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?

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.

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.

Tony EH

ridelikeaturtle wrote: »

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

Obviously if I'm on an incline, or facing a strong headwind, I'll drop down. But yeh, most of the time I'm 52 11. ¯\_(ツ)_/¯

ridelikeaturtle wrote: »

But there's no hero points for staying in the "big ring" all the time, and it's not a measure of masculinity.

I'm not looking for that?

ridelikeaturtle wrote: »

If you find yourself "grinding"

It's not ME grinding. It's the chain "grinding" against the derailleur.

ridelikeaturtle

Tony EH wrote: »

I'm not looking for that?

Sorry, no not you, but I've seen a lot of douchebags in my time who think it's a pissing contest and use "being in the big ring" as a measuring stick.

(It's a bit like guys who use the term "chicken strips" on the back tyre of your motorcycle, it's a sign they've no idea of how to go around a corner.)

magicbastarder

Tony EH wrote: »

Is that not normal?

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

my own experience is that on the flat i typically find myself in 52/16; 52/11 would be far too grindy for me.
what sort of speed/cadence are you managing?

Mehaffey1

Jan Ullrich that you back?

magicbastarder

Tony EH wrote: »

It's not ME grinding. It's the chain "grinding" against the derailleur.

grinding means pushing needlessly hard at a big gear.
at a cadence of 60, which is reasonably low, you'd be doing 36km/h in 52/11 - that would be bloody hard to maintain on the flat, and drain your reserves fast.
YMMV, but doing a higher cadence in an easier gear, for the same speed, is usually the advice you'd hear; e.g. 52/15 at 80rpm will give you roughly the same speed and would generally be easier to maintain.

Tony EH

magicbastarder wrote: »

my own experience is that on the flat i typically find myself in 52/16; 52/11 would be far too grindy for me.
what sort of speed/cadence are you managing?

I have no idea.

Tony EH

magicbastarder wrote: »

grinding means pushing needlessly hard at a big gear.

OK, exchange "grinding" for "rubbing".

magicbastarder wrote: »

at a cadence of 60, which is reasonably low, you'd be doing 36km/h in 52/11 - that would be bloody hard to maintain on the flat, and drain your reserves fast.
YMMV, but doing a higher cadence in an easier gear, for the same speed, is usually the advice you'd hear; e.g. 52/15 at 80rpm will give you roughly the same speed and would generally be easier to maintain.

Look, all I know is that when I'm out cycling, I'm usually in 52/11. I know what gear I cycle in. Of course I'll gear down if I meet a rise or I'm in a string headwind, etc. Obviously, if I'm climbing Greenhills Road, I won't be doing it in a big gear.

This is all getting off the point though, which is about the chain rubbing against the derailleur on my bike and whether I should remove it or not.

tuxy

Tony EH wrote: »

Look, all I know is that when I'm out cycling, I'm usually in 52/11. I know what gear I cycle in. Of course I'll gear down if I meet a rise or I'm in a string .

People are only questioning it because 52/11 is over 50 km/h assuming your cadence is not way too low. That's a tremendous speed to be able to maintain on a road bike and faster than than top level pros who need a TT bike to hold that speed.

That said 52/11 should not cause chain rub. I've had the problem before but once I fix the problem while off the bike I can't think what would make it happen under load out on the road.

Difficult to get the camera focus but this is what my bike looks like in 52x11
You can see there is about 1mm clearance. Does your bike have that?

https://i.gyazo.com/406e11d5e4e41f1754ca0dc3557d28d3.png

Tony EH

tuxy wrote: »

Difficult to get the camera focus but this is what my bike looks like in 52x11
You can see there is about 1mm clearance. Does your bike have that?

https://i.gyazo.com/406e11d5e4e41f1754ca0dc3557d28d3.png

Yep. Clearance seems to be fine and there's no wobble or looseness in the crank.

tuxy wrote: »

That said 52/11 should not cause chain rub. I've had the problem before but once I fix the problem while off the bike I can't think what would make it happen under load out on the road.

I think I'm just going to replace the derailleur at this point.

Anyway, thanks to all for the help.

tuxy

Tony EH wrote: »

Yep. Clearance seems to be fine and there's no wobble or looseness in the crank.



