Sprockets JT vs Sunstar

Status
Not open for further replies.
Joined
Dec 23, 2009
Messages
5,653
Location
Central IA
Hey, just looking at doing a sprocket swap on a 99 Magna 750 for a friend. She bought it and the guy geared it for more acceleration, but it is getting horrible mileage now since she rides in out of town a lot. Got a new x ring chain for it, but I see that JT and Sunstar both make a decent selection of sprockets for it. Anyone ever have a bad experience with either? Looks like JT makes a few more options, but I thought Id see who here had some experiences with them on bigger bikes.
 
I am not liking the 17-tooth JT front sprocket that I got for my Vulcan. It dropped the RPMs as it should have (factory sprocket is 16T), but it causes more drive train noise and results in more vibration that can be felt through the footpegs. The JT one does not have rubber dampers built into it like the factory sprocket does. I am going back to the stock sprocket next week.
 
I have used both on smaller 250 cc bikes. The current ones on this bike are sunstar. I was also thinking of going up a tooth on my front sprocket on my Triumph.
 
I have used them both in big bikes and had no trouble with either. Both went over 20,000 Km with and x ring chain which is good considering these bikes produce 165-185HP right out of the box.
 
The biggest problem with cheap sprokets is not being tapered to allow smooth engagement of the chain. Some have a 90º angle between the side and the tooth tip and results in noise, and if not aligned can actually pull the counter shaft out of the case. You'd think it would break the chain first, but not in my experience.
 
On one of my bikes I went up 2 teeth to 16 on the front sprocket(that is the same as taking 7 teeth off the back sprocket 14/48) and my rpm's went down as did any vibration I had in the foot pegs and handle bars. My gas mileage went up but I could not accelerate as fast in 5th gear(that is why they put 4,5 or 6 gears in bikes) All I had to do was down shift and off I would go.

ROD
 
Sunstar is an OEM manufacturer, JT is not, while JT may be okay I've seen instances where they are not machined properly.

If you want precision guaranteed, SUNSTAR
 
i've run sunstar. pretty decent. now i only run Ironman (also sold as MSR heavy duty) but they are not for all bikes make/models.

and of course part of keeping a sprocket alive is making sure the chain is perfect. which is its own can of worms.
 
Normally Id swap the chain as well, but it has SUPER low miles on it. I think I will try the Sunstar and if its not enough for her I can drop a few teeth on the back with a JT.
 
Originally Posted By: Quattro Pete
I am not liking the 17-tooth JT front sprocket that I got for my Vulcan. It dropped the RPMs as it should have (factory sprocket is 16T), but it causes more drive train noise and results in more vibration that can be felt through the footpegs. The JT one does not have rubber dampers built into it like the factory sprocket does. I am going back to the stock sprocket next week.


I had the same experience with aftermarket sprockets. I went back to oem because of the rubber damper. It does make a difference if you spend a lot of time on the highway.
 
Most the rubber damped OEM front sprockets are made by Sunstar, if you buy a generic sunstar it wont have the rubber dmaping.

Personally I always bought the oem fronts, and after market rears. I ran aluminum rears for 20 years. I went back to steel and the longevity is Five fold over aluminum, Like that iron man Sunruh mentioned.

But the weight savings of aluminum is not worth it, the longevity and your pocketbook will be alot happier with steel.
 
yeah i run oem fronts and high quality steels back.

i can put 3 - 4 years of racing on a ironman rear where alum is about 1/2 a season. oh and get any kind of dirt/grim/mud/sand on alum and its toast!
 
Originally Posted By: Mackelroy

Personally I always bought the oem fronts, and after market rears.

I just looked into availability of an aftermarket rear sprocket for mine. Sunstar doesn't make one. Neither does AFAM. JT may be the only option...
 
I took a look at the Sunstar site on the Vulcan, and yep only seem to make the Front sprocket. I guess stock rear is just a 3rd party stamp out, when you take it off see if you can find a name on it.
 
I will say that on my Yamaha Virago XV250 I had to use a Sunstar front and JT rear to get the setup I wanted. So far on my small cruiser, which does not see any abuse, the JT holds up well enough over the 5k miles thats on it. I like it cause its blackened steel so it doesnt look as dirty with all the chain lube all over it.
 
Last edited:
Status
Not open for further replies.
Back
Top