The range of 428 sprockets on our site gives you the same spread as your standard 525/520 in terms of final drive/ max speed. The main difference (apart from the obvious weight and friction loss (30% less weight compared to a 525), is that for each rear tooth of adjustment on the 520/525/530 (0.625 pitch) set up, theres a net increase/decrease of 4mph, but with the 428 (0.5 pitch) this adjustment is generally 3mph- hence the 428 set up providing 25% finer adjustment. Additionally, one of the issues with changing gearing normally is that more than 1 rear tooth on or off the rear will alter the wheelbase by a massive 9mm, which affect the handling massively. You will notice with the 428 set up that the standard wheelbase can be retained much more consistently, in most cases well under 5mm. As a rider, the key here is the adjustability: (example) A 525/520 set up, running 15/47 sprockets would rev out at 162mph in top gear. If the rider had a problem with gear selection/ revving out at one point of the circuit, the only option would be to either go to 15/46 or 14/45, these would then rev out at 166 or 158mph respectively and also give a similar 4mph adjustment in shifting right up through the gears. As you know, this usually ends up with a compromise at most circuits, especially when running a stock gearbox. However- with a 428 set up running similar gearing, you would have a choice of 17/54 (160mph), 18/57 (161mph), 17/53 (163mph), 18/56 (164mph). The finer adjustment right through the gears means you can almost eliminate the need for compromise and find the ‘perfect’ gearing for the rider and circuit without affecting wheel base to a high degree. http://shop.t3-racing.co.uk/428-rear-sprockets-1172-p.asp
