One of the best mods we made was the rear sprocket. We
switched from a stock 48 to a 49-toother—a Renthal, to be
exact. This small change really tightened up the powerband,
relieved frequent stalling and helped our lap times substantially. At the same time the stock chain, which was junk at
that point, was tossed in favor of a RK GB520MXU sealed
motocross chain, which is perhaps the lightest sealed-ring
unit available. The chain feels non-O-ring light and takes serious abuse with virtually no stretching. Keeping the chain in
line, we used BRP’s super-strong chainguide, a high-impact
unit that resists bending, can absorb a tough blow and still
retain its shape, and has a high-wear factor.
We tested four exhausts with a sole goal: broader powerband. We really did not want to carve up the decent bottom
power of the stock system, did not want to sacrifice the
ambient racket and, if possible, get a weight savings to boot.
Hey, there isn’t a cheap dual exhaust made, and stock is
quiet and decently productive and is just a shade meek in the
mid to top. The bottom line here is, lighter is good, quiet is
preferable and retaining bottom and inspiring the mid to top
would really help that soft side of the CRF450.
DR.D NS- 4 STAINLESS
Unlike the stock Honda exhaust that uses a larger-diameter
mid-pipe at the split, DR.D runs the same size, as the unit
meanders back to the carbon mufflers. The weight savings is
excellent; the stocker weighs in at 10. 6 pounds, and the
entire DR.D system scales out at 7. 9 pounds. Fit is superb,
and mounting up required no grunt work to get the brackets
to line up.
Power: Definitely softer off the bottom than stock, though
the mid-to-top power received a good gain. The CRF benefited from a good mid hit and yanked harder and longer, which
excited the powerband, something every one of our higher-end testers praised. The one demerit came from the vet guys
who all commented on the softer roll-on.
A BIG BAR
We wanted a big bar, and the Renthal Twin-Wall Windham
bend fits our need, on the money. It’s strong, light, has the
perfect bend and is durable beyond belief.
GETTING A GRIP
We’re getting to the point that gluing our grips on is so
Judd Nelson. AME’s bolt-on unit has a great pattern, is soft,
is durable and takes about a second to install.
2013 HONDA CRF