Model Year Identification

Thank You!

Firstly, a big Thank You to everyone who supplied data for this section. It pleases me to see there is significant worldwide interest in these bikes. I would still like to gather more VINs and motor numbers for my research. It would help validate the approximate number of bikes produced.

I would also like to make an accounting of what bikes are in what part of the world. It would be a simple registry of the model year, bike, and location - something like 2014, TR300i, Scotland. If you want to be more specific with your location, that's fine too.

To contribute data, you can reach me via Trials Central, username: konrad.

Chassis Number (VIN)

Even though modern trials bikes have a 17-character chassis number, they do not completely follow the North American convention I am used to seeing. Even an EU-specific VIN decoder does not work with the OSSA. Here is what I have pieced together:

All chassis numbers comprise 17 characters and, in addition, have a leading and trailing asterisk (*). As is typical, they are found on the headstock.

The VIN may or may not employ a security code (also called a Check Digit) as the 9th character. Based on the VINs I have evaluated so far, 2011 bikes do not follow the convention, whereas later bikes do.

All the VINs I've seen begin with “UCNTR” and are of the form: UCNTRxxyyyzzzzzzz

Wikipedia tells me the first 3 characters of the VIN for a vehicle manufactured in the European Union encode the country of origin and the specific manufacturer. As of 2024, “UA” through “UG” were unassigned. It would seem OSSA nabbed “UC” for themselves without ever making it official.

“TR” probably stands for trials.

“xx” encodes the displacement. “30” is a 300cc bike. “28” is a 280cc bike. “25” is a 250cc bike. I don't have any 125cc examples, but it's possible to make a guess.

“yyy” is the year, and possibly more: “??A” = 2011, “??C” = 2012, “??D” = 2013, “??E” = 2014, “???F” = 2015.

The 10th character of the EU standard is as follows: “A” = 2010, “B” = 2011, “C” = 2012, “D”= 2013, “E” = 2014, “F” = 2015. So the only discrepancy is the first year of production (2011) which used “A” instead of “B”. OSSA may have planned to start selling bikes in 2010.

“zzzzzzz” (last 7 digits) is the ID number, presumably in order of manufacture.

Engine Number

The location of the engine number is on the left side between the alternator cover and the cylinder near the fuel injector connector.

All motor numbers comprise 13 characters and, in addition, have a leading and trailing asterisk (*).

They are of the form: *MTRxxxIyyzzzz*

“M” likely just means motor.

“TRxxxI” is the model/displacement. Options for “xxx” are 250, 280, and 300. I have no information for the 125, but assume it is the same.

“yy” is the year: 11 = 2011, 12 = 2012, 13 = 2013, 14 = 2014, 15 = 2015.

“zzzz” (last 4 digits) is the ID number, presumably in order of manufacture.

Numbers Matching?

Don't fret if your chassis numbers don't match your engine numbers.

Only one of my bikes has matching numbers. Another is reasonably close. The numbers for the 2011 bike are vastly different (motor 764 in chassis 165). Maybe early on OSSA was trying to obfuscate how many bikes were being produced.

I think later bikes are more likely to have matching numbers than earlier bikes.

Notes

I find it curious that none of the VINs have “B” (2011) as a year designator. First-year bikes sold as 2011 models had their chassis manufactured in 2010 and engines manufactured in 2011.

It's also possible that bikes sold as 2015 models were using up 2014 chassis and engines. But admittedly, I only have a single data point.

This is just speculation, but I am not aware of any 2015 OSSA trials bikes, only Explorers. This could make sense because that would have been after the merger with GasGas. GG had their own trials bikes to sell, but nothing like the Explorer.