So I am looking at drivebelts for my dna50 and have found that different sites sell different length belts. The manual doesn't give me a set spec, my old one was 126 / 18.5 but when you start researching companies they say "fits dna50 - 135/18.5" or "fits dna 130/18.5", so how does one choose the best length? I assume that a longer belt rides higher on the variator whereas shorter belts will reach max length earlier and reduce top speed a little but might snap sooner? Any advice as to how you measure the perfect length for a bikes variator / clutch setup?
Piece of string around the old belt, then measure that length. Measure the width, although it can be difficult if it's proper worn. Most belts are around the 18mm thickness. Anything close will be fine, but too short and it wont reach the top of the variator, too long it wont get the low revs.
The old belt shredded after a transmission incident. Ill run a thin rope from the clutch spindle to just inside the top of the variator and see what i get.
Thanks, the issue im having is that different manufacturers give different sizes for the same bike varying from 826 to 840 . It might be that different materials lead to different lengths so maybe kevlar is longer or shorter. I like the price on your link so ill buy that one, thanks
ok, when it comes to the dna/liberty, there WERE some models that came wiht the small roller variator. this usually accounts for the majority of varience in belt length and thicknesses, go for the longest widest belt listed for your model year and engine size... alternativly find a website that uses your engine number to prefix parts/walk into a piaggio dealer and give them your reg number, if its a fairly untouched standard bike they can tell you the exact size it came with
