I wonder, if Honda were to use the new XR650 engine in a quad would the stock motorcycle gearing be good for an ATV? From what I've read in these forums it seems like Yamaha and Bombardier could have done a better job with the transmission gear ratios in the DS650 and Raptor. Does anyone know if the motors in those quads use the same gearing as they use in motorcycle form? Did Honda change the ratios in the XR400 motor for use in the TRX400EX?

 

Yes, honda changed the gearing from 15/45 on the xr400 to 15/38 for the 400ex. The 400ex looses the higher rpm cam and gets more of a "torquer" cam to pull the extra weight around. If Honda would ever come out with the 650ex (and they won't), it will be conservatively geared like the Raptor. The Raptor got almost "street-bike" overall gearing. Why? Anyone over 16 years of age can ride and more conservative gearing helps keep acceleration numbers down and unexperienced riders are less likely to get hurt. Just my opinion!

 

Thanks for the reply Garyc660R. I was thinking about the gearing in the tranny too: 1st, 2nd, 3rd, 4th and 5th. I wonder if the atvs are using the same internal gears as in the motorcycles that the motors were originally developed for.

 

I think that he's right, otherwise the 400EX and the Raptor would have had 6th gear. Of course I don't mind much, I rarely use all of fifth gear, too scary thinking about hitting a tree at 75!