I bought a serp belt 9186352 from Tasca maybe 3 years ago and it was longer than the original 1995 take off(i never discard old parts). I double checked the tasca web site then and that was the only belt shown so I put it out of my mind. I checked that old belt and finally got a number off it 9146557, and it's seems to still be available. I put 9146557 in tasca and it comes back with a serp belt and it says it fits my 95 volvo. There is also a hyperlink there for 'belts and pulleys' and when i click on that i get a diagram with more parts but this diagram lists the proper belt as 9186352. Now the longer belt gets a different routing so it can wrap around the alternator pulley more and get a better grip. Implied is the longer belt and new routing is the way to go and fortunately I think the idler and alt still turn the same direction. Anybody have the scoop? The belt on the car I haven't taken off yet, the dealer put it on in 2005. It has what is considered the short belt routing. Here is Robert with some more info. What OEM belt is in your VOlVO? Did you change the routing? I bet using the longer belt with the short routing would not work.
https://www.youtube.com/watch?v=vyoNw8B6QWM

BTDT. The longer belt will not work on the same routing as the old, shorter belt. Confused me, thought I had the wrong belt until I bothered to check on the routing. I had no drive belt problems before or after.

Don't second guess the longer belt/new routing. Volvo wouldn't have gone off and changed it just for nothing. Plus you've got that one in your hands right now.

I had to soap it to get it to slide over the idler pulley. When I released the tensioner - it only kicked back 1/4 inch. Well maybe the belt will stretch a bit. I'll have to call it a success unless something blows up when i fire it up. I manually put a 30mm on the crank bolt and turned it through 2 compression strokes (i.e. not much).

When you say short belt routing - do you mean really short, eliminating the AC compressor?

I got my really short belt from IPD, I think that they had several routing diagrams.

I think that your new belt is probably made of EPDM which does not crack, they wear out like tire treads and you need a gauge to tell when they are worn out. Gates was offering a free gauge.

Robert explains it all.

https://www.youtube.com/watch?v=vyoNw8B6QWM