Problems with Rear Mechs

drhaggis

Pinno wrote:

Badly adjusted front mech.
The cage of the front mech should sit perfectly parallel with the chain:

[image removed]

A and B is wrong, C is correct.

Have you got a workstand? If not, get someone to hold up the back wheel and see what the chain is doing in the above gears when pedalling or failing that assistance, turn the bike upside down old school. (Put cloths on the floor to protect the saddle and the stem).
Back pedalling with the bike upright may elicit the right conditions to create the noise but it may not.

It should be reasonably easy to ascertain squeaks from rubbing.

Thank you Pinno! in the end, given how much cr*p there was in the jockey wheels, I thought it was worth a shot, so I got some for under a tenner. I replaced them yesterday night, which messed up my gears (chain started slipping), but playing with the cable tension seems to have fixed it. No squeaking in the 80 km I put in today, but let's see if it lasts.

pinno

No problem.

Now you can sneak up on those Haggii(?) loafing on the road.

ilovegrace

Help !!
Decided to "fine tune " my rear mech < ultegra 10 speed , for a sportive on Saturday and made it worse !!
The main issue is when on small cog at the back there is a grinding noise , I have tried the lower limit setting at different places but cant get away from the noise.
I have also tried to set the gears and they are hit and miss .
Where am I going wrong
regards
ILG

figbat

Cable too tight?
Dirty jockey wheel(s)?
Worn jockey wheel(s)?
Dirt or other foreign object on the lower limit stop?
Worn chain?
Worn cassette?

keef66

Assuming it was set up properly in the first place it's not normal to need to adjust the limit screws unless you've swapped wheels or replaced a derailleur. If gears go out of adjustment it's usually just a matter of tweaking the barrel adjuster a bit. Did this problem appear suddenly or has it slowly developed? Did it follow a fall or knock to the bike, or some maintenance involving removing the rear wheel, mech or cassette?

Is the wheel properly in the dropouts? I've occasionally had odd shifting when the rear wheel's been out and I've not got it fully back in before tightening the QR.

Alternatively could the mech hanger be bent? I recently fitted a 11-36 cassette with a MTB rear mech on the winter bike and the first ride out it was like a bag of spanners. When I checked the mech alignment it needed straightening in 2 directions. Slick and silent now.

ilovegrace

Thanks chaps
Did a little tinkering last night. Gears running better but still a little noisy.
Going to have to pop into http://www.yorkshirecyclehub.co.uk/ and see if the nice chaps there will give it a quick look see.
Ps
For anyone visiting or planning to visit North Yorkshire moors area the Yorkshire cycle hub should be on your list of places to visit.
regards
ILG

itboffin

Today I discovered B screw tension can make down shifting sluggish

pinno

itboffin wrote:

Today I discovered B screw tension can make down shifting sluggish

brokenbanjo

Anyone got any advice on how to replace the bloody ridiculous barrel adjuster on an Ultegra R8000 rear mech. It is an infernal contraption to use. What’s wrong with the older type?

pinno

brokenbanjo wrote:

Anyone got any advice on how to replace the bloody ridiculous barrel adjuster on an Ultegra R8000 rear mech. It is an infernal contraption to use. What’s wrong with the older type?

https://www.youtube.com/watch?v=_39lFgsF1eg

secretsam

Eternal question: are rear mechs "intelligent"? On a non-electronic setup, does it matter if you use a 9, 10 or 11 speed mech - surely it's the gear lever (STI, etc) that decides how much the mech moves?
In which case, could you use a 9 speed rear mech with an 11 speed setup?

pinno

SecretSam wrote:

Eternal question: are rear mechs "intelligent"? On a non-electronic setup, does it matter if you use a 9, 10 or 11 speed mech - surely it's the gear lever (STI, etc) that decides how much the mech moves?
In which case, could you use a 9 speed rear mech with an 11 speed setup?

No. Unfortunately life is not that simple.

The parallelogram is different between the mech's (of whatever speed).
There is also a slight difference between a 10 speed Campag and a Shimano 10 speed..

"MTB rear derailleurs from 6 to 9 speeds, and road RDs from 6 to 10 speeds are interchangeable and compatible. Slight difference in jockey wheel thickness is not a problem – a 6 speed RD will work on any number of speeds – up to 9 with a MTB and up to 10 with a road bike. It is the same ratio of derailleur cage movement per cable movement, so the shifter levers determine the movement and the number of “speeds”.

