Top Pull Front Derailleur for 52/42/30 Triple
I'm building up a cyclocross frame with an ultegra triple, as it will be used mainly for gravel trail and road use. Trouble is, the cables are top mount, and the ultegra front derailleur is only bottom pull. I've looked at XT/XTR, but they won't handle a 52t ring, and their top-middle minimum is 12t.
Any suggestions for shifters?
Independent Fabrications uses a pulley on their frames that allows for top tube mounted cables, yet the ability to use a bottom pull der. Maybe there is an aftermarket version of the pulley? Good luck.
Everyone seems to think a pulley exists, but no one knows where to find it.
I've been in contact with Indy Fab, but they don't offer anything aftermarket, and thought any LBS would have it. Unfortunately all of my local stores have no clue as to what it is or how it would work. They tell me I need a top pull derailleur only - which would be a mountain derailleur, which I've heard is a nightmare to setup with STI shifters.
First and foremost I want you to make sure that the frame is built to allow that large of a chainring up front as most cross bikes only have 48t in the front. Mount the crank and check to see that there is sufficient clearance between the chainstay and the large ring. If it is too close it will scrape under load and the chain could also become wedged in the presence of dreaded chain suck. If all is ok there then go back to the dealer with the following idea. Quality Bicycle Products (a major US distributor) should have the parts that you need for the project. You need one of the following to fit your seattube (1 1/8 = QBP FD9000, 1 1/4 = FD9001, 1 3/8 = FD9002) it is an e-type front derailler clamp for the seattube. It has a threaded hole on the back of it that you are going to mount a pulley (part #FS1091 from Quality) on. This setup should allow you to use that road derailler with your top tube routed cables. The cable goes down and around the pulley and then to the derailler. These two parts should only set you back about 20 to 25 dollars and it will work perfect. One tip - you may need to grind the face of the clamp where the pulley mounts so that the pulley lines up perfectly with the cable - how much will depend on the frame. If you have any Questions repost and I will check back. Good Luck.
"Cross Bikes and Singlespeeds rule"
Appreciate your help BikerRyan, actually the problem was solved in a similar method. QBP has been out of stock on the pulley, without plans to make anymore, but through a stroke of good luck, specialized had one left over from their 2000 s-works CX bikes. The 52 triple did indeed fit on the frame, and the bike rides wonderful.
Try www.cyclocrossworld. They sell a seat tube mounted clamp with pulley for converting a top pull frame for a bottom pull derailleur (under the specialty parts category).
You can also come up with the same thing by combing QBP's (Quality Bicycle Products) Shimano E-style derailleur adapter clamp with a shifter pulley replacement (which is I believe what Cyclocross World does, they look identical).
QBP part numbers are:
FD9001 (clamp for 28.6mm seat tube, black)
FE9011 (clamp for 31.8mm seat tube, black)
They also have silver clamps.
You can order QBP products from places such as "Mud, Sweat, Gears" (www.bikeusa.com). Just do some searches for the above mentioned part numbers on their website.
We ordered and received these items recently, so they do have them in stock.
One additional note: mountain bike derailleurs won't work with road levers (even though there are top pull versions available) as they require more cable pull. We found this out the hard way. The eventual fix was to use a road derailleur with the adapter mentioned above.
Last edited by dessert1st; 08-15-04 at 01:31 PM.
FYI, I believe the part # for the 31.8mm clamp is FD9011, not FE. You can also find the same part rebranded under "Problem Solvers" (or is that just an arm of QBP?).
Thanks a ton for the info, Dessert1st!
A late reply, on this thread but i ran into it recently:
Originally Posted by dessert1st
I have a road bike WITH a mountainbike derailleur and it works perfectly!
It's a cyclocrossbike with shimano 105 9x3 speed shifters, with a top pull deore LX FD-M567 (not sure its a double or triple cage) and a DOUBLE crankset. The cable intake of the triple shifter is well enought to move the mountainbike derailleur over the double. You have to use the high-low settings ofcourse. Shifts smooth, and with the intermediate adjustment clicks of the shifters you can avoid the chain hitting the derailleur cage even when using the chain diagonal on small-small or big-big rings. It works with 44-38 chainrings mounted on, and with 52-38 chainrings mounted.
BUT: Now I've put on a triple crank (and bracket) the derailleur won't move the whole range: lack of cable intake of the roadshifters. Tried to reduce the armlength of the pulling cable on the derailleur, but it didnt work (might possibly work, maybe the cage is not right and my connection plate was crappy). I have bought a triple road derailleur and now i'm going to order an Umlenker on speen.de (sorry, sounds like advertising, but i like their solution, not using a pulley.)
I hope the solutions I mentioned get more common in bicycle shops, forums and on information sites like sheldonbrown and m-gineering.nl. I could provide pictures.