This was a fun little project to 3d-print a replacement brake lever for my xr650l, and to then have the CAD so I can print a spare whenever I need it, and also so I could play with the design to tune it to exactly my liking. If I wanted it to be slightly longer or shorter, different grip patterns or handle profiles, thicker or thinner, whatever.
Getting it into CAD accurately was actually kind of fun, but not without its challenges. First I took some pictures of the existing brake lever on a white background with decent lighting from the top and the side. Then imported those pictures into Onshape, and adjusted them to the correct scale by measuring the handle, drawing a box that size, and then scaling the pictures. This was only really to get the overall shape, I went in later and adjusted the model using caliper measurements directly from the OEM brake lever. As you can see I took some liberties with the end of the lever which had been sawed off by the previous owner of the bike so they could fit under the aftermarket handguards. I added something closer to a ball shape, for better grip, and to comply with the law. Turns out you’re not supposed to have sharp brake levers. Not sure if that applies when you have handguards as well.
Anyway. Here’s how the final product came out, printed on a Markforged Mark Two with carbon fiber reinforcement. I had a worry that a 3d printed brake lever might fail right when I needed it and make me crash or something, so I went a bit overboard and made it ridiculously strong. Usually brake levers are designed to fail at a certain point along their length so if you drop the bike on them, they fail before your much more expensive brake assembly. I’m quite sure in the case of this lever, it would demolish the brake assembly if pushed hard enough. I would say, after some more motorcycling experience, I would probably trust a non-reinforced 3d printed part as long as it was printed with decent filament and printed in a good orientation. You really shouldn’t ever be pulling your front brake lever with all your might, and it doesn’t take very much force on most motorcycles I’ve tried to completely lock up the front brakes. That being said, if you decide to download and print one of these for yourself and install on your XR, do so at your own risk.
Take care,
Denis
Take care,
Denis