Front derailleur removal

Tony EH

I keep getting grinding on my front derailleur on my Giant Contend. Brought it the shop to get it aligned. The grind is still there.

This is happening the worst when the gears are in the 52/11, which is what I cycle the most as that's where the speed is. I wouldn't care if it was happening in the higher gears. I've tried adjust the limiter screws to no effect. I even tried just pulling the derailleur to see if I could force it. No joy. I know about the trim on Shimanos, but that's doing nothing.

I cannot stress how bloody annoying it is. :mad:

At this point I just want rid of it. I never shift down to the smaller ring on the front anyway, so it's not of that much use to me. But the grind and rub is driving me up the wall. I discussed it with the bike shop and they said he wouldn't because the chain would come off. But, I had it done with an older Giant Defy before and that was fine. The chain never came off.

Anyone else has this nonsense? What was your solution?

Also, am I the only one who can never get to grips with these bloody front derailleurs?

magicbastarder

Tony EH wrote: »

This is happening the worst when the gears are in the 32/11.

you mean 52/11?
have you checked to see if the high limit screw on the FD is not engaged when in that position?

Weepsie

Tony EH wrote: »

This is happening the worst when the gears are in the 32/11, which is what I cycle the most as that's where the speed is. I

Are you meaning your in the small chainring and lowest cog? If so then it's probably because you're in that gear and crosschaining which wouldn't be recommended. You'd be better off in the big ring and a middle cog like a 50/16 combo or so

Weepsie

If it's 52/11, then disregard my comment

magicbastarder

Weepsie wrote: »

Are you meaning your in the small chainring and lowest cog?

i assume not as he said "I never shift down to the smaller ring on the front anyway"

grinding away at 52/11 must mean you've got some set of leg muscles.

Tony EH

magicbastarder wrote: »

you mean 52/11?

Yep. Slip of the keyboard.

I'll edit.

magicbastarder

...and i just realised i asked a question you'd already answered anyway, re the limit screws. whoops.

Weepsie

Could your derailleur them be ever so slightly bent? I had it on one of mine once. I carefully bent it back outwards and it was fine then.

Tony EH

magicbastarder wrote: »

grinding away at 52/11 must mean you've got some set of leg muscles.

The legs are grand. It's the upper body that's the problem. :pac:

Seriously though, there's definite rub happening in the highest gear that I can't seem to remedy and I'm at a loss.

Tony EH

Weepsie wrote: »

Could your derailleur them be ever so slightly bent? I had it on one of mine once. I carefully bent it back outwards and it was fine then.

No, it's not that. It's just back from the shop and the guy said the unit is fine, but was misaligned. It was too high as well.

But, I'm still getting rub on the highest gear.

ridelikeaturtle

Where exactly is the FD making contact with the chain?

Once you identify that, see how you would rotate the FD so that it clears the interference. The angle of the FD should be adjustable with the mounting screw (on braze-on mounts). Check it by manually moving it in/out with the cable disconnected. You might need a bit of trial-and-error, but it only needs to be done the one time so it's worth messing with it, then forget it forever.

Tony EH

ridelikeaturtle wrote: »

Where exactly is the FD making contact with the chain?

That's it, I can't localise where the rub is if I turn the pedals by hand. This rub only happens when I am on the road with every revolution.

The chain ring itself is fine.

RebelButtMunch

Could the axle of your chain set be loose? Downward pressure causing it to bend outwards?

G1032

Best tutorial I've ever found for adjusting Shimano front derailleurs are Shimano's own instructions!! Try look up the derailleur model on the Shimano website and you can download the manual.
I find their manual better than any YouTube video anyway

Tony EH

RebelButtMunch wrote: »

Could the axle of your chain set be loose? Downward pressure causing it to bend outwards?

I don't think so. Nothing feels loose.

ridelikeaturtle

Tony EH wrote: »

That's it, I can't localise where the rub is if I turn the pedals by hand. This rub only happens when I am on the road with every revolution.

The chain ring itself is fine.

Then it's gotta be where it's closest, if it only happens when you apply large torque. I'd start from there, and make the "margin of error" just that bit more.

Tony EH

ridelikeaturtle wrote: »

Then it's gotta be where it's closest, if it only happens when you apply large torque. I'd start from there, and make the "margin of error" just that bit more.

I've checked, very slowly, turning the crank to see if there's a point where the chain is close to the derailleur. But I can't see a point where the chain gets close. It seems to be aligned correctly, with plenty of space either side.

RebelButtMunch

Have you tried tightening everything. Seat post. Pedals....

Tony EH

RebelButtMunch wrote: »

Have you tried tightening everything. Seat post. Pedals....

Yeah. It's definitely not something like that.

G1032

Just to throw it out there... Could it be something like worn jockey wheels from the rear throwing the chain slightly off line......

G1032

Is the derailleur the correct height above the chainring

Tony EH

G1032 wrote: »

Just to throw it out there... Could it be something like worn jockey wheels from the rear throwing the chain slightly off line......

Bike's a year old and is a commute bike. The wee plastic jockeys look fine.

Tony EH

G1032 wrote: »

Is the derailleur the correct height above the chainring

Yep. It's just back from the shop.

ridelikeaturtle

Well, if you never shift off the big ring, just remove the FD entirely. You'd effectively have a 1x drivetrain.

magicbastarder

you'd need a rear derailleur with a clutch mechanism though.

railer201

I had a problem with a front derailleur - part of it was rubbing against the chainwheel ring next the one engaged. If e.g. the 52 was being used, then a section of the FD which protrudes downward was rubbing the adjacent ring. Raising the FD a little solved the problem.

I would again inspect the FD closely, turning the pedals by hand and look at the FD/ring/chain for a minimal clearance and adjust to give a little more. Metal bends under pressure and a gap of 1/2 thou can easily be eliminated when pedalling. 'Engineers blue' could also be useful, applied all over and under the FD. Inspect after a spin and see where the blue has been rubbed off.

triggermortis

If you never use the small ring, I’d take off the small ring and the front mech and probably fit a chain catcher.
I need most my gears on most spins so would rather fix the problem. GCN and park tools have great videos on YouTube and there’s no better way of figuring out how your bike works than messing about with it. At worst you can take it back to your LBS if you can’t sort it, and at best you’ll learn a useful skill and save a few quid

saccades

magicbastarder wrote: »

you'd need a rear derailleur with a clutch mechanism though.

Narrow/wide makes more of a difference - regularly forgot to engage the clutch with no impact.

Eamonnator

Tony EH wrote: »

I keep getting grinding on my front derailleur on my Giant Contend. Brought it the shop to get it aligned. The grind is still there.

This is happening the worst when the gears are in the 52/11, which is what I cycle the most as that's where the speed is. I wouldn't care if it was happening in the higher gears. I've tried adjust the limiter screws to no effect. I even tried just pulling the derailleur to see if I could force it. No joy. I know about the trim on Shimanos, but that's doing nothing.

I cannot stress how bloody annoying it is. :mad:

At this point I just want rid of it. I never shift down to the smaller ring on the front anyway, so it's not of that much use to me. But the grind and rub is driving me up the wall. I discussed it with the bike shop and they said he wouldn't because the chain would come off. But, I had it done with an older Giant Defy before and that was fine. The chain never came off.

Anyone else has this nonsense? What was your solution?

Also, am I the only one who can never get to grips with these bloody front derailleurs?

Fair play to you.

Tony EH

Eamonnator wrote: »

Fair play to you.

Is that not normal?

Surely if I'm on a flat run that's where I'd be the most, no?

ridelikeaturtle

Tony EH wrote: »

Is that not normal?

Surely if I'm on a flat run that's where I'd be the most, no?

No, it's not normal, not if you do any hills or encounter strong headwinds.

Push whatever gear you like, and whatever feels comfortable that you can sustain. But there's no hero points for staying in the "big ring" all the time, and it's not a measure of masculinity. Often, it will only slow you down over being in a more appropriate gear.

When I see someone cross-chaining in the big ring, it's usually because they haven't got their FD dialled in, or working correctly at all - so they just end up foregoing the FD altogether and try to achieve a comfortable gear using the RD. The wear-and-tear on their chain, and knees, must be painful.

If you find yourself "grinding" away with low RPMs, and your knees start to hurt, and it's hard to take off from a stop... you may like to consider a different gear.