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• #2
Don't run the little ring on the little sprocket.
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• #3
^^This.
Try to use about 2/3rd of the bigger sprockets when in the little ring and 2/3rd of the smaller sprockets when in the big ring.
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• #4
Well..duh! :)
Regardless of whether its a gear I'm going to regularly use, it still shouldn't be an issue. -
• #5
It's me again :)
I've got a problem with the chain rubbing the front deraileur at a certain point every rotation. I only get this in the highest gear on the inner ring and it happens from about the 4th gear when on the outer ring. getting gradually worse when changing up to the highest gear.
I notice my rear derailleur has a few issues shifting from the 5th cog to 6th and sometimes skips it altogether going directly onto the 7th cog.
This is the first time I've worked with gears. I've watched a few videos however they have all been for indexed gears. So unsure how to solve the 5th to 7th gear issues.
As for the front derailleur I'm sure it could just do with a tweak to fix but that's just the most obvious solution.I've including a couple of pictures incase it is indeed my rear derailleur at fault.
I've noticed the shifter at it's most pulled down is millimeters away from the spokes. Is this normal?
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• #6
in 1st gear on back, its normal for cage to be very close to spokes. BUT you need to make sure its trimmed to ensure it doesn't go into the wheel, and that the cage is parallel to spokes or perpendicular to the ground.
As for the 5-6-7 skip, thats pretty common, chances are the centurion jockey wheel has a bit too much play in it (so the shift becomes vague) or chain/cassette is on the way out.
If you ever get a new front mech, hit me up as i'm after that dura ace front mech like that.Ok, problem in hand, rubbing when you get to the extents of the rear block, totally normal, if you have friction gears you need to trim them a little when this happens, if you have indexed gears then you have a different problem.
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• #7
If the rub happens only at certain points in the rotation, that would indicate that your chainrings aren't true. (And there's likely to be other problems as well). It's easy to check trueness by watching the chainrings relative to a static point as you turn the cranks. Depending on how bent they are (and whether they're bent nearer or further from the axle) you can use an adjustable spanner to straighten them out. I've used a mallet before and it's worked reasonably well for a lousy steel chainset. But if it's something a bit better (and your's is), then the adjustable spanner is one answer.
Once your chainrings are true, then you can look into the other issues.
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• #8
After exhaustive reading / watching youtube clips and spending hours trying to adjust the FD I'm about to give up.
The problem is that chain rub occurs when I'm in the middle chainring and either the smallest or largest rear sprocket. It actually starts to rub slightly on the gear just before that. When adjusting cable tension i can get it to stop rubbing on either the smallest or largest sprocket but not both. Is the FD cage too narrow? It's perfectly parallel and I've tried different heights. It shifts perfectly fine. I'll be happy to buy a wider cage if that will sort the issue.
Many thanks
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• #10
Thanks hippy, been over parktools plenty of times. Even with barrel adjustment I cannot get the rub to stop on both the small and big sprocket whilst being on the middle chainring. If the one end is clear, the other end will rub heavily. If I make fine adjustments they both still rub.
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• #11
You should generally be in the big ring or small ring before you hit their respective end of cassette.
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• #12
^This.. It's good that you don't use the whole width of the cassette.. The skewness of the chain causes extra wear to the whole drivetrain.. Live with it..
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• #13
good as, the way it is intented.
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• #14
Thanks guys. Even on the middle chainring? I was under the impression cross chaining only applies to the inner and outer chainring on a tripple FD
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• #15
I'd be a little unhappy about this too, though I hear the point about preferred chain alignment.
I'm assuming that you've tried ALL height variations - I'm asking because the profile of the inner plate often changes across its face, and that can cause chain rub and can often can be dealt with by some subtle height changing.
If that's not the case, then your fr derailleur is too narrow for the gear range and chainstay length (the length will affect the chain angle). So either live with it, buy a new one or experiment with some potentially disastrous widening techniques. I'd do the latter if the derailleur isn't too special.
