31.8/28.6 clamp band adaptors?

kingofthetailwind

I've had a few problems with my GT Grade, recently upgraded to a 4700 chainset and Hollowtech BB to replace a warped FSA Vero chainset. But I'm still having chain rub issues.

In the big chainring and outermost 2 or 3 gears I'm getting chain rub against the outer derailleur plate. The H limit screw is all the way out. I can increase cable tension to stop the chain rub, but I'm having to use so much tension that it stops the derailleur shifting to the small ring. With the chain off I can pull the derailleur out by hand and it looks like it should be able to come out far enough, but only just.

So basically the derailleur isn't moving out far enough I think. The seat tube is 28.6mm. The 4700 band-on FD is for 28.6mm and 31.8mm seat tubes. Should there be a shim fitted, or is the 4700 FD designed to work with both seat tube dimensions without a shim?

Only other thing I can think of is that the FD is damaged.

The Rookie

It must have the shim fitted or it will be slipping down the seat tube!

Just go through the indexing again.

arlowood

KingOfTheTailwind wrote:

I've had a few problems with my GT Grade, recently upgraded to a 4700 chainset and Hollowtech BB to replace a warped FSA Vero chainset. But I'm still having chain rub issues.

In the big chainring and outermost 2 or 3 gears I'm getting chain rub against the outer derailleur plate. The H limit screw is all the way out. I can increase cable tension to stop the chain rub, but I'm having to use so much tension that it stops the derailleur shifting to the small ring. With the chain off I can pull the derailleur out by hand and it looks like it should be able to come out far enough, but only just.

So basically the derailleur isn't moving out far enough I think. The seat tube is 28.6mm. The 4700 band-on FD is for 28.6mm and 31.8mm seat tubes. Should there be a shim fitted, or is the 4700 FD designed to work with both seat tube dimensions without a shim?

Only other thing I can think of is that the FD is damaged.

In the past, when I've bought front derailleurs that accommodate 2 seat tube diameters (FD 5700 and 5800 specifically) they have come supplied with the shims already in place. These look like 2 semi circular rubberised pads on the inside of each half of the the derailleur clamp. The default size is for 28.6mm seat tubes. If you have a 31.8mm seat tube you have to remove these shims. They are stuck in place with some adhesive pads IIRC.

Your FD 4700 is similarly set up and would probably have been supplied with the shims already fitted. See the attached tech doc from Shimano that shows the shims for both the band-on type and the clamp for a braze on type if you have to use that method.

http://si.shimano.com/#seriesList/19

Check out the EV-FD-4700 pdf on the above link.

If you did not remove any pads when you fitted the FD then I suspect it is mounted correctly.

The FD4700 is the new long actuator arm design (like the FD5800 and 6800). These appear to be more problematic to set up with cable tension being critical. Have a look at this video - it is for a 5800 front derailleur but the process will be the same for the FD4700 I reckon

https://www.youtube.com/watch?v=hlbenKUx9JM

kingofthetailwind

arlowood wrote:

KingOfTheTailwind wrote:

I've had a few problems with my GT Grade, recently upgraded to a 4700 chainset and Hollowtech BB to replace a warped FSA Vero chainset. But I'm still having chain rub issues.

In the big chainring and outermost 2 or 3 gears I'm getting chain rub against the outer derailleur plate. The H limit screw is all the way out. I can increase cable tension to stop the chain rub, but I'm having to use so much tension that it stops the derailleur shifting to the small ring. With the chain off I can pull the derailleur out by hand and it looks like it should be able to come out far enough, but only just.

So basically the derailleur isn't moving out far enough I think. The seat tube is 28.6mm. The 4700 band-on FD is for 28.6mm and 31.8mm seat tubes. Should there be a shim fitted, or is the 4700 FD designed to work with both seat tube dimensions without a shim?

Only other thing I can think of is that the FD is damaged.

In the past, when I've bought front derailleurs that accommodate 2 seat tube diameters (FD 5700 and 5800 specifically) they have come supplied with the shims already in place. These look like 2 semi circular rubberised pads on the inside of each half of the the derailleur clamp. The default size is for 28.6mm seat tubes. If you have a 31.8mm seat tube you have to remove these shims. They are stuck in place with some adhesive pads IIRC.

Your FD 4700 is similarly set up and would probably have been supplied with the shims already fitted. See the attached tech doc from Shimano that shows the shims for both the band-on type and the clamp for a braze on type if you have to use that method.

http://si.shimano.com/#seriesList/19

Check out the EV-FD-4700 pdf on the above link.

If you did not remove any pads when you fitted the FD then I suspect it is mounted correctly.

The FD4700 is the new long actuator arm design (like the FD5800 and 6800). These appear to be more problematic to set up with cable tension being critical. Have a look at this video - it is for a 5800 front derailleur but the process will be the same for the FD4700 I reckon

https://www.youtube.com/watch?v=hlbenKUx9JM

Yeah, I think you're right. Not a shim issue. I think it might be an issue with how the FD cable is clamped. There's a "converter PIN" on the actuator arm that can be set in two different positions. I remember not being able to figure out how to use this, and just clamping the cable over the top of the bolt as you would with older derailleurs. The cable looks like it should be clamped under the bolt, with the converter pin in the position that gives the best shifting.

StillGoing

Is it not the same as 5800 where you set the FD in the small chainring and largest sprocket, clamp the cable tight, shift up to the big ring and then have to use an inline cable tensioner to dial out the chain rub in big chainring and smallest sprocket?