anyone ever build a 2speed hirondelle style

[frameteam2003]

Waiting for parts to arrive for a fixed gear I'm building,I got to playing around with rear hubs,freewheels and BB cups.Finaly figured out how to add two freewheels to the same side of the hub using a spair BB cup.So my next kustom just might be a Hirondelle Schwinn 2speed cruzer.2freewheels,one chain,two speeds,no shifter!Pedals rotate forward for high gear--pedals rotate backward for low gear.

[FlatTop]

Very cool. For those who can't visualize any better than I can, here's an old Hirondelle setup: http://www.m-gineering.nl/retrog.htm

and a new version:
http://members.westnet.com.au/rjharrop/recumbents/retro-direct/Retro-Direct2.htm

[wearyourtruth]

that's awesome... the things people think of... :)

[MacG]

Can you provide some more details on how to get two separate freewheels next to eachother on one hub? I recall hearing about how bottom brackets use the same threading as freewheels/cogs, but I haven't had that type of bottom bracket apart yet. Do you need to shorten the threading on the hub at all, or are there enough left-over threads on the inner freewheel to attach the bottom bracket piece?

Here's a better question: Where would you go about getting a larger-than-usual freewheel? Everything that I have seen for sale is usually less than 20 teeth. I want to find something more like 30 teeth or more. Can freewheels be disassembled and have larger sprockets installed in place of the typical 14 or 16 tooth sprocket?

[FlatTop]

Harris sells a double freewheel, but they go the same direction, and that won't work, right?

[frameteam2003]

I'm building one at present.I tryed taking the freewheel apart and brazing on a 24 tooth sprocket---got it to work but not as well as I'd like.The heat warped the freewheel some so it drags a little.I've been hunting around and bikeparts wairhouse has a 22 tooth sprocket and 16 tooth so I'll have to order some to build this kustom(schwinn frame).A regular 5/6 speed rear hub will work as for the spacing--screw on the big freewheel then screw a BB cup into the treads left on the freewheel and screw the second freewheel onto the BB cup---I plan on using a third freewheel minus the paws for the ideler.

[MacG]

Nope; you need two separate ratchets to make it work.

The freewheels both will have their ratchets oriented for operation in the same direction of rotation, but when one cog is being 'used', the other cog needs to be spinning backwards rapidly. If the cogs were locked together on a single ratchet (like the double freewheel you mention), the bike would be able to coast, but the pedals would be locked solidly in place in addition to the bike being unable to roll backwards. :)

I dug an old Schwinn "Le Tour III" road frame out of the small bike boneyard beside my house and did some work on it last night in preparation for attempting to build one of these contraptions. In doing so, I disassembled and repacked the bottom bracket. I definitely see how the bottom bracket cup can be used to stack two freewheels now. I even have one freewheel suitable for the high gear scavenged off of an old bmx wheel.

I looked around to find a freewheel with a large cog, but the largest they get is into the 20s of teeth. I want more like 30 teeth, which appears to not exist. I do have a plan, however. 30ish-tooth cogs can be had by disassembling an old multi-gear freewheel. The only problem might be that these sprockets are designed to allow the chain to jump off of the teeth relatively easily, which is an undesirable quality in a transmission that is not supposed to shift gears in this manner. This aside, these cogs are almost exactly the right size to slide on over the outside of a freewheel, requiring just a little grinding to remove the four stubs and enlarge the hole by about 1/8".

[FlatTop]

The multispeed cogs ought to work, I think. My thought being that you will take care to create a near-perfect chainline, and that the Hirondelle setup provides a greater degree of "chain wrap" around the cogs, keeping it trapped to some degree.

Since you Hirondelle re-creators are working on Schwinns, I'll address this question to both of you: How much will you need to modify the frames? Will it be a minor massaging of the chainstay, or a heat-with-a-torch, put in a zigzag and reshape deal?

[frameteam2003]

With mine I'm using freewheels that will use 10 speed chain(3/32) not the 1/8 chain used for a standard bikes---this chain is more flexable.If you start with a ballooner frame you might get by with no mods--I'm using a middleweight frame and want to use a 2&1/4" tire so will have to widen the rear some for the tire.I also plan on brazing on the return sprocket,but this could just as ez be done with a bolt on.BTW a breese 10 speed front sprocket works good to,as it's a thin clover leaf made for the 3/32 chain.

