Bigger chainring

[Giff]

If I go to a 38t chainring from a 34t to move into the larger, lower sprockets more often, do I need to add 4 extra links to my chain length?

 

[MrPeaski]

I would think you would need to add some links, but first make sure you can actually get a 38 in, it may be too close to the chainstay for comfort.
Follow this link to get chain ring diameters and see what would fit comfortably
Chainring Diameter by Tooth Count

 

[MrPeaski]

What the above table shows is basically for every 2 teeth you need at least an extra 5mm of clearance between the chainring and the closest part of the chainstay.
i.e to go to a 38 you need at least 10mm of clearance between the current 34 and the chainstay.

I'd also check that it doesn't decrease when the suspension goes through its travel

 

[Giff]

Great advice thanks. I will check it out. G.

 

[Voluptua]

Clearance issues aside - since the chain only runs around the front half of the chainring, you'd expect only two extra links required.