Dream Thumper: CCM 500 Four-Valve Works Replica

1 of 29: ’79 CCM 500 Four-Valve Works Replica Moto-Crosser…  

CCM (Clews Competition Machines) remains one of the most revered names in the history of off-road motorcycles. In the early 1970s, when two-strokes dominated motocross at the highest level, Alan Clews — a successful trials and scrambles rider — set out to build a BSA-powered four-stroke motocrosser that could compete with the Japanese and European smokers, working at first out of his garage. 

Though the CCM machines with their big 500cc and 608cc “Stroka” engines were heavier than the oil-burners, some riders prefer their broader powerbands and greater torque. CCM achieved its greatest motocross successes in the mid-1970s with riders John Banks and Vic Eastwood.  The firm took home second, third, and fourth place finishes in the British championship, as well as several top five finishes in the FIM World Championship.

Clews and company had proven that a British-built thumper could rival the dominant two-strokes of the global heavyweights. Of course, CCM took the learnings from their works race bikes and put them right back into their hand-built production machines. 

Today, these BSA-powered thumpers are properly revered. Go to any vintage motocross event and you’ll feel yourself pulled to the sound of a British big single thumping away in the pits. Way back in 1975, Cycle World described the allure of their CCM 500MX:

“THERE IS NOTHING, no engine currently made, that produces the torque impulses of a big Triumph or BSA Single. There is something about the sound, the violently solitary firing impulses of a big Single, that awes people. Leaving our CCM 500MX to idle, and resting against our van, we found our-selves just sitting and staring at the motor as it thumped away…”

Our buddy Peter Kendall, whose Honda XR650R restomod we recently featured to wide acclaim, has had a love of CCM’s since he was a boy. It all started on the family “cattle station” (ranch) in Western Queensland in the late 1970s:

“We were one of first families to transition from mustering cattle with horses to using bikes. Sometime in the late seventies we had an English station hand (cowboy) working at home who had a love of bikes, and in particular CCM’s. He was always raving about how quick they were and how good they sounded, which started my infatuation with them.”

Boy-Peter “desperately needed” to learn more about these hand-built motocrossers. With no internet available at that time, he took matters into his own hands. 

“I wrote to Lester Rowley (the Australian importer) pretending to be Dad (I was 11 at the time) saying that I wanted to buy one to muster cattle. Lester wrote back to me (Dad) answering all my questions, such as can you get them with a left side gear change, etc., and diplomatically suggested that it may not be the best choice for cattle mustering…”

Rowley also sent Peter a brochure of CCM’s latest weapon, the 1979 CCM 500 Four-Valve “Moto-Crosser,” a replica of their works bikes claimed to make 50+ brake horsepower at a weight of just 236 lbs — incredible numbers for a four-stroke of that era! The CCM 500 was dynoed at 45 hp at the rear wheel. To compare, a brand-new Honda CRF450R — nearly 50 years later — produces ~52 rear wheel horsepower and weighs 245 lbs. 

The CCM frames were an oil-in-frame design constructed of Reynolds 531 tubing, TIG and bronze welded, and the bikes ran proprietary magnesium forks and Öhlins rear shocks. As these bikes were completely hand-built, only 29 were produced for the 1979 model year. 

While Peter no longer has the letter and brochure from Lester Rowley, he now has the 1979 CCM 500 Works Replica he always wanted. David Sheppard — the equipment manager for Peter’s construction company and a fellow dirt bike enthusiast — found the bike for sale in Italy after years of searching. 

While it wasn’t in the pristine condition the seller claimed, it gave Peter and David the opportunity to bring the bike to better-than-new condition. They sent the frame and swingarm to Geoff Morris Concepts for repair and replating, while MPE Suspension rebuilt the trick period-correct Öhlins dampers.

Peter sourced the parts from UK BSA specialists Performance Engineering Services (PES) for a full engine rebuild, which Murray Stead of Brisbane’s Retro Motorcycles handled. 

“We went to town on it and put all new bearings in it, rollerized the camshaft, replaced the piston, liner, valves, guides, etc,. and fitted a complete new competition gearbox from PES.”

