rear wheel sensor, sprocket change?

pb3 · April 10th, 2022, 08:37 PM

hi all,
noticed on my non-ABS '22 there is a "rear wheel rotation sensor." I have yet to find the rationale in the service manual, is this just for speedo operation or more?

also, anyone change sprocket sizes without an ECU fault generated?

tia,
parker

DannoXYZ · April 11th, 2022, 07:10 AM

Rear-wheel speed sensor is for ECU to determine what gear you're in for gear-indicator on dash. Is it still indicating correct gear?

What ECU code# are you getting? If it's #25, it's gear-indicator routine that's complaining about new engine-speed to wheel-speed ratio. How many teeth did you change sprockets? Seems limit is right around 7.1% change or more is when it starts complaining.

To clear and reset error code:

- unplug clutch-switch under clutch lever

- jumper connector on harness side with U-shaped wire, or paper-clip (warning: this will allow bike to start in gear. So make sure it's in neutral with clutch-lever squeezed before starting).

- start engine and idle for 30 seconds.

- ride for at least 10 minute with 5 or more minutes above 20mph.

- turn key off to shut bike down

- repeat 3 more times

- on 4th start errors will clear and everything functions normally again

pb3 · April 11th, 2022, 09:59 AM

sorry, no codes yet! and no sprocket changes. only 259 miles.
7.1% change, can you check my math to make sure I'm understanding...

on my 250, oem was 14/45. i installed 14/44. 3.214 vs. 3.143 meaning 2.2% change?

on my 300, oem 14/42, installed 14/40. 3 vs. 2.857 = 4.8%?

DannoXYZ · April 11th, 2022, 11:22 AM

Math looks good.
What gearing are you changing to on 400?
Seems there's some annoying buzziness at 5500rpm cruising-speed that people change gearing to get away from.

pb3 · April 11th, 2022, 11:56 AM

i'm not sure, what are your suggestions? OEM is 14/41

DannoXYZ · April 11th, 2022, 08:13 PM

Seems Ok ratio to me, I like it as it is. Try it and get used to it. Then when it comes time to replace chain & sprockets, you might have an idea of changes you want, if any. Most people add tooth or two for faster acceleration on track. Commuters add tooth in for more relaxed cruising.

April 10th, 2022, 08:37 PM	#1
pb3 ninjette.org member Name: parker Location: STL Join Date: Apr 2009 Motorcycle(s): 09 n250, 14 n300, 22 n400 Posts: 98	rear wheel sensor, sprocket change? hi all, noticed on my non-ABS '22 there is a "rear wheel rotation sensor." I have yet to find the rationale in the service manual, is this just for speedo operation or more? also, anyone change sprocket sizes without an ECU fault generated? tia, parker

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April 11th, 2022, 07:10 AM	#2
DannoXYZ ninjette.org certified postwhore Name: AKA JacRyann Location: Mesa, AZ Join Date: Dec 2011 Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C Posts: A lot. MOTY - 2018, MOTM - Nov '17	Rear-wheel speed sensor is for ECU to determine what gear you're in for gear-indicator on dash. Is it still indicating correct gear? What ECU code# are you getting? If it's #25, it's gear-indicator routine that's complaining about new engine-speed to wheel-speed ratio. How many teeth did you change sprockets? Seems limit is right around 7.1% change or more is when it starts complaining. To clear and reset error code: - unplug clutch-switch under clutch lever - jumper connector on harness side with U-shaped wire, or paper-clip (warning: this will allow bike to start in gear. So make sure it's in neutral with clutch-lever squeezed before starting). - start engine and idle for 30 seconds. - ride for at least 10 minute with 5 or more minutes above 20mph. - turn key off to shut bike down - repeat 3 more times - on 4th start errors will clear and everything functions normally again

April 11th, 2022, 09:59 AM	#3
pb3 ninjette.org member Name: parker Location: STL Join Date: Apr 2009 Motorcycle(s): 09 n250, 14 n300, 22 n400 Posts: 98	sorry, no codes yet! and no sprocket changes. only 259 miles. 7.1% change, can you check my math to make sure I'm understanding... on my 250, oem was 14/45. i installed 14/44. 3.214 vs. 3.143 meaning 2.2% change? on my 300, oem 14/42, installed 14/40. 3 vs. 2.857 = 4.8%?

April 11th, 2022, 11:22 AM	#4
DannoXYZ ninjette.org certified postwhore Name: AKA JacRyann Location: Mesa, AZ Join Date: Dec 2011 Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C Posts: A lot. MOTY - 2018, MOTM - Nov '17	Math looks good. What gearing are you changing to on 400? Seems there's some annoying buzziness at 5500rpm cruising-speed that people change gearing to get away from.

April 11th, 2022, 11:56 AM	#5
pb3 ninjette.org member Name: parker Location: STL Join Date: Apr 2009 Motorcycle(s): 09 n250, 14 n300, 22 n400 Posts: 98	i'm not sure, what are your suggestions? OEM is 14/41

April 11th, 2022, 08:13 PM	#6
DannoXYZ ninjette.org certified postwhore Name: AKA JacRyann Location: Mesa, AZ Join Date: Dec 2011 Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C Posts: A lot. MOTY - 2018, MOTM - Nov '17	Seems Ok ratio to me, I like it as it is. Try it and get used to it. Then when it comes time to replace chain & sprockets, you might have an idea of changes you want, if any. Most people add tooth or two for faster acceleration on track. Commuters add tooth in for more relaxed cruising.