Dropping Chain on gear change
Mccraque
Posts: 819
Odd one this....please help me understand what I'm missing!?
I'm running a 2x10 on my 29" Hardtail. All has been well until recently.
Now - whenever I change up to the big ring on the front (when in the small cogs at the back), I drop the chain off the front (chain ends up around the crank arm).
This dooes not happen when in the larger cogs on the rear.
I'd assumed it would be limiter screw.....but any further in and the front mech doesn't come across far enough to even change into the big ring. The front mech also appears perfectly positioned (rather than wide of the big ring)
It's only started happening in the last few weeks. Nothing has been changed in this period. Chain wear is fine.
SRAM X9 Rear Mech, X7 Front mech.
Thank you!
I'm running a 2x10 on my 29" Hardtail. All has been well until recently.
Now - whenever I change up to the big ring on the front (when in the small cogs at the back), I drop the chain off the front (chain ends up around the crank arm).
This dooes not happen when in the larger cogs on the rear.
I'd assumed it would be limiter screw.....but any further in and the front mech doesn't come across far enough to even change into the big ring. The front mech also appears perfectly positioned (rather than wide of the big ring)
It's only started happening in the last few weeks. Nothing has been changed in this period. Chain wear is fine.
SRAM X9 Rear Mech, X7 Front mech.
Thank you!
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Comments
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adjust the front mech stops.0
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I've done that Chunkers...0
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If what you say is correct then check its height and angle.0
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It's parallel to the chainrings, height looks fine. Doesn't look in any way bent.
I'm guessing it may not be the mech. Could it be the chainrings themselves?0 -
How are the teeth on the big ring? any broken/bent/excessive wear?0
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They've done around 1200 miles, Pilch...but they look ok. The chain has always been swapped at 0.75%. They don't look shark finned, worn or bent...0
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There shouldn't be enough room for the chain to come off unless it's moving out too far, it can sometimes be picky to get it far enough to shift yet without allowing the chain to go over. Are you running a double front mech or triple, and are the rings as for the lower two on a triple or the larger double specific ones?Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0
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2x10 - specific ring0
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Eh?0
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The Rookie wrote:There shouldn't be enough room for the chain to come off unless it's moving out too far
As The Rookie says, its shouldn't be possible for the chain to come off. The front derailleur outer plate should be about 2mm above the big chainring teeth - no more, and it should move just far enough out that the chain just misses the outer plate when on the smallest sprocket.WyndyMilla Massive Attack | Rourke 953 | Condor Italia 531 Pro | Boardman CX Pro | DT Swiss RR440 Tubeless Wheels
Find me on Strava0 -
Is that the cranks and chainrings or the front mech?Mccraque wrote:2x10 - specific ringCurrently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0 -
Do you have a front shifter where you can adjust cable tension ? If so try that .0
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Read what you wrote and delete the obvious louse up!cyd190468 wrote:You shouldn't really be changing up to the big ring if you're on the small cogs at the back. Very low chain tension makes for sloppy gear changes.Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0 -
Australia is upside down.I don't do smileys.
There is no secret ingredient - Kung Fu Panda
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Parktools0 -
as a rule - I don't ride with the small small combination. My point being that the further down the range on the cassette (towards the small), the more the chain comes off and wraps around the crank arm.
I'm not buying this "well don't use the small cogs" type advice.0 -
why shouldn't you use small small. Sort of pointless going 2x then.0
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Using small-small or big-big makes the chain run at quite an angle so increases wear. In terms of the ratios, small-small will be the same as big-medium sprocket so there is no need to "cross chain" as its called.WyndyMilla Massive Attack | Rourke 953 | Condor Italia 531 Pro | Boardman CX Pro | DT Swiss RR440 Tubeless Wheels
Find me on Strava0 -
but then you need to change the front. If small small allows you to build up speed down a small incline then you can see and up coming up where you want your inner of the 2 rings then that's better than all the correction shifts.
2x should mean you should be all good with every gear. Unless of course you're bodging a 2x with a triple and have not corrected the chainline.0 -
Or still has a triple mech where the steps in the cage don't align with the rings....Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0
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We are unecessairly complicating this.
This is a dedicated 2 x 10 chainset. The mechs are correct. It is not a triple botch job.
At some point, I have to switch from small ring on the front, to big ring on the front.
If I happen to be in the smaller cogs on the rear cassette, then when I make that switch, the chain bounces off the chainrings at the front, and wraps around the crankarm.
Other than this, all the gears run smoothly, change smoothly.
The limiter screws and mech height appear to be correctly set.0 -
Picture of set up.I don't do smileys.
There is no secret ingredient - Kung Fu Panda
London Calling on Facebook
Parktools0 -
FTFY and that was only because you wouldn't answer the fricking questions when asked the first and second times so we had to extract them like money from the chancellor!Mccraque wrote:I WAS unnecessarily complicating this.
This is a dedicated 2 x 10 chainset. The mechs are correct. It is not a triple botch job.
Spelling corrected for you.
OK, down to poor setup then.Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0 -
The Rookie wrote:
FTFY and that was only because you wouldn't answer the ******* questions when asked the first and second times so we had to extract them like money from the chancellor!Mccraque wrote:I WAS unnecessarily complicating this.
This is a dedicated 2 x 10 chainset. The mechs are correct. It is not a triple botch job.
Spelling corrected for you.
OK, down to poor setup then.
Thanks for your pearls of wisdom, Rookie. I tried to answer everything I thought had been asked. When considering your responses - perhaps realise the not everyone is as lucky to be so experienced or as gifted a bike fettler as yourself.
I took it my LBS in the end. They adjusted the front mech fractionally. It now works.0 -
There were plain and simple questions if you read back through the thread, you didn't answer them.
Setup then!Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.0 -
Chunkers1980 wrote:why shouldn't you use small small. Sort of pointless going 2x then.
I think it mainly applies to 3 piece, 2x and 1x should be fine surely? The crossing is no where near severe.
On my 3x8 I pretty much have it in 2 90% of the time and use almost the full range in the rear, if I am in granny I only use the 3 biggest rear cogs.0 -
The Rookie wrote:There were plain and simple questions if you read back through the thread, you didn't answer them.
Setup then!
It was always going to be set up wasn't it? I just needed to know how to make the adjustment.0 -
Gibbo3771 wrote:Chunkers1980 wrote:why shouldn't you use small small. Sort of pointless going 2x then.
I think it mainly applies to 3 piece, 2x and 1x should be fine surely?.
That's exactly what I said0
