At least this topic got some discussion going about vendors supplying instructions.
My reply to Dogman Dan was too sharp and mildly insulting, DD I apologize for that. Also, I would like to thank you for all the time and valuable service you provide to ebike users. Especially, I'd like to thank DD for posting the details of his long tail bike builds, great detail, photos and results. Also thanks to others who have provided help and advice.
Back to instructions provided with parts and kits. It is not unreasonable to expect adequate instructions to be provided.
On the other hand, if a vendor provides instructions, those instructions could potentially be used against that vendor, in legal proceedings. Failure to provide instructions can also be used against the vendor in similar proceedings. The vendor has to take the path of least risk. Perhaps not providing instructions is that path of least risk. Perhaps not.
Vendors buy parts and kits for resale. The products they buy change from time to time and the vendor may not be aware of the changes. For that reason, instructions based on previous products may not be accurate for newly arrived products, thus causing potential problems for both the end user and the vendor. Placing the burden of finding instructions on the end user, sort of shifts the task and liability of providing instructions from the vendor. Sort of. If I were a vendor, I'd like to think that I'd provide adequate instructions, but I'm pretty lazy, so probably I'd take the same path Luna takes. Besides that, vendors do not have the time or resources to test products they receive, especially to repeat test looking for potential changes.
The kit that Luna supplied was very good to excellent. One watt meter / battery gauge had the decal inverted so it showed input and output on the wrong sides of the meter, but the connectors, male and female, were on the correct wires, there were instructions for the watt meters. The torque arms supplied were not correct, the flat spacing on the axle holes was too large for the axle flats on the hub motor kit. No instructions were provided for the torque arms. Only the watt meters had instructions and the one watt meter we used failed at close to 8 miles of riding.
If I were to buy a kit, I'd probably buy from Luna, or possibly not, reasons for not would be to get the motor windings that I'd like. The connectors on the Luna kit were excellent, that is a big plus for Luna. Battery? The battery I got from Luna meets all my expectations.
About me, BS in engineering from The University of Texas at Austin, MS in engineering from The University of Texas at San Antonio, member of Mensa, admirer of Texas A&M.
By the way, I did help my friend. His ebike conversion is up and running.