10 and 11 speed MTB derailleurs, as well as 11 speed road bike derailleur are not interchangeable. Different cable pull ratio and parallelogram movement for each. There are exceptions from these rules, so if some combining (mix-matchin) is planned, it is best to first read the post about bicycle rear derailleur compatibility."

https://bike.bikegremlin.com/1278/bicyc ... atibility/

drhaggis

...and then there is Tiagra 4700.

Does that one have the 11-speed geometry or the 10-speed one?

keef66

DrHaggis wrote:

...and then there is Tiagra 4700.

Does that one have the 11-speed geometry or the 10-speed one?

It definitely has the 11 speed cable pull / ratio. So for instance a 4700 RD will work with R7000 STIs, or you could fit a R7000 RD to an otherwise 4700 groupset. Whether you'd ever want to do that is another question. And would the 11 speed chain be happy with an RD meant for 10 speed, or the 10 speed chain with an 11 speed RD?

charleyfarley

Hi, I'm new to this forum and have read the rules. I'm almost afraid to post in case I get banned. So I hope I'm putting this in the right place. Also, I didn't realize BikeRadar is British. I'm a Brit but live in the US, so I don't speak metric as in Km and that kind of thing.

I was reading up in this forum about jockey wheels. I have two bikes, one with a Sram X5 group and one with a Shimano Tourney group. I service the chains every 100 miles, and found the Sram top jockey wheel tends to wobble side to side, a bit. Gear changes are fine, but neither of the jockey wheels on the Shimano wobble at all, so I assumed the Sram wheel was worn; I've put 6,000 miles on it from new.

Just yesterday I ordered a new set of jockey wheels, so I'm going to change them even if they don't need it. I'm glad I found out, on this forum, that the upper wheel intentionally has some play in it because if I installed the new wheels and found the top one still has play in it, I'd wonder what was wrong.

I dismantled the jockey wheels, yesterday, just to take a look to see if the wheel or the center sleeve was worn. I'm baffled as to what they wheels are made of. They are so light, I figured they are plastic, but I doubt plastic would hold up to a chain being run over it for 6,000 miles.

pinno

CharleyFarley wrote:

I'm almost afraid to post in case I get banned.

It's not that bad
It used to be.

Post away. Please post pics of nakedness.

Glad this thread was of assistance.

charleyfarley

Pinno wrote:

CharleyFarley wrote:

I'm almost afraid to post in case I get banned.

It's not that bad
It used to be.

Good to know. Thanks.

Post away. Please post pics of nakedness.

Not of me, I hope!

pinno

CharleyFarley wrote:

Pinno wrote:

CharleyFarley wrote:

I'm almost afraid to post in case I get banned.

It's not that bad
It used to be.

Good to know. Thanks.

Post away. Please post pics of nakedness.

Not of me, I hope!

I was going to say 'naked ladies' but the PC Stasi are omnipresent.

StillGoing

SecretSam wrote:

Eternal question: are rear mechs "intelligent"? On a non-electronic setup, does it matter if you use a 9, 10 or 11 speed mech - surely it's the gear lever (STI, etc) that decides how much the mech moves?
In which case, could you use a 9 speed rear mech with an 11 speed setup?

SRAM rear derailleurs work to the shifter and are not speed relevant. If you've got 10 or 11 speed shifters, the rear derailleur will operate correctly. Applies forwards and backwards with the various models, so a 2019 22 will work with a 2010 Apex, Rival, Force or Red 10 speed and the same in reverse, ie a 10 speed Apex, Rival, Force or Red rear derailleur will work with 11 speed shifters.

colinsmith123

Ultegra DI2 Problem. When I shift to the large sprocket, after 5s it auto-shifts back to the 2nd sprocket. It does this on both the 39 and 52 chainring.
I can tell you what I have tried and eliminated:
Unplugged the battery to simulate a "hard reset", a bit like restarting a computer or phone
Rear hanger bent - checked and fixed that. It was out by 10mm
Incorrectly adjusted limit screws - followed Shimano manual instructions. Even tried winding it completely out.
Incorrect indexing - followed Shimano manual instructions
Spacer on the cassette - same cassette and wheel as came with bike

I don't have the e-tube wireless adaptor. And having read about this, seems it can cause more problems than solve.

Any advice greatly appreciated.

My final option is drop the bike off at the bike shop tomorrow as a last resort, but it is a 50 mile round-trip. Collect Saturday.