[MacG]

I can guarantee that a two-speed freewheel where the two cogs are locked together will not work. In order for the chain to move, the two rear cogs need to turn opposite directions, which eliminates the possibility of a two-cog freewheel doing the job. THis happens because the chain goes diagonally from the bottom of the front chainwheel to the top of one of the rear cogs.

With regards to chainstay modification, I think I'll slice a chunk out of it and reinforce it with some scrap steel. I had to do a similar modification to the (former) chainstay on the first tallbike I built because the (now vertical) slack side of the chain would hit the (former) chainstay before it made it out to the highest gear on the freewheel.

The method the guy linked above used to fix his chainstay looks pretty good except that I think it could add more flex than would be desired. I'll probably try to come up with something that keeps the columnular strength of the stay as close to how it's supposed to be as possible.

[frameteam2003]

O.K.--I ordered a freewheel designed for an elect. scooter ---looked like the same threads as a regular bike hub.The scooter freewheel has flanges to bolt on the sprocket,this may give me a large28 or36 tooth low gear---if the treads are the same---will let you know when it arrives---sam

[frameteam2003]

The scooter freewheel arrived today---same treads,so will be able to simply bolt on any size sprocket I need.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7186482952&rd=1&sspagename=STRK%3AMEWN%3AIT&rd=1
this isthe ebay link to show a pic of the scotter freewheel---sam

[Noah Scape]

I know this is not the same, but it uses the reverse pedaling concept. In this tallbike build, the guy used a stoker tandem crankset with chain running to both wheels – upper wheel runs to the left (larger) chainring and the right small ring runs the bottom wheel. When you pedal forward you are driving the bottom wheel and the top wheel is freewheeling. When you pedal backward, you drive the top wheel. The tires fit snuggly together. So much so that when you pedal backwards, you feel a dramatic boost of power/speed!

[frameteam2003]

Noah,that's a very cool idea---lots of thought went into that one.
Today I built up the hirondelle.Got it to work(wheel will spin/no riddin yet) but still will need a lot of work.That's the hard part of a kuston---we gotta build everything from scratch and make it work,not just bolt together a pile of parts---but that's the fun---sam ps--I did have to widen the frame to get the chain to clear---not hard just some work with a jack & clamps

[zealanderthal]

Can't wait to see a picture!

[FlatTop]

Hirondelle/retrodirect followers: There is a similar post on this subject on another forum:
http://www.bikeforums.net/showthread.php?t=144590
A few different twists in this project.

[frameteam2003]

check out the new post under bicycle mechanics title : Retro-Direct Drive. I think we've started something!---sam

[FlatTop]

check out the new post under bicycle mechanics title : Retro-Direct Drive. I think we've started something!---sam

You mean, Hirondelles and retro-direct drive bicycles are gonna be the fixies of the 2005-2010 era? :D
You guys truly have your fingers on the pulse ;)

[MacG]

Success!

I got the last pieces put together and was able to test drive the contraption late last night. Everything works pretty well so far; I've ridden it around the neighborhood a few times, testing out the low gear on the uphills and the high gear on the downhills. I need to build a means to shift the chain between the two front chainrings and it will be nearly ready for it's first commute.

http://www.basementfreaks.com/members/karl/retro_direct/pictures/01t.jpg (http://www.basementfreaks.com/members/karl/retro_direct/pictures/index.php?img=01.jpg) http://www.basementfreaks.com/members/karl/retro_direct/pictures/02t.jpg (http://www.basementfreaks.com/members/karl/retro_direct/pictures/index.php?img=02.jpg)

http://www.basementfreaks.com/members/karl/retro_direct/pictures/03t.jpg (http://www.basementfreaks.com/members/karl/retro_direct/pictures/index.php?img=03.jpg) http://www.basementfreaks.com/members/karl/retro_direct/pictures/04t.jpg (http://www.basementfreaks.com/members/karl/retro_direct/pictures/index.php?img=04.jpg)

http://www.basementfreaks.com/members/karl/retro_direct/pictures/05t.jpg (http://www.basementfreaks.com/members/karl/retro_direct/pictures/index.php?img=05.jpg) http://www.basementfreaks.com/members/karl/retro_direct/pictures/06t.jpg (http://www.basementfreaks.com/members/karl/retro_direct/pictures/index.php?img=06.jpg)

