The original post below is dated so I will try to explain anew the problems with these devices – crampbuster and similar.
At highway speed your throttle is rotated anticlockwise about 33-40 degrees. If mounted flat at closed throttle then they are facing too far down at highway speed.
For these devices to work as a wrist rest then at closed throttle they need to be angled as shown in image on right and not flat as shown in the promo photos.
If you have them angled up like this then its awkward and very easy to accidentally open the throttle when reaching for the brake as there is not enough space on the grip between the device the switch gear.
It’s probably hard to imagine until you try, I was told all this by people but went ahead and got the devices anyway then said Ah, now I see why people told me not to bother.
Excuse this rudimentary drawing as I try to illustrate the problem since I have already sold the devices. The marketing that you fit them flat and then can hold the throttle open is not the reality.
What would work better is if the wrist rest portion swiveled and sat parallel with the grip when not in use then could be rotated perpendicular when at highway speed but it would be difficult to engineer.
You probably are thinking well my throttle doesn’t turn that much when I am on the highway these things will work for me. I thought the same but found all the throttles on my bikes actually rotate that much. If you decide to try one get the most narrow model.
Hope this makes the problem with these things clearer – I wish I had taken photos of the devices while testing but never thought to write about them until much later. Original post now below.
Throttle Rocker Vs Crampbuster
Both are small devices that affix to the throttle grip suggesting you can hold the throttle open by your palm/wrist so you can release your grip around the throttle and stretch your fingers for a bit. However for this to work both need to be angled higher than horizontal due to the amount of throttle rotation needed for highway speeds which I found a problem when trying to use the front brake lever.
The Throttle Rocker is rounded down on the inside and this interfere less when the throttle is in closed position but still I found I needed it angled up and would occasionally accidently open throttle unintentionally. It fixes to your throttle grip with a Velcro loop which unfortunately just doesn’t manage to hold it in place for very long (flat rubber ring underneath might help). No matter what I did it kept coming loose.
I purchased the Crampbuster last month for my Easter tour and it is affixed not by Velcro but rather by it being made of spring steel that you spread and push onto your grip. Once installed it can be rotated up but never down with how it is designed.
To work on highway the device still needs to be angled up at closed throttle and I found the Crampbuster often made me accidentally open the throttle and it was hard to reach around it to the front brake lever and not be opening the throttle which nearly caused an accident twice.
People say simply rotate the Crampbuster up and out of the way and later on highway rotate into place but I found it still was blocking some of the grip or interfering with the brake lever if pointed towards it. It really is an awkward device to try use however there is a thin version and perhaps this would be better.
My wide crampbuster had a very firm bite onto my grip and difficult to rotate while riding. It marked/scuffed my grip quite noticeably with just a couple of turns from the pressure it has. You will possibly ruin your grip by rotating it frequently.
Theses sort of devices in my experience don’t work. Still if you are in some pain touring then perhaps try the narrow model crampbuster but be aware of the issues.
Better solution would be just to stop for a few minutes break, this will also let you stretch legs and your bum from seat, get the circulation going more to wrists and give you better focus back on the bike. A few minutes stop will not blow out your ETA and will help you ride safer and arrive in better shape. Better than buying a crampbuster would be buy an insulated drink bottle or flask for those breaks.
Related to this I have also tried throttle locks, the Vista and Photon but these either have the bike slowing or accelerating giving no more than a couple seconds relief before you need to disengage.
As of 2014 I have electronic cruise control – there is no substitute but taking a regular break remains how I avoid fatigue on tour, I use cruise control more for avoiding speeding and for avoiding frustration when stuck on a divided one lane road with slow vehicles.