PBM Aprilia's Michael Laverty will switch to the team's ART bike vacated by Yonny Hernandez for the upcoming Motorland Aragon MotoGP round while his GPMS-framed machine will be ridden by an as-yet-unnamed replacement.
Laverty rode the Aprilia at Monday's Misano test in order to make a comparison between it and the bike he has been on all year and after being given the choice by team boss Paul Bird, he has elected to ride the ART.
"It was a really good test and all the things we have been talking about with the GPMS bike, mainly the lack of deceleration, and as soon I jumped on the ART, it was so much easier to stop," said Laverty, speaking to bikesportnews.com this afternoon.
"It was a totally different bike to ride and I was stopping in so much less distance. I was braking at the same markers as I had been all weekend and stopping to early for the corners so it required a different way of riding.
"What it did show was the strengths of both bikes, the things the PBM does better than the ART and vice versa. The ART chatters a load more but we now have a direction with the stopping performance. If you put the ART strengths with the PBM strengths, you would have an ideal motorbike."
One of the reasons why the ART bike performs better under braking is the electronics. The Aprilia has an exhaust valve which works with their own system, but there is no channel for it on the Marelli spec-ECU run on the PBM bike, so it can't be used.
"The Aprilia V-four carries a lot of inertia and doesn't decelerate very well. Aprilia know this so run the exhaust valve which, when closed, creates more deceleration. We can't control that on the spec-ECU so we have to run without it, which is the biggest problem.
"I didn't really get stuck in to do outright laptimes on the ART but after the test was done Paul gave me the option to race whichever bike I want. Ideally, it would be nice to keep on with the PBM bike but I don't think we can make the changes in time for the next few races. I can perform better on the ART, so we are going to use that and we will try to come back with the PBM before the winter."