I'm so glad that Beta has decided to provide us with both the 15T front sprocket along with a 13T sprocket for the RR-S'. I don't know if they do this for any other bike but thank goodness they do. Here I was, thinking that the stock 15T and whatever the rear is, 48T?, would work and that I could easily make it work, I was wrong. 15T is indeed too tall-or is it short?, for a lot of the trail riding that I do where there may be steep hills or tight turns. I had learned it the first time I got into some tight trails the first day I got the bike off road but thought that it was because I was new to the bike, that once I got used to it I'd easily overcome whatever the gearing was. Even at my brother in law's farm, where he had a switchback road carved into the side of a mountain, the very steep parts needed a bit more wheelspin and throttle than I thought necessary, then this past Sunday, the gnarliest patch of land that we had ridden on for years, proved that I needed to try the 13T front sprocket. Thankfully the sprocket bolt came off with no trouble, I just had to put a stick in the spokes to get the sprocket to not turn. There was no so much slack in the chain I had to move the adjusters way out. I also learned that only one big nut on the rear brake-side needs to be loosened and that the adjusters are a 10mm and a 13 mm, I think the nut is a 24mm. The sprocket nut is a 17mm. As soon as I let the clutch out for the test ride, I knew that I'd stick with the 13T. Even on the street I didn't notice a difference at least while riding like I normally do on the street, it was when I tooled around the yard was where I found that I could creep up to the small hills and even the angled curbing and with no clutch or mad throttle, I could simply twist and go, no need for any clutching or picking up speed before hitting anything to go up and over it. Nice. With the 15T it was a lot more busy and way more clutching and speed was needed and I definitely didn't like it. I almost never used 6th gear on the street or anywhere as by the time I'd get up to 60+ MPH, the bike would be shaking so bad that I'd never touch the gear. Now I think I'll use it and be happy with the speed.