Sunstar is the largest OEM supplier of motorcycle and all terrain vehicle (ATV) sprockets and brake discs in the world. In fact, if you’re on a Japanese machine most likely it came from the factory with Sunstar. Sunstar offers the Works Triplestar combination that is lightweight, looks good, and from what I found out recently, is pretty damn durable for an aluminum sprocket. Since Sunstar sprockets came stock on our YZ450F and I’ve had great luck with them, I thought why not try out their Triplestar sprockets, to see how long they last.
The one problem about aluminum sprockets is they simply don’t last long right? I have tested Renthal aluminum sprockets in the past that have broke teeth within 4 engine hours. That’s not acceptable! I am also a firm believer of when your sprockets get worn out and its time to change them, it’s also time for a fresh chain, so make sure to try and always change the whole drivetrain at the same time. This test isn't a big elaborate techy kind of test, but more of a testimonial of what I thought of the Sunstar sprockets. It’s not easy to talk about a sprocket, so let me just tell you how long it lasted and give you some other food for thought.
I am lucky to get ten engine hours on an aluminum sprocket out here on the west coast so changing out my drivetrain every couple weeks is the norm. Yes, I can ride up to ten engine hours every 7-10 days. Shockingly, I have just over 16 engine hours on this Sunstar Triplestar sprocket and it looks like this (see above). Not bad right? The Sunstar quality has been superb and when I told the guys over at Sunstar that I was shocked on how good the sprockets were, they acted surprised that I was so shocked. I know Sunstar comes on a lot of production machines, but in the racing world they’re not as prevalent in my mind for whatever reason. I kept the standard 13/49 gearing on the YZ450F and haven't had an issue with the Sunstar Triplestar sprockets breaking teeth yet. I am very impressed on the quality and durability of the brand.
Now I know most of you are asking yourself “why doesn't he use steel sprockets or at least a Twinring”? I like to keep aluminum on my test bikes because every time I’ve had a chain failure, it has been with a steel rear sprocket. Rear steels are hard on chains, especially if you’re a moto guy, so for my peace of mind, I stick with aluminum. I have ran steel sprockets in the past and although they last a long time, I have snapped more chains running steel sprockets than aluminum, so I choose to stick with the lighter rear sprocket. Mix matching a steel countershaft sprocket with an aluminum rear is not uncommon for me and when doing that steel/aluminum combo, I have experienced zero chain failures. If I was running an o-ring chain on my test bikes, I can run steel rear sprockets with better results. If you’re a off-road guy that rides a ton of mud, this sprocket test may have nothing to do with you. Steel sprockets, o-ring chains, and GNCC type racing is the norm, but for moto what I described above is what I felt.
If you’re looking for an aluminum rear sprocket that has a great lifespan look no further than this Sunstar Triplestar.