Hi all, I'd like some advice on the correct belt size for a 19% reduction pulley on my R53. The original belt went 1 month ago and I've been using a JCW ~11% (6K1374) with an Alta adjustable tensioner to keep me on the road until I can order the correct belt from OS.

Its arrived today from a 3rd party supplier here in Australia and is as follows: Gates K060539 (6PK1370) the label states: Sc Pulley Belt for 2% Crank pulley w/15% or 17% Sc Belt..... this reads to me as a 17%?

Before I put it on I'd like to check if anyone here has had expirence with this belt on a 19% pulley? Or is the Gates K060535 (6PK1360) the correct belt for my setup?

Also, all other pulleys in config are stock.

 

I use Gates K060532 on a 17% SC pulley with all other pulleys stock. It was a tight fit getting it on there when new, but has given no trouble yet in 3-4 months.

 

OK based on advice from Alta to my supplier the 17% belt be fine to go on a 19% pulley???. I'll be testing it out in the coming days and hopefully no squealing

Given the rarity of 19% pulleys in community, has anyone put a 15% belt on a 17% pulley and did it squeal?