Bicycle Mechanics - Upgraded FD cannot shift to large chainring
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Hi, I have been browsing this forum for awhile and this is first time I can't find a solution from previous posts. I recently did my first ground up build on a mtb. I took the components from an old bike and try to install them to the ebay carbon frame. The parts are for 8 speed shimano with alivio RD. The FD is originally a bottom bracket mount C101. Because the FD mount is too low and will interfere with the carbon frame, i bought a Alivio M431 FD (high mount or down pull) and installed on the carbon frame. Also, i know if i took out the C101, i need to take up the space by a spacer. So i bought a BB spacer to take up that gap. I got the RD all setup shifting flawlessly. But the FD, i tried all possible method, the FD just could not push the chain to the large chainring. i read thru all the parktools page, sheldown page and also the official shimano document, plus i have don't FD adjustment before. The FD shift between the small and middle chain ring no problem. But it just cannot shift from middle to large. It feels like the FD is pushing the chain to the back of large chainring but the chain cannot catch to the chainring to bring it up. The crankset is a shimano parts, but its probably a non series parts b/c i cannot see the series name on the crank arm except shimano.
Is the FD compatible with the parts that i have?? Or i need to replace the crank also??? Thanks in advance for the help.
05-21-12, 10:47 AM
Can't see it. [I work hands-on]
does it work without the cable hooked up,
but not when you pull on the cable from the control lever?
05-21-12, 11:00 AM
Any chance the inner cage plate of your fd is hitting the middle chainring so it can't move far enough outboard? You may have to raise the fd to clear it.
05-21-12, 11:27 AM
Also, i know if i took out the C101, i need to take up the space by a spacer. So i bought a BB spacer to take up that gap.
In addition to the FD height concern, are you certain you need that spacer? Unless your BB shell is 68mm, I don't understand the reason for the spacer; I would believe the *e-type* FD you previously used had the BB-mount taken into consideration in its design. Perhaps the added spacer is enough to push the large ring outside the reach of your replacement FD. When you installed the FD, did you manually check its reach prior to installing the chain?
It doesn't work even pull by hand. I can move it by hand in full motion and set the high limit when the chain is not installed. So i know it can reach without problem. I set the height base on the shimano doc, which is 1mm. I use a penny to set the height and it is the lowest i can do without jamming the cage to large chainring. The M413 has lost the pro set gauge sticker when i got it. That's why i use a penny to set it. I thought i suppose to set it as close as possible.
For the spacer on the bottom bracket, i know i need to do it because after removing the e-type bracket, if installed without the spacer, the chainring will touch the frame.
05-21-12, 07:48 PM
Sounds like your front derailleur cable is too slack. Tighten the cable so any movement of the shifter starts the front derailleur moving and see if it works better.
05-21-12, 10:50 PM
Take another look at your cable routing and compare it to what you see on the installation instruction sheet. The cable should go around the outside of the pinch bolt. If you secure it at the inside of the bolt, you change the leverage and reduce the amount of travel.
The cable is routed to the outside of the pinch bolt. I will try to capture a video to show what is the problem. There is the word "hyperdrive" on the cage of the FD, does that mean i have to use the same series of components with "hyperdrive"??
05-22-12, 09:09 AM
It doesn't work even pull by hand.
... then throw it away and buy a new one.
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