View Full Version : Transmission design question

28 November 2012, 0904
I have been keeping track of the information on the new Brammo Empulse R and continue to wait for someone to actually purchase and receive one and then report on its performance. What caught my eye recently is a comment that "neutral" is located between second and third gears in the bike's transmission. I sort of thought that there was a DOT regulation that required neutral to be located between first and second gears on motorcycle transmissions. Does anyone know if that is true or not?

I recall that during the 1960's some of the early Japanese motorcycles had a rotary transmission, where neutral was located at the bottom of the gear set. I believe Bridgestone motorcycles used this system. I think Bridgestone use a selector that would let you choose between a 4-speed rotary shift, where you could go directly from 6th gear to neutral and then be able to shift into first gear (apparently useful for urban riding in Tokyo). Or you could select a 5-speed transmission that would lock out the shift from top gear to neutral and make you run back through the gears to get to neutral, which was still at the bottom of the gear set. I believe that sometime during the late 1960's or early 1970's DOT decided that this system had to be standardized for safety reasons and mandated that neutral be located between first gear and second gear on motorcycles.

If this is true (and I am not sure that it is), Brammo might have a problem.

28 November 2012, 0939
I believe FMVSS is the primary federal regulatory document concerning production motorcycle operation.

Here's a document the NHTSA provides for motorcycle manufacturers:

49 U.S.C. 30112 requires all motor vehicles (including motorcycles and motor-driven cycles), to
comply with all applicable FMVSS in effect on their date of manufacture.

FMVSS and regulations that apply to motorcycles, mopeds or motor driven cycles, including three
wheeled vehicles are as follows:
1. FMVSS No. 106, Brake Hoses
2. FMVSS No. 108, Lamps, Reflective Devices, and Associated Equipment
3. FMVSS No. 111, Rearview Mirrors
4. FMVSS No. 116, Motor Vehicle Brake Fluids
5. FMVSS No. 119, New Pneumatic Tires for Vehicles Other Than Passenger Cars
6. FMVSS No. 120, Tire Selection and Rims for Vehicles Other Than Passenger Cars
7. FMVSS No. 122, Motorcycle Brake System
8. FMVSS No. 123, Motorcycle Controls and Displays
9. FMVSS No. 205, Glazing Materials
10. 49 CFR 565, Vehicle Identification Number Content Requirement
11. 49 CFR 574, Tire Identification and Recordkeeping
12. 49 CFR 575.6(a)(2)(I), Consumer Information
13. 49 CFR 576, Record Retention

Here's the relevant bit from FMVSS 123 (http://www.gpo.gov/fdsys/pkg/CFR-1998-title49-vol5/xml/CFR-1998-title49-vol5-sec571-123.xml):

2. Foot operated gear change
Left foot control
An upward motion of the operator's toe shifts transmission toward lower numerical gear ratios (commonly referred to as “higher gears”), and a downward motion toward higher numerical gear ratios (commonly referred to as “lower gears”). If three or more gears are provided it shall not be possible to shift from the highest gear directly to the lowest gear, or vice versa.

28 November 2012, 1538
I think that last regulation is the one that was aimed at Bridgestone - right after they were forced out of the business of making motorcycles by the other Japanese manufacturers. So I guess the location of neutral is left up to the manufacturer.

28 November 2012, 1558
and continue to wait for someone to actually purchase and receive one

me too. :O

29 November 2012, 0856
The EPA numbers sure give the win to Zero. Even accounting for the slightly higher battery capacity, Zero's range is better. This may be totally a result of the 23% weight penalty for the Empulse. The only real hope for the Empulse is acceleration numbers. Comparing the two side by side, zero-60, 20-75, 50-90, etc. would be very interesting.

As far as extreme cornering, and braking. That would matter to you racing types, and could be addressed by any number of aftermarket sources.

29 November 2012, 1343
[QUOTE=Warren;33880]The EPA numbers sure give the win to Zero. Even accounting for the slightly higher battery capacity, Zero's range is better.QUOTE]

Because a transmission (close ratio even more so) over a standard drive cycle actually makes an electric motor less effecient, heavier and more costly. ohhh- and apparently causes a two year delay.

Word is the Empulse transmission is very "clunky". The 70's called and said they want it back.

29 November 2012, 1514
Speaking of Zeros, I visited my Zero (and every Japanese brand) dealer today and they had an "Authority" 9 kWh Zero S on the showroom floor. I was pretty impressed with the way it was set up. It had the oval "crash-hang-stuff-on-them" bars on either side, one of which had a siren on it and the other side was ready for a billy club and a donut bag. The bike also had hard saddlebags, strobe lights, a windshield and 50/50 dual-purpose tires. Everything was blacked out, of course. A very nice setup for urban stealth policing and off-road trail patrolling.