My Upgrades

My Upgrades

Making changes/improvements to any motorcycle is based on personal preferences and riding style.  I have a lot of development time in the OSSAs, so they suit me well.  I like to tinker and have always relied on my engineering ability to somewhat compensate for my lackluster riding.

The OSSA is in direct contrast to my Montesa 4RT - that bike just seemed to work right out of the crate.  But unless I wanted to spend a fortune on titanium, it was never going to be as light as the OSSAs.  I am an elderly weakling, so the weight of the bike is of paramount importance to me.  Also, did I mention I like to tinker?  There was nothing to tinker with on the 4RT.

If I have learned anything in life, it is that generalizations are fought with peril.  Judging by the vast differences in trials venues around the world, conditions where you ride may not be anything like where I ride.  You may not ride like me.  I came to trials quite late in life, and it shows in my riding style.  I only half-jokingly say that trials is the perfect geriatric motorsport - it is accessible at nearly any level of ability.  I never ride when it is really wet (damp is okay), partly because I hate cleaning bikes, and partly because it increases the difficulty dramatically.  Take that into consideration when you review my upgrades.

Early Frustration

Although I do enjoy the challenge of working on bikes and improving them, I also enjoy riding.  The former takes away from the latter.

Having been burned in the past by being an early adopter of motorcycle technology, I showed a bit more restraint in buying my first OSSA (the 2011 TR280i).  In fact, I did not buy the bike until the season after it was offered for sale.  I first saw the bike at a club event before I was competing in trials.  At the time, I did not even realize it was EFI but was captivated by the backward cylinder and innovative design. 

When I did eventually have a test ride, I found it very difficult to start and almost immediately ran out of fuel.  But I was still intrigued and conducted my due diligence - even calling the importer - prior to purchase.  I was lured by the low weight and the fact that the EFI system was designed/manufactured in Japan by Kokusan Denki.  However, what really clinched the sale was that an OSSA dealer was setting up shop only 1.5 hours away from me.  That, and the fact the seller had upgraded to a TR300i Factory and was sticking with the brand. 

I made contact with the new dealer and we had a productive conversation.  He admitted to not being a computer guy and had some trepidation about taking on the line.  I offered my consulting services in exchange for access to the dealer programming and diagnostic tools and technical information.  But shortly after our initial meeting, the dealer (who was an enduro rider and only wanted to sell the Explorer) had a falling out with the importer.  So ended our collaboration.

As you may remember from the introduction, I bought the TR280i partly to study its fuel injection system.  There are many reasons fuel injection may be desirable including improved performance, improved emissions, and to automatically maintain correct fueling with changes in altitude and/or ambient temperature.  However, all this comes at the price of a great increase in complexity, to say nothing of manufacturing cost.  Since I ride at a nearly constant altitude, much of the benefit of fuel injection is lost on me.  The fact that it was not a 1-kick starter was a huge drawback for me in competition.  None of my carburated bikes gave me that trouble.

The effort required to kickstart the TR280i 60 or 70 times during the course of a competition was something that really sapped my energy.  But I did (and still do) love the OSSA's low weight, chassis, and suspension (plus the innovative design) and that is why I am willing to put up with all its faults.

I decided to try a TR250i and have never looked back.  It is much easier to kick than the 280.  The 250s are also quieter and produce a smaller shaking force (rider-perceived vibration) than their larger-piston siblings.  Yes, the 250 makes slightly less torque, but it is sufficient for my needs.  In fact, a lot of my tuning efforts have gone towards making the power delivery soft and predictable - that way it is easier to maintain traction.   And, if I need more, I can always just twist the throttle farther. 

In the early days of ownership, I pondered replacing the EFI with something along the lines of a Mikuni BN “pumper carb.”  These carburetors are used where high g-forces (e.g., karts, airplanes) upset fueling.  This type of carb is also used in 2T applications like chainsaws where the varied orientation of the tool does not permit a traditional float bowl to work.  As appealing as that seemed at the time, the ECU would still be needed to run the ignition and I did not know how much that was (or was not) part of the problem.

Glad I stuck with the EFI.