UPDATE: I HAD ANOTHER GO AT IT TODAY. TURNS OUT IT WAS IN FACT THE LIMIT SCREW. HALF A TURN AND FIXED!!

charleyfarley

Pinno wrote:

... A chain that gets pushed over the largest cog on the cassette towards the wheel can have a catastrophic effect:
Broken spokes, a mangled rear mech, a locked up rear wheel. If you don't suffer an injury, you will be looking at a potentially hefty bill.

I bought a new Specialized Fatboy SE from a bike shop. [I'd bought two other bikes from them.] A couple of months after buying it, I took a longish ride. I hadn't put the bike through its paces at this point. Fifteen miles (24km) from home on the return trip, going up a hill I changed down to the lowest gear and the pedals suddenly jammed. The chain had come off the largest sprocket and gotten jammed around the axle. Thankfully, the pie plate prevented it going into the spokes.

It took me about fifteen minutes to get the chain out and back onto the sprocket. It was pulled tight around the chain ring so I couldn't get it off to give me enough slack to pull on.

Back home I put it up on the work stand and ran it through the gears. Not only would the chain run off the large sprocket, but it wouldn't go onto the smallest sprocket. Apparently the LBS didn't consider it necessary to check the bike over to make sure it was in good order. And I just assumed that the bike, being new, would be in good shape. I adjusted the limit screws, myself, rather than go back to the shop.

Also, on that bike I noticed how odd the rear disc brake looked. The caliper bolts stuck way up in the air. I found that they didn't use the right length bolts when the bike was assembled, so they threaded a 3/4" (20mm) stack of washers on the bolts and then bolted them in. I cut them down to the right length. So, this was two botch jobs on a brand new bike. Across three bikes, they did five botch jobs, which pushed me to do my own wrenching. And they claim to be professional!

Incidentally, a few years ago, on another bike forum, I watched a discussion where members were talking about things they do to a new bike. One guy said the first thing he does when he gets a new bike, was to remove the pie plate. I don't know if there is a purpose for that and I didn't ask him, but from my later experience with having the chain come off, I figured he must have been simple, or maybe I'm missing something.

pinno

CharleyFarley wrote:

One guy said the first thing he does when he gets a new bike, was to remove the pie plate. I don't know if there is a purpose for that and I didn't ask him, but from my later experience with having the chain come off, I figured he must have been simple, or maybe I'm missing something.

That's what is called in the cycling vernacular as a 'Dork disc'.
It's purpose is to stop grease and oil from going on to the spokes and axle.
The chances of it holding up if a chain comes into contact with it is slim - you were lucky.

When you have set the rear mech limit screws up, there's no reason for it to go over. Unless you change the wheel. They look silly, they get brittle in no time and sometimes once the little plastic retaining tabs break, they rattle and move around.

A dork disc is not going to save a rear mech properly bent up because the chain has jammed.
I followed a guy up a hill once. Brand new Bianchi frame. He has never been a particularly friendly bloke and before the start of that run, had waxed lyrical over his one piece carbon handlebars and stem combo - well over £200 for (what I calculated to be) a weight saving on my set up of 43 grams.
Anyway, he's a competent fettler. And I did wonder why he was struggling to go up this steep(ish) incline and I watched the chain go over the biggest rear sprocket, the chain jammed and his new SRAM mech just folded. Mech hanger was bent too. Spokes were notched and paint was taken off the chainstay.

I tried not to smile and left him to walk home.

charleyfarley

Pinno wrote:

CharleyFarley wrote:

One guy said the first thing he does when he gets a new bike, was to remove the pie plate. I don't know if there is a purpose for that and I didn't ask him, but from my later experience with having the chain come off, I figured he must have been simple, or maybe I'm missing something.

That's what is called in the cycling vernacular as a 'Dork disc'.
It's purpose is to stop grease and oil from going on to the spokes and axle.
The chances of it holding up if a chain comes into contact with it is slim - you were lucky.

Here in the US it's called a 'dork disk' or 'pie plate.' From my observation of biking websites, they say it's to protect the spokes. No mention is made of oil going onto the spokes. Where would it come from, anyway? I use a chain lube (Rock N Roll) which sets as a kind of waxy film but it's not wax. That won't go anywhere near the spokes. The disc is made of polycarbonate, and that would have to be hit with a sledge hammer to break it. The chain didn't phase it at all, which surprised me.

When you have set the rear mech limit screws up, there's no reason for it to go over. Unless you change the wheel. They look silly, they get brittle in no time and sometimes once the little plastic retaining tabs break, they rattle and move around.

