Many riders jump on their Triumph Street Triple 675 and enjoy the ride without giving much thought to the suspension. However, understanding and adjusting your suspension can dramatically improve handling and comfort. Let’s delve into whether the stock suspension on the Street Triple 675 is actually suited for the average rider.
Online resources, like the Race Tech’s Spring Rate Calculator, offer insights into ideal spring rates. According to this calculator, the stock spring rates for a 2009-2010 Street Triple R are approximately 0.9 kg/mm for the front forks and 12.6 kg/mm for the rear shock. These figures raise some eyebrows when considering rider weight.
Plugging typical rider weights into the Race Tech calculator reveals a surprising discrepancy. To optimally utilize the stock front spring rate, a rider would need to weigh around 235 lbs. Even more surprisingly, to properly load the rear spring, the calculator suggests a rider weight of a massive 364 lbs! While some motorcycles are indeed designed to accommodate two-up riding, the Street Triple 675, like its Daytona sibling, is generally considered a solo-rider machine. This significant mismatch suggests the calculator might not accurately reflect the Street Triple 675’s intended suspension setup.
Practical experience and expert opinions further challenge the calculator’s results. Experienced suspension tuners emphasize the importance of achieving correct sag – the amount the suspension compresses under the bike’s own weight and the rider’s weight. Dave Moss, a well-known suspension expert, recommends general sag ranges for sportbikes: 32-38mm for the front forks and 28-32mm for the rear. These ranges are crucial for optimal handling and feedback.
Feel The Track! offers a wealth of informative articles on motorcycle suspension tuning, providing further context and guidance. Additionally, a YouTube video featuring a 2008 Triumph Street Triple suspension evaluation (pre-R model) highlights the importance of sag. In the video, Moss suggests a rear sag of 40mm for a 180lb rider and praises a 38mm sag for a 140lb rider as “right on the money,” indicating the stock suspension might be best suited for riders in the 120-150lbs range.
Another crucial point from Dave Moss, highlighted in Feel the Track articles, is that excessive preload adjustment to achieve proper sag is a sign of an incorrect spring rate. If more than five turns of preload are needed on the rear shock, it often indicates the spring is too soft. This reinforces the idea that the stock Street Triple 675 springs might be on the softer side for many riders, especially those above the 150lb range.
Finally, considering the Street Triple 675’s unique geometry and rider position, which differ from the Daytona, raises further questions about ideal sag ranges. Maintaining a balanced 50/50 weight distribution, as often recommended for optimal handling, is also influenced by suspension setup and sag. Determining the precise sag ranges tailored to the Street Triple 675’s specific characteristics remains an important aspect for riders seeking to fine-tune their bike’s handling.
