I have a valentine 1 which I have had for years, with a couple of upgrades. I use the HARD system with it. IMO, the Escort X50 is your best bet - it is smaller, cheaper and can use an earphone jack. The HARD system is potentially unrealiable as it runs on batteries and relies on electronics. the batteries are 2* CR2032 button cells, at $5 each. Makes for expensive running costs.
Mounting depends on the bike. The BMW is a pain, as the instruments move with the bars, which makes it hard to fabricate a mount. I made a specail mount for the top of the master cyl. As time and money permits next year, I will make a waterproof perspex box to take an Escort, and mount it as a stealth installation under the bottom of the fairing upper. There is a site in one of the threads on teh K1100.org forum about this.
Like towbars, RD mounts are easy enough to make, but fiddly and time consuming to do a good job.
Geoff
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