bike design

In article
<[email hidden]>,

rob said:

Hi, has anyone seen a setup like on www.steppebysteppe.com.au

i'm curious about getting schlumpf mountain drive to use with a
rohloff speedhud but worried about the torque issues when loaded up on
a steep incline, as i am making a similar vehical to them

I have no idea whether the mountain drive would be up to the torque
requirements, but Schlumpf would know; ask them.

However, any sort of quadricycle is unlikely to have a very high top
speed. As vehicles, they mostly suck, and the only half-justification
that makes sense is their desire to have an amphibious vehicle (and I
remain convinced they would be better off with an off-road tandem
pulling a large folding or inflatable boat in a purpose-built trailer).

The reason I mention the low top speed of quad-bikes is it means you can
gear for the lowest expected speed and then just hang the top end. If
the bike spins out at 30 km/h, who cares? You aren't going to try to
pedal a quadricycle to speeds higher than that anyways, and the handling
is probably terrifying above such speeds. After all, the whole design is
utterly ridiculous.

Anyways, if you hang the top speed, a Rohloff's huge gear range allows
you to get a really low gear, and the Schlumpf may be redundant.

I don't think the Schlumpf is a hard retrofit, and standard cranksets
are cheap, so just try one of those first.

For that matter, since you're building something as stupid as a
quadricycle in the first place, consider modding a 3-speed gearhub as a
mid-drive transmission, which would give you, fairly cheaply (I'm
assuming that if you're building your own quad you're capable of light
machining) a ridiculous amount of gear range.

--
Ryan Cousineau [email hidden] http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

Ryan Cousineau said:

The reason I mention the low top speed of quad-bikes is it means you can
gear for the lowest expected speed and then just hang the top end. If
the bike spins out at 30 km/h, who cares? You aren't going to try to
pedal a quadricycle to speeds higher than that anyways, and the handling
is probably terrifying above such speeds. After all, the whole design is
utterly ridiculous.

You said it! That thing is wildly impractical. It just needs some
square wheels to add the finishing touch.
-Paul

Ryan Cousineau said:

Quoted message said:

The reason I mention the low top speed of quad-bikes is it means you can
gear for the lowest expected speed and then just hang the top end. If
the bike spins out at 30 km/h, who cares? You aren't going to try to
pedal a quadricycle to speeds higher than that anyways, and the handling
is probably terrifying above such speeds. After all, the whole design is
utterly ridiculous.

Paul G. said:

You said it! That thing is wildly impractical. It just needs some square
wheels to add the finishing touch. -Paul

Perfect for the Flintstones though.

I wonder if they are going to put a tow hitch on the front so they can
hire local mules or donkeys to tow it when it breaks down? And a push
bar on the back so 1 can push while the other steers.