Two Daves Racing ER650 Supertwin

Kawasaki ER650 Supertwin


Many racers do not want to give away their secrets but Two Daves Racing isn’t shy about it.  What started off as a mild 650cc parallel twin commuter (Kawasaki ninja 650r or ER6) turned into this beautiful and very capable supertwin racebike as shown below by Two Daves Racing.  The bike has over 85bhp at the rear wheel and can easily reach speeds of 150mph+.


A brief specification of the Kawasaki ER6 Supertwin is as follows:

Kawasaki ZX10R Forks with Maxton conversion
Maxton GP10 rear shock
Kawasaki Versys Swingarm
ValterMoto rearsets
Brembo RCS19 master cylinder
Kawasaki ZX6R/ZX14R calipers
SBS Sintered Racing brake pads
Translogic Dash
Datalogging via AiM Solo (GPS)
ACU Rain Light

Radicool radiator & silicone hoses
Dynopro ‘ramair’ airbox
Bored throttle bodies
Billet inlet cam & modified exhaust cam
Gasflowed cylinder head
JE 12.5:1 high compression pistons
Lightweight flywheel
Sigma Slipper Clutch
Programmable ECU (PC3 I believe)
Power Commander quickshifter
Renthal sprockets with Regina GPZ chain
Bespoke underseat Quill exhaust

Bespoke underseat Quill exhaust
Bespoke underseat Quill exhaust



Versys swingarm swap 1.2kg reduction in unsprung weight with more torsional rigidity.
The Versys swingarm swap offers 1.2kg reduction in unsprung weight with more torsional rigidity.
 replaced the (very capable) Maxton-converted standard ER6 forks for a set of Maxton-converted Kawasaki ZX10R forks
The (very capable) Maxton-converted standard ER6 forks were swapped out for a set of Maxton-converted Kawasaki ZX10R forks

For those of you considering this fork swap, here is what was on our parts list:
* 2004-2005 Kawasaki ZX10R forks and front wheel spindle
* Modified 2006-2007 Kawasaki ZX10R yokes (note: 2008-2010 ZX10R bolt straight in)
* Kawasaki ZX10R/ZX6R front mudguard
* 2004-2007 Kawasaki ZX10R Tokico calipers (or 2009< Kawasaki ZX6R/ZX14R Nissin calipers)
* 50mm Clip-on handlebars
* New brake pads & brake lines
* 54mm Steering damper clamp (if needed)
* and any other bolts/spacers/etc that you also wish to replace at this time

Kawasaki ZX10R forks were used in the fork conversion
2004 -2005 Kawasaki ZX10R forks were used in the fork conversion.  These forks were used for many reasons: the axle diameter and rotor diameter is the same, and the only thing needing to be custom made would be wheel spacers.

The Tokico brake calipers found on the 2004-2007 ZX10Rs were well-documented to have plenty of power but lacked in feel – for this reason we decided to opt for the common conversion of fitting 2009< ZX6R/ZX14R Nissin calipers. SBS Sintered race pads were chosen as they will work well in both wet and dry conditions. 2008< Honda Fireblade monoblock calipers were also considered as they are also a straight swap onto these forks, but the Nissin calipers appeared at the right time so we opted for those.

2009 ZX6R ZX14R Nissin calipers
The 2004 – 2007 ZX10R calipers had plenty of power, but lacked in feel, so some 2009< ZX6R / ZX14R Nissin calipers were put in place.



The wiring harness is no longer doubled up like most piggyback ignition systems. The PC3 harness is integrated into the stock harness and has cleaned up the loom.
Foam was used to keep vibration down
Foam was used to isolate vibration away from the electronics.

If you want to read more about Two Daves Racing check them out on their blog.  They do not post often, but when they do post its QUALITY READING.


Riding motorcycles and wrenching since my preteen years, I have moved from motocross to street bikes. Being a teen back in those days it was tough to get me off of the bike. Now days even though I am very busy being a dad I still have my weekends and go to the track to race and on occasion will do a track day or two.

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