3 Speed Hub As Jackshaft Question.

[Intrepid Wheelwoman]

Just thought I'd throw this into the mix as an option. I don't know if anyone is looking to use a multi speed coaster brake hub, but Bendix made some sturdy hubs in the past and a lot were sold. I'm most familiar with the single speed hub and being robust and common it is my usual choice when building a rear wheel. They are easy to take apart and reassemble and I have never had one fail on me.

Although I have a salvaged 2 speed cable type Bendix, it sits on a shelf waiting for something to happen. It occurred to me that the two speed might answer most needs for a lower gear and a normal one, especially if it is robust.

Bendix also sold an automatic which was operated by kicking back on the pedal. It was commonly called a "kickback Bendix) Every kid wanted one, but only the rich kids got them.

Anyway, here's a page giving schematics on all of the Bendix models. The 2 speed looks a lot more complicated inside to me.

http://www.trfindley.com/pgbndxhbs.html

SB

That Bendix page will be be a very useful resource Silverbear, thanks for posting the link.

I used one of those kickback hubs on my tricycle and found it to be a seriously good and useful hub. Originally I was going to use a Sturmey Archer 3 speed hub, but after trying out the kickback hub I had no reason at all to change it.

I'm following this thread with considerable interest by the way and I'm strongly considering using a SA 3 speed hub as a countershaft gearbox coupled to an electric motor on my Hercules trike rebuild.

 

[silverbear]

Anne,
Your intention to use a 3 speed SA hub in conjunction with an electric motor got me thinking about how an internally geared hub could be used in the normal driven sprocket and shift cable on the right side with the driven chain connecting to the electric motor and with the polarity hooked up so that it runs the chain clockwise. (The direction of travel on an electric motor depends on the polarity of the battery, correct?) The opposing side of the hub would need a driving sprocket with chain connected to the driven sprocket on either the left side of the rear wheel (if a two wheeler) or to a driven sprocket on the axle of a three wheeler. Does that make sense? I'm out of my league here stretching me little brain with hard thoughts. I won't cry much if you tell me I'm daft and to go sit in the corner. Sniff...
SB

 

[Intrepid Wheelwoman]

I think you have the idea alright Silverbear I'm going to be doing some experimenting myself and trying things out to see what the best way to do this will be. And since I'm doing this on a tricycle I have quite a lot of room in which to lay the components out.

 

[cannonball2]

Your idea sounds pretty cool SB, keep it in the think tank. Its kinda similar to my trike build.

This IS the way to go with an intermediate drive. One can if Im seeing this right just add two of the same sprockets with a spacer side by side and eliminate the custom real wheel sprocket. Would just require a simple U type bracket to hold the hub mounted to the seat post, then just set up the chains and shifter mechanism. As Brown said would pedal start and also offer engine braking. You gear the bike for top speed with the final ratio, then the other two gears are lower. COOL! Way to go Brown! http://www.ebay.com/itm/FULL-WARRAN...017?pt=LH_DefaultDomain_0&hash=item27eda2fbc1

 

[brown]

Your idea sounds pretty cool SB, keep it in the think tank. Its kinda similar to my trike build.

This IS the way to go with an intermediate drive. One can if Im seeing this right just add two of the same sprockets with a spacer side by side and eliminate the custom real wheel sprocket. Would just require a simple U type bracket to hold the hub mounted to the seat post, then just set up the chains and shifter mechanism. As Brown said would pedal start and also offer engine braking. You gear the bike for top speed with the final ratio, then the other two gears are lower. COOL! Way to go Brown! http://www.ebay.com/itm/FULL-WARRAN...017?pt=LH_DefaultDomain_0&hash=item27eda2fbc1

Yep that is the one I bought but from Amazon. it is on it way. I have a couple of bike ahead of that project put hope to start soon.

 

[silverbear]

Other than being more robust, how is the SA hub you have a link to different from the old SA hubs to be found on bikes from the 60's? Does it function differently?

I can't wait to see pictures of what you guys are up to.
SB

 

[cannonball2]

Its different in that it has no free wheel feature. Its just as happy turning either direction. It is effect "locked", if on a bike the pedals keep turning when you stop pedaling . On the MB it will work the same on either the right or left side. Its normal mode is 1:1 and it shifts down to two lower ratios.

 

[brown]

I can't take the credit. If you look back at bowljoman's post at the beginning of this tread.

He is the one that posted the link for the fixie hub. I didn't even know they made a 3 speed fixie hub til then.

