Altis Sigma vs Altis Delta: which is bigger?
The Altis Sigma is the bigger bike. Its wheelbase is 3.7 in (95 mm) longer (50.6 in (1,285 mm) vs 46.9 in (1,190 mm)), its seat sits 1.2 in (30 mm) higher, and it weighs 24 lb (11 kg) more.
With a 31.9 in (810 mm) seat, riders around 5'5" and up can get the balls of both feet down once suspension sag is counted, and riders around 5'10" and up can flat-foot it. On the Altis Sigma, with a 33.1 in (840 mm) seat, riders around 5'8" and up can get the balls of both feet down once suspension sag is counted, and riders around 6'1" and up can flat-foot it.
Silhouettes are traced from manufacturer side-profile photos and scaled so the wheel-to-wheel distance matches the published wheelbase, so small parts like mirrors and fenders may be off by a few percent.
Questions
Is the Altis Sigma bigger than the Altis Delta?
Yes. The Altis Sigma has the longer wheelbase, 50.6 in (1,285 mm) vs 46.9 in (1,190 mm), and is 78 in (1,980 mm) long overall vs 59.4 in (1,510 mm) for the Altis Delta.
Which has the lower seat height, the Altis Sigma or the Altis Delta?
The Altis Delta, at 31.9 in (810 mm) vs 33.1 in (840 mm) for the Altis Sigma, a 1.2 in (30 mm) difference.
How tall do you need to be for the Altis Sigma vs the Altis Delta?
Roughly: the Altis Sigma suits riders from about 5'8" (balls of feet down) and the Altis Delta from about 5'5". Shorter riders manage both with lowering links or a slimmer seat. Enter your height above to see yourself next to both.
Which is lighter, the Altis Sigma or the Altis Delta?
The Altis Delta: 161 lb (73 kg) vs 185 lb (84 kg) for the Altis Sigma. Manufacturers don't all weigh the same way, so treat small gaps as a wash.
Which is faster?
The Altis Sigma has the higher claimed top speed: 75 mph vs 62 mph.