WHAT IS IT? The Renthal Twinring sprocket combines
a specially enhanced, 7075 T- 6 aluminum-alloy center hub
with a long-wearing, high-strength, nickel-coated, steel
WHAT’S IT COST? $99.95.
CONTACT? www.renthal.com or (877) 736-8425.
WHAT STANDS OUT? Here’s a list of things that stand
out with the Renthal Twinring sprocket.
(1) Production. How does Renthal attach the steel
outer ring to the aluminum inner? The outer ring is
expanded by being heated and then shrink-fit onto the
cooler inner hub. Cold-rolled pins are then used to secure
the two parts.
( 2) Competition. Renthal cannot lay claim to being
the innovator of this idea. It has been tried several times
before, most notably by Supersprox, which has been
building aluminum/steel hybrid sprockets since 2001.
Many Vet riders will also remember the Sidewinder
Stealth/Tri-Metal sprockets, which were private-labeled
( 3) Concept. The typical rear sprocket is made from
lightweight aluminum but exhibits one major flaw—
aluminum wears out quickly. And in the process of wear-
ing out, the soft aluminum teeth engage the chain rollers
improperly, stretching the chain. A steel sprocket lasts
longer and mates to the chain better, but a solid steel
sprocket is heavy—three times heavier than an alumi-
num sprocket. And that weight is not only unsprung but
rotating. The solution (for Supersprox, Sidewinder and
Renthal) was simple: bond a ring of durable steel teeth
to a lightweight aluminum carrier.
( 4) Lifespan. How much longer will a Twinring
sprocket last than an aluminum sprocket? Approximately
three times longer.
( 5) Weight. How much heavier is the Twinring
sprocket than a comparable aluminum sprocket? It
weighs 12 ounces more than an all-aluminum sprocket
and 12 ounces less than an all-steel sprocket.
( 6) Price. How much more does a Twinring sprocket
cost than an aluminum sprocket? A Renthal Ultralight
rear sprocket has a suggested retail price of $69.95,
which is $30 cheaper than a Renthal Twinring. But, the
extra cost is made up for over time, as the Twinring
lasts longer than an aluminum sprocket.
WHAT’S THE SQUAWK? The two most common
squawks are weight and price.
If you are a smart investor, this is a five-star
RENTHAL TWINRING ALUMINUM/STEEL SPOCKET
product; but, it’s a three-star product for the
hardcore racer because of the added weight.
MXA TEAM TESTED