Change Cable Front Derailleur

[sitchey]

Hi
I was on here a few weeks ago about changing my grip shifter gears to a trigger unit with brakes

I started the upgrade today.

I got the old gears off, I removed the old grips. I had to run on new brake cables as the old ones were freyed. This was ok as got the connected to new brake gear shifters.

I got the back gear new cable connected and working but having issues with the front derailleur.

I'm unsure if I'm doing it right but so far I can only gears to switch on the lower and middle front gears. The grip shift was also having probs when I got the bike going into the high gear so I think it could be the derailleur or just that it was not set up right in the first place

So I'm hoping for some advice. I've added some photos of the unit to this thread. It looks a basic unit but it can never go to the large gear. When I tried adding the new cable the derailleur presses itself back in towards the bike. When I push it out then tighten the cable the best I can get is two gears working.

I'm prob doing it wrong so I wanted to ask for some advice. if I am changing the cable on the front what steps should I follow? Should I start with the derailleur on the smallest gear and the shifter on gear 3? Should I remove the chain?

Sorry I'm just starting out with bikes and am learning as I go. So any input would be great

Thanks

 

[mrandmrspoves]

First thing to do is see if you can shift the derailleur further by hand. If you can, then the cable is not tight enough, routed incorrectly, or the shifter is faulty. If you can't, it may be the High stop screw needs loosening off.

 

[Garethgas]

Loosen the high limit screw

 

[sitchey]

Ok cheers. So the h and L screws on top. Just loosen the high screw?

Yes derailieur can move further by hand. What is the best way to get the cable tight? Should I start with chain on small gear and the derailleur close to the bike? Or should I start with the chain on high gear and derailleur out to towards the peddles?

 

[mrandmrspoves]

Use the shifter to put the chain on to the smallest chain ring. Then make sure the shifter is in slackest position (as in gear 1)
Now you need to take all the slack out of the cable, which is usually best done by loosening the clamp bolt on the derailleur.

 

[sitchey]

I'm loosing mind with this.

I've adjusted the h and l screws and the best I can get is

1st gear - goes into low gear
2nd gear - the derailleur moves over 2nd gear but chain stays in first
3rd gear - the derailleur moves right to the end and the chain goes in 2nd gear but it sticks and grinds as u can feel it wanting to go up to 3rd gear.

I have loosened the h screw all the way out but it still can't get into the 3rd gear. 2nd gear runs fine when you drop from 3rd back into 2nd. But u can't get 2nd from 1st.

This is the same prob I had with the grip gears when I first got the bike. I could hit 1st and 2nd but only got into 2nd when pushing into 3rd. Its new cables and shifter but the same prob. Would it be the derailleur or fly wheel?

The derailleur is tight and can't be moved and the cable is tight. It's very easy to move from 1st to 2nd on shifter. 2nd to 3rd is really tight.

 

[Garethgas]

just to add to the above:
When you're in the smallest gear (as above) and you loosen the cable, nothing will happen.
What you're aiming for is to have full travel of the cable so the idea is to have no tension in that gear without any 'free' play.
I hope I haven't confused the issue!

 

[Garethgas]

If you can get it onto the big cog, try adjusting the hi limit screw anticlockwise and see if you can see any movement.
Edit: If nothing happens, try taking some slack out of the cable when in gear 1

 

[sitchey]

Hi Gareth

No I can't get into the big cog. Best I can get is into the middle cog and that's by putting shifter into 3rd not 2nd

 

[Garethgas]

The best I can suggest is to follow the link below and do it in the exact order as suggested. It's explained far better than I ever could
In the morning, you'll be riding

http://www.parktool.com/blog/repair-help/front-derailleur-adjustments

 

[sitchey]

Cheers Gareth I'll have a look.

I think my derailleur is off. In this picture u can see the bottom end of the derailleur is pushed more towards the cogs than the front part. I tried to adjust the mount on the derailleur that is round the bike to move. But it won't budge. It's a star head screw and bolt on a clasp but I think its run as it's not budging even with a cordless.

But in addition to that I think in trying to pull the cable too hard/much I have broken my shifters! It's now only able to shift through 1st and 2nd. When u push the leaver up to 3rd it just moves freely.

Building, diy, electrics and computers, yet I can't fix a bike?!

 

[Globalti]

The advice to loosen the H limit screw was wrong, this won't make any difference at all. If the original shifter was able to pull the derailleur into 3, that limit screw was fine and the only problem is insufficient cable pull.

The H and L screws just limit the range of movement of the derailleur so if it was working before, leave them alone.

With the shifter lever in 3 and the chain not quite making it onto the big ring, just try pulling the inner cable outwards where it runs along the down tube, to tighten it. Does the chain make it onto the big ring? There's your problem.

Loosen the cable clamp bolt. Allow the derailleur to drop to the small ring. Pull the cable to take out slack and fully return the lever to 1 and screw fully home (clockwise) any cable adjusters on the frame or the lever body. Grip the end of the cable with pliers and pull it over the top of that cable anchor bolt, then tighten the bolt. Now begin to tighten progressively the cable tension adjusters until the cable is taut enough in 1 position that it begins to move the derailleur, even with the lever on 1. Stop tightening and test. You can simulate the effect of further cable tension by pulling the cable outwards as described earlier.

If, after all this, the shifter still can't pull enough cable to lift the chain onto the big cog, you've got a compatibility problem as the pull ratio of the shifter is wrong.

Once you've got it working, reset that limit screw so the chain can't drop off the outside.

 

[Garethgas]

Hi Globalti.
Normally, you'd be right but the derailleur is a replacement so the hi/low screws haven't been set.
Also, my advice to loosen it (in big cog) and look for some movement was a preface to tightening the cable (as I said).
It was late, and I was trying to give a very quick bit of help as no one else seemed to be about.
He was also posting additional info during my posts
I've just read it back and I still think it's correct and in context.
I left him with the park tool link for a better explanation to get him sorted.

 

[Globalti]

Sorry, I hadn't twigged that it was new.

 

[sitchey]

Cheers guys. Yea it was late. Going to have another go when I get in from work.

On the actual shifter not moving into 3rd gear (even when not clamped into derailleur) any advice

These are the shifters I bought

http://www.ebay.co.uk/itm/221050498913

Also sorry if I didn't say, but the derailleur isn't a replacement. It's what came with the bike when it was bought. But the bike was never able to get into 3rd gear