be had. I've also read here that some Shimano road triple mechs would handle it, particularily the Dura Ace 7703 with it's "stated" 23 tooth capacity.

Honestly, I'm getting to a point.

Ebay searching has turned up a number of M900's <bottom pull> and M901's <wrong clamp diameter>. The seat tube is 34.9mm; cyclocross pulleys I've found online only go as large as 31.8 <except for one one wiggle.co.uk, but they only ship in uk>. People have mentioned fashioning your own out of Shimano e-clamp adapters, but they only go as large as 31.8 as well.

So can I not use a pulley? Is my only option to wait patiently for an M901 to pop up an eBay? Help.

-Lon

you got alot of BS on the FD picks. What you need is a shimano triple road front, and you don't need the DA version. Any FD is likely to have trouble covering that ranage,but you have to start with one that has a curvature designed for the 52 big ring. Get a braze on and a shimano adapter clamp for your seattube size. Then get or craft( a simple pulley will work) a pull reverser so the road bottom pull will work with your top pull cable routing.... Personally, I don't see the point in a 52 if you need a 24. Life would be simpler with somethng like an inexpensive Sugino triple with 110/74 BCD and 24/36/46 or 48 rings.

boudreaux said:

Personally, I don't see the point in a 52 if you need a 24. Life would be simpler with somethng like an inexpensive Sugino triple with 110/74 BCD and 24/36/46 or 48 rings.

I said I'd spare the details, but here it is real quick. I was running a touring setup, 28/38/48 with 11-30 in the rear, but was finding I needed more on either end. I'm a messenger in San Francisco; this is my basket bike that has served me very well. It goes without saying that e have some serious grade here; so, I needed the lower gear to flatten everthing in front of me even when the bike was loaded. I also race <alleycats> this bike and use it for longer excusions; I found myself spinning out regularily... I've lost races with a downhill finish and a tailwind because I've spun out that 48 tooth big ring.

So that in a nut shell is why I'm doing this to myself. Anyway, so all those other FD picks won't work.... not even the xtr 901?!

-Lon

boxofoilyrags said:

I said I'd spare the details, but here it is real quick. I was running a touring setup, 28/38/48 with 11-30 in the rear, but was finding I needed more on either end. I'm a messenger in San Francisco; this is my basket bike that has served me very well. It goes without saying that e have some serious grade here; so, I needed the lower gear to flatten everthing in front of me even when the bike was loaded. I also race <alleycats> this bike and use it for longer excusions; I found myself spinning out regularily... I've lost races with a downhill finish and a tailwind because I've spun out that 48 tooth big ring.

So that in a nut shell is why I'm doing this to myself. Anyway, so all those other FD picks won't work.... not even the xtr 901?!

-Lon

Details are always helpful.I think you need 2 bikes.

boudreaux said:

Details are always helpful.I think you need 2 bikes.

lol!
I do. This one is my all around beast of burdon/ work bike. The one I ride regularily is a fixed gear.