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• #16
I've tried 1, 2 and 3mm heights. After spending about 8 hours on this and almost busting my cable, I've decided to book it in for it's first free service. My LBS said it shouldn't rub in those combos so I'll see if they can get it right. If they can't either I might look at another FD.
I'll read up on cage widening as well.Thanks for all your suggestions.
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• #17
Thanks guys. Even on the middle chainring? I was under the impression cross chaining only applies to the inner and outer chainring on a tripple FD
No, the available chain ring/sprocket combinations are dependent on two things: chainline and chainrub.Chainline refers to having such extreme combinations (big/big or small/small) that the chain runs at an angle that causes excessive wear of itself and the cassette and chain ring.
The wider the cassette the greater the problem: a 1x5 set-up will happily run all options.
Chainrub is more apparent when using the smaller rings, because the bigger rings overlap them: you might get rub in the two highest gears and the small ring, but none from the lowest and the big ring (but chainline could then be the issue).
With a triple, I would set it up so that the available gears are evenly in the centre, ie lose one gear from either end.
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• #18
chatterbox, which actuation system are you using? i.e.:
downtube friction
downtube indexed
Shimano indexed
Sram indexed
Campagnolo indexed -
• #19
Thanks Scilly Suffolk
rive gauche, it's a Shimano indexed.
Tripple front and 9 on the rear sprocket.I see the cable is at more of an angle at 2 x 9 compared to 2 x 1 which only has a slight angle (1 being the smallest rear sprocket) So could in theory adjust it in such a way that 1 just clears and 9 rubs. Only issue is then 7 and 8 rub as well then.
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• #20
I adjusted my wife's mountain bike FD today. She has the Shimano Deore LX as apposed to my Deore. The cage is wider and I was able to adjust it with no rub in any of the gear combos in a matter of minutes. It also has no issues shifting as I know some people said the wider cage won't shift as easily.
The LX is about 5 years old now so not sure if the new models are still wider. But this might definitely be an option for mine.
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• #21
I have older shim LX FD with wider cage, can dig out and take a pic if you like?
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• #22
Thanks rive gauche, were you thinking of selling it?
I got my bike back from the LBS today and all they did was adjust cable tension so it doesn't rub when on the smallest sprocket at the back, but it now rubs on the 3 biggest sprockets. So we can safely say it isn't possible to not have chain rub on the Shimano Deore in this config.
I can live with a bit of rub in just the outermost sprockets but this is too much. I'll shop for a wider cage.
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• #23
I'll take a gander at its condition and post a pic for you, it won't be much. If you could state the width of the lx mech on your wife's machine that'd help too.
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• #24
ok, here's a selection of would be suitors, give me a hint and I can measure up dimensions, or give me the part number stamped on the back of the cage
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• #25
rive gauche, thanks for the offer and uploading the pic. I have however managed to get a new Shimano Deore LX (T660) top swing FD for really cheap.
I'm happy to report that I don't get any rubbing in any of the gear combos! And it only took me about 45 minutes to swap and adjust it.
For anyone interested the new cage is about 19mm at the front and the old Deore cage (FD-M590) is about 17mm. Amazing what 2mm can do.
Even with the wider cage, it's shifting better than before. It's only really wider towards the opening so it doesn't affect shifting ability.
I've just finished putting together my new geared bike (soon to be in current projects..) and discovered I've got a fair amount of chain rub against the outer ring when in the smallest sprocket.
My chainline should be correct, I'm using a Campag 102mm BB with Campag script era (1995 onwards) cranks which i believe is right.
Both chain rings are modern 9/10 speed TA rings which if anything should be slightly thinner than an 8 speed ring (I doubt there is any difference...) and they are 39/50 so the spacing between them is actually quite small.
The chain is a SRAM 8 speed, which is the same width as a Campag 8 Speed (7.1mm) so this shouldn't be an issue...
Finally, the chain rub is worse is on the top side of the chain, suggesting it isn't a case of having the lower limit setup correct, at least i think thats the correct assumption!
No idea whats up really, its not the most important gear ever.. but it is annoying. I suppose a 9 speed chain chain might solve the issue, but shouldn't really be necessary.
Any ideas?