Hi,
I'm almost done with conversion to YZ forks. Just waiting for some inner parts of forks.
I was considering using 2 piston brake caliper but I switched to 4 piston because tenere is big bike.
In fact, pistons in Tenere calipers are the smallest ones:
Caliper cylinder inside diameter
32mm - 30mm � 1 in XT660R with Disc 298.0 � 4.5 mm
34mm - 30mm � 2 in XT660X with disc 320.0 � 4.5 mm MC - 12.7 mm
28mm - 28mm x 2 in XT660Z with Disc - 298.0 x 4.5 mm and MC - 16mm
So if you want to reuse some brake caliper I would use different ones then original Tenere. For example BMW f650GS has also just one brake caliper with 300mm disc.
Useful links:
http://www.f650gs.crossroadz.com.au/ForkUpgrades.html
http://advrider.com/index.php?thread...99113/page-271