Shimano 105 Triple FD Spring Tension
 

Hello folks,

I'm new to the BF forums and am trying to work out a problem with my Shimano 105 triple front derailleur. I bought a NOS Cannondale T1 last fall with the intention of doing some touring. The bike came with Ultegra Flightdeck brifters, 105 road triple (50/39/30) and 105 FD, 10 speed (11 - 32) casette and a long cage Ultegra RD. The setup worked very well with the rear setup shifting very quickly with a nice click and a light touch of the brifter. The front setup shifted almost as well except that it took more effort to make the shift from a smaller to a larger ring against the spring and when downshifting from larger to smaller there was more of a clunk than a click in the drivetrain. But the system worked well.

I made some significant changes to the drivetrain over the winter to more reflect what I want to do with the bike (tour with a trailer) and to shift the the total gear range lower. I kept the rear setup but swapped out the 105 road triple for a Sugino XD2 46/36/24 triple, kept the 105 FD, changed the compact drop bars for bullhorns and am now using Silver bar end friction shifters.

The setup works well except for the force required to move the 105 FD against the spring when shifting up and the amount of shifter friction required to maintain the derailleur in position. In other words, the FD spring seems to be overly stiff for the present shifting setup. It works but I don't consider the setup to be optimal.

There is no way to adjust the spring tension lower on the 105 FD and was wondering if there is a derailleur out there that will work better with friction shifters than the present setup. Obviously, indexing isn't a factor. I was looking at the IRD Alpina FD as a possible option. It comes in a model for either brifters or trigger shifters but what I really need is something that does its work with lower spring tension. Thoughts? AL

Front derailleurs typically have rather stiff springs since they have to shift the "high tension" side of the chain and often have to do it under load if the rider doesn't anticipate the shift in time. A softer spring would make moving the shift lever easier but probably fail to shift when needed.

Sun Tour Powershifters and Simplex Retrofriction levers had a one-way ratchet that bypassed the friction adjustment when upshifting in front (or downshifting in back) to help overcome the spring tension. These are no longer in production but you may be able to find them NOS or used.

To my knowledge, there's a very narrow band of spring tensions among the various FDs. The reason it the makers are all trying to find a balance between enough spring force to reliably down shift (large to small) under moderate load, while keeping the spring resistance to upshifting as low as possible.

One reason you might be fighting so hard on upshifts might be housing friction. Try field stripping the cables and either replacing (best) or at least lightly greasing the wire. I've found that a light smear of Graphite, or Moly-disulfide grease down the length of the wire works best.

I've been using a 105 Front Triple Derailleur with bar end shifters for many years and miles. No problems. I'm not being a smartass but is it possible you have hand strength issues? Carpal tunnel or arthritis? If so, I wonder if you might be able to fit a longer lever onto the shifter for more leverage. Might be a simple solution to your problem.

I also wonder if it might not be a drawback to the bullhorns. I assume that the shifters are installed facing away from you, so that instead of pulling the shift lever towards you, you have to push it away(to shift up), and you don't have nearly as much leverage. Got a pic of your bar set-up?

I would guess that the cable is binding in the housing as FBinNY said. I would consider a new cable and housing from Shimano or Jagwire. The OE cable and housing is not always the best quality.

I've heard, and I don't know that it's true that shimano road FD's have a shorter cage than mtb FD's and FD's from other brands which give more leverage with the longer cage. That might be complete crap, but I think I read that somewhere when someone was trying to work a shimano FD with Campy brifters after using a Campy brifter and found the force required was too much until they switched to a shimano mtb FD and then it was fine.

One other thought. Take a second to double check that the cable is connected to the correct side of the pinch bolt. It goes to the far side of the bolt. Also double check the limit screw settings especially the outer.

Connecting to the near side lowers leverage, making you work harder, and causes over-travel which many compensate for with the outside limit screw.

A tight limit screw, commonly used to correct for poor trim or over-travel, makes upshifting harder, because you have to stretch the cable to complete the shift. It also results in the snapping, aggressive downshift you describe since the cable tension is added to the spring pulling the FD inward.

