Threadless sprocket race?

[CRASH]

I've never seen this in all my bike years. Is this by design, or is this a major malfunction? The race itself has no flat ends or groves to grab to tighten/loosen, