Ivan: I can give you some info, but I haven't used them more than maybe half a dozen times, so I may not be a very good source of info.
Pros:
- Silky smooth mechanism, nicely formed parts, etc.
- Trivial to install: no adjustments.
- No periodic post-installation adjustments (that I'm aware of).
- Magically maintains friction when rolling on the throttle, yet releases a bit when rolling off.
Cons:
- Very expensive.
- Very difficult to set while actually in motion.
- Like all throttle locks, gives your hand a rest but can't maintain actual speed up and down hills.
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And now look what you've done: you've made me rant. Whenever this subject comes up, I get near livid at the BMW engineers, or bean-counters, or somebody at the company. Here's a supposed
Grand
Tourer, the largest scoot in their lineup, with
throttle-by-wire and umpteen sensors and a nice TFT display, and no cruise-control option!?!?. Tell me, how hard would it be, to have factory cruise, especially given throttle-by-wire? And would probably have added a euro in cost.
I've had real cruise control on a couple of long-term bikes. I added an MC Cruise to a 650 Burgman, and my Victory bagger came stock with it. To top it off, both of those bikes used real throttle cables, i.e., before throttle-by-wire sophistication. And BMW has cruise on a lot of bikes already, so it's not as if they would be programming from scratch. Heck, the latest RTs even have
adaptive cruise control -- I don't even have that on my car.
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Oh, where was I?
First off, I had use of the '22 C 400 GT only for five months in 2022 and then one month in 2023, before I had the engine problem. And then I managed to only put c. 400 miles on my '23 before winter set in. During those times, I did not do any overnight trips, nor any mostly-all-day highway slogs. I do have one such trip planned for this spring, so I will get some use then.
In the meantime, I only had time for what I'd call some experimentation, as opposed to actual meaningful use.
To elaborate on some of the points above, I was pleasantly surprised that the level of friction seemed to remain intact when increasing the throttle opening, to adjust the speed upward. And, as I say, the Wunderlich product magically eases off the friction when decreasing the throttle opening, which is a nice safety feature. I don't know how it manages this trick.
OTOH, what I've done for these experiments -- keeping in mind that I'm not an expert here -- is to pull off the road, close the device, i.e., set a friction level, and then pull back on the road; either that, or coast when no traffic was around, and set it while coasting. That is, I'm certainly not adept at righty-tighty setting up the device, while at the same time holding the throttle steady, or perhaps increasing it, while in motion. The two actions are sort of in opposite directions.
Oh, and I'm not familiar with your reference of thread-lock and lubricants. I just put it on when I got it, adhering to the one admonition of not holding the adjustment wheel while tightening the bolt. The
https://www.wunderlichamerica.com/mm5/instructions/42370102.pdf document doesn't reference either threadlock or lubricant, unless I'm overlooking it somewhere. (BTW, regarding the '23 bike, the techs at Max BMW swapped over the Wunderlich stuff when the '23 bike came in, when I wasn't there.)
So, because of what I perceive as a sort of clumsy setting operation, if I were doing this again I think I'd give the Kaoko a shot: see
https://kaoko.com/product/ccf137/# and
https://kaoko.com/how-it-works/ . That product requires some finness to set up, and perhaps also periodically, but its activation motion seems more natural to me. So that's the trade-off there.
And both the Wunderlich as the Kaoko are pretty expensive, but, um, so is the scoot. And they both probably work as well as throttle locks can.
I had an Atlas throttle lock installed on my second Burgman 650
by the Atlas folks themselves at the Americade rally one year. Fast forward a few years, and the thing developed a problem -- lost a screw or something -- when I wasn't even using it; the problem caused it rotate, which in turn prevented my being able to use the front brake completely, which in turn was pretty stressful (and I was two-up at the time -- I pulled over, figured out and temporarily fixed the problem, and the next day took it off the bike and threw it out). So I guess there's something to be said for spending the coin.
I don't know whether any of this helps, but that's all I got on the product.
And don't get me started on the ridiculous Schrader valve placement in the wheels ...