New Chainrings... and now the chain gets stuck

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My 8 year old Shimano Sora chainrings were getting a bit knackered, so I decided to get new ones. With the intention of saving effort (yeah right), I went to a local bike shop.

He got me some new chainrings and fitted them, along with a new chain and cassette. The chainrings are Stronglight 5083 and 7075 types.

I went out today, and upon changing gear to go up a hill, the chain became stuck in between two rings. I couldn't pull it out, so I had to remove the chainrings in order to free the chain. I've never had this happen in all the years I've had the bike.

I've now been adjusting the gears, and I notice that the chain is a bit prone to getting a little bit caught in between two rings. I never noticed this on the old Shimano rings. And the gears don't shift as well.

Any ideas? Only thing I can think of is that the chain and cassette are 10 speed ones, and the Shimano Sora crank is designed for a 9 speed system. I notice that a piece of 9 speed chain is too thick to become jammed in between the rings, but the 10 speed chain is just the right size.

Thanks
steve30
 
My 8 year old Shimano Sora chainrings were getting a bit knackered, so I decided to get new ones. With the intention of saving effort (yeah right), I went to a local bike shop.

He got me some new chainrings and fitted them, along with a new chain and cassette. The chainrings are Stronglight 5083 and 7075 types.

I went out today, and upon changing gear to go up a hill, the chain became stuck in between two rings. I couldn't pull it out, so I had to remove the chainrings in order to free the chain. I've never had this happen in all the years I've had the bike.

I've now been adjusting the gears, and I notice that the chain is a bit prone to getting a little bit caught in between two rings. I never noticed this on the old Shimano rings. And the gears don't shift as well.

Any ideas? Only thing I can think of is that the chain and cassette are 10 speed ones, and the Shimano Sora crank is designed for a 9 speed system. I notice that a piece of 9 speed chain is too thick to become jammed in between the rings, but the 10 speed chain is just the right size.

Thanks
steve30
9 speed crankset and 10 speed chains can cause issues, as you’ve just discovered.
 

Ajax Bay

Guru
Location
East Devon
the chain and cassette are 10 speed ones, and the Shimano Sora crank is designed for a 9 speed system
To be clear, Sora is a 9 speed system and the rings you've had procured and fitted are suitable for either 9 or 10 speed drivetrain. Have you 'upgraded' the Sora STIs, cassette and chain to 10 speed in the past?
A 9 speed chain width (outside dimension) is about 6.7 mm and for a 10 speed chain it's 5.9mm. The chainline difference between the two rings (correctly fitted) is 5mm (so less than that between the inner face of the outer ring and the outer face of the inner ring). If the OP has managed to get a 5.9mm chain stuck between his two chainrings, there's something awry - as @cyberknight has suggested.
 
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OP
OP
steve30

steve30

Veteran
Yes, I changed to a 10 speed cassette and 10 speed shifters some years ago. I just retained the original Sora chainrings/cranks.

Thanks for the replies.

Here's a picture in case anyone in interested.

chainrings_rule.JPG
 

davidphilips

Veteran
Location
Onabike
looks like you with have to get another chainset, secondhand from ebay may be best value? You could if you fit a double 10 speed as long as you dont need a very low gear. when that chainset is removed it may be a good time to give the bike a good polish.
 

Ajax Bay

Guru
Location
East Devon
Changing the crankset is unnecessary - and why would you want to lose the benefit of a triple? The dimensions of the crankset where the large and middle rings bolt on (together) (5 bolt and assumed 130mm BCD) will not be different on a (new to the OP) '10 speed' crankset. To try and determine why the chain can fit/jam between rings, the OP needs accurately to measure the distances between the large and middle and middle and small rings, and make deductions from that. Edit - having watched video (part). Get one (or 5) replacement chainring bolt/nuts. More of a chance that the chain will jam if the rings are not secure and therefore the gap between them varies.
ETA: https://www.planetx.co.uk/i/q/CSBFSA4/chainring-bolt-set-for--4-bolt-chainset
 
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