http://www.basementfreaks.com/members/karl/retro_direct/pictures/07t.jpg (http://www.basementfreaks.com/members/karl/retro_direct/pictures/index.php?img=07.jpg) http://www.basementfreaks.com/members/karl/retro_direct/pictures/08t.jpg (http://www.basementfreaks.com/members/karl/retro_direct/pictures/index.php?img=08.jpg)

http://www.basementfreaks.com/members/karl/retro_direct/pictures/09t.jpg (http://www.basementfreaks.com/members/karl/retro_direct/pictures/index.php?img=09.jpg) http://www.basementfreaks.com/members/karl/retro_direct/pictures/10t.jpg (http://www.basementfreaks.com/members/karl/retro_direct/pictures/index.php?img=10.jpg)

Here are the gear combinations and corresponding gear inches that can be achieved with my configuration:
42/32 = 35.4in (pedal backwards with small ring)
42/16 = 70.9in (pedal forwards with small ring)
52/32 = 43.9in (pedal backwards with big ring)
52/16 = 87.8in (pedal forwards with big ring)

It's amusing to note that everything on this bike came out of a scrap steel dumpster (and not all in one piece or trip) with the exception of one of the freewheels (BMX bikes are surprisingly rare there) and the bottom bracket cup used to build the rear hub (because I didn't have one laying around that wasn't already attached to a bottom bracket). The first things to be replaced with new parts will be the 16t dumpster freewheel because it is worn enough to jump under heavy pedaling, the tires because the back one has leporasy or something, and probably the chain, since dumpster chain can be like a continuous game of russian roulette.

For shifting the front chainrings, I'm torn as to whether I should just bolt on a standard front derailer or if I sould try to create a device as seen on an original Hirondelle (linked earlier in thread) that works like a derailer split in half so that you are able to shift from the smaller to the larger ring when pedaling forwards, and from the larger to the smaller when pedaling backwards. I guess the theory is that when you want a lower gear, you will probably already be pedaling backwards, so why waste time changing directions twice just to be able to get to your granny gear. Any multispeed biker knows how much of a pain it is to shift from a large chainring to a smaller one while barely creeping along as an unexpected hill appears. Take that sensation and add to it the necessity to stop pedaling, pedal the other way through the shift, and then begin pedaling the way you were before again. It would be doable, but I think the original style shifting system would be that much cooler, if I could get it to work, and it would make shifting while ladeping up hills that much easier.

On a related note, I've pondered ways to add derailers to a traditional multispeed bike to allow it to be shifted at a standstill or low speed by pedaling backwards, and haven't come up with any bright ideas yet. The problem is always that during the shift, the chain is centered on two different sprockets, which means that any shifting system able to accomodate that without binding up would either need to be able to intelligently (mechanically somehow) be able to track with the chain, or have enough slop in it that it would suck to use.

[MacG]

This evening I accomplished some more work. I replaced the dumpster chain with some new hyperglide I had stocked up for a rainy day and also put a new schimano 17t freewheel in place of the 16t dumpster freewheel that was jumping quite a bit under heavy load. The drivetrain feels much nicer now, and I guess the next step there is to fix the tensioner up with a proper spring and make it more compact.

I found an interesting (and theoretically entirely predictable) new problem that I don't recall reading about anywhere else yet. As I was savoring the smoothness of the new chain by turning the pedals slowly by hand with the bike suspended, I noticed that the right pedal was loose. ...and so was the left!

Back in the ancient history of bicycles, some brilliant person decided that the left pedal should have a lefthand thread because it kept falling off due to precession, where something being turned inside of another thing will turn backwards due to rolling along on the edges. (Wow; that was a terrible description...) Anyways, if you don't understand why left pedals need a lefthand thread, try reading this (http://en.wikipedia.org/wiki/Precession#Torque-induced_precession).

Because of all the backwards pedaling going on, my pedals managed to loosen themselves to the point of being slightly wobbly. I doubt that they were tightened on terribly well when I put the frame together, but just the same, it would be a bit unnerving and also a bit dangerous if one of my pedals simply fell off while spinning backwards up a hill in traffic, so I need to do something about this.

I've read a bit about homebrew tandems having similar problems because the builder used a normal crank for the (left side) linking chain's pedals. I think some blue loktite or perhaps just cleaning all of the grease and oil residue off of the pedal threads and crank holes and reassembling with excessive torque may keep them put. Anyone else that has a rideable retro-geared bike encounter this yet? (all two of you or so...)

