berg motor in an alloy mx'er frame?

yes enginehardware has done this to a honda frame with a "700" kit

viewtopic.php?f=9&t=8408&hilit=+honda

Dave clarke racing also had a fe400 engine in a cr250 frame (2001?) a few years back.

I know they had to cut a small recess in the one frame spar to allow the kick starter to go through the flu arch

I've always thought it would be an excellent project

the problems with the berg are compromised seating position due to the fat tank, to make up for that the front wheel loading is very high which in turn gives us a compromised front/rear weight distribution.

then you have 07 and 08 forks being a stupid design and not having enough travel and a PDS rear with a near vertical shock .. not much geometric progression.

if you go to a nice stable jap chassis like the RMZ450 or the YZ range you solve all those chassis issues in one go and get a longer straighter intake tract. the berg air filter position is beautiful but the inlet tract is far from ideal

the other choice although it does not have a rear link is the 2010 ktm450sx .. very nice chassis

if you look on KTM talk in the RFS section there are some really nice build photos/threads of RFS engines in 2010 type chassis

the biggest issue i believe will be that the chain is on the wrong side, the engine is only 10mm taller than a 450 and about 10mm narrower, the exhaust routing around the down tubes will also be interesting

BBR built one once........just once.
Check out 1997. Article was in Dirtbike Aug of 1997.
http://www.bbrmotorsports.com/Company/H ... story.aspx