CARRY ON SCREAMING
How Honda’s late-’70s air-cooled MT125RS came to form the backbone of a thriving 125cc class in the Classic Racing Motorcycle Club
The ins and out of the hotlycontested CRMC 125cc class
OVER 40 YEARS ago, Honda UK boss Gerald Davidson had the brilliant idea of breathing life into UK road racing by creating a big-money one-make series using a bike with an engine based on Honda’s 125cc Elsinore motocross engine. Designated the MT125R2, the bikes were developed in Japan by Honda’s Racing Service Centre (RSC), the precursor to HRC. It shared many parts with the CR125 motocross engine, though the road racing version (56mm x 50.7mm, 123cc) used a different spec cylinder to the CR with a larger intake, and a larger 34mm Mikuni carburettor.
Another difference was the close-ratio gearbox and its gearshift pattern. Both had a standard one-down/fiveup pattern, but on the MR the gearlever was flipped rearwards to suit the road racing rearset footpeg set-up, with a different shift linkage behind the engine cover to retain the original gearshift pattern. The lightweight tubular steel chassis was also modified with a revised swingarm to switch from motocross spec to road racing. The 1977 bikes produced 26bhp at 10,500rpm, increased to 28bhp the following year, which also saw a redesigned expansion chamber. The original MT came with a cable-operated front disc, but the ’77 model was updated with an hydraulic disc.
Honda UK ordered 45 of them to run in an eightround series with 35 bikes on the grid chasing a prize kitty of £10,000 – back then, one of the biggest purses in British road racing. The series was strictly policed to ensure the bikes remained unmodified with only gearing and carburation changes permitted but no restriction on make of tyres. The bikes were run by the UK Honda dealers and the rest is history – extremely close racing by all the top racers of the day ensued.
The inaugural series was won by Clive Horton, from Charlie Williams and Derek Huxley – all of them wellrespected national class competitors at the time – among a grid of other notable names like Barry Woodland, Rod Scivyer, Bernard Murray and Richard Stevens.
Fast-forward to the present day and you can still see a grid of these little missiles, albeit mixed in with the later pre-1986 water-cooled RS125 Hondas and the occasional Yamaha TZ125 at all CRMC rounds.
The class is divided into ‘Piston Port’ (for the MTS) and ‘Open’ (the later RS bikes) and offers some of the closest, hardest racing the club has to offer.
I’ve raced an MT for many years and, having raced many different bikes, I can testify the MTS are one of the hardest bikes to ride but also one of the most enjoyable. My 85kg machine has a very cramped cockpit (unless you are eight stone and four feet tall) and a knife-edge powerband which starts at 9000rpm and is over by 10,250. The RSC factory rev counter doesn’t even move or display engine rpm until the engine is spinning at 5000rpm.
Just getting off the line is a heady mix of maximum revs and serious clutch slipping for a hundred yards, but once underway you try to climb under the tank and keep the throttle pinned. Thank goodness for the sixspeed close-ratio gearbox.
Slipstreaming becomes an art form and you apply the gas earlier in a corner than on any other bike. The one really special thing about riding an MT is the corner speed you can maintain – it’s addictive. During one particular race at Donington Park, I peeled into Redgate with seven other bikes – we all sped through there eight abreast. I swapped position three times mid-corner and headed off down Craner laughing my head off.
The MT125R is easy to maintain, with parts readily available and if you don’t try and jet it to the nth-degree you will get a season’s trouble-free racing.
The later RS125S might be faster and more technically developed machines, but the class is a good mix with battles all the way down the field
You can see a grid full of these little screamers hurtling into Coppice and Charlies at the next CRMC round (see below).