XR500 C&J Mugen - Baja Commander



Honda XR500 C&J Mugen Baja Commander Al Baker replica

When I got the first C&J frame off eBay (white frame) in 2010, my research immediately brought me to this photo of the elusive "White Machine" built by Al Baker in 1980/1 and ridden by Johnny O'Mara. I started considering building a replica, from the ground up.

The MX version for Johnny O'Mara (who are the dudes with the mos?)
As time went by and my research progressed, I learned that there had been (at least) another similar yet different bike, one built for the desert expanses of the Baja.

The Baja Commander version, Al Baker won the Mexicali 250 with it in 1981
This motorcycle was to become the living laboratory for Al Baker's development of the XR500 in partnership with Honda Japan and Mugen. As Al Baker became the Mugen dealer in the USA he started commercializing the "Baja Commander" kit that he had developed with Mugen. This kit went on to be used on XR500 and XR500R as far as the UK by John Banks Racing (JBR) for example and the official Honda bikes for the Paris Dakar 1982 (winner: Cyril Neveu Honda XR550). This gave a new dimension to my thinking and led me to change direction with my project.

In the meantime, I had started to hoard various bits and pieces from eBay and swap-meets to assemble the base from which to actually get started building a motorbike. The old white frame was missing the foot peg brackets. This was my first big stumbling block. Fortunately through various kind folks met over the Web, I got hold of Jeff Cole's phone number.

At some stage, the garage was simply full of eBay boxes with many unsuitable parts. I was loosing it... I had to regroup. The March 2011 San José motorcycle show was the right occasion to at least assemble a self- propelled motorcycle.
As of April 2011. Wrong swing arm and shocks, wrong exhaust header, wrong tank, etc.
This was an OK bike that attracted a bit of attention at the show and got me to meet some very nice folks. But it was clearly not the bike I was aiming for. I deconstructed everything and started from scratch with... a whole new C&J frame and swing arm (banana) I got from Jeff Cole, a pair of Ohlins etc...

The ex-eBay white frame would go to a more generic MX C&J.

A big breakthrough occurred when I finally read a period article that mentioned that the tank on the Baja Commander was simply a ... Vesco SFLA (Skinny Fat Leading Axle). There were 3 of them for sale on eBay... I could have bought a brand new white one from Clarke (who bought Vesco's moulds), but I did not.

Another big break through was to acquire off eBay a NOS Al Baker Mugen reverse megaphone, like the one on the original bike. I could finally claim that there was at least one authentic Mugen part on the project! I also finally found locally an exhaust manufacturer who attempt to do a copy of the Mugen header (this did not turn out quite right in the end, a long story).

As of December 2011
As of December 2011 I had in the garage something that resembled Al Baker's Baja winning bike. There were still some parts that would not fool the expert eye, but the illusion of the replica was growing. It suddenly dawned on me that to make the whole project a reality I should take the bike to the Baja and race it.

So I signed up with Score International for the Baja 250 in March 2012. There was still so much to do... The bike was nowhere near ready to move, let alone race in the Mexican desert and I was certainly not in a condition to do any strenuous physical activity...

January 2012 with a reasonable copy of the Mugen header

The following few weeks saw a rather unpleasant succession of rushed trips to the welder's shop to finish some bits on the frame and exhaust. A misunderstanding led to the welder discarding the nice Mugen-like header he had built and replacing it with a mere copy of the stock one, I was not amused...

For the motor I got a 91mm Wiseco in a rebored jug, and splashed out on a super trick cylinder-head by EdCo (see all specs under) with desert race Megacycle cam. This was very last minute work.... Crazy. I also got a stunning aluminum billet clutch basket and a rebuilt crank with a Carillo rod, but did not have time to fit these. The bottom end, remained stock Honda.

XR500 Cylinderhead by EdCo with Megacycle camshaft, RD springs etc.
XR500 Cylinderhead by EdCo with Megacycle camshaft, stainless +1mm valves, RD springs etc

The bike and I did make it to the Baja 250... just about. You can read all about it here (Score International Baja 250 2012 on a 1981 XR500 Baja Commander replica)

Before the start of the Baja 250 San Felipe March 2012
March 2012, before the start of the Baja 250

Marker 110, Baja 250 San Felipe
Marker 110, Baja 250 San Felipe

We also made it back to California in one piece to live and tell!! This was the whole point really :)

With Jeff Cole in Fallbrook . March 2012

On the way back from Mexico, we stopped to meet Jeff Cole and show him the bike.