[frameteam2003]

O.K. come clean---where'd you get that big rear freewheel! I see you also did some mods to the rear stay.So far it's just you,Pierre,and me building these.Pierre used two chains with out modifing the stays and mine will be a lot like yours(one chain),only built on a cruzer frame.Check out Pierre's page: http://users.skynet.be/ppc/retrodirect_drive/
sam---PS those left pedals with left threads were a Wright Bros invention.

[ppc]

I've read a bit about homebrew tandems having similar problems because the builder used a normal crank for the (left side) linking chain's pedals. I think some blue loktite or perhaps just cleaning all of the grease and oil residue off of the pedal threads and crank holes and reassembling with excessive torque may keep them put. Anyone else that has a rideable retro-geared bike encounter this yet? (all two of you or so...)

Hmm yes, I didn't think about that, but you're quite right, the pedals can indeed work themselves loose with a retro-direct bike. It hasn't happened to me because I don't ride backward a whole lot (just to get up the hill to and from work, and to accelerate) and because I have nature's very own thread locking glue in my crank holes: rust :)

[MacG]

O.K. come clean---where'd you get that big rear freewheel! I see you also did some mods to the rear stay.
I cheated. The big one is actually a pretty standard 16t BMX freewheel the LBS had in their used junk bucket for $5. I have a handful of multispeed dumpster freewheels laying around, and upon disassembling a few with my shiny new homebrew chainwhips (yay!), found that the splined sprockets from one particularly odd-looking 5 speed freewheel was almost exactly the right size to slide over the outside of the BMX freewheel's body. The best part was that to get it to fit, I just had to grind a hair off of each of the three spline teeth on the inside hole. This allowed me to get a darn near perfect sliding fit. To attach it, I used 3/8" bolts through the holes that already existed in the 32t sprocket. Two bolts hold the larger sprocket onto the freewheel's teeth with oversize washers, and the other two provide anchoring against rotation by locking carefully sized washers into the gaps between teeth on the freewheel. This mechanism is heavy and ugly, but it works for the time being. The same method could be used but without the heavy bolts by tack welding the larger sprocket onto the freewheel's teeth. I originally planned to do this, but I was afraid of how the bearing races and lubrication would react to the heat and had no way to disassemble the freewheel to perform the welding.
PS those left pedals with left threads were a Wright Bros invention.
I thought that might be the case! Gotta love those Wright Brothers!
...and because I have nature's very own thread locking glue in my crank holes: rust :)
I must try some! Is it expensive? :D

I took the bike out this morning for a quarter mile or so (it's cold out!) and the new chain and freewheel are much smoother and the jumping is gone.

Here's a link I haven't seen passed around in this thread yet: http://www.frankb.us/gears/
I like his design for a tensioner more than I like mine. I think I'll adapt mine to be more like that.

[ppc]

I like his design for a tensioner more than I like mine. I think I'll adapt mine to be more like that.

Ditch the front derailleur and you won't need a tensioner, just a fixed idler :)

[MacG]

Here are some graphics I put together using AutoCAD to show how the Hirondelle-style retro-direct works.

-----

This is the basic setup. The sprockets on the right are the front chainring cluster attached rigidly to the pedals and bottom bracket. There happen to be two for reasons of even more gears, but this exercise would work just fine with only one gear. The sprockets on the left are on the rear wheel, and each is attached to it's own indepenent ratcheting freewheel. Both ratchet in a manner that is capable of driving the bike forwards and freewheeling for coasting. This is set up just like a single speed bike, but there are two freewheels stacked next to eachother. The small sprocket in the lower middle is a tensioner with a spring on it to keep the chain taut.

http://www.basementfreaks.com/members/karl/retro_direct/retro_diagram_1.png

When the chain is added, it is routed like this. These diagrams are for a single-chain Hirondelle-type setup, which is not exactly what ppc is doing, but both achieve precisely the same functionality in the end. Note that the chain crosses up from underneath the front chainring to pass over the top of the larger rear freewheel.

http://www.basementfreaks.com/members/karl/retro_direct/retro_diagram_2.png

This diagram shows only the chain that is tensioned when the pedals are being turned forwards, which provides the high gear. The 52-tooth chainring (turning forwards) is turning the 16-tooth freewheel forwards. The rest of the chain goes around the idler and turns the other freewheel backwards on it's way back around, having no effect on the force applied to the wheel (and making a nice clicking noise).

