The front brake is well known deficiency on 1st model KLR 650s. When I bought my KLR it was equipped with the 320mm oversize front rotor that is available from several sources. It also had the recommended braided SS brake lines. The brakes were OK, but not as powerful as I prefer for an aggressively ridden street bike. I have upgraded the brakes on a number of my other bikes, mostly vintage stuff. I took a look at the stock caliper and master cylinder. The stock caliper is a 38mm single piston sliding pin design. I dug out my box of calipers that I have accumulated over the years from parts bikes and eBay. My first inclination was to use a 4 piston Tokico that was used on many Japanese street bikes in the 90s. The housing for the rear pistons interfered with the spokes, so I grabbed a 2 piston sliding pin Brembo from the rear of a Guzzi California. Hmmm, it has a 32mm & 30mm piston. That will be about a 33% increase in mechanical advantage over the stocker. No interference with the spokes either. As it turns out, this caliper is also used on the front of KTM Adventures, BMW F650s, and Guzzi Quotas. I think we have a winner. The stock master cylinder is a 1/2" bore. That is already pretty small. About the smallest MCs I have seen readily available are 11mm. I found a 11mm bore Nissin from a Honda CRF150. You could also buy a new one from http://www.mikesxs.net part #08-4003 for $76.00. The 11mm master cylinder provides an increase of 22% in mechanical advantage - about the same as the larger rotor. I fabricated a bracket to adapt the caliper on Sunday. Normally, I have done this from aluminum. In this case though, I used steel since I was working away from home and didn't have much in the way of machine tools. Working with steel plate allowed me to weld it up from 3 pieces. I put everything together and took it for a test drive. WHOAA! I didn't know if it was really possible for me, but I think I may have created a front brake that is stronger than I want or need. The CRF MC has a shorty 2 finger lever on it, and I can lock the front wheel without much effort. :eek1 I rode it to work today, and I am liking it better, but only gentle pressure is needed on the brake lever. I'm going to change the pads out first, but I think I might go back to the stock MC. Anyways, I think a KLR owner looking to upgrade his brakes has some options. Especially, if he has metal fabrication capabilities. The master cylinder upgrade is cheap and easy. The caliper upgrade is also fairly cheap if you can find a suitable caliper used. The bracket fabrication is not terribly difficult. The rotor upgrade can be a simple bolt-on, has bling, but it is the most expensive option.