When I bought the Triumph Street Triumph, I knew that I was buying a reasonably expensive motorcycle but it was the sportiest of the class by a fair margin. Long before I got the Arrow exhaust to release the full 106PS, I changed the throttle tube for a more aggressive feel. Shortly thereafter, I also added a popular performance mod, the Rs 2,600 15-tooth sprocket (one tooth down from stock) from the Daytona, a direct fit.
The results were very encouraging. The Street Triple felt vibrant and responsive in a way that really surprised me.
About 10,000km later, I wore the OE chain to the point where I needed to replace it. And I decided to opt for even more aggressive gearing. So I hunted down a 49-tooth rear sprocket that would drop the top speed from over 220kmph to just over 200kmph while offering a whole new dimension of acceleration. It was during this research that I discovered that Triumph uses a thicker 525-pitch chain and sprocket as stock and Triumph fora were full of owners who had opted for the popular (and about 500g lighter) 520-pitch chains and sprockets to great results. As it turns out, 520 is a more popular pitch and that's what Performance Racing had in stock.
Fitting the new front and rear sprocket was easy, and we needed a chain breaker tool only because I miscalculated the links required (equal to stock) and ordered a chain two links too big. Once we cut two links off and riveted the chain back, we were in business.
The difference in performance remains staggering. Triumph fora call this the 'power wheelie mod' and I can see what the stock gearing isn't this low. The Street Triple leaps forward in the lower gears, and lifting a wheel, with intent or inadvertently, is stunningly easy. Combined with the quicker throttle action, my Triumph is perhaps a little too aggressive for most tastes, but I would recommend this gearing to people who use the bike in varied conditions.
What has happened is that the motorcycle runs about 700rpm higher in the revs at all speeds. The extra torque gives it a delicious snap while I can still cruise at about 7,500-8,000rpm on the highway. At the racetrack, the gearing makes the Triumph feel super crisp and in traffic, I can now run as high as fifth gear which is impossible with the stock gearing.
My gearing is -11 per cent, which is very drastic. Even a tooth or two on the rear sprocket can make a big difference on any motorcycle. The flexibility to play around is higher with bigger machines, naturally, but sprocket is one more way to personalise the nature and power delivery of your machine. Best of all, chain cost aside, it is really inexpensive.
Driven 15-tooth front steel sprocket: Rs 6,000
Driven 49-tooth rear steel sprocket: Rs 8,000
DID X-ring chain: Rs 18,000