Do removable baffles affect economy?

That's a very good point. Also it depends where the OP considers the tank to be full.

We need more numbers.

How many litres of fuel for the 80 odd miles?
Baffle removal decreases back pressure on the engine a little bit but my 03 with a Wolf after market exhaust never had a remap and was still giving 115-120 to a full tank before the light came on.

[yorkie_chris]

Originally Posted by Dicky Ticker

How many litres of fuel for the 80 odd miles?

Exactly, talk mpg or some figures that can relate to that or it's meaningless.

Originally Posted by Dicky Ticker

Baffle removal decreases back pressure on the engine a little bit

Back pressure is the biggest "it depends" answer going. For an exhaust like most any bike engine the back pressure is going to be more dependant on the exact resonance of the pipe, the cams in use, the rpms you're at and the throttle position too. Which could decrease OR increase efficiency and fuel consumption at any given set of variables.
I reckon they all near enough average themselves out over the full scope of use.

Did you notice less miles without baffle?

Minimal,only between 1-5mpg depending how much twist but the acceleration was better and the engine seemed free-er The system was supposed to give +4bhp but as I never had it dynoed I cant confirm this.
4bhp on standard is hardly enough to make a great difference but it did sound the dogs danglies under power with the roar and deceleration with the pops
Only other modification was to the air box which was removed and a race filter system fitted but hardly worth the effort probably just as good with a K&N filter and standard box unless you were doing the whole cams, ports and remap

P.S.The baffle lived under the seat as it was not particularly noisy at low revs for town work and resonace can be affected by the outer polish on the down pipes/box according to a certain British Race team of a former 125cc specialist called Bradley before he hit the big time