http://www.basementfreaks.com/members/karl/retro_direct/retro_diagram_3.png

This diagram shows only the chain that is tensioned when the pedals are being turned backwards, which provides the low gear. The 52-tooth chainring (turning backwards) is turning the 32-tooth freewheel forwards. Note the crossing of the chain, which is what allows the backwards rotation of the pedals to produce a forward motion of the bike. The rest of the chain goes around the tensioner and turns the other freewheel backwards, having no effect on the force applied to the wheel.

http://www.basementfreaks.com/members/karl/retro_direct/retro_diagram_4.png

[ppc]

For those interested in the retro-direct system, there is now a Yahoo group dedicated to it. We'll try to gather as much information as possible on the subject, and I'm hoping it'll entice more cyclists to convert their bikes, and hopefully build some kind of retrodirect cycling community.

Feel free to join and post away: http://sports.groups.yahoo.com/group/retro-direct/

[frameteam2003]

For a better idler do a bit more dumster diving and come up with a cheap derailer with the claw hanger--like a shimino positron.File off the brads that hold the paralle arms together.Instant spring loaded arm.I took this apart(one c clip) and filed off the stop and brased a flat bar stock to the arm,drilled and tapped for the pully and then brazed the hanger to my frame---could just as EZly have been bolted.---sam

[frameteam2003]

new photos:
http://pg.photos.yahoo.com/ph/frameteam2003/album?.dir=/900a
still in early stage---sam

[James H Haury]

That retrodirect thing is wild.It would be really neat if some manufacturer jumped on it and did really well with it.i guess in some ways bikes are like fashions old ideas are recycled.V brakes were used before only they were not called that

[frameteam2003]

Not a compleat project by any means---no brakes---will have disk brakes on back when finished.:
http://pg.photos.yahoo.com/ph/frameteam2003/detail?.dir=900a&.dnm=7262re2.jpg&.src=ph
sam

[ppc]

That retrodirect thing is wild.It would be really neat if some manufacturer jumped on it and did really well with it.i guess in some ways bikes are like fashions old ideas are recycled.V brakes were used before only they were not called that

2 speeds goes completely against the marketing efforts the industry has deployed for the past 30 years to make cyclists believe that 10 speeds is better than 9 that's better than 8 that's better than 7... What's more, retro-direct drives provide an additional speed pedalling backward, i.e. "like a dork" for most people.

In short, the last time it was popular was before the derailleur, and the only kind of people it's likely to attract today are curious tinkerers, and those who are tired of doing the Shimagnolo dance.

[James H Haury]

So call me a curious tinkerer.I am not so cycnical as to believe that it cannot garner a wider audience.Perhaps pedaling backwards uses a different set of muscles than forwards and it can be promoted in that fashion.I for one am sick of the dance of Shimano.When will the ever multiplying gears end.?

[frameteam2003]

I think the only place in the market for retro-direct drive would be in the kustom (aka Choppers) market.This could be added to those wal-mart west coast chopper bikes etc.For a cool something different second gear.But as for now it all ours!!---sam

[ppc]

Perhaps pedaling backwards uses a different set of muscles than forwards and it can be promoted in that fashion.

Having done about 900km retro-direct, I can tell you this: the muscles are roughly the same, apart for the glutes that seem to work even harder than on a recumbent when honking backward, but mostly, if you don't acquire proper backward-pedalling techniques immediately, it's VERY hard on the knees.

Spinning and honking backward isn't the most natural thing to do, so basically when you start doing retro-direct, the deal is: concentrate on pedalling just right until it becomes second nature, or else your knees will be shot in very short order. I'm not sure Walmart wants to risk being sued by customers who acquired knee problems as a result of buying a retro-direct Walmart cruiser ;)

[James H Haury]

Point well taken liability may prevent it from ever becoming really huge. i admit reversal.

[jimmythefly]

FYI most unicycles have (or should have) loctite on the pedal threads, due to the backpedaling.

