Bendix hub

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kchurch86

kchurch86

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What am I looking at here? It came off a '55 Schwinn Racer girl's bike, not sure if it was original to that bike. There are no markings on the hub body that I can see. It's 36 hole.

The axle is off-center to the hub flanges. There's a small screw that threads into one end of the axle. The opposite end has a flathead screwdriver slot in the end of it.

91dfc2dc4fa19e555eea733e2bcebbc9.jpg


575c4bba892d67068130012fe5394877.jpg


5693d23a14a0df1c5b922386059713f9.jpg


It's got big, beautiful flanges, about 3 3/8"

3 1/8" center to center spoke holes.

06864536d86cd0c844cf05955a766274.jpg


When I turn the cog by hand, the hub flanges turn at a slower speed. Turning backwards seems to cause it to brake, and resuming forward turning results in some clicking sounds from within while the flanges resume forward rotation...sounds like a mechanism of some kind...though it's hard to judge if it changes speed at any point.
 
kchurch86 said:
Thanks! Interesting. So, how does the toggle hardware attach and actuate?

Sent from my VK410 using Tapatalk
Click to expand...

1z3126t.jpg

You're missing the stuff from the bottom right of that schematic, plus (i'd assume) the shifter and cable..

The first link has a description of how to install and adjust the shifting. "After the EX shift control is assembled to the handlebar, the cable is connected to the toggle assembly, and adjusted. Proceed as follows: scfew the toggle assembly on the axle until the plunger just touches the shifting rod in the axle. This can be detected as a slight added resistance. Then back off the toggle assembly until the bolt points along the rear frame member to which the cable casing will be clamped. Screw the cable tube on the toggle bolt about 1/4". Install the rear stay anchor clamp about 9" from the axle. Take all slack out of the cable and securely tighten the clamp. Shift the unit to high gear by pulling up the EZ Shift control lever. Try to mov the toggle by hand. If it moves, the gears are not shifted. If this occurs, shift to low gear and screw the adjusting tube further on the toggle bolt. Repeat until you are sure the gears are shifted. Lock the toggle in place by securely tightening the jam nut on the toggle bolt. BOTH JAM NUTS MUST BE SECURELY LOCKED B/C THEY HOLD THE ENTIRE UNIT IN PROPER ADJUSTMENT. Then assemble the anchor clips and clamps as shown."

HTH.

RRB Member @us56456712 uses these hubs; he could probably answer specific questions, if/when you track down a shifter, cable, and toggle hardware for it.
 
Thank you for all of that! I missed the part that describes the "plunger" and "shifting rod in the axle". I couldn't see how there was anything on the hub that could cause it to change speeds, I never considered the little screw in the axle!

I think I'm going to try my hand at building some linkages.

Sent from my VK410 using Tapatalk
 
Not sure if they're all identical in size, or what parts you're missing, but I once made a replacement rod for one of those with a temple piece from a pair of aviator sunglasses. o_O:crazy:
 
kchurch86 said:
Thank you for all of that! I missed the part that describes the "plunger" and "shifting rod in the axle". I couldn't see how there was anything on the hub that could cause it to change speeds, I never considered the little screw in the axle!

I think I'm going to try my hand at building some linkages.

Sent from my VK410 using Tapatalk
Click to expand...

They are fairly easy to rebuild. Almost all of these have bent axles as the axle is hollow and made from soft steel. Many also have stripped threads on the axles. In the winter you can usually find them on eBay for a decent price. I got several, for spares that way. I have rebuilt them for others, as well as myself. I wouldn't try and build linkage as they have a weird thread pitch and are finicky to adjust with the right stuff. The parts that hold the cable to the frame are expensive if you use original Bendix fittings. I used old junk spring cable clamps and a clamp from an old 10 speed as the final one just before the hub to keep the cable taught. If the girls bike has the clamps then keep those. Because girls didn't ride their bikes like the boys you might luck out and have a straight axle. I straighten the axles by clamping the nut into a vice and tapping on another nut on the opposite side of the axle, then rolling the axle on a flat. I then adjust the position of the nuts to slowly take out the bend. They bend easy so no curb jumping. I use mine for single track and have given up straightening it. Are you going to relace it to the original rim? I can help you here if you are going to use a different rim. Be careful with the shifting rod in the axle as it has very fine threads and the steel is soft and easy to strip. On of my buddies stripped his during reassembly, but I have never had that problem. Once I assemble the hub and relace it to a wheel I mount it in a frame and put it in a bike stand. I then push the shifting rod in and out with a small screwdriver and if it shifts while peddling I know I am good to go. I rebuilt my first one dry with no grease, just to see if it worked. I didn't want a mess if I had to take it apart and try and figure out where I went wrong. This was unnecessary as it worked and I had to take it apart for grease anyway. They are a blast to ride but have weak brakes and you have to back pedal real far to get the coaster brake to engage. back pedal distance increases when you are in low gear. They came with either 18 or nineteen teeth cogs.
 
