I've seen a few posts about gearing and torque calculations but I figured I would bring it up again.
This time around my hypothetical scenario is optimizing top speed for a straight, the one i have in mind is about 1/2 mile at NCBIKE but that's just because I'm going there in a few weeks.
I've been running Bike plus rider characteristics through a program I wrote back when I was on BOLT and I'm getting the following things using all the ratios from
http://brammoforum.com/index.php?topic=2642.msg19791#msg19791Top speed is typically drag limited somewhere between 7 and 8k rpm due to the torque drop off.
Stock gearing:
5th gear: or eqiv 6th gear with 42T rear
Top Speed:113 mph
70-112: 13.52s 750 m (.468mi) sort of using this parameter as a high speed corner exit onto the straight.
6th gear:
Top Speed:121
70-112:11.95s (on a .5 mi straight it would make sense to shift to 6th at 6krpm because it will improve your speed in that distance)
70 to top speed 1498 m (.936 mi)...basically not going to hit top speed unless you're at Daytona
-2T 6th gear (36T)
Top Speed:123 (PWR LIMIT)
70-112:11.64s (same as above this slightly helps in the .5 mi straight but we're starting to get drag limited)
70 to top speed 1521m (.95mi)..again not really relevant because of how long it takes
I'm sure my Cd and Af #'s arn't entirely accurate but I'll try to derive some better #'s from my data logs at NCbike.
My conclusion is that at least for a decently long straight I'm staying with the stock gearing for the time being. For a 1/4 mi straight I might not come out of 5th. For those people that have gone to the 42T rear how has that been?