[MacG]

Not a compleat project by any means---no brakes---will have disk brakes on back when finished.:
http://pg.photos.yahoo.com/ph/frameteam2003/detail?.dir=900a&.dnm=7262re2.jpg&.src=ph
sam


That's looking really nice, Sam! I'm at a disadvantage right now as my pile of bike projects is living half buried in a snowbank outside my garage. Minnesota makes garage tinkering unpleasant this time of the year to say the least. :)

[frameteam2003]

Cold in Tx too---but no snow---should be warning up in a day or two--I plan on having it painted and back together by this weekend if all goes well.I'm suppose to go to Mn(Faribault) this summer to visite a Bro-In-Law---get yours going and we'll cruze around the block---sam

[MacG]

I was itching to go biking today, but decided against it since even though it was above freezing (by two degrees), there was intermittent slushy rain coming down all day and sticking to the pavement. I like biking, but none of my bikes have skates or skis (yet).

To get my fix, I brought the retro-direct bike into the basement along with an experimental fixed-gear I had built over the summer and didn't especially care for. To make the long story short, I disassembled both bikes and put the important components together with the other frame, which is a few inches lower than the highe Schwinn frame the retro-direct was built with originally.

I did things a little differently this time around. Instead of cutting the chainstay and welding in an offset, I bent it with a wooden jig and a big C-clamp. Now the crossed section of chain clears the chainstay nicely with no extra weight or weird structural problems like before.

I also came up with a different kind of tensioner that has no swinging arm at all. The derailer sprocket is simply suspended in midair by a tensioned spring attached to the frame closer to the bottom bracket. I need to make a few fancier parts (especially the spring's forward mount) but overall it works extremely well. Instead of having to manually align the idler, it is self-aligning and seems to find the angle that is friendliest to the chain's path. It's also a ton lighter than the ugly contraption I had made from steel tubing for the first version of the bike.

http://www.basementfreaks.com/gallery/images/b929b400957e4f16ae8da8c8e26834f3.jpg (http://www.basementfreaks.com/gallery/gallery.php?img=f036ddc205a8f8aa2a16898772e5dbdc)

http://www.basementfreaks.com/gallery/images/74234316ff8aa30176185ab087bb474b.jpg (http://www.basementfreaks.com/gallery/gallery.php?img=1e8558477fc4cb29e2a33a4525f5c36a)

compared to this:

http://www.basementfreaks.com/gallery/images/21799a3ee047d5c33b7c8949e5fd1db0.jpg (http://www.basementfreaks.com/gallery/gallery.php?img=9b05de73d43f8c4ec1110c6bcc5312bc)

No shifter or dual-ring fronts yet since I haven't found any suitable cranks or rings yet. I may have to take you up on your offer, Mark. :)

I took it for a quick test ride down the street and back after getting everything together and it seems to work pretty darn well. I do want to change out the "low" sprocket in the rear for one or two fewer teeth, but I might change my mind once I get the 52t ring up front back...

[MacG]

I'm suppose to go to Mn(Faribault) this summer to visite a Bro-In-Law---get yours going and we'll cruze around the block---sam

I'm about 45 minutes north of Faribault. Sounds like a plan!

In other news, rumor has it that a retro-direct ice bike may make an appearance at the world championship ice bike races this January in Mendota Heights.

[ppc]

I did things a little differently this time around. Instead of cutting the chainstay and welding in an offset, I bent it with a wooden jig and a big C-clamp. Now the crossed section of chain clears the chainstay nicely with no extra weight or weird structural problems like before.

Would you mind posting a photo of the stay that shows the result of your creative bending? I might do that too on another bike I'm converting, only I'm a bit worried of crushing the tube.

I like your floating idler. Nice job :)

[MacG]

Would you mind posting a photo of the stay that shows the result of your creative bending? I might do that too on another bike I'm converting, only I'm a bit worried of crushing the tube.

I like your floating idler. Nice job :)

You got it:

http://www.basementfreaks.com/gallery/images/4aaa45807f1f06762ddf7f247e82eb29.jpg (http://www.basementfreaks.com/gallery/gallery.php?img=ed68c51e682462c1a03c917e536f8bb9)

http://www.basementfreaks.com/gallery/images/7dae82ca0b9b038105d9926f8fad1f10.jpg (http://www.basementfreaks.com/gallery/gallery.php?img=363b122c528f54df4a0446b6bab05515)

My bending jig was rather primitive, involving a big C clamp and some scraps of wood. I made a bridge-like piece about a foot long with cradles at either end to spread the load out over a larger part of the stay and prevent kinking. In the middle, I put a C clamp on this that reached around to the back side of the stay and clamped against another scrap of wood that also had a rounded groove to spread the load over some surface. I think I fared pretty well considering how much effort and expense went into the bending job. ;) Once I got the C clamp torqued down as tight as I dare, I whacked the stay in a few spots with a block of wood and a hammer to help shock the steel into the new position a bit. I found that I wasn't getting much of a bend with smooth pressure, but the shock of the hammer added enough oomph to speed things up a bit. I applied and removed the clamp about three times to get the result I liked, changing the direction of the bend and the contact areas slightly with each reapplication to make a smoother bend.