us56456712 said:
They are fairly easy to rebuild. Almost all of these have bent axles as the axle is hollow and made from soft steel. Many also have stripped threads on the axles. In the winter you can usually find them on eBay for a decent price. I got several, for spares that way. I have rebuilt them for others, as well as myself. I wouldn't try and build linkage as they have a weird thread pitch and are finicky to adjust with the right stuff. The parts that hold the cable to the frame are expensive if you use original Bendix fittings. I used old junk spring cable clamps and a clamp from an old 10 speed as the final one just before the hub to keep the cable taught. If the girls bike has the clamps then keep those. Because girls didn't ride their bikes like the boys you might luck out and have a straight axle. I straighten the axles by clamping the nut into a vice and tapping on another nut on the opposite side of the axle, then rolling the axle on a flat. I then adjust the position of the nuts to slowly take out the bend. They bend easy so no curb jumping. I use mine for single track and have given up straightening it. Are you going to relace it to the original rim? I can help you here if you are going to use a different rim. Be careful with the shifting rod in the axle as it has very fine threads and the steel is soft and easy to strip. On of my buddies stripped his during reassembly, but I have never had that problem. Once I assemble the hub and relace it to a wheel I mount it in a frame and put it in a bike stand. I then push the shifting rod in and out with a small screwdriver and if it shifts while peddling I know I am good to go. I rebuilt my first one dry with no grease, just to see if it worked. I didn't want a mess if I had to take it apart and try and figure out where I went wrong. This was unnecessary as it worked and I had to take it apart for grease anyway. They are a blast to ride but have weak brakes and you have to back pedal real far to get the coaster brake to engage. back pedal distance increases when you are in low gear. They came with either 18 or nineteen teeth cogs.
Click to expand...

Eh, I'm a machinist. Challenge accepted. ;)

In all seriousness, thank you for all the information! I'm willing to bet I'll be bugging you once or twice throughout this process - you've been warned.

As far as I can tell the axle is straight, and the threads are actually in very good shape. Once I cleaned all the dirt and crud from the threads, the nuts were able to travel smoothly down the entire length of the ends. I don't believe the hub is original to the bike it came from, only because there were no signs of any cable clips, clamps, or a shifter anywhere on the frame or bars.

I just mic'd up the axle for diameter and gaged the pitch, then checked through my tool collection and found a couple 3/8-24 taps and dies. I also scrounged up some material to use for building a different version of the piece that screws onto the end of the axle.

Which brings me to my first question: The screw in the drive-side of the axle, that is what the plunger pushes against to change speeds, right? I'm assuming it is...and I assume it must be held in a given position to stay in that gear...right? The return spring keeps outward pressure on that screw, which I have to guess is in position for LOW gear, and when the screw is pushed (and held) in the "in" position, that must be HIGH gear, right?

If those assumptions are right, then I think I have a pretty simple idea for a linkage system, no cables required.

Thanks again for the information!
 
kchurch86 said:
Eh, I'm a machinist. Challenge accepted. ;)

In all seriousness, thank you for all the information! I'm willing to bet I'll be bugging you once or twice throughout this process - you've been warned.

As far as I can tell the axle is straight, and the threads are actually in very good shape. Once I cleaned all the dirt and crud from the threads, the nuts were able to travel smoothly down the entire length of the ends. I don't believe the hub is original to the bike it came from, only because there were no signs of any cable clips, clamps, or a shifter anywhere on the frame or bars.

I just mic'd up the axle for diameter and gaged the pitch, then checked through my tool collection and found a couple 3/8-24 taps and dies. I also scrounged up some material to use for building a different version of the piece that screws onto the end of the axle.

Which brings me to my first question: The screw in the drive-side of the axle, that is what the plunger pushes against to change speeds, right? I'm assuming it is...and I assume it must be held in a given position to stay in that gear...right? The return spring keeps outward pressure on that screw, which I have to guess is in position for LOW gear, and when the screw is pushed (and held) in the "in" position, that must be HIGH gear, right?

If those assumptions are right, then I think I have a pretty simple idea for a linkage system, no cables required.

