Triumph 1927 SD 550 cc side valve frame # 34776 engine #109815 AMT
The SD (Spring Drive) was in fact a somewhat modernised version of the famous model H, which had grown out of the “Trusty” veteran Triumph.
By the mid-twenties belt drive was losing its appeal to many motorcyclists, so Triumph designed a model with chain secondary drive.
The primary chain is protected by a well-engineered aluminium case and runs in an oil bath to minimize maintenance of chain and clutch. The powerful 550 cc engine (bore x stroke =85×97) has lots of torque.
The machine is equipped with three speed gearbox and 26×3 beaded edge tyres.
This SD has not run for a long time and will need careful recommissioning before putting her back on the road again.