Here's a detail of my low gear freewheel adaptation method while I'm at it:

http://www.basementfreaks.com/gallery/images/52034d7de92fbd35c9b3f3f47048638e.jpg (http://www.basementfreaks.com/gallery/gallery.php?img=ea59c27f53097a2de40b94ea80f4714b)

[ppc]

Nice job. I might try that too. It doesn't look too safe if the bend needs to be anymore severe than what you did though.

Thanks for the pics!

[frameteam2003]

Bending shouldn't be a problem on old steel or even cro-moly.I'd worry on any higher quality steel or alum etc bike.Doesn't seem to take a lot to clear the chain.---sam

[ppc]

Bending shouldn't be a problem on old steel or even cro-moly.I'd worry on any higher quality steel or alum etc bike.Doesn't seem to take a lot to clear the chain.---sam

That's true, but what I'm looking into is replacing my dual-chain setup with a standard retro-direct, single chain setup. But I want to retain my current gearing, meaning that I'll need a 44T ring as much inboard as possible, and an adapter to install a 40T ring as the low-gear cog on the inner freewheel. I can make the adapter, but the real issue is that a very big cog at the back will rise the chain a lot, making it cross the chainstay much closer to the BB than on your bike. Given the size of the chainring, I'm not sure it's doable without cutting/re-welding. But I'll investigate when the temperatures rise a bit above freezing.

[frameteam2003]

I used this freewheel to bolt the largest hub to:
http://cgi.ebay.com/NEW-Clutch-Freewheel-for-Gas-Electric-Scooter-Parts_W0QQitemZ7209054658QQcategoryZ11332QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
makes bolting on a large ring easy and by first screwing on a nut for a spacer I was able to move the sprocket closer to the hight gear sprocket to keep the chain strighter---sam

[MacG]

I used this freewheel to bolt the largest hub to:
http://cgi.ebay.com/NEW-Clutch-Freewheel-for-Gas-Electric-Scooter-Parts_W0QQitemZ7209054658QQcategoryZ11332QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
makes bolting on a large ring easy and by first screwing on a nut for a spacer I was able to move the sprocket closer to the hight gear sprocket to keep the chain strighter---sam

Can you tell me if that freewheel has threads extending all the way through the body, or if they stop before reaching the outer surface?

My inboard freewheel has threads stopping partway through (since the extra threads are unnecessary when the freewheel is used under more common circumstances), and I have a washer made from an old spoke bent into a circle to space the inner freewheel off of the hub a few threads to get more purchase for the BB cup.

If this freewheel you used is threaded all the way from face to face, I might as well pick one up so I can eliminate the ghetto-washer and possibly narrow my hub assembly enough to take the extra nut off of the axle (currently needed to get enough spacing inside the dropout).

Also, what provisions does this freewheel have for removal? I assume the picture shown on the auction is the back face of the freewheel. Does the other side have the four recessed notches for a BMX freewheel remover? Or does it have some other method or none at all?

Here's my current setup with the lacking threads and 4-prong remover provisions for comparison:

http://www.basementfreaks.com/gallery/images/c94d42a650b1f41bd802a84846c59d33.jpg (http://www.basementfreaks.com/gallery/gallery.php?img=db7330f5ae0cff7a7422cf017ef9817d)
(click for larger image)

---------------------------
edit:

In other news, I just put the bike back together with some used cranks, rings, and wheels that I picked up from the Sibley Bike Depot (http://www.bikeped.org/Depot.html) for a very reasonable price. (thanks John!)

I weighed it after assembly and it tips the scales at about 28 pounds. I figure that's not too bad at all considering it's a steel frame I found in a dumpster, the wheels and cranks are nothing bleeding edge, and it has two freewheels and more chain than most road bikes.

[frameteam2003]

The scooter freewheel has threads all the way through but NO way to unscrew it!I guess when they brake you just take it apart and use plyers.That's the only drawback to them.