billmac Posted July 15, 2013 #26 Posted July 15, 2013 This is all rather interesting. I bought a Venture Rear end for my VMax to lose power and gain MPG! hahahaha. Just need to finish fabricating the shock mount................ Should have read about this first then just do an even switch of rear ends with a venture rider looking for a v-max and both would have save money. yesterday on a 171 mile ride I got 47.08 mpg on my RSTD one up.
RSTDdog Posted July 15, 2013 #27 Posted July 15, 2013 There is no affect on the speedometer as both gear sets us the same number of teeth on the ring gear. Mike Correct me if I'm wrong, I haven't had one apart, but it appears to me from the microfiche the speedo sensor is reading off the pinion gear which is splined directly to the output shaft of the engine. The vmax rear means you are turning more rpms for a given speed, so the gear spinning by by the speedo sensor(essentiallya hall effect sensor I guess) is turning faster for a given speed. what am I missing?? Is it enough to make a difference?? Has anyone checked?
playboy Posted July 15, 2013 #28 Posted July 15, 2013 Correct me if I'm wrong, I haven't had one apart, but it appears to me from the microfiche the speedo sensor is reading off the pinion gear which is splined directly to the output shaft of the engine. The vmax rear means you are turning more rpms for a given speed, so the gear spinning by by the speedo sensor(essentiallya hall effect sensor I guess) is turning faster for a given speed. what am I missing?? Is it enough to make a difference?? Has anyone checked? You guys are over thinking this whole thing. Just do it you will love it. The speed pick up is on the pinion but 33 teeth on the ring gear is 33 teeth no matter what your using to turn it. So speed odometer will not change. Yes I have made the swap. I haven't seen any increase or decrease in MPG Just Miles Per Grin. This is a performance modification which happens to give some better MPG's the greatest benefit for me is pulling the trailer and I have no doubt that it lessens clutch wear and fatigue. Take off is so much smoother with or without trailer. When the fun wears off maybe I will make a 70 mph test.
VentureFar Posted July 15, 2013 #29 Posted July 15, 2013 Playboy you are making me grin just listening to your throttle hand grin. VentureFar...
MikeWa Posted July 15, 2013 #30 Posted July 15, 2013 You guys are over thinking this whole thing. Just do it you will love it. The speed pick up is on the pinion but 33 teeth on the ring gear is 33 teeth no matter what your using to turn it. So speed odometer will not change. Yes I have made the swap. I haven't seen any increase or decrease in MPG Just Miles Per Grin. This is a performance modification which happens to give some better MPG's the greatest benefit for me is pulling the trailer and I have no doubt that it lessens clutch wear and fatigue. Take off is so much smoother with or without trailer. When the fun wears off maybe I will make a 70 mph test. Ha ha ha the greatest benefit for me is being able to outpace a 2012 Harley Ultra Glide CVO with a Screaming Eagle 110 on the freeway on ramps. The smile just lasts and lasts. Although I believe doing so does hurt the fuel mileage a bit. Heck I even smile just thinking about it. Mike
Guest tx2sturgis Posted July 15, 2013 #31 Posted July 15, 2013 (edited) The speed pick up is on the pinion but 33 teeth on the ring gear is 33 teeth no matter what your using to turn it. If the speed sensor is reading the pinion gear rotations, and that gear is now turning faster (per given road speed) due to a gearing change in the final set of gears, (pinion and ring gear), then the speed indicated, and the mileage reading, will increase a bit. Its not unlike changing the old style speedometer drive on the old style car transmissions when you swapped out the rear end for a different ratio. (if the bike's speed sensor was reading the ring gear then the sensor would be unaffected by a change in gearing) The bike will seem to be getting more miles per gallon because the pinion gear will be turning more revs per mile traveled, and the odometer will react accordingly. It might be a small difference or even an actual gain, but when doing these tests, someone should probably use a GPS to figure actual mileage traveled, or compare two bikes odometers on the same trip from gas pump to gas pump. I don't doubt there is a definite performance increase, but the ACTUAL miles per gallon would seem to be a bit less, although I'm just speculating. The Speedohealer is a good way to make the necessary corrections if an owner wanted the corrected speed to display on the speedometer. Now back to lurking... Edited July 15, 2013 by tx2sturgis
MikeWa Posted July 15, 2013 #32 Posted July 15, 2013 Both gear sets use a ring gear with 33 teeth. The speed sensor counts the teeth on the pinion gear. Even with the gear change it still takes 33 pinion teeth to make the ring gear go around one time. So that is still 33 speed sensor pulses per wheel revolution. So changing to the v-max gear set does not change the speedometer reading in any way. Mike
Guest tx2sturgis Posted July 15, 2013 #33 Posted July 15, 2013 The speed sensor counts the teeth on the pinion gear. If that is true, and I have no reason to doubt it, then that clarifies it for me. I made the assumption the sensor was counting individual revolutions of the pinion gear, not the pinion gear teeth that pass by the sensor. 33 pinion pulses per wheel revolution is different than one pulse per pinion revolution. I stand corrected. Thanks for that. But just in case you guys want to get a more accurrate speedometer reading, the Speedohealer is still a good option. I installed one 6 years ago and its still working fine.
Kirby Posted July 15, 2013 #34 Posted July 15, 2013 I just installed a Speedohealer on my 09 last week. Sure is nice to be reading what the actual speed is. But with a 7.9 % correction factor I think my odometer is really off now.
Guest tx2sturgis Posted July 15, 2013 #35 Posted July 15, 2013 I just installed a Speedohealer on my 09 last week. Sure is nice to be reading what the actual speed is. But with a 7.9 % correction factor I think my odometer is really off now. Several years ago, I did a writeup on the Speedohealer on this forum, but I dont remember the exact difference between speed and mileage correction on the RSV. The short version is this: If you set it to read dead accurate on miles per hour, then the odometer will be off a small amount, and if you set it to be dead accurate on the odometer, the speed will be off by a small amount. This is a 'slew' factor built in to the RSV speedometer, and not a flaw in the Speedohealer itself. Most owners choose the speedometer to be accurate, but instead, I chose the odometer. My indicated speed is now only off by less than 2.5 mph at about 70 mph...I can live with that. Without the Speedohealer it used to be off by about 10 miles per hour. Remember, the resolution of the Gen 2 RSV LCD speedometer is 2.5 mph increments, so anything less than that is mostly unoticed by the rider. One more thing that is a by-product of using the Speedohealer. Since it will now indicate a bit less miles per hour than when it was uncorrected, it will also indicate a few less miles you travel on a gallon of gas. Your true MPG didnt change of course, but now it will be reading more accurately, instead of being somewhat inflated by the original factory readings. It is what it is.
IronMike Posted July 16, 2013 #37 Posted July 16, 2013 A couple of us did this before when we changed the Clutch on a Roadstar and needed to get the MPG different with w full lock up clutch. (Shimmed) After several test runs and fuzzy math we got down to GPS's and Filling the bike on the Level surface using a Four FT long Level and filling on on the side stand and to a specific point in the tank neck. (We punched a hole it the inside of the neck for a reference.) And we never came up with a solid number anyways.
MikeWa Posted July 16, 2013 #38 Posted July 16, 2013 What was the cost of this upgrade? Cost of v-max gear change is around $400 with shipping. Mike
awsmsrv Posted July 16, 2013 #39 Posted July 16, 2013 What was the cost of this upgrade? The Speedohealer is about $115-120 now.
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