velospace is about bikes and the people who ride them marketplace photos random forums








Fuji Special Road Racer Retrodirect

Bike tags: Road bike | Commuter | 64cm | blue | Fuji | more tags >>
Bike photo
Click to view other photos

1972 Fuji Special Road Racer 25"

Origin8 Tiki moustache bars, Profile 14cm stem

Generic fork, Nishiki headset

Mavic cxp11

Mavic MA40

Sugino Maxy 165mm

performance campus pedals

22t forwards, 16t backwards, 40t/50t chainwheels

This drivetrain gives a low gear pedaling forwards and a higher gear pedaling backwards. Additionally there is a front derailleur to access a total of four gears, two pedaling forwards, two backwards. The BB cups, pedals and chainring bolts must have loctite on them to keep from undoing while pedaling in reverse. This is a very fun ride.

People who friended this bike Aaron C, snakechild, Micklol, Laurel.Aitken, jellyfish, Roni Solomon DDS, eaglerock, Kyle Dickinson, swardenh, yoxscotty, SpaceGhost, vdubug, whysamsam, payne, dirtle, LuisRidesaBike, solofe, mushroom, andreas, marctenor, redbeard, M0THER, the fumingator, avail86, debido666, velocepedestrian, tuccibird, Rustee, Brannigan, My New Toy, ryuj1n, joaobola, phantom1313

that drivetrain

That drivetrain i messing with my head, can you coast? i understand its not a fixed gear but you can't coast right? can you do fixed gear style skids? really cool, good job!

how hard was this to make?

how hard was this to make? any info on making one of these would be awesome. total mindfreak to see someone pedaling backwards and going forwards huh

Not too hard, but there are

Not too hard, but there are some fiddly bits. Use a dicta brand freewheel on the hub, those have threads that go all the way through. Then screw in an old bottom bracket cup to extend the threading, adn the second freewheel goes on the BB cup. Might need some spacers in there also, and I had to respace the hub a bit.

The main challenges are chain tensioning, and chainstay interference. There was only one configuration here (with the smaller freewheel inboard and being driven in reverse) where the chain didn't rub on the chainstay. Classical retrodirect bikes had a very curvy right chainstay to clear the chain.

The Kore chain tensioner works, but it's pretty fiddly (wouldn't clamp on a chainstay that small, hard to make it hold its angle) If I were doing another I might rig up part of a rear derailleur on an e-type derailleur mount off the bottom bracket.

One possibility with the chainstay

...is to clamp a piece of galvanized electrical conduit underneath the chain tensioner's clamp, as I did on the non-driveside chainstay in this build to spread the torsion from a drum brake arm. If you use a hacksaw or Mototool to slice the conduit into a half-cylinder, you get a few millimeters of spacing; the clamp from the gadget holds the conduit in place.

Did you have to redish the rear wheel once the freewheels were mounted?

Neat

Wow that drivetrain is cool, never seen something like that. Does it feel weird to keep moving forward but pedaling backwards?

???????

this is awsome i love the chain line on the last pic

Wow!

That's impressive, I'm sure Sheldon Brown would love this.

Uh...uh....

...WTF?

That is wild. What purpose does it serve?

That settles it; I'm starting a cluster for gimmick rigs...

I think this design has been

I think this design has been around since the early 1900's. Hirondelle (France) made one called the RĂ©tro-Directe that is in Jan Heine's book 'The Golden Age of Handbuilt Bicycles':

"The gear mechanism is remarkably simple: The chain is wound in a figure-eight around two freewheels (of different sizes). One freewheel is engaged when pedaling forward, the other when backpedaling. To change gears, one simply reverses the pedaling motion and pedals backwards."

It goes on to say their top-of-the-line model had a front derailleur that gave it 4 speeds. Interesting design. :)



velospace | About | Privacy Policy | Terms of Service | contact | blog | status | site map | ©ActionHub.com