06 Stumpy Front Derailleur Problem Plz Help!!
I had enjoyed my stumpy for the last couple of years but in the last couple of months I have a problem that my mechanic claims is common with this bike because of the design and I wonder if anyone had this problem and how to fix it.
When riding the chain will not drop form the middle ring to the small one under load, only of flat of downhill but is slow to do it. I had changed the cable, changed the middle ring and the chain so the only thing I haven't replaced is the derailleur from the stock Shimano Lx and wonder if if that the right thing to do before I spend my money.
The main problem is that the derailleur won't push the chain in enough and is already adjusted to do it and as the mechanic said that is as much the front derailleur will go because of the frame design.
Any advise? Is anyone familiar with this?
Last edited by bajamtnbkr; 12-22-2007 at 05:52 AM.
I had a similar problem with my Kona. I don't think most bike shops can properly set up shifters for load since they setup it up on a stand and then refine it in a parking lot.
This is what I have swapped out over the years:
With orginal deore FD and chain it was really slow under pressure.
I put an XT FD on and new chain and it got a bit quicker.
My crank was spent and I got the last gen XTR crank and that made a huge difference.
When its all said and done my current stuff can shift slow, but thats only when the FD is out of whack. It took a little bit, but I'm getting better at setting up FD. I'm not sure how yours is setup but this is what I look for:
- setup your shifters so you have a bit of cable adjustment in both directions.
- Make sure when your in the smallest cog up front the left side and bottom of the FD is between 1mm .5mm away from the chain.
- Make sure you can get up to to the largest cog easily and all gears are shifting clean.
- It won't be 100% correct for the trail, so you if you left a bit of adjustment in the shifter you should be able to work out in the first few minutes of your ride.
The park instructions also aren't bad, but just leave some room for adjustment on the trail.
I would also double check the number of spacers on the driveside of your crankset. I had a SJ comp with the stylo, and I'm almost certain the shop f'd up and put the wrong number of spacers on. After I switched to a different crankset that was properly setup, 60% of my FD went away. From there I followed the Park Tools website as best I could, and it shifts under legitimate load 80% of the time. The FD cable pinch bolt is in a retarded location in relation to the frame of the < '07 SJ's and, consequently, it is very difficult to get the correct cable tension. Make sure there isn't too much cable tension. And double check chain life just in case.
Honestly, the '06 that I've had has had all kinds of funky drivetrain issues from poor FD performance to skipping under load during the chain stretching process.
That is what I was wondering if the 06 is known to have this problem. I'm not concern about the spacers since the bike performed great for almost two years without any issue until the last couple of months, I have the original Stylo crankset without changing anything.
Originally Posted by half_man_half_scab
I have an 06 s-works stumpy that shifts fine, but I run an xtr. With a new cable, perhaps you have too much cable tension. Try turning your cable adjuster in 2 turns (increase slack) and see if such a change helps for downshifts (middle to small ring). You should notice a faster response time and a bit more umph from the FD spring if helpful.
What I do:
-A bit of slick honey occasionally on the FD cable where exposed
-Set the FD to rub slightly on the small front cog and first gear combo when on a stand (works fine when you're riding)
-Lube the FD friction points with Tri-flow at regular intervals
I made the switch to an XTR FD some time ago. It solved the front derailleur issues. You might have a little slop in that FD after 2 years of use. Make sure you install it correctly and you should be okay.
2013 DeVinci Leo SL
2012 Niner Air9
2009 SE Racing SoCal Flyer
2003 TiSport Gman
Because of its frame design 06 Stumpy can not use the long cage FD, only the SHORT FD.
To get the same shifting force as a Long FD, the Short FD needs a stronger spring, that means that it is easier that during the time the short FD spring becomes weaker, and shifting performace decreases.
Fix is to use a good quality FD, at least an XT or even better an XTR.