We've long wanted to switch to a tubular handlebar for this bike, so we could lower the front end a little, and take advantage of all the different 7/8" bars that are available. Also, we wanted wider bars than stock.
We had a Renthal ultra-low handlebar in the shop, and a pair of Outlaw Racing bar mounts, so after a lot of measuring, we drilled the triple clamp and got to work. There's not much to work with on the pregen triple, unless you are able to fab something to translate the stock mounting holes to 7/8" bar mounts, so we decided to just drill two holes in the center section and mount the risers there. We placed a couple of nylon buttons under the mounts, and rubber spacers under the nuts that secure the risers under the triple clamp.
Seems to have come out well, and I like the feel and look (my daughter hasn't tried it yet, but she thought the clipons were "a little reachy," as she put it. If we decide to switch back to clip-ons, we can plug the new holes with plastic covers.
The Renthal bar is lightweight and has good vibration-absorbing properties, so the absence of bar-end weights doesn't seem to be an issue. The width feels good. The bike is probably too sensitive to rider inputs with the front this low, especially with wider bars, so ee'll probably raise the front an inch from what is shown in the pics. We wanted to see the maximum before making final adjustments.