At practice April 2012



Specs

 
Frame + swingarm
  • 2010 build by Jeff Cole, Fallbrook, CA.
  • Fitted with opening for future brake light switch.
  • Will receive stand bracket. Etch primer, 4 layers of paint (Natural White 056) and 2 layers of clear coat.
  • Period swing arm axle, zinc plated with new end nut.
 
Rear shocks
  • Period piggyback Ohlins, 17.5 in., rebuilt with all new parts from Ohlins USA
  • Repainted with clear top coat.
  • Can't yet figure out how Al Baker got them fitted back to front.


Front fork
  • 1983 CR480R 43 mm Showa
  • New steering bearings (AllBalls), new bush guides (very hard to find XXXX), new seals (XXXX, I do not recommend, very, very  hard to fit), rubber boots (DC Plastics, excellent)
  • Scutcheons painted plain white, home made decals (scan original, enlarge, edit graphic, laser printed on clear adhesive vinyl).
  • It is the wrong fork. A 41mm one is waiting to be restored. Will receive emulators and springs for my weight.
 

Front wheel and brake
  • Stock XR500R 1981 hub and DID rim polished, new bearings.
  • Stock spokes and nipples re-plated (zinc by Caswell DIY kit, excellent).
  • Double Leading Shoe back plate from 1982 CR480R
  • New paint and clear coat. All steel bits (including axle) zinc plated
  • Custom cable, extended 3 inches (Pro-Motion) to allow future fitting a XR headlight. New cable guide.



Rear wheel and brake
  • Stock XR500 1980 hub and DID rim polished, new bearings
  • Stock spokes and nipples re-plated (zinc by Caswell DIY kit, excellent).
  • Stock XR500 1980 back plate with 1983 XR500R aluminum lever
  • New paint and clear coat. All steel bits (including axle) zinc plated
  • 1976 MR250 cable adjusted and cut to fit (now THAT was a royal pain in the ...) and welded at front with silver solder.
  • Custom return spring from Orchard Supply Hardware :)
  • Pedal from 1981 XR500R zinc plated with new brass bearing
  • Stock XR500 1980 aluminum brake stay
  • Stock XR500 1980 axle
 




Body
  • Aluminum side covers by Jeff Cole, paint and clear coat.
  • Seat base from CR250R 1979 with new nylon inserts and new brackets, new foam (XXX very hard), new cover (XXX will be replaced with ribbed version as per original).
  • New mud guards, Johnny O' style (XXXX)
  • Period Vesco SFLA tank and cap, lined inside, paint and clear coat outside (adhesion promoter XXXX, flexible primer), with aluminum brackets to fit, sitting on foam padding and 1979 CR250R rubber mount. 1979 CR250R petcock.
  • Foot rests from 1981 XL500S, zinc plated
  • Skid plate from 1979 XR500 modified at rear to fit frame mountings (have to ask Jeff why this is not a straight fit)
 


Controls
  • New Gunnar Gasser (made in Sweden, XXX)
  • New brake and clutch perchs and levers (XXX)
  • Period and NOS rubber covers
  • New handles
  • New clutch cable
  • New cut off switch
  • New handle bar (XXX)
  • New throttle cable (XXX)
 Electrics
  •  Stock 1980 XR500 &V CDI and coil, new HT lead, 1981 XR500R spark plug
  • 1983 XR500 front plate and rear light
  • 1981 6V headlight
  • Vapor electronic speedometer
 


Motor
  • Stock XL500S 1981 bottom end and gears (PD 01) for now (trick XR500 - PE01- with welded crank and Carillo rod in the works)
  • 91mm HC Wiseco piston (520cc)
  • Cylinder head and rocker cover by EdCo, stainless +1mm valves, ported and polished, RD springs, titanium tips, brass guides, blueprinted inlet pipe
  • Megacycle camshaft 144.20 fast desert riding
  • Period Lectron carburetor (pre Power Jet), with clear bowl rebuilt and tuned for XR500 (Lectron, Texas)
  • Billet aluminum clutch basket by Movingmikes
  • Exhaust header copy of Mugen part (Pipelyne, San José) needs more adjustments
  • NOS ex Al Baker Mugen muffler (quite proud of that catch), fitted with approved spark arrestor
  • Home made aluminum air box with UniFilter unit
 Miscellaneous
  •  All (I really mean ALL) small hardware is either new or re-plated (zinc)

Honda XR500 C&J Mugen replica . First ride after Baja 250 2012




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