Wheel differences - early and late Gen IIs

In preparing for a European tour next week, I got new tyres fitted. I've known that the latest years of the Gen II FJR have different wheels from earlier, but never knew what the difference was. Now I know one difference.

The ABS wheel speed sensors are different, and I thought I'd just show them in case anyone's interested.

The earlier uses a toothed disc on the wheel (picture of my '06)

(Click on image for larger view)



and presumably a coil with a magnet in the pick-up (a "variable reluctance" transducer).

The later uses a ring of what look like alternating magnets (picture of my '10):



and presumably just a coil (with a ferrous but non-magnetised core) as a pick-up.

These pictures are of the rear wheels, the fronts are similar.

No idea why Yamaha chose to change; I've not heard of any underlying problems with the older, so I can only assume it's a cost issue.

The ABS system changed in 2008. According to Wikipedia, Yamaha just changed suppliers, so it's possibly just different, but not necessarily "better". The switch could have been simply motivated by cost or manufacturer/supplier politics.

Somewhere around here someone did an excellent job documenting the changes to the 2008 FJR. They did 'improve' the abs in 08 supposedly. I think, maybe, it was like going from two channel to three channel or some such kind of techno talk.

Thanks for posting the photos. I have always wondered what the difference was physically.

Edit: Found the '08 info provided by Constant Mesh way back when: Clicky HERE.

All new ABS system for 2008. The ABS system now features a linear controlled 3 position system (was previously a 2 position system), an ECU integrated compact hydraulic unit, and a new active type wheel sensor with a new magnetic rotor. The benefit is a reduced weight and better lever feedback feeling when the system is operating.
The front and rear wheel rims have been revised to accommodate the new ABS wheel sensors.

Click to expand...

Have you tried counting the 'segments' on each wheel? It would be interesting from from a cruise control/VSS point of view. If you know the wheel circumference and the number of segments then you know the Pulses Per Mile (PPM).

Don

Donal said:

Have you tried counting the 'segments' on each wheel?

Click to expand...

On 2008+, there's 42 pulses per revolution. The service manual says so (I didn't actually count). This was actually important information for getting my Motty AFR tuner to properly convert the signal to speed for data logging and for determining what gear the bike is in (it calculates it based on the ratio between engine RPM and wheel speed) for per-gear settings.

I think this is the first time that the answer of "42" is not a smart-ass reference to the hitch-hiker's guide to the galaxy

It also looks like the sensor ring bolts on and is replaceable now? I know the old one is pressed on, and it's "buy a new wheel" time if it gets damaged.

Edit: Nope, not according to the Yamaha-motor.com microfiche

I confirm 42 pulses per wheel revolution (I counted 84 magnet sections in my piccy), presumably alternating N-S-N-S... The older unit also had 42 teeth, so same pulses per rev for both.

To get pulses per mile:

Rear wheel diameter 17 inches,

Rear tyre width: 180mm, aspect ratio 55%, so tyre adds 180 x 0.55 / 25.4 x 2 or 7.8 (near enough) inches to the diameter, so total diameter = 24.8 inches.

Circumference = PI x diameter = 77.9 inches

There are 63360 inches to a mile, so 63360 / 77.9 = 813 revolutions per mile, 813 x 42 = 34156 pulses per mile (OK, some rounding errors in there, but I'm sure that's good enough).

UselessPickles said:

Donal said:

Have you tried counting the 'segments' on each wheel?

Click to expand...

On 2008+, there's 42 pulses per revolution. The service manual says so (I didn't actually count). This was actually important information for getting my Motty AFR tuner to properly convert the signal to speed for data logging and for determining what gear the bike is in (it calculates it based on the ratio between engine RPM and wheel speed) for per-gear settings.

I think this is the first time that the answer of "42" is not a smart-ass reference to the hitch-hiker's guide to the galaxy

Click to expand...

mcatrophy said:

I confirm 42 pulses per wheel revolution (I counted 84 magnet sections in my piccy), presumably alternating N-S-N-S... The older unit also had 42 teeth, so same pulses per rev for both.

To get pulses per mile:

Rear wheel diameter 17 inches,

Rear tyre width: 180mm, aspect ratio 55%, so tyre adds 180 x 0.55 / 25.4 x 2 or 7.8 (near enough) inches to the diameter, so total diameter = 24.8 inches.

Circumference = PI x diameter = 77.9 inches

There are 63360 inches to a mile, so 63360 / 77.9 = 813 revolutions per mile, 813 x 42 = 34156 pulses per mile (OK, some rounding errors in there, but I'm sure that's good enough).

Click to expand...

Thank you both for the info :clapping: that fits in nicely with the upper limit for the Rostra (all electronic) CC of 38,600 PPM

Don

UselessPickles said:

I think this is the first time that the answer of "42" is not a smart-ass reference to the hitch-hiker's guide to the galaxy

Click to expand...

Great book, good movie.

RaYzerman19 said:

'UselessPickles' said:

I think this is the first time that the answer of "42" is not a smart-ass reference to the hitch-hiker's guide to the galaxy

Click to expand...

Great book, good movie.

Click to expand...

And here's what made it a "good" movie.....

Took 3 fukin years to get it dickdribble? Damk!