Suspension and motor refinements highlight the 2011 CRF450 from Honda. And both bikes are quieter thanks to new mufflers that produce just 94 decibels.

The following is a release from Honda:

2011 Honda CRF450R

Long regarded as the bike of choice in the big-bore motocross division, the 2011 CRF450R incorporates improvements that will help this bike retain its premier standing. The prodigious powerband is now even stronger thanks to more low-end pull and midrange grunt along with enhanced throttle response via a new throttle body. Revised suspension linkage and settings yield improved control, increased ride plushness and enhanced rear-wheel traction. A new Honda Progressive Steering Damper (HPSD) produces even better tracking traits than before, and a new muffler meets the 94-decibel sound level required by some racing organizations in 2011. All this and more make the 2011 CRF450R a shoo-in to maintain its dominant role among open-class MX bikes.

New for 2011

• Revised engine tuning and new 46mm throttle body increase low-end and midrange power and give improved throttle response.

• Front fork features a lighter cartridge cylinder and all-new valving for improved control and increased ride plushness.

• Revised shock valving yields improved control and increased rear wheel traction.

• New suspension linkage produces improved chassis balance and increased rear wheel traction in rough-track conditions.

• Honda Progressive Steering Damper (HPSD) features larger piston diameter (20mm to 24mm) for improved tracking traits.

• Redesigned muffler lowers sound emissions to 94 dB.