26sep2003

Three-speed long bike!

Sort of a cross between the traditional head-tube over seat-post tandem and BRC Summer. Two Murrays: one gray with blue trim, one silver with blue trim. The stoker bike is the gray 3-speed, and it contributed the fork and the blue fenders and the wheels and brakes, and the blue seat and the blue-grip handlebars. (The captain bike had 24" wheels with adorable blue rims.) But it's not a tandem; there's only the stoker seat and bars.

The steering linkage may involve chain and 3-speed cogs.

It's got tremendously bad shimmy - some of the Scarecrow Hardware should solve that. The SCHW deserves its own page. It's pipehanger hardware - two-piece screw-down clamp for around a pipe, and threaded-rod out off the side.

Working titles: Foots, Randem, ThatsAmore, ThatsAMurray, ThoseAreMurrays, HeyEddie.

Seems like it should make a good cargo bike, or Radio Box B mount.

Ready for sculympics tomorrow? That's a pretty good maiden voyage trip - not far and lots to carry.

Needs: steering, stabilizing, tubes patched, bottle cage, ??

Could use: front (1P) crankset removed.

26sep2003

Probably the SCHW really did it. I haven't _ridden it since, but the frame feels flexless. One piece from the stoker top tube (open frame) to each captain seatstay.

Steering is still a big deal. Have an old sturmey cog bolted to the bottom of a BMX stem with the stem bolt through some appropriate washers. If I had an even longer stem bolt, I could stabilize that with a piece of wood and bolts or something. Then a chain to the stoker steering, with a cog around the stem.

Off by a half-link, didn't think in time of making one of the cogs 19tooth (didn't realize I had scads of those, too). Tried a firm spring - way too loose.

So I guess the only reason springs survive in Summer's steering train is that its head tube is so vertical. At any rate, anything slacker and even sturdy springs just stretch instead of causing any actual steering. This is getting really tedious.

I guess the tubes are holding air. Somewhere I have some of those tabs that turn a mousetrap rack into one that can take panniers with 0-rings.

?fall2003

Tried solid steering linkage with two sets of handlebars and brush guards! Nah...

19jan2004

Had a thought, maybe the chain drive with a sprocket up front is the right thing, but maybe secure the chain to the bars somehow and take up slack by sliding the attachment points along in the toward-stem/toward-grips direction. If the attachment points end up much further apart than the width of the sprocket, there'll be some odd gear-ratio effect... [Won't work, has to be down at the very base of the stem instead of up on the bars.]

20jan2004

One nice thing is, in case of hardware failure, all the parts from the original 3-speed are still there. You could build a bike out of this pretty quick. In fact, it might be a good idea to carry extra saddle and pegs in case there's any need for it to become a two-seater.

23jan2004

Well, at that point you might as well carry two extra wheels and a chain =/

20jul2004

Grr, I'm going to make some progress on this even if it takes some brazing (I'm not so allergic to the idea lately; even Scarecrow started welding). But probably not if it takes starting over with the SCHW. So I think I should reinstall the front steering BMX stem and cog, and then give the rear one a good look. Maybe it would work with the right size cogs (an 18 and a 19?) and a tack or two. And I could survive a tensioner.

I think patching that tire is probably not what I'm in the mood for just now.

21jul2004

Got the front bits back on. YK, I forgot, the thing could use to be put together different. (For one thing, the drive bottom bracket is REALLY low.) The bars are sadly low, too. So one thought is to mount a whole separate higher head tube and leave the current stoker head tube structural only. Note, top of stoker head tube is about the right height for the rear steer cog to sit.