Originally Posted by
toast2266
Like grskier said, very much depends on the bike. But plenty of bikes have a leverage ratios somewhere in the neighborhood of 3:1, meaning 5 mm more stroke would add something like 15mm of travel. And assuming your eye to eye isn't changing, that extra 15mm is coming at the end of the travel. For non-high pivot bikes, the arc the wheel is following is going substantially forwards at the end of the travel, meaning there's a pretty good chance you'll run into clearance issues between the tire and the seat tube (or worse, a seatstay brace and the seat tube).
For something like the 130 LR, that bike gets overforked (10mm longer than the regular version). So a 2.5 mm longer stroke shock more or less matches the increase in travel at the front. The frame is exactly the same (and obviously has the clearance to accept the additional travel). Worth noting though that the longer fork slackens the bike a bit and raises the BB a few mm, which plays nicely with the extra travel in the back.