The bike is nearly three years old, and the pie plate is in excellent condition, despite our summers being in the 90s each day [making plastic brittle), and about 6,000 miles (9,656km) on it. Maybe there are thin plastic ones and thicker polycarbonate ones. I don't know, but mine isn't disintegrating. Having had one bad experience with the chain coming off, I'd prefer to leave it where it is. I know when the limit screws are set properly, there's no reason for the chain to come off, but other things can happen. I read about a guy who had sticks go into his derailleur and push the chain off and into his spokes, on his trail bike. I ride pavement, so it's not likely to get sticks or stones jam something up. I think that without the pie plate I'd have been looking at re-spoking the wheel, and having to get a taxi ride home. And I doubt the crummy bike shop would have fixed it for free.

Do you think it's up to the buyer of a new bike to check the brakes adjustment and derailleur operation before you ride it? This was a bike shop with 40 years of service. I do better work than their shade tree mechanic.

I followed a guy up a hill once. Brand new Bianchi frame. He has never been a particularly friendly bloke and before the start of that run, had waxed lyrical over his one piece carbon handlebars and stem combo - well over £200 for (what I calculated to be) a weight saving on my set up of 43 grams.
Anyway, he's a competent fettler. And I did wonder why he was struggling to go up this steep(ish) incline and I watched the chain go over the biggest rear sprocket, the chain jammed and his new SRAM mech just folded. Mech hanger was bent too. Spokes were notched and paint was taken off the chainstay.

I tried not to smile and left him to walk home.

A little bit of schadenfreude is good for the soul.

pinno

CharleyFarley wrote:

Do you think it's up to the buyer of a new bike to check the brakes adjustment and derailleur operation before you ride it?

No of course it isn't.
I haven't bought a complete bike out of a shop since 1988.

The rest - we can agree to disagree

charleyfarley

Pinno wrote:

CharleyFarley wrote:

Do you think it's up to the buyer of a new bike to check the brakes adjustment and derailleur operation before you ride it?

No of course it isn't.
I haven't bought a complete bike out of a shop since 1988.

The rest - we can agree to disagree

Apparently, you know more about my bike and the pie plate than I do. Yes, we can disagree because I always disagree with bullshitters. I'm outa here!

imposter2.0

That went well...

The purpose of the pie plate/dork disc/whatever is to protect the spokes in the event of the chain going over the top. Nothing to do with 'grease and oil' - although I'm sure the spokes also may get dirty when the chain hits them...

ballysmate

I'm sure the dork disc could serve both purposes. Act as a guard for errant lube and as a safety feature to guard against incompetent adjustment.

pinno

Ballysmate wrote:

...to guard against incompetent adjustment.

You said it.

CharleyFarley wrote:

Pinno wrote:

CharleyFarley wrote:

Do you think it's up to the buyer of a new bike to check the brakes adjustment and derailleur operation before you ride it?

No of course it isn't.
I haven't bought a complete bike out of a shop since 1988.

The rest - we can agree to disagree

Apparently, you know more about my bike and the pie plate than I do. Yes, we can disagree because I always disagree with bullshitters. I'm outa here!

Bye.

TBH, I never thought that the little plastic disc would actually save your spokes from a kicking should the chain go over and...
Who actually retains their dork discs in case of this event?!

Monty Dog wrote:

Also known as a 'dork-disc' - I remove them every time I service a bike and hand it back to the owner saying it is superfluous to purpose.

P_Tucker wrote:

Its to stop the chain shifting off the end of the cassette and getting jammed between spokes and cassette. If your derailleur is set up properly, its entirely unnecessary and hideously ugly.

Slowbike wrote:

As said - limit screws ... check those and you're good to go.
Having a dork disk doesn't give you 100% protection anyway ...

orraloon

We-ell... start of last year I got some luvverly new wheels. Actually went and procured a dork disk for just in case the rear mech, though was / is properly adjusted, decided to fling itself into those lovely new spokes. Ok, so I looked like a dork. See if I care.

Took me to the back end of last year to relax and say, is ok, is adjusted properly, it cannot over throw, remove da plahstuk.

Confession over.

pinno

orraloon wrote:

We-ell... start of last year I got some luvverly new wheels. Actually went and procured a dork disk for just in case the rear mech, though was / is properly adjusted, decided to fling itself into those lovely new spokes. Ok, so I looked like a dork. See if I care.

Took me to the back end of last year to relax and say, is ok, is adjusted properly, it cannot over throw, remove da plahstuk.

Confession over.

Say 3 hail Mary's.