# Q for technocrats

Discussion in 'Bicycle Mechanics and Repairs' started by ozboz, 14 Jun 2018.

1. ### ozbozÜber Member

Location:
Richmond ,Surrey
Hi , I have just had a 10 speed 11-36 cassette fitted to back wheel , so I need to have a longer chain , Ive worked it out by numbers ;

Length of chain stay. 15.75 x 2. 31.5
Teeth on large CR. 52. /4. 13
RC large ring. 36. /4. 9
+ 1. 54.5
So chain should be 54.5’’.

I don’t want to fit new chain if it’s wrong length

Any one see a problem here ?

2. ### CycleopsGuru

Location:
Accra, Ghana
That's the mathematical method. You can cross check by using the physical calculation, big cog to big cog omitting the RD plus two links I think, or is it one?

3. ### ianraukTattooed Beat Messiah

Location:
Atop a Ti

I use the 2 method (1 Link pair)

Location:
Atop a Ti
5. ### raleighnutGuru

Location:
On 3 Wheels
^^^^^^^ same for me.

6. ### bpsmithVeteran

As above. Works for me every time and very easy to do.

7. ### mjrComfy armchair to one person & a plank to the next

And what's more, it still works if your bike shrinks because you ride it in rain!

Dogtrousers likes this.

9. ### pawlVeteran

One if using a master link

Cycleops likes this.
10. OP

### ozbozÜber Member

Location:
Richmond ,Surrey
Hi all ,
Well , all went well !
Judging by the gap between the jockey and 36 cog the Wolfs tooth has done its jo b well , I’ll be looking at getting my Surly upgraded also now ,
I went with the numerical method , as a person who has Dyscalculia numbers are my Achilles heel , but with a tape and calculator , easy peasy !! even for me !!
I did check it out with the app @Smokin Joe posted , there was a 1/2’’ difference , but that was sorted ,

Last edited: 15 Jun 2018