12-25 to 13-29 longer chain?

[mikewill53]

Hi,
Im hoping someone can help. I bought a bike with a 12-25 cassette and a standard crankset. I changed the crankset to a compact so I shortened the chain... I've just upgraded to a 13-29 cassette. It changes gear fine on my bike stand but I was wondering if its best to lengthen the chain?
Regards
Mike

 

[Nigelnaturist]

Run the chain over the large front and large rear without going through the RD, you should have an overlap of one link, for the chain to be the correct length.

 

[raleighnut]

^^^^ Wot he said.