Motorcycle gear indicator

[Hangman]

Hi Ron,

the circuit was published in "ELEKTOR" magazine.

I don't recall the exact name for it but you should find it as "gear indicator".

If you want to obtain the source code, meant to alter the highest gear to shift (normally five), but newer motorbikes have a six gear transmission box you might PM me your email-address. I'll send both, source and hex file to you, free of charge.


Default setting of the original hex file is 5 gears.

 

[Mr RB]

Counting up and down pulses from some sensors placed on the gear lever is not a great system for a gear indicator.

Often the lever might be nudged but not shift properly, so the count would be wrong.

A much better system is like the OP suggested, to compare the engine RPM with speed sensor PPM and tell the gear based on that ratio.

 

[vsaar]

A much better system is like the OP suggested, to compare the engine RPM with speed sensor PPM and tell the gear based on that ratio.

This will work only when the clutch is engaged and the bike is moving. When slipping the clutch to get moving, or coasting with clutch disengaged, the engine vs. bike speed ratio can be anything and will give garbled reading.

 

[Hangman]

Counting up and down pulses from some sensors placed on the gear lever is not a great system for a gear indicator.

Often the lever might be nudged but not shift properly, so the count would be wrong.

A much better system is like the OP suggested, to compare the engine RPM with speed sensor PPM and tell the gear based on that ratio.

I think it is ideal.

If the gear isn't shifted properly the next action is repair, either DIY or have a motorbike specialist repair it. The shift lever always travels the same way.

This applies not only to motorbikes but also to cars.

I guess we're talking about motorbikes, not mopeds.

 

[Mr RB]

This will work only when the clutch is engaged and the bike is moving. When slipping the clutch to get moving, or coasting with clutch disengaged, the engine vs. bike speed ratio can be anything and will give garbled reading.

Agreed, and it's a known problem. The commercial products simply ignore readings out of range, and only after a tach:speed ratio is within a correct range THEN it will display the new gear. If the reading is out of range it just keeps displaying the last gear that was correct. It's hard to argue with professional designs.

(re counting gear lever movement); I think it is ideal.

If the gear isn't shifted properly the next action is repair, either DIY or have a motorbike specialist repair it. The shift lever always travels the same way.

Apart from the gears won;t wlways change from toeing the lever. Some gearboxes like Suzuki have fast synchros and will go into gear very nicely. Other gearboxes (Yamaha, Harley) need to be toed hard and then you have to wait for the "clunk" until it finally goes into the new gear, and if you are not used to that delay you can need to toe the thing a couple of times to change one gear.

Also on most motorcycle gearboxes you can move the lever 95% of the way and it won't go in, so your sensor would pick that up too.

Besides those problems you still have the other significant problem that the user would have to install two sensors on their bike in exactly the right position to detect the gear lever end of travel.

Compared to being able to tap into the existing tach and speed signals, and just use some math, it doesn't seem "ideal" to me.