I think I'm just going to replace the derailleur at this point.

If there is clearance then it's not possible for the chain to rub on the derailleur. The problem must be else where.

hesker

tuxy wrote: »

If there is clearance then it's not possible for the chain to rub on the derailleur. The problem must be else where.

Bent chainring

tuxy

hesker wrote: »

Bent chainring

Wouldn't that rub if you were to spin the crank while off the bike. From what I understand everything seems fine until there is a rider on the bike.

Tony EH

By the way. it's a 50/11. Not a 52/11.

Sorry for the misinformation, which is embarrassing. But, I'm just some guy with a bike, not an expert.

nilhg

hesker wrote: »

Bent chainring

Or lose chainring bolt, may only become obvious when under full load and not while up on the bikestand.

magicbastarder

tuxy wrote: »

People are only questioning it because 52/11 is over 50 km/h assuming your cadence is not way too low. That's a tremendous speed to be able to maintain on a road bike and faster than than top level pros who need a TT bike to hold that speed.

i know it's not the answer to the question you asked - but i'll repeat what tuxy said. unless you've legs like tree trunks, staying in 50/11 most of the time is creating unnecessary work for yourself. unless you are incredibly fit, i would regard the defaulting to this gear as being an issue you need to address before dealing with chain rub in that gear.

i'm reasonably fit and genuinely could not remember the last time i was in that gear - and i'm including descents i've hit over 60km/h on.

cletus

The engineers bluing is a great idea, or if you can't get that, a blue Sharpie should work in a pinch. Very easy to see then where (if at all) the derailleur is rubbing

Mehaffey1

Cones on the back wheel could be at fault but would be obvious pedalled on a stand.

Tony EH

magicbastarder wrote: »

i know it's not the answer to the question you asked - but i'll repeat what tuxy said. unless you've legs like tree trunks, staying in 50/11 most of the time is creating unnecessary work for yourself. unless you are incredibly fit, i would regard the defaulting to this gear as being an issue you need to address before dealing with chain rub in that gear.

i'm reasonably fit and genuinely could not remember the last time i was in that gear - and i'm including descents i've hit over 60km/h on.

Look, I don't disbelieve you, honestly, and no, I am not "incredibly fit" either. Far from it I can tell you.

But as soon as I have a good momentum going, I switch into the highest gear I can, whether that's just my half hour cycle to work or longer runs at the weekend. Perhaps I'm being woefully inefficient and doing it all wrong.

Maybe it's because I don't do very long runs perhaps? I don't know. As I said, I'm just a guy with a bike. I'm not looking for kudos here or trying to big myself up, I'm too long in the tooth for nonsense like that. I just wanted to see if anyone could enlighten me as to what the issue was with the derailleur.

In any case, a buddy of mine is coming over later and we're going to take it off. That should let me know whether the derailleur is the actual problem or not.

ridelikeaturtle

Two sets of eyes are better than one, good chance one of you will see something the other didn't.

Tony EH

Right so, the end of this drama was all so very simple. My buddy came over this morning, took off the old derailleur and fixed a new one of the same type he whipped off of his Giant that he doesn't use any more. The rubbing noise has now gone. Happy bleedin days. All done in 30 minutes too. It would have took me hours so I was glad to let him have at it.

Now, with that done, I decided to head off on a cycle with my now silent silent bike. So I headed out on the N81 towards Russborough House.

So yeah, maybe I'm not in the 50/11 as often as I think . So perhaps it's my daily commute to work where I usually sprint that's giving me that impression. In fairness, though, that trip to Blessington involves some deceptively steep inclines.

What I do know, is that when I am in the 50/11, it is gloriously silent and not distracting me any more.

One thing I will say, that ride out to Blessington is a divil for having to avoid catseyes and there are really shitty sections of road that are terribly uncomfortable to ride on.

Anyway, it was around three hours, there and back again to Dublin. I have no idea it that's good or not...and I'm sunburnt.

ridelikeaturtle

Are you running 25c tyres? If not, that's an option, you can run lower pressures, makes a noticeable difference.

Tony EH

No, 700x35's.

tuxy

A giant contend has clearance for 35mm?