Front Derailleur Problem

decrrrrrr

Gears has been always something I hated and my knowledge only goes so far with them. I searched around, but I haven't come across this specific problem. Posting this one out there and maybe I'll learn something new.

I'm looking at the the gears on a bike that has been laying in a shed for a 4/5 years.

There is a problem when the bike is in top gear(i.e. big ring/small cog) and the chain is running against the front derailleur. Chain also rubs on the last 3 cogs as well

Adjusting the H Screw does not work as it does not move the derailleur far enough away from the frame.

Derailleur looks to be aligned with big rings.

Where to next. Do I need to look at the wire and tension on it

D

Chips Lovell

Check the cable tension. If it's loosened, it means that the first part of the shift movement is simply picking up the slack and you aren't adding enough tension to shift it out the whole way.

Chain rub in big ring/big cog combos though is normal.

scottreynolds

decrrrrrr wrote: »

Gears has been always something I hated and my knowledge only goes so far with them. I searched around, but I haven't come across this specific problem. Posting this one out there and maybe I'll learn something new.

I'm looking at the the gears on a bike that has been laying in a shed for a 4/5 years.

There is a problem when the bike is in top gear(i.e. big ring/small cog) and the chain is running against the front derailleur. Chain also rubs on the last 3 cogs as well

Adjusting the H Screw does not work as it does not move the derailleur far enough away from the frame.

Derailleur looks to be aligned with big rings.

Where to next. Do I need to look at the wire and tension on it

D

Yeah the tension, the wire should be fine. I'd reset the H/L screws and start again by tensioning. Thinking about my bikes I can set the front der to different positions based on the rear cog I'm using -- basically just trimming using the gears.

decrrrrrr

By tension, do you mean adjusting the barrell up by the shifters?

Chips Lovell

decrrrrrr wrote: »

By tension, do you mean adjusting the barrell up by the shifters?

If there's a barrell, great. Otherwise, unscrew the cable from the derailleur and pull it tight then screw it on again.

decrrrrrr

el tonto wrote: »

If there's a barrell, great. Otherwise, unscrew the cable from the derailleur and pull it tight then screw it on again.

The barrel seemed to do the trick. Would be happier with a slightly bigger track. Will get it on the road though and see how it goes.

One question for future reference - if I was to unscrew the cable and start again, what position should the H/L screws be in i.e. fully tightened, fully loosened or somewhere in between?

Cheers,

D

Chips Lovell

decrrrrrr wrote: »

One question for future reference - if I was to unscrew the cable and start again, what position should the H/L screws be in i.e. fully tightened, fully loosened or somewhere in between?

I've never actually checked. My guess is the best bet is somewhere in between.

concussion

About half way, that way you can fine tune it after setting your cable.

TinyExplosions

The cable has no bearing on the H/L screws, so they can (and should) be set with no cable tension at all. They adjust the limit of movement of the derailleur at the upper and lower end. The cable just pulls it up to high position, or drops it down to it's lower end.

DirkVoodoo

Tiny is right. H/L limits are independent of cable tension. Once your limits are properly established, that's it. If you look at that very handy video where the lad adjusts the rear derailleur, he does so without the cable attached to show people that limits have nothing to do with the indexing of gears.

If your limits are fine, leave the screws as they were. Of course, it can't hurt to fine tune everything I suppose.