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View Full Version : Cush drive vs std drive?



scorry
17th November 2008, 11:16
Im on the lookout for some new wheels for my wr450 but soon to be yz450.

the deal on TM seems to be the cheapest option at 1700 for wheels discs & sprockets

just trying to figure out the advantages of a cush drive vs the std sprocket bolted to the hub.

the cush drive wheels are dearer but i have heard that the std drive is hard on gear eg bolts, sprockets & the hub

wondering if anyone out there has had any probs with std drive breaking anything?

and of course if there has been issues with cush drive too i would love to know too.

thanks heaps

oh and if anyone has some wheels that would fit my yammy please PM me so we can sort out a deal

rudolph
17th November 2008, 11:34
A Cush Drive on a silgle and twin cylinder bike is a bit of a must, I have fitted Harley wheels to my CB900 with out Cush drive with no problems but on a single you might mark or damage the gears?

SeppoDave
17th November 2008, 14:53
Each pulse of a firing cylinder effectively "hammers" all the components of your drivetrain between the crankshaft and road surface to propel you forward (or slow you down). Road bikes and most big enduros will have a cush hub to dampen the effect of the torsional forces generated while accellerating and decellerating, because there isn't much "give" in the contact patch between the tyre and the road surface.

If you didn't have a cush hub, the hammering of the engine pulses would take its toll on the weakest link in drivetrain, which could be any of gears, bearings, sprockets, chains, spokes(yes, really) or tyres. Now, I can't tell you how long it would take to damage these components, but most road bike manufacturers seem to think it's worth it.

In general, most pure dirt bikes have rigid hubs. This is due to the fact that there is always a little give in the off-road traction surface, and at the expense of weight savings, the cush hub would have little benefit.

What about motards? Get to the point!

Pioneers in supermoto were building their racers from dirt bikes, lacing up road rims to their original (rigid) hubs so they could mount sticky tyres. They really didn't have a choice. As the sport gained popularity, more aftermarket parts became available, as well as ready-made wheels with cush hubs built-in. I can only assume that the reason there is still a debate on cush vs standard hubs is that there are still people in the sport who were around before we had a choice, and they are sticking with what they know.

The manufacturers who sell dirt bikes in a motard form like KTM, Husky, Aprilia, and Husaberg all offer cush drives on their road-registerable motards. I can't say for your Yamaha, but you'll probably have to go to the aftermarket. You might investigate if the XT660x or XT250x rear wheels have cush hubs, or if they would fit your 450.

Apologies for the long-winded response!

Dave