Front derailleur not shifting to large ring, even when push by hand

michael.ashley3

Hi all,

I've just upgraded my bike to all 11 speed and have just put on the front derailleur, however I'm having issues getting it to shift the chain to the largest ring. I did all the usual of cable tension and limit screws (having it at its loosest) but I still couldn't get it to shift. Even when pushing it down by hand I can't get it to move far enough to pick up the chain and get it to stay on the largest. Am I missing something? I took it to the bike shop today, but it's a two week wait as they're so busy atm! Any suggestions welcome.


I've got;
FD - sinmano 5800
Crankset - FSA Vero pro JIS 52/34T
BB - Square Taper JIS

fenix

What bits have you put on ? Presumably you had the big ring working before ?

michael.ashley3

All the components above were new or bought off ebay, and I've put on them on myself - so this is the first time setting it up. Shifters work fine and back gears + derailleur work fine

wongataa

Have you followed the Shimano instructions?

Ben6899

This is likely a chainline issue. Is the new chainset installed correctly?

siddy1972

I’m not terribly familiar with JIS, but maybe they are like ISO square taper BB’s and have different axle lengths? You sure you have the right length for your crank? The big ring looks miles away from the chain stay in the picture.

photonic69

Does look like there is a big gap between the Bottom Bracket and the centre of the crank! Something wrong there.

Maybe post some more pics of this area please.

Ben6899

siddy1972 said:

I’m not terribly familiar with JIS, but maybe they are like ISO square taper BB’s and have different axle lengths? You sure you have the right length for your crank? The big ring looks miles away from the chain stay in the picture.

Yeh that's my concern. Looking closer, there's way too much spindle showing at the BB.

michael.ashley3

wongataa said:

Have you followed the Shimano instructions?

I downloaded the PDF and followed it, also looked at park tools.

siddy1972 said:

I’m not terribly familiar with JIS, but maybe they are like ISO square taper BB’s and have different axle lengths? You sure you have the right length for your crank? The big ring looks miles away from the chain stay in the picture.

I've just come across this idea too. I assumed that my original BB would be fine as it fits my frame. It was originally set up as a 8 speed, but I'll assumed that square taper BB's are universal.

I had to tighten low limiter until it couldn't move in order for it to even line up with the lower ring and largest big ring at the rear (I immediately thought was strange)

Some more images

In this one I've loosened the limit screws to normal and shifted my rear gear to 2nd, you can see it's touching the right of the FD.


I thought there might be too much space too, tired to tighten the crank bolts agin, but could get any movement, will try again.


Chain doesn't look the straightest from this angle when it's in 2nd.

me-109

Your BB axle is way too long. You can see the axle in the pic above. The inside of the chainset should be flush with or slightly inside the outer flange of the installed BB. Measure the gap between those two points (might be easier to mark the axle where the inside of the crank sits) and deduct that figure from the overall length of the existing axle to arrive at the length you need. If you can remove the BB then the casing will have the axle length marked on it.

siddy1972

michael.ashley3 said:

wongataa said:

Have you followed the Shimano instructions?

I downloaded the PDF and followed it, also looked at park tools.

siddy1972 said:

I’m not terribly familiar with JIS, but maybe they are like ISO square taper BB’s and have different axle lengths? You sure you have the right length for your crank? The big ring looks miles away from the chain stay in the picture.

I've just come across this idea too. I assumed that my original BB would be fine as it fits my frame. It was originally set up as a 8 speed, but I'll assumed that square taper BB's are universal.

I had to tighten low limiter until it couldn't move in order for it to even line up with the lower ring and largest big ring at the rear (I immediately thought was strange)

Some more images

In this one I've loosened the limit screws to normal and shifted my rear gear to 2nd, you can see it's touching the right of the FD.


I thought there might be too much space too, tired to tighten the crank bolts agin, but could get any movement, will try again.


Chain doesn't look the straightest from this angle when it's in 2nd.

The axle length relates to the crank it’s being mated to. Not really a function of the frame (which are generally 68mm shell width).
If I were you, id find out the axle length you need from the manufacturer data and measure what you have there.
I’m pretty sure yours is too long- shorter BB required I’d say.

Ben6899

https://shop.fullspeedahead.com/en/files/index/download/id/c33d4de33950dba881c8ced1b7799ac9128/

Page 1. You need this (https://www.amazon.co.uk/FSA-SHIMANO-BB-7420-CASSETTE-COMPATIBLE/dp/B07ZKPLVS6) according to that document... which gives a 124.5mm axle.

But double check your bottom bracket shell is 68mm AND English threaded, otherwise it's a different model you need.

i.bhamra

As others have said, BB looks wrong, logic suggests you need JIS but they come in different lengths. Measure your old BB and and get one closet in length to that to try would be my suggestion. Maybe even try your old BB if it's still smooth and free from play (square taper usually are!)

michael.ashley3

me-109 said:

Your BB axle is way too long. You can see the axle in the pic above. The inside of the chainset should be flush with or slightly inside the outer flange of the installed BB. Measure the gap between those two points (might be easier to mark the axle where the inside of the crank sits) and deduct that figure from the overall length of the existing axle to arrive at the length you need. If you can remove the BB then the casing will have the axle length marked on it.

Thanks. I managed to get the crank much closer with a bit more elbow grease, but it might worth taking it off to check what you said.



The chain now rubs against the inside of the big ring when I manually push the FD, but it doesn't pick it up to move it onto the large ring. I've set it around 1/2mm from the teeth.

Ben6899

I think at this point, you need to double check what bottom bracket is in there. If you take off either the drive- or non-drive side crank arm, is there any text stamped on the end of the bottom bracket?

Ben6899

What bike is it? Maybe we can figure out what's already installed?

siddy1972

michael.ashley3 said:

me-109 said:

Your BB axle is way too long. You can see the axle in the pic above. The inside of the chainset should be flush with or slightly inside the outer flange of the installed BB. Measure the gap between those two points (might be easier to mark the axle where the inside of the crank sits) and deduct that figure from the overall length of the existing axle to arrive at the length you need. If you can remove the BB then the casing will have the axle length marked on it.

Thanks. I managed to get the crank much closer with a bit more elbow grease, but it might worth taking it off to check what you said.



The chain now rubs against the inside of the big ring when I manually push the FD, but it doesn't pick it up to move it onto the large ring. I've set it around 1/2mm from the teeth.

Like Ben says- I think it may be a good idea to stop and take stock of your parts. You may force it on a bit further with additional force, but you’ll probably end up shearing the bolt or wrecking the crank tapers...

michael.ashley3

Ben6899 said:

What bike is it? Maybe we can figure out what's already installed?

It's a Cannondale Optimo, the component list only says FSA cartridge for the BB.

I've just taken off the left arm and it says 118 and according to that PDF I need a "BB-7420 ST Square Taper Bottom Bracket (JIS)" which is 110.

So I think we've sold the issue! If I was allowed to see you all, I'd buy you a beer. Upgrading has been a little frustrating - just when you think you've bought everything you always need one more thing!

Ben6899

Well it looks like you're sorted now, or on the way there at least!

I'll PM you my address and you can have me a box of Theakston OP delivered...

focuszing723

photonic69 said:

Does look like there is a big gap between the Bottom Bracket and the centre of the crank! Something wrong there.

Maybe post some more pics of this area please.

Nice call from that photo.