Thunderbolt Lightning and Wide Range Gears

Doug Goncz said:

Lightning Cycle Dynamics's Thunderbolt uses a boom to
adjust rider leg length. The boom extends forward to the
SWB cranks. An accessory chain take up device allows
changing boom length without changing chain length, which
is usually required.

So when my Thunderbolt comes in from my dealer, I will
check on using that take up device to facilitate my wide
range gear set. ( 657% )

It is 24/35/51 x 34/29/23/19/16/13/11, and so:

24+11 = 35, 51+34 = 85, 85 - 35 = 50, well out of my
derailer range.

I don't know yet if it is a spring device or a set and
forget thing. If the latter, it would only provide minor
adjustments of where in the wide range gearing the
derailer failed. If the former, it will provide a fully
integrated system offering all 21 gears, 10 of which are
duplicate, without worry of crashing the drivetrain.

I have a friend who runs a 54/44/24 crank and an 11-32 8-
speed cassette on a Lightning P-38 without any chain "take-
up" device. As long as the chain is not too loose in the
lower gears without it, I would remove the chain take-up
device to reduce drivetrain friction (unless you are
planning to have more than one person ride the bike on a
regular basis).

--
Tom Sherman - Quad Cities (Illinois Side)