It was only after that I thought of using in as the main drive hub.

I hope this works. It could change how I build 2 stroke bikes from now on.

 

[cannonball2]

Im definitely saving my money for the hub. Will probably go ahead with the build using the fragile Shimano and make the hub mount 130mm to fit the fixie hub. Then just swap/re-engineer for it when I get it. I will use it as an intermediate "transmission".
The idea of a left side drive only makes a shifting bike appealing again.

 

[brown]

The fixie hub is available in 130mm too. I chose the 120mm because I wanted the extra space available for me to create the freewheel adapter for the right side pedal chain.

 

[cannonball2]

A big thanks to Bowljoman for the fixie hubs link!! I some how missed it.

I bought one this morning a 120mm out of the box but all parts still sealed in the bags for $124. What sprockets run on this? Shimano Dura Ace?
I like the idea of the bar end shifter will work great on the left side. This thing has 160% range-that's great. Am going to run it in an MTB frame due to the fact the frame spacing is wider and I can juggle the rear wheel to get the left side sprocket to line up with the slightly off set chain line.
So far I see no blind sided issues with this idea, either as an intermediate trans or an actual wheel hub. The intermediate may be easier as all stock sprockets can be used and the mounting of the hub is really a non-issue. Im thinking of raising the final drive ratio, like from a 44 to a 42t rear sprocket. There will be plenty of low range, raising the final will lower the cruise rpm.

 

[cannonball2]

Found the S3X cogs. Only found 13t guess that will work. Will be more compact. Bought the 3/32 versions to take up less space since I have to stack two. The BMX chain should work just fine. They were cheap enough @$3.45ea. The Shimano BMX cogs I believe will fit but the notes with the hub say they are a tight fit on the splines. They offer more cog sizes.
Also ordered two 1 1/8 double split lock collars to make the hub mount. This makes an easy mount. bolts right to the seat tube and grips tight enough to allow up and down movement for some chain alignment/adjustment. Now if the stuff will just show up!

 

[Intrepid Wheelwoman]

Good progress CB

On Sheldon Brown's website there is a method or two outlined for converting an old SA 3 speed into a fixie hub. Could be useful for us tinkerers of slender means. The one hitch though is with this conversion the hub will have quite a bit of backlash.

 

[cannonball2]

Thanks IWW! I have Sheldons site in my favorites will check it out.
I read a review of the S3x and it mentioned there was a bit of slop in the shifting. Im thinking its probably designed in maybe to allow the clutches a bit of slack since the pedals are driving all the time on the fixie.
Don't know how this will translate to being motor driven/shifted but gut says back off a bit and shift. The internals of this hub look pretty substantial.

 

[cannonball2]

Took a bit of looking but I found the conversion. Seems simple enough. However I repaired the Shimano 3spd by scratch building a shift key, very easy. It also explains what this is a fragile hub. Strangely when the outer hub is driven as I proposed it behaves like the SA fixie conversion except it will freewheel. When driving the hub, you get two speeds at the sprocket(I was expecting 3). Normal(1:1) and an over drive(1.25) Guess that's right the sprocket makes 4 turns to the hubs 3. It does this OD in 2 positions. So if an SA hub does likewise then one could gear the bike for the OD position then shift to the normal position for a lower gear. Or gear the bike for the normal position and then shift to the OD to have a taller cruising gear. This is with no mods to the hub other than adding a driving sprocket to the hubs spoke flange.

 

[silverbear]

Do you have a link to the Sheldon Brown conversion?
SB

 

[cannonball2]

Here it is SB. http://sheldonbrown.com/awfixed.html

 

[silverbear]

If someone does this, please take pictures as you go.
SB

 

[cannonball2]

Got the SA fixie 3sp yesterday. Its a nicely made piece and comes with shifter, cable, spacers, etc.
Will base this build on a 700c fixie frame combined with the rolling gear from a 26" MTB. Will be a single speed(pedaling). I feel better on an MB closer to the ground than my limited inseam will allow with the 700c wheels. Did preliminary gearing and haven't decided exactly which way to go. Can gear it extremely high and run 2nd gear as normal, or gear normally and run in 3rd(lock up) as normal. Common sense says to gear normally and run in lock up and not run the planet/sun gearing constantly. That's probably how it will go. Will start a thread on this when it happens.

 

[silverbear]

If you would, please leave the link to the new thread here so we don't somehow miss it.
SB