Homebuilt tandem and 26" wheel question
I have a homebuilt road tandem using 26" wheels, and I wanted to replace the incredibly cheap set (from abandoned low-end MTBs) that I currently have on it. I see Performance has an inexpensive pair (http://www.performancebike.com/shop/...0#ReviewHeader) using Rhyno Lite rims and Deore M525 hubs. I've heard good things about the rims, but does anyone have experience with the hubs?
Just for show, here's a shot of the tandem. (I know the stoker saddle is too low--we fixed it later. ) It has single-side drive with 40-tooth timing rings; the rear one is just bolted to the outside of the stoker crank, which is an MTB triple with the 48 tooth ring swapped for a 52. No eccentric BB or idler--I adjusted the chain tension with a half-link, and it seems pretty good as is. Shifting is by an old set of Campy (!) friction barcons. .
Oh, and the most important detail: the frame. The front is an old Miyata MTB; the rear is a Trek 820. Additional tubes are 1.25", 0.9mm 4130, and the keel tube has two of them in parallel for extra stiffness. Overall design is direct lateral-ish--there's tube from the head tube to the captain's seat tube and another from the seat tube to just above the rear bottom bracket (I wasn't brave enough to try to miter it to intersect the keel tubes). I did the mitering on a Bridgeport using hole saws, clamped the thing up using aluminum bars with string for alignment, and took the whole mess off to a shop for TIG welding. The Miyata uses a 1" BMX headset, so it has a nice beefy head tube. Head tube angle is ~70-71 degrees, which gives the bike roughly 2.4-2.5" of trail. The stoker compartment is relatively generous--something like 29" if I remember correctly. I had it out on Saturday for 50 miles with a friend who's a strong cyclist, and it all worked out pretty well--handles nicely enough, no noticable frame flex, and we blew past a moped that decided to try and pass us. Total weight is in the vicinity of 42 lbs, which strikes me as pretty reasonable, given that I made no real attempt to save weight.
Last edited by dsmyers; 04-28-08 at 12:36 PM.
pan y agua
that is something to be proud of. i'm sure the late Sheldon Brown is smiling while looking at your creation!
have you beefed up the fork steer tube yet? i believe that is something that should be done right away.
Thanks--those are kind words. I wish he could have seen it--it was because of his website that I started working on this, and I got a bunch of the parts from Harris.
Originally Posted by the desert fox
I have not reinforced the fork steerer tube--it's a pretty solid 1" MTB fork--but I might replace it with the 26" Long Haul Trucker fork (apparently you can kludge a 1.125 threadless fork to work with 1" BMX cups...the horror...).
Very cool build! But it begs the question.... what will you call your bike? I think “Miya-Trek” sounds nice. But “Trek-Mi” sounds nice too.
Good lookin' tandem duo . . . and tandem!