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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: neg on March 30, 2025, 05:44:11 PM
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Hi y'all, been working on my first K75 cafe. This is my first post after scouring this forum for a few weeks. I am wiring the BEP and have a question regarding SPD.
I have a speed sensor attached to the wheel. I've read on the forum that the speed sensor must go through the BEP before connecting to the Acewell for calculations that the Acewell doesn't support. If I insert the Speed+ wire (green) from my Acewell into the BEP SPD clamp, I assume I need to pass my speed sensor wire (also green) into the cluster's BEP pin 7 because my BEP has SPD carved next to pin 7 (along with a toggle switch for SPD and BAR); however, that is my RES low fuel (solid white) wire. I am not seeing instructions regarding this step in my BEP instructions. That is very confusing because I'm sure I don't want to override the low fuel wire for SPD, along with ABS for BAR. Where exactly do I pass my speed sensor and Acewell speed wires with the BEP as the mediator?
I have the same question regarding BAR carved into pin 8 on the BEP. Thanks!
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If you're using Acewell's wheel speed sensor on your wheel instead of the original BMW one mounted on the rear drive, why can't you just connect the Acewell speed sensor directly to the Acewell input harness? It shouldn't reject signals from its own device.
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The BEP is meant to substitute for the OEM cluster and simulate its functionality. You are not supposed to attach your own sensors to the BEP. The K-bike's speed sensor in the rear drive gets conditioned by the electronics in the BEP and presented as a signal on the SPD output. You then connect your Acewell gauge speedometer input wire to the SPD connector. Forget the speed sensor that came with your Acewell. Put it back in the box because you won't need it.
As for the BAR output, it is non functional on your k-bike. It is meant for bikes pre-1984 with the old style 4L/7L indicators. Your bike has a float.
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The acewell can accept both direct input from the oem sensor as a custom pulse generator.
It could be run trough the bep but there is absolutely no need to do so.
My advice is -from experience - go with the oem sensor directly on the input from the acewell. 1 its a cleaner look. 2 fork mounted cables and open sensors are prone to impact while riding and dying because of it or ending up dislocated barely generating signal.
Plus its easier to connect and repair.
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Awesome. Thanks everyone! Just got back from vaca and will try out these suggestions this week.