Ah because this book on the Bradley M3, page 97 and 98 says the motorcycle and the ground radar were dropped during development because of "expense, stowage space and the safety issues involving gas for the motorcycle".
The Bradley and How It Got That Way ... - Google Book Search
And at the time I was working at the Armor Engineeer Board..
The GSR (Ground Surveillance Radar) wasn't even part of our MOS, and basically was a worthless piece of equipment. The vehicle would have lost two of the scouts to be able to carry the equipment and the operators. I've worked with the GSR... we used it overwatching the East/West German border during inclement weather, and it would be silly for a scout or recon team (5 or less soldiers) to carry one.
NONE of the Bradley's I've been on had any place for a GSR (it's sizable it would have needed special storage). The GSR may have been somebody's brilliant idea, but it was killed well before the Bradley went into production. I've never even heard of the GSR being put on the CFV.
The motorcycle on the other hand, we did have mounts for (NEVER saw the bike). The only fuel concern at the time was it was gas, and the army was going to all diesel.. (the M151 was gas, replaced by the Diesel powered HMMWV).. even our tank recovery vehicle the M88 originally came with a gasoline engine, but due to logistics it was switched out for a 12 cylinder diesel, BUT we still had a supply of mogas that the bike could run on, fuel wasn't a concern.
When the turret of the Bradley is surrounded by almost 200 gallons of fuel.. (if I remember right) 75 gallons underneath, and another 150 along the side and in front of the turret, do you really think a 2.5 gallon gas tank is going to be a concern??
No, that is the politically correct answer..
The GSR was still used, and was transported by it's operators in their own vehicles.. the bike was history.