Hi, Bill. Here's my thinking on comparing the RE (Royal Enfield Bullet 500) to the S40.
MSRP difference around here is about 1100$. It would cost me that or more to modify an S40 into a standard (see
www.rycamotors.com for a kit price list).
A drag race between an S40 and a RE would be interesting (and perhaps a little laughable given the laid-back character of both bikes) --
Suzuki claims: Torque @ RPM: 45.5 Nm @ 3400 rpm. Horse Power @ RPM: 31 hp @ 5400 rpm
RE claims: 41.3 Nm @ 4000 rpm, 27.5 BHP. Advantage S40 by about 10% on both measures.
Suzuki says wet weight of the S40 is 381 lbs versus 412 for the RE. Advantage S40 by 31 lbs or 8%.
With these figures I suppose the S40 would edge out the RE in the quarter-mile, but not by much.
My bet would be that with riders of equivalent skills that the standard RE would leave the crusier S40 behind in the curves.
As for build quality, the Indians ditched the old tooling they got from the British and are using the latest methods to make their new unit construction engine. I hear that they are outsourced to make engines for Japanese clients! They back it up with a 2 yr/unlimited miles warranty. That's better than Suzuki's for the S40. Time will tell with the new RE engine.
However the S40 still has the cam chain problem it has had since 1986. The new RE engine uses hydraulic lifters (no valve adjustments) with pushrods (no cam chain issues). The RE is fuel injected, while the S40 still has a carb. Both bikes have front disc brakes and electronic ignition and 5-speeds.
S40 gets about 50 MPG. RE claims 85 MPG, probably really about 70 MPG.
I'm not saying the RE is clearly superior to the S40, but it may be a reasonable alternative offering a standard riding position.