How many extra links to start with for the chain (11 speed)

[mooboyj]

Howdy,
I'm going from the following on a Santa Cruz Tallboy LT:

32 tooth chain ring
11-42 cassette

to

30 tooth chain ring
11-50 cassettee

How many extra links should I start with?

 

[beeb]

What drivetrain? Shimano 12sp has extra links compared to 11sp and earlier...

 

[moorey]

Appears going from 11 to 12.

 

[Daniel Hale]

don’t you wrap around the 50t, and the front chain ring & add 2?

 

[creaky]

Don't assume the previous chain length is the right 'baseline' for calculating the length of a new chain. RD cage length has an effect also.

Measure it as per the manual, drop your shock off one mount and compress the suspension to check clearance.

Assuming shimano ... page 10

https://si.shimano.com/pdfs/dm/DM-MARD001-00-ENG.pdf

 

[moorey]

don’t you wrap around the 50t, and the front chain ring & add 2?

Not taking Derailleur into account?

Bloody single speeders.

 

[Daniel Hale]

Not taking Derailleur into account?

Bloody single speeders.

that’s what the add 2 is for, but yes ss chains are much easier to work out

 

[SummitFever]

Not taking Derailleur into account?

That's what the extra 2 links are for.

However, with the bigger jockeys wheels on the 12 speed RDs and the chain growth possibilities with full suspension, I'd start with an extra 4 links and drop down if the chain is too slack in the smallest cog on the rear.

 

[moorey]

That's what the extra 2 links are for.

However, with the bigger jockeys wheels on the 12 speed RDs and the chain growth possibilities with full suspension, I'd start with an extra 4 links and drop down if the chain is too slack in the smallest cog on the rear.

I interpreted Dan as looping 50t and front ring without Derailleur.

 

[stirk]

@mooboyj don't forget derailleur size!

Heaps of info on the web's and it's the one task I've not fucked up.....yet, you'll be right.

 

[SummitFever]

I interpreted Dan as looping 50t and front ring without Derailleur.

Yes indeed. No derailleur involved.

 

[moorey]

Yes indeed. No derailleur involved.

I say 2 links is no where near enough. Even without chain growth it’s too short.
I don’t believe there’s a one size fits all formula.
I fit them to suit the bike, it’s drivetrain, and it’s chain growth.

 

[mooboyj]

Ninja edit, it's 11 speed.

I think 4 extra links would be the place to start?

The current setup shifts faultlessly and is actually really nice, but Tassie and ageing legs...

 

[mooboyj]

That's what the extra 2 links are for.

However, with the bigger jockeys wheels on the 12 speed RDs and the chain growth possibilities with full suspension, I'd start with an extra 4 links and drop down if the chain is too slack in the smallest cog on the rear.

4 was my guess as well. Or 143.54 cm according to one of the formulas I found.

 

[ozzybmx]

Wrap it around on your biggest rings, pull the chain together till it looks like this. Once fitted, check it in the smallest cog.

Sometimes I go at it again and remove 2 more links till its right.

Straight from Parktool website. https://www.parktool.com/blog/repair-help/chain-length-sizing

 

[Nambra]

Wrap it around on your biggest rings, pull the chain together till it looks like this. Once fitted, check it in the smallest cog.

Sometimes I go at it again and remove 2 more links till its right.

Straight from Parktool website. https://www.parktool.com/blog/repair-help/chain-length-sizing

View attachment 359919

And don’t forget to fit the reflector...

 

[ozzybmx]

And don’t forget to fit the reflector...

What ! no dinner plate between the cassette and spokes

 

[Dales Cannon]

4 was my guess as well. Or 143.54 cm according to one of the formulas I found.

Yep that will be enough slack to start with.

 

[Nambra]

What ! no dinner plate between the cassette and spokes

Too much rotating mass man, you should know that!

 

[The Duckmeister]

don’t you wrap around the 50t, and the front chain ring & add 2?

Dumb way of doing it. Doesn't allow for chain growth, nor does it allow any tolerance to increase either chainring or large sprocket.

Better way is chainring & small sprocket, through the derailleur (which is at its most retracted at this point), and pull just enough tension so there's no contact between free chain & the wrap around the top jockey wheel - I usually aim for a finger thickness gap. If there's a possibility you'll change to a smaller ring at some point, cut two extra links off. This method allows scope to increase things as well, and allows enough tolerance for chain growth.