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As title - was looking at the geo info for the new Airdrop Edit MX, and it gives BB drop figures for front and rear (there's a 19mm difference between them; like the difference in radius between 27.5 & 29 wheel sizes).
Surely BB drop is just a single measurement taken below an imaginary line between the centres of the rear & front axles? So why two figures? I'm confused (not difficult, I'll admit). Anyone enlighten me?
I’d imagine they’ve used horizontal lines from each axle, rather than a diagonal between them.
Mullet BB drop figures haven’t reached a consensus on how they’re measured yet
Surely BB drop is just a single measurement taken below an imaginary line between the centres of the rear & front axles? So why two figures? I’m confused (not difficult, I’ll admit). Anyone enlighten me?
If it was on a line between wheel centres it would change with wheelbase which would confuse people even more.
@Brant, so where's the 'drop' normally measured from then? Only asking as I'd never seen two separate figures quoted before. If the bike had Ohlins vs Lyriks the different axle to crown would skew those numbers anyway, wouldn't it?
@sharkattack, agreed, looks great! Just curious about the numbers..
Seen quite a few brands listing two separate figures (Santa Cruz Heckler ebike for example). Not sure it helps. Those with only one tend to use a line between the two wheel axles, and measure vertical distance from BB axle to that diagonal line. As Sharkattack says... just ride it.
I’ve always assumed that if BB drop looks like a 29” figure it’s off the front axle and if it looks like a 27.5” number it’s off the rear axle. Measuring off a diagonal line would be totally confusing, I really hope that no-one is doing that!