Posting up a cable resource with respect to
this thread
You will get MUCH improved starting (cranking speed will improve and it will give quicker starting) by increasing the conductance of the power cables to (& from!) the starter.
YOMV, but mine (& Triumph's) is that the frame is not intended to be a current carrying component.
That means you add a new cable from the battery negative to the engine ground point.
On most bikes a 'kit' normally comprises three components overall for best results:
Battery Positive to Solenoid, Solenoid to Starter and Battery Negative to Engine Ground
On the R3 of course, there are only two, since the Solenoid is integrated on the Starter.
It's easy enough to execute but for most of us, the difficult part is in accessing a heavy-duty crimp tool to crimp the terminals onto the wire!
Here is a really nice resource to have your cables made up:
http://www.genuinedealz.com/custom-cables/custom-battery-cable-assembly
You can use whatever combo of wire colour and heatshrink you choose and they will pre-assemble it for you in your specified lengths
e.g. you can have both black, with black heat-shrink on the ground and red on the positive;
or if you prefer you can make the positive cable itself red.
You will want 1/4" lugs of course.
Just be sure you give yourself adequate (but not excessive) length for routing. (use a scrap piece of a small gauge wire or string to estimate)
Note that their lengths are in ft so if 30" put 2.5, or 27" would be 2.25 etc
I would suggest 6AWG minimum, or better, you can go 4AWG.
The simplest way to install is just to connect in parallel with the existing cables.
If you want to make them yourself, you can still get all the materials you need from GD - they also sell
solder pellets and you can use these to attach the terminals - just stick the terminal in a vice, drop in the pellet, heat it with a torch and then stick the cable in. But I would personally recommend having them pre-assemble & crimp them.
I have no affiliation with Genuinedealz - just a recommendation for a good resource.
How to solder terminate your own cables: