Designed and Manufactured Exclusively in the USA!
Tire Conversion And A Performance Close Ratio!
is a plus 30mm (1.18") extension kit for late model (1991 and
up) Big Twin five-speeds with trapdoor access (helical
details). It also fits earlier five speeds that have been updated
with a splined clutch kit. (At present, we don't offer
a Sportster kit.) We offer transmission spacers
Johnson Engineering's breakthrough TwistGear-based close ratio
set, tire clearance is provided by extending the transmission and engine
sprocket shafts as opposed to the potentially unstable workaround
offsetting the wheel, entire drivetrain, the transmission only, or
various combinations of the above. The billet
transmission spacer shown in photo is for FL/FXR applications. Dynas
require a two-piece spacer, while STs use our exclusive cast one-piece
at bottom of page.)
About My Twin Cam?
about a wide Twin Cam? Then forget about the transmission offset
kits. The only way to fit wide skin behind a TC is by extending the
offsetting the entire drivetrain (don't forget to put your foot down),
or offsetting the wheel. For
of TwistGear performance and Twin Cam power in a wide tire profile...perfect!
Up To 230mm — And Wider!
extended main and input shafts safely move primary 30mm outwards.
30mm extension (trapdoor assembly shown at left) means
real rear tire fitment
of at least 230mm (Canadian manufacturer Custom
uses WideGear in their own demo bike, offers 240mm ST and Dyna conversions)
can be achieved without offsetting the
result is a huge
of 100mm of additional tire width when installed using a chain
final drive. When a 1.5" belt is retained, 60mm
(i.e., a 190mm tire when 130mm is stock) is
the maximum width increase without additional modifications for
more clearance. Use of a narrower, 1.125" belt for more clearance
is another option, but due to the higher stresses generated by larger
engines hooking to bigger
tires through a close ratio box, there is a greater
risk of belt damage or failure as a result. Practically speaking,
chain conversion is the simplest method of gaining additional
clearance, and has the added benefit of many more (and simpler
to install) ratio options, although a good many riders are hesitant
to give up the comfort and convenience of their belt.
Not If You Can Help It
from the front, WideGear's massive 30mm engine spacer is at
right, with our 30mm extended main gear seen on end (left).
Right behind the maingear is the transmission,
kept in line with the drivetrain with our billet spacer for
FLs and FXRs. Spacers are also available for STs and Dynas.
of the inherent drawbacks of the other wide tire conversion methods
currently used include intentionally offsetting the rear
wheel to gain clearance, which can introduce a nonlinear tracking
situation, as well as headaches trying to fit fender and struts.
If wheel offset is used in addition to any factory offset, the results
can be alarming. Another factor to consider when dealing with wheel offset
in particular is the tire design. Different manufacturers products
can have a dramatic impact on riding stability.
the engine and/or transmission, the main method of providing the
necessary clearance for a wider tire, has the undesireable side effect
of intentionally repositioning the center of gravity to the left
(outboard) to an even greater degree than offsetting the primary
alone. When combined with an offset wheel, the resulting ride can
watched a wide tire conversion rider fighting the handlebars,
what direction the bike will take going into a curve, you've seen
the effect extreme offset has on handling.
(right) avoids these shortcomings by using spacers between the
tranny and engine,
and mainshaft 30mm (1.18") outward. (Notice the helical
angle of the extended main gear, as well as the extended engine
sprocket nut and coupler in the photo.) And although the weight
of the primary is moved outboard, the additional penalty created
and starter are also moved is avoided, as is the extreme weight
relocation caused when the engine is also offset.
For Plenty of Clearance
by side comparison shows TwistGear profile, left, and WideGear's
massive plus 30mm, right. The extra 1.18" of extension accomodates
a wide variety of tire widths, without the need to offset the
transmission or engine.
said, if show's the name and sitting's the game, WideGear provides
an excellent starting point for stuffing that fat skin between
the rails. WideGear gets you going by allowing for an additional
2.36" of tire width, and if more is needed, than tranny offset
with appropiate spacing at the engine is always an option. For
all around performance, though, offset should be avoided, particularly
when the aggresive gearing of our close ratio tranny is factored
into the equation.
is the only close ratio engineered approach that retains proper design
weight distribution, while maintaining the overall integrity of the drivetrain
as it relates to the driven wheel.
cast transmission spacer (ST only) is one third the weight
of billet, and heat treated to resist additional
stress placed on components by extending the primary.
revolutionary kit features the superiority of a one-piece fifth-gear
and countershaft combo, and our unique cast spacer for STs. (Dynas
use a 2-piece
spacer, while FLs and FXRs require a billet spacer, which is a slightly
higher special order option.) Installation can be completed without
removing the engine or transmission, although
the total conversion process remains a fairly complex procedure
best undertaken by knowledgable technicians familiar with the necessary
skills required for critical suspension and drivetrain modifications.
kit contains all necessary parts, including extended clutch pushrod,
transmission spacers, starter coupler, extended compensator sprocket,
and nut. Also included are our exclusive triple
lip oil seal, chamfered transmission spacer, and 4-point
also features a needle bearing (extra cost) that fits
the engine sprocket
nut for outboard engine shaft end support. (A suitable outer primary
with a built-in support shaft or nub is needed to utilize this feature.)
is the only performance oriented conversion kit available today.
Manufactured in the USA, our gear components are the highest quality
available, and are superior to offshore, imported kits. If you're
interested in checking out just how good WideGear can be or need
info on just
riding, then check out our gearing
charts for answers to these commonly asked questions. You'll know
ahead of time whether or not you need more gear or engine speed reduction,
depending on your riding style.
and TwistGear® are trademarks of Johnson Engineering, Inc. Buell™,
Dyna™, and Sportster™ are trademarks of the Harley-Davidson
Motor Company. No affiliation with the Harley-Davidson Motor Company
is implied or inferred.