I'm going to pay a visit to my LBS to discuss the issue. I'm using Shimano SIS cables. They're brand new. The cable is bolted to the inside of the derailleur. Routing it to the outside really increases the forces required to upshift (I tried). The bar ends do face away on my bullhorns but that isn't the issue. I have no problems with my hands. The leverage isn't there to easily move the derailleur against the spring. It takes only a very light touch to downshift. Everything works soomthly.

I can't help but think that himespau is on to something. I suppose it could be said that the 105 FD is a performance derailleur meant to be used with a set of brifters. My new Silver bar end shifter might not be up to the task of controlling the 105 FD. Has anybody used the IRD Alpina FD with a friction shifter? Al

the 105 FD should work absolutely perfectly wih your shifters. There is something else going on here.

The most likely culprit, as FB mentioned, is a mis-routed FD cable. See the excellent sketch I prepared. THere is a little 'tab' on the washer behind the pinch bolt (washer shown in red on sketch), and if the cable goes under this tab then the length of the lever arm the cable is pulling is significantly shorter and you get the exact problem you describe. Routing the cable under the tab is incorrect, and if you have it this way you do not have your derailleur set up properly. THe cable must run over the tab before being clamped under the pinch bolt.

http://bikeforums.net/attachment.php...hmentid=238437

I'm not sure I can tell from the sketch above, but if the OP uses his eyes and employs the rules of leverage he learned at the playground when he was 5 he can figure it out. If he remembers playing on seesaws (teeter totters) he should know that the lighter person sits farther out on the plank to balance against a heavier rider farther in.


Likewise with the cable, he'll get the most leverage (lightest pull) if the cable is routed around the side of the bolt farther from the pivot (distal side). (left side on levers pointing left, right side on levers pointing right)

I'm almost sure that the other issue is that he's forcing the cage against an overly restrictive outer limit, which is why the lever sometimes won't hold against the return tension ---cable + spring, vs spring only.

The Grand Accounting
 

I'd like to thank everyone for their replies. The problem was solved without having to buy multiple front deraillers.

After reading all of the replies, I took the FD off the bike. The cable was routed under the flange not only reducing the mechanical advantage, but also putting a bad bend in the cable and breaking a couple of strands. The routing mistake became very apparent after holding the FD in my hand.

I took the opportunity to reroute both derailleur cables to make for a better run and re-wrapped the left handlebar. I wasn't completely satisfied with my original attempt. I replaced the standard cables with a couple of stainless cables. Everything now shifts well.

The job isn't complete without a few pics. One is of my Cannondale T1 with a Wike Tourite trailer. One shows my handlebar setup (bullhorns and aero bars). I still wanted to get out of the wind when required and thought that I would give the aero bars a try. And the last shows the properly routed cable. Thanks again. Al

http://bikeforums.net/attachment.php...hmentid=238461http://bikeforums.net/attachment.php...hmentid=238462http://bikeforums.net/attachment.php...hmentid=238463

Thanks for the followup and I'm glad the "problem" is now solved. Improper routing of Shimano fd cables is a very common occurance and there have been several threads discussing it here. For index systems it can be a deal breaker but for friction shifters it just makes the shifting more difficult as you discovered.

Good looking rig!

Thanks, I like to tinker. Al

Briefly raising a zombie to say HAHAHAHA THANK YOU!!!! Trying to solve a tough-to-shift issue on my wife's bike and this is *exactly* what I was doing wrong. God bless bikeforums... once again you have saved the day.

(I'm sure this undead thread will shamble off to wherever it came from if we give it a little time.)

p.s. In terms of serving its purpose, that is indeed an excellent sketch. :thumb:

Thanks for bringing back this Zombie Thread.

I recently installed a used Shimano 105 triple fd (no instructions) on my Trek 1100 to update )8-speed cassette, new wheels, 8-speed dt shifters, and 105 9 speed derailleurs) from the Suntour Edge deraileurs and shifters, triple 7-speed freewheel. I wasn't exactly happy with the cable routing (cable had too sharp a bend where it met the fd), and when I spotted this thread, it told me exactly what was wrong.

The funny thing is the Shimano fd on my 93 Trek 2300 and 97 Trek 1499 were routed the same exact way I initially routed the cable on the Trek 1100, and they are routed correctly whereas the newer 103 fd now on the Trek 1100 was wrong when installed the same way.

Technology and methods change with time, and I guess it would pay to get and read the instructions on newer components when you go to install them.