Thanks again for the information!
Click to expand...
The small slotted screw head inside the axle on the drive side is indeed what changes the gears. I'll have to pull mine down from overhead storage to see if it is in high when it is all the way in. I can't remember off hand. It will give me a good excuse to ride it again. I raced it last year and haven't used it since as I am working on a newer vintage race bike. The adjustment is a hair trigger, but once it is working it stays well without further adjustment, but turn the barrel a half turn and, well forget it, the cranks will just spin. For some reason 3/8 x 24 TPI did not work on mine so that the original chain stay nuts fit. I re-tapped one axle and used non original bolts but it is threaded for other parts besides the chain stay nuts. I just figured it had weird Bendix specific pitch or something? I remember making new exhaust header collars for my Triumph motorcycle. I used brass instead of steel as the steel always broke. The header collars measured 17 TPI but did not fit well and I had to hammer them in. Brass grunching against aluminum. I thought that might be a different pitch as well? Not a machinist, just a hack here so I don't really know what I am talking about.
 
us56456712 said:
The small slotted screw head inside the axle on the drive side is indeed what changes the gears. I'll have to pull mine down from overhead storage to see if it is in high when it is all the way in. I can't remember off hand. It will give me a good excuse to ride it again. I raced it last year and haven't used it since as I am working on a newer vintage race bike. The adjustment is a hair trigger, but once it is working it stays well without further adjustment, but turn the barrel a half turn and, well forget it, the cranks will just spin. For some reason 3/8 x 24 TPI did not work on mine so that the original chain stay nuts fit. I re-tapped one axle and used non original bolts but it is threaded for other parts besides the chain stay nuts. I just figured it had weird Bendix specific pitch or something? I remember making new exhaust header collars for my Triumph motorcycle. I used brass instead of steel as the steel always broke. The header collars measured 17 TPI but did not fit well and I had to hammer them in. Brass grunching against aluminum. I thought that might be a different pitch as well? Not a machinist, just a hack here so I don't really know what I am talking about.
Click to expand...

That's interesting about the threads. I don't know jack squat about Bendix company history (or anything vintage bicycle-related really, I'm still very much a newbie), but I wonder if at any point parts were made under the Bendix name at other factories? Or maybe with different thread forms depending on year or model...like a buttress thread or something odd like that.
 
kchurch86 said:
That's interesting about the threads. I don't know jack squat about Bendix company history (or anything vintage bicycle-related really, I'm still very much a newbie), but I wonder if at any point parts were made under the Bendix name at other factories? Or maybe with different thread forms depending on year or model...like a buttress thread or something odd like that.
Click to expand...
Check out your tap with the Bendix bolts, I might be wrong for yours but all my hubs have been like that. I still have to get it down from storage. I almost got it down last night but decided to try out my 1992 Giant as I just put a whole new drive train on it including the spindle.
 
If I recall correctly pushing the rod in (by pulling on the bell crank) locks MS36 into the center of MS2 for direct drive (high), and releasing it allows the spring to push it into the planetary gears MS37+MS19 (low) just as you have surmised. The rest of the hub is an ordinary Bendix coaster brake, on which most modern ones are based.
 
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FWIW, every Bendix i've ever seen ran a 3/8x24tpi axle...i never messed with a manual 2 speed, so maybe they're different. But the redbands, the kickbacks, the 70 and 76 hubs...they all take 3/8x24tpi hardware
 
I had one of those hubs missing the rod and yoke sub assembly, but I rode it anyway. I remember it being geared very high, hard to get going but would cruise along nicely after it got rolling.
 
Is there any chance a 3 speed shimano toggle housing would fit on the bendix 2 speed? I'm having a rough time tracking one down.
 
Got this Monark a couple days ago.
208285-20220902-144426.jpg

It's equipped with a Bendix 2 speed manual hub, and as there is a lot of info in this thread, I thought I would ask my question here...
2 speed hub.jpg
2 speed hub 2.jpg

The hub shifts ok now but there seems to be an extra nut and lock washer on the non drive side.
There is no rear stay anchor clamp on the bike now (circled in red). Is this necessary?
 
kchurch86 said:
Thank you for all of that! I missed the part that describes the "plunger" and "shifting rod in the axle". I couldn't see how there was anything on the hub that could cause it to change speeds, I never considered the little screw in the axle!

I think I'm going to try my hand at building some linkages.

Sent from my VK410 using Tapatalk
Click to expand...
The deal with the Bendix manual 2 speed is that the cable is in a metal casing that is secured to the frame of the bike. The cable pushes the toggle into the axle to achive low gear. The key is the lever ,it is on a cam and when you shift into low gear the position of the lever holds the toggle in for low. The lever and cable are the importent part, a standard 3 speed has a spring to return the gear and the lever pulls the shifter into the correct position. In the 2 speed case it is the lever that does the work of pushing and holding the shifter in against the spring that wants to push it out and into high gear. I again state the lever and cable are specific to this type of hub. A regular 3 speed lever will not have the strewngth to hold the hub in low gear.
 

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