They also performed an oil filter modification, which involves rerouting some oil galleries in the side plate and adding a remote-mounted spin-on filter.

“The four-valve versions were notorious for camshaft and rocker wear so most of these mods are designed to correct these shortcomings, and I believe most of the bikes which are actively raced in the UK have done this mod and achieve good reliability and engine life.” 

The result is one very rare, very fast, and very sexy hand-built thumper, believed to be the only 1979 CCM 500 Works Replica in all of Australia. We can’t help but smile at the pluck of boy-Peter writing to the Australian importer, and we’re so happy that boy’s dream was realized. Thanks so much, Peter, for sharing this bike and the story behind it — this is what it’s all about.

CCM 500 Four-Valve Motocrosser: Owner Interview

• What’s the make, model, and year of the donor bike?

’79 CCM 500 Works Replica.

• Why was this bike built? 

I grew up on a cattle station (ranch) in Western Queensland in the 70’s and early 80’s, and we were one of first families to transition from mustering cattle with horses to using bikes. Sometime in the late seventies we had an English station hand (cowboy) working at home who had a love of bikes, and in particular CCM’s. He was always raving about how quick they were and how good they sounded, which started my infatuation with them.

Of course back then there was no internet and very little info available; I had only seen the occasional photo in an Australian Dirt Bike Magazine or Trail & Track, but I desperately needed more info, so I wrote to Lester Rowley (the Australian importer) pretending to be Dad (I was 11 at the time) saying that I wanted to buy one to muster cattle. Lester wrote back to me (Dad) answering all my questions, such as can you get them with a left side gear change, etc., and diplomatically suggested that it may not be the best choice for cattle mustering…

He also sent me a brochure of the latest bike, the ’79 four valve, which I had for many years (I wish I still had it and the letter). I then grew up and lost interest in bikes and got more into racing cars and boats; however, the desire to own a ’79 Works Replica always remained.

• What was the design concept and what influenced the build?

A realization of a lifelong dream of owning one since I have loved them since I was a child. I now own a construction company and my equipment manager is also a vintage dirt bike enthusiast who also got infected by my enthusiasm to find a CCM, and he really was the one who kept looking on my behalf.

He eventually after a number of years found one for sale in Italy, which was supposedly in mint condition, etc., had all the right matching frame/engine numbers, and most importantly was a ’79 Works Replica (one of 29 built), so I bought it.

When it arrived it obviously wasn’t in mint condition but it was a genuine WR and was complete, which was really all we wanted.

• What custom work was done to the bike?

We stripped the bike completely, sent the frame and swingarm to Geoff Morris Concepts for repairs and replating, and I must say he did a magnificent job as it looks brand new.

The engine was a more difficult proposition, as it was not cost effective to send it to England to any of the CCM guys over there, so I ended up sourcing all the latest parts from PES in England for it and getting Murray Stead from Retro Motorcycles to do all the work here in Brisbane. It turned out to be a two year ordeal; however, we went to town on it and put all new bearings in it, rollerized the camshaft, replaced the piston, liner, valves, guides, etc,. and fitted a complete new competition gearbox from PES.

We couldn’t get a new Interspan ignition for it so we fitted a PVL system, which took a bit of work to make fit, but it works perfectly. We also did the oil filter mod that is well known to B50 owners, which involves rerouting some oil galleries in the side plate and adding a remote mount spin-on filter that neatly sits at the bottom of the frame downtube.

The four-valve versions were notorious for camshaft and rocker wear so most of these mods are designed to correct these shortcomings, and I believe most of the bikes which are actively raced in the UK have done this mod and achieve good reliability and engine life. The Öhlins suspension was also completely rebuilt by MPE Suspension.

• Any idea of horsepower, weight, and/or performance numbers?

Yes it was claimed to produce 50BHP @ 7 000rpm and weigh 236lbs (105kg’s).

• Can you tell us what it’s like to ride this bike?

It’s very quick. However, given its rarity and the fact it has a right side gear shift, I don’t ride it very often.

• Was there anything done during this build that you are particularly proud of?

I think in general the quality of the restoration and period correctness given its rarity are its best attributes.

• Is there anyone you’d like to thank?

Yes, David Sheppard for managing the entire restoration.