ON THE PACE
The addition of the 250cc powered motor to the Ossa model range was very welcome, as the company can now offer a complete range of machines to suit all riders, classes and abilities. With a choice of 125cc, 250cc, 280cc and 300cc engine power what type of rider goes for a 250cc, you may ask? The 250cc class of any manufacturer is not the biggest selling model, it’s usually the 280cc or 300cc, so who purchases a 250cc? This size of engine capacity attracts many of the newcomers to the sport who want easy-to-use power and this new model fits ideally into that class with its smooth, usable power. Steve Dixon is a regular competitor and award winner in the Northern Centre and that’s where Trial Magazine visited recently to let him put the 250cc Ossa through its paces.
The Ossa machines have been around now for a few seasons, and have gained themselves a reputation for delivering very good smooth, usable power even with the larger 280cc and 300cc engined models, using the latest fuel injection technology. With the very early models they had a few teething problems with the gearbox, but fundamentally the machine performed very well. With the vastly experienced UK importer Nigel Birkett in charge these early problems were addressed first hand, eradicated, and we now arrive at the 2014 models offering a tried and tested product. If you want any proof of the machines’ reliability Jonathan Richardson finished with the fastest time at the 2013 Scott Trial taking third overall; enough said!
EVOLVING
What Ossa has done to move forward with the machine is look at components they have had problems with in closer detail. You must remember that, compared to their rivals, the Ossa machines are the only really ‘new’ machine on the market as the other manufacturers have simply evolved their older models over a period of time. You can argue that the Jotagas, which is also from Spain, is new; which it is, but in the engine department it follows the conventional design of the modern single cylinder two-stroke, whereas the Ossa engine features its reverse cylinder technology, new to the trials motorcycle, and a programmable fuel injection system.
Early complaints with the throttle response time have been improved, as has the way the motor performs, with modifications to the clutch which affords a better experience for the rider. Another change that has improved the machine’s reliability is better production and assembly techniques.
The 250cc cylinder has been developed from scratch with Ossa seeking out the best compromise for an easy but effective power delivery which can offer more torque across the whole rev range, and especially at low and medium engine speeds. To further improve engine efficiency the cylinder head has been reviewed and adjusted in order to work with the new injection maps that accurately self-adjust to varying conditions of temperature and altitude. The reverse cylinder sits nicely on the engine, which has also seen a change with the motor’s main component, the crankshaft, now having a ball bearing which minimises vibration and reduces stress on the transmission.
Housed inside the slim width crankcases the gearbox has been reinforced in certain areas with a new design of the gears and shafts to offer a more robust, smoother and more positive action. To improve reliability and reduce friction, which in turn improves performance, the crankcase design has also been changed to allow the use of 450cc of oil compared to 350cc on the older models.
The clutch has a new spring and pressure plate configuration that ensures uniform working and provides a longer life to the disks whilst giving a better feeling and smoother actuation.
Earlier models were criticised for the machine’s starting ability but a new electronically controlled battery capacitor system has been fitted along with a new wiring circuit which has been redesigned for greater simplicity and reliability.
STRONGER
Once again small but important and detailed improvements have been carried out on the frame and its associated components, aimed at making them stronger and more reliable. It may be only a small change but a stronger rear-drive chaintensioner spring ensures a more constant tension in this very important area, proving once again that the factory is listening to the buying public’s past criticisms.
Still at the rear, new linkage connecting rods and a rocker arm are fitted with larger diameter shafts to ensure its strength and give a more positive feel to the suspension and improve durability. Also at the rear the shock absorber is an Ohlin’s TTX Variable Progressive System type.
At the front quality has also been high on the agenda with the old steering-head bearing seals now replaced with larger diameter sealed ones that prevent moisture from entering the bearing housings. The latest 40mm Marzocchi aluminium front forks are fitted, and along with the rear suspension the settings have been revised, using competition experience to increase performance and improve feeling for the rider.
Carrying on with the quality of components, new Braktec clutch and brake master cylinders have a new design that improves the feeling and control. The machine certainly looks good in the flesh, with its fresh and modern design incorporating a white base for the design and a powerful green standing out on its black frame to give the Ossa a distinguished but sporty look.
Both Steve and I agree that the machine’s looks make you want to jump on it and put it through its paces as it’s got a sort of premium image about it — but how would it perform? We were about to find out.
The machine we tested was a 2014 model but not brand-new out of the box. It had been used in a few events prior to our test and so the motor and suspension were well bedded in.
INSPIRING
Steve had a quick play on the machine to get a feel for it as he was used to riding his usual mount which is a 280cc Scorpa, and came back with a smile; always a good start!
We just adjusted the handlebar and lever positions before he started the test and left the suspension settings alone as Nigel Birkett had set these up for Steve prior to the test.
As I was snapping away taking pictures, I soon realised how at home he felt on the machine as he started to get confident on some of the more difficult hazards at the test venue.
Steve: “I found myself straight away comparing it to my own Scorpa, which is normal when you test another machine, but it soon became apparent how modern the Ossa feels. On the move the machine feels pretty good straight away, inspiring me to quickly drop into the river and put the machine through its paces on the rocks and banks.
“With its very high mounted air filter intake, which is just below the headstock, you can forget the fear of drowning the engine in the water, it really would have to be a freak accident to fill it full of water — or a very deep river! The exhaust note is nice and crisp, and no matter what you do with the motor the performance from the fuel injection system remains the same with no sense of it loading up when it’s left on low engine revs. You soon feel very comfortable, with my only problem being the position of the rear brake as I missed it with my boot on a few occasions.”
BALANCE
With Steve taking a break for a drink we both got the opportunity to discuss the machine, as I had last year tested the 300cc Ossa.
Steve and I agreed that the machine’s biggest attribute is the superb handling and suspension behaviour giving you confidence to close the throttle and hold the line up a hazard.
Steve: “The power from the 250cc motor is more than adequate and along with the improvements to both the engine and the clutch its delivery is super-smooth. The physical size of the engine, with its very narrow width, is strange at first but once you get used to it you can squeeze through the tightest of gaps leaving you to focus on other parts of the hazard.
“Gear selection is very precise and along with the clutch action it allows for a very smooth ride, with the throttle response very exact when required”.
The fuel tank on the Ossa is located in front of the engine, where on a conventional machine the frame tubes would run, making you think that the machine would feel front-heavy on the steering.
Steve: “It’s quite surprising that you do not really feel this sensation of the front being heavy as the overall balance of the machine is superb and gives you a very positive feel. The motor is also lively enough to address any quick changes in direction”.
As I have already mentioned I rode the 2014 300cc version last year and so we both came to pretty much the same conclusion on the Ossas. That is that they are addressing any previous issues with the machines and making progress at a very rapid rate, producing a superb range of machines to suit all abilities. If you fancy a new 250cc why not try to Ossa, we think you will be very impressed.