Following a few premature failures of the kit TRF201 idler gear, RW Racing have, by popular demand, created a precision machined replacement. The first batch of Idler gears should be going out to shops on the 30th July. These will be a direct replacement to the kit original items.

http://www.oople.com/rc/photos/misc/news/rwidler.jpg

These will be available from M-K-Racing and FusionHobbies a.s.a.p. we're told.
RW Racing are also in the process of creating a one piece solid layshaft for the TRF201 also - stay tuned for more information on that.