Kush Sprocket

I know there is a lot of debate out there if it is neccessary to use cushioning devices on dual sport bikes. I ride a 2006 KTM 525 EXC mostly on the road. The bike has a 160 rear tire on it. Because I tend to err on the side of caution, I decided to try a Kush Sprocket. So far after around 300 road miles, I am very pleased with the results. The bike doesn't seem to jerk as much when getting on and off the throttle and the sprocket looks the same as when I put it on. I will update this thread thoughout the summer.

I learned about the product at:

http://kushsprockets.com/sprockets

That subject is always in the back of my mind when we hit extended sections of pavement connecting riding areas. I've always wondered how many miles a standard dirt bike transmission can withstand without doing any damage. Or is it only an issue if you are hard on and off the gas like the SM guys?

The Cushdrive is a good idea for road use. Your clutch probablt already incorporates a rudder or spring damping system, but virtually all bike designed for road use use a cushclutch AND a cushsprocket. It helps reduce shock to all components in the drivetrain. The harder you are on/off the throttle, the more critical it is.

Just installed one today on my dualsport KDX. I tightened the sprocket bolts to 32 N.M./ 24 ft-lbs along with blue loc-tite. I'll wait till tomorrow install a new X-Ring chain, test it out, and report back. I thought it would weigh more but was pleasantly surprised. I lubed up the axle with a little bit of Bel-Ray waterproof grease.

Did you by any chance actually weigh the sprocket? If so, how many teeth on the sprocket?

Did you by any chance actually weigh the sprocket? If so, how many teeth on the sprocket?

I just weighed my 47T Kush Sprocket and it weighs 1 lb 11 oz (27 oz).

Just for a reference, my 48T KTM Alloy sprocket weighs 10.6 oz.

Michigantrailrider

Thanks for the info. My 48T SuperSprox (Stealth) composite sprocket weighs 26 oz, so 27 oz for a 47T Kush sprocket isn't bad at all.

That's interesting they are that close in weight.

Took it out on a 19 mile road ride. While the seat feels smoother, I'm now noticing the vibration in my grips (it's still a 2 stroke). Hopefully it's the last sprocket I buy for years to come. Just having the Kush allows for peace of mind on and offroad.

I have emailed them several times and always gotten a quick reply. I asked about making the outer sprocket out of the 7075-T6 also but he has said maybe in the future, they are just keeping up with their orders now. I would still like to see an all aluminum version because that would keep the weight down and their $85 price tag is reasonable for the trick technology when compared to good quality aftermarket aluminum sprockets. I just don't want to accept the 1 pound weight penalty and have had good reliability with 7071-T6 sprockets in the past.

Swiss

Just curious Swiss, what kind of riding do you do? I ride for fun so the 1 pound difference is pretty much a wash for me. I think it would be quite a challenge for them to make the sprockets out of aluminum due to wear on the joint where the two sprocket sections rotate.

Never rode a bike with one, but the reviews claimed that you get a longer gearbox and chain life, smoother shifting...think i will stand by the sideline and observe for while before I commit.

Michigan,

I also ride for fun, mostly Mountain trails and Desert. The "joint" that you are talking about is separated by the cushion material where the sprocket and the carrier touch each other and by the cushion seal and ceramic balls where they rotate against each other. If there would be any wear then it would happen on the carrier anyway with their normal aluminum steel combination but it doesn't. Most of the better aluminum sprockets are made from 7075-T6 and have been for 30 some years. Bad alignment or lack of lube will destroy a rear sprocket fairly quickly. Admittedly quicker on the Aluminum than the Steel but damage to both. Old stretched chains, same thing.

But you are looking at the whole "just 1 pound" issue. Well, while possibly more critical on a MX bike being ridden at full race pace it is still unsprung weight which does affect the suspension compliance when riding at almost any pace. Saying "just 1 pound" is a tough one for me, I count ounces and they do add up. Just 1 pound here and there is why a Honda 250 CRF-X weighs 253lbs Factory listed wet weight compared to 227lbs for the CRF-R model. Just a few ounces here and a pound or so there and the lighting/battery and suddenly 26lbs is added on. The battery and electric start and headlight aren't making all of the difference. Ounces here and pounds there. Personally I like the weight of the MX model a lot better than the Enduro X model. When I built my XL350 based Enduro/Trail bike back in '74/'75 I had it at about the same weight as the new CRF250-R model. That would have been about 228lbs with 1.5 gal. of gas compared to the new 250 Honda at 227lbs. As the years have gone by I have improved the suspension travel from the old 7"f/6"r up to 12.5"f/12.5"r and the weight has remained the same, within a pound or two. Right now I am working on pulling some "extra" weight off to see what I can get it down to. It is easier to both ride and pick up when it weighs less, regardless of where the weight is located.

I need a cush drive sprocket and would love the Kush version, but with the sprocket being 7075-T6 rather than the steel.

XL400-3.jpg

The bike at 403cc and about 40hp as I built it back in the '70s.

XL486-2.jpg

Same bike 20+ years later. Same frame, same basic engine (486cc and about 50hp), same weight.

Swiss

Swiss, thanks for sharing the pics.

I wasn't talking about the area where the dampening material is located. The area where the ceramic balls ride is the area where it seems likely wear would occur. You can easily heat treat steel to reduce wear in this area.

I do like the idea of riding the lightest bike possible. I like my YZ450F in the woods, but I also like the idea of having extra fuel capacity and street legal lighting both of which have added weight to the bike. The pay off for the extra weight is the fact that I can ride more miles without being concerned about running out of gas or getting stopped by the law when I need to hit the road to find gas or another trail.

Bottom line, I guess we all have to individually decide what it will take to maximize the fun we have on our bikes.

Thanks for the reply.

Never rode a bike with one, but the reviews claimed that you get a longer gearbox and chain life, smoother shifting...think i will stand by the sideline and observe for while before I commit.

I'm glad you are going to observe before you commit. I think that is what is so good about TT. I've learned so much on here and I thought maybe this thread would help others do the same. Since I started this thread, I've put over 200 more miles on the sprocket so I now have over 500 miles on the sprocket and it stills looks new.

Thanks

I just wanted to mention, I now have over 1,000 miles on the Kush Sprocket and it still looks and functions like new.

Does anyone have a picture of this sprocket ? The web pictures site are very vague

Does anyone have a picture of this sprocket ? The web pictures site are very vague

If you go to Google Images and search Kush Sprocket, you will find some pictures of the sprockets as they are shipped and on bikes. I hope this helps.

Just to update everyone, I now have over 4,500 miles on my Kush Sprocket and it still looks and functions like new. In fact, I am getting ready to replace my tires as the sprocket outlasted a pair of Avon Distanzias.

If you go to Google Images and search Kush Sprocket, you will find some pictures of the sprockets as they are shipped and on bikes. I hope this helps.

Just to update everyone, I now have over 4,500 miles on my Kush Sprocket and it still looks and functions like new. In fact, I am getting ready to replace my tires as the sprocket outlasted a pair of Avon Distanzias.

Did it help your chain life as they say it would?

I do a lot of clutch up to the BP wheelies. Do you think this will has any influence on this sprocket life?

Edited by crazy_dave

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