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Is Changing the rear sprocket possible?

First, thanks, Peter, for explaining a search method: "rear sprocket", for me, did not yield useful information.

r.e. changing sprockets. The on-board electronics, ECU, TCU, etc, are generic until a VIN is coded into the system. The VIN can be changed using a Megatech license, no? So if one were to change the VIN to a known bike with an 89-tooth sprocket as standard equipment, then the reprogramming should take care of itself. I would expect the VSS, TCU and ECU would be the ones primarily affected. The brake encoders are mounted directly to the wheels, so antilock braking should be OK. The engine RPM would be 12-13% higher in any gear / speed, indicating to the computer that the rear wheel is "slipping", spinning faster, presummably throwing codes on vehicle stability, even the pitch and yaw sensors are stable. There is probably some master curve with engine RPM vs Gear vs Speed that has a control band about it that incorporates the relative sensor inputs. That would also be true for the F3-P vs F3-S, which were essentially the same machines with different control parameters programmed in.

If an ECU can be re-flashed to alter the fuel curves, despite government pollution specs, then the other modules should be able to handle gearing.

There wouldn't be anything illegal r.e. vehicle registration, as the printed VIN on the vehicle still matches the government vehicle registration.

Further rumination, I wonder if I could take the "digital gauge cluster" and rear wheel / belt from my 2018 F3T and install on my wife's F3L to see if it would work? The "T" has an 89-tooth sprocket vs the 79-tooth on the "L".

Wayne
 
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This is just my thought on this subject...I think the computer systems are counting pulses...And when the pulses between the engine speed, gear speed & wheel speed get out of the programed limits the bike goes into the limp mode???

Could making this sprocket change be as simple as having a modified tone wheel or wheels to simulate the the original sprocket size and not recognize the newly changed sprocket???

Jese from Peters side of the world told me his code reader shows the source of the error codes???

larryd
 
The 89T TCM is a different part number from the 79T TCM. But apparently it isn't that simple. Bosch seems to have hard-coded VIN-related information in the console and maybe the ECM and VCM. Just like the console options change based on whether on not a radio is installed, I believe the console tries to match VIN-related information across TCM and VCM. You can see this behavior with BUDS which provides VIN-related options for firmware upgrades. Just a hypothesis.

If someone wants to experiment, I have an 89T TCM and larryd has the 89T sprocket and belt.

Thanks for clearing that up ....Knowledge is power .....and I learned something today :thumbup::thumbup::thumbup:....Mike
 
I'm sure it can be done. The only thing you need to do after the install is use BUDS to reprogram the shift points. The speed sensors are on the brake disc's for ABS, VSS, and speed sensing. The only thing that would confuse the nanny is speed vs rpm which can be programmed using BUDS. I have read about the procedure in the past, but have never tried it because I had no reason to.
 
I wonder if you could swap out the ECU and sprocket from a 89 tooth bike to one with 79? If the computer is swapped, I would think it would work. Probably not, but just something my feeble mind was thinking about. I am just thankful that I do still have one with the 89 tooth (2016 F3L Special Series). It even gets better gas milage.
 
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