loose chain only on granny gear?

[moorey]

Cassette isn't an extender, to my eye. 11-34 at best I reckon.

 

[pharmaboy]

Cassette isn't an extender, to my eye. 11-34 at best I reckon.

Sorry, I wasn't clear - I mean the front rings. 24 42 or something . That deraileur can handle any normal 2x setup, but not if he's running something weird like a 24 granny and a 42 big ring

 

[moorey]

Sorry, I wasn't clear - I mean the front rings. 24 42 or something . That deraileur can handle any normal 2x setup, but not if he's running something weird like a 24 granny and a 42 big ring

Sorry. My bad. Recommended 14t max difference in front rings, isn't there? Could be an issue for OP with a middy if so.

 

[pharmaboy]

Sorry. My bad. Recommended 14t max difference in front rings, isn't there? Could be an issue for OP with a middy if so.

14t is correct for front derailleur recomended capacity, but rear deraileurs have a total capacity of I think 37 teeth, so 11-34, is 23, leaving an allowed difference of 14. If it's 36 put back he can go 12 only or 16 at front if it's an 11-32

Fuck me, I have some uselss stuff inside my head........

 

[moorey]

I intentionally deleted knowledge of front derailleurs many years ago. They are dead to me.

 

[pink poodle]

Au contraire, looks like only 11-34t to me.

Cassette isn't an extender, to my eye. 11-34 at best I reckon.

34 is huge in my world...23t is maxxxed out.

I intentionally deleted knowledge of front derailleurs many years ago. They are dead to me.

I agree. Front derailleurs don't belong on mountain bikes. Time for 1x9 for minimal cash outlay in this scenario. You will experience minimal loss.

 

[botch]

Its an 11-34 cassette and 24-36 chainrings up front.

I definitely think it has lost something....to me it doesn't look right. I gave my bike a full strip down today and put it all back together, however i haven't put the chain back on as i ran out of my regular cleaner. Once it's on i'll have another look....hopefully it has sorted itself out. If not, i guess i may start looking at a 2x10 setup, assuming i'll need a new derailleur.

Cheers

 

[pink poodle]

1x...1x...1x...1x...1x...1x..1x...1x...1x..1x...1x...1x..1x...1x...1x...

 

[stirk]

1x...1x...1x...1x...1x...1x..1x...1x...1x..1x...1x...1x..1x...1x...1x...

I get it, but it is a sacrifice of gearing range some people don't want to give up.

I needs my granny, sub 1:1 ratio, living in the Blue Mountains with the long steep climbs, I am giving up the high range for the simple 1x lifestyle by gearing low going with a 30T ring.

But my 2x will be missed when going down hill on the trails as I will miss that little extra speed the higher gearing give you.

Need to learn how to spin!

 

[ming]

Maybe it is a Specialized thing. I had a Stumpjumper with 3x9, and could not get a chain length which was safe in big-big and also had tension in small-small. Lots of problems dropping chain in small gears, due to the low tension. Finally worked out that it came standard with a medium cage rear.
Bought a long cage, and problem solved - but why it came with a medium is a mystery to me.

Back to the OP pictures, the chain looks too long to me. In the big-big combo, it is not very tight. Can you undo the top bolt on the rear shock and move the suspension to fully compressed while in the big-big gear. The chain should be almost straight through the jockey wheels.

 

[The Duckmeister]

By the way OP, that isn't "easy gear front and rear". Its actually "small small".

The easy gear front and rear is small front ring and big rear cog.

You shouldn't ever use small small because it has a terrible chain line, and more importantly, the chain tension in that combination is extremely high and it will wear your drivetrain really quickly. That's why its sometimes okay to have a loose chain in that combo, because you should never shift into it.

The bit in bold is completely wrong. There is fuck-all chain tension in small-small, because the rear derailleur is close to its most relaxed state, so isn't doing all that much to apply tension to the chain. The gears can tend to run like shit in that combination due to chain slap from insufficient tension. Any extra wear is due to the relatively few points of chain engagement, therefore each point bearing greater proportional load.

Excessive chain tension and the problems that go with it are found at the other extreme, big-big. The derailleur is pulled hard against its spring, so exerts greater force to pull back at the chain. The greater radii of the front & rear sprockets mean the effective length between the closest contact points is reduced, thereby exacerbating the extermity of the chain angle. This high oblique tension poses a real risk of bendiing the derailleur or pulling it clean off if there is not enough chain length.

It's OK to have a little bit of slack in the small-small gear, because the chain growth in some suspension designs requires it to ensure there's enough chain length to prevent damage in big-big under high suspension compression. It's very rare for suspension to be fully compressed when in that gear, but there are some people who do select gears & ride that badly that it's possible!

View attachment 304665

That's big big and about what it should look like

I would add that's how it should look in big-bigwith the rear suspension in full compression. Stick it in that gear & deflate the shock, then cut your chain to suit.

 

[MARKL]

".............

 

[wkkie]

....also make sure your b screw is pressing against the derailleur hanger properly.

This! I had this problem with my recent build. Only on 1 X up front and spotted the issue early on. It didn't take it sitting out far to loosen the chain up a fair bit.