My freehubs are Shimano and they far outlast my chains. The rear derailleur and shifting play a part in shortening chain life. Since I have removed both derailleurs, I am seeing longer chain life. I had a talk with Staton, Inc about what options there are for switching to just a little bigger chain than the 9 speed chain.
See Staton, Inc for these chains and full width #415 sprockets
http://www.staton-inc.com/store/index.php?p=product&id=1752
By chain numbers forget about using #25, #35 and 219 GoKart Chain as these are high speed precision chains and would be derailed easier than standard bike chain when debris get on the chain and breeches the chain pathway to the sprockets.
By ascending width the #40 chain series, which would all have the same pitch -- meaning they will fit the teeth spacing and depth of a thin bike chainring but as the chains get wider a wider sprocket can be used.
1. 12 speed chain
2. 10 speed chain
3. 9 speed chain
4. 5 -8 speed chain
5. The standard 1 speed chain, which is the #410 chain.
6. The KMC #410 HD chain has bigger side plates than the standard one speed chain.
7. The KMC #415 HD chain.
8. Some of kid's motorcycles use a #426? Chain which is quite wide for fitting in the space of the double chainring at the BB.
I decided to try the 415H chain and when it arrived its size seemed quite large but once it is on the bike it looks like a good heavy duty set up. When using the #415 series which has an internal width of 3/16" the standard one speed chain rings 1/8" will fit the chain pitch but there will be some sideways play unless you get wide enough chainrings. When the Cyclone steel chainrings are bolted together with one milled face to the inside, the combined tooth width will snugly fit into the #415 chain.
A set of 2 Cyclone chainrings, when mated, do not always have a 104 BCD pattern that aligns precisely with the rings teeth so I clamped the #415 chain around the 2 ring set and drilled out the 2x 4 holes of the 104mm BCD pattern to 25/64" which gives a very tight fit with the metric female chainring bolt part.
The chainrings are attached to the freehub using the adapter sold by Projection racing of GB.
The chain combination as seen from the underside of the BB
The bigger #415 chain needs a chain tensioner wheel larger than those used with 10 speed chains.
As seen from the rear
So far the quieter setup has been working fine. But now the weaker link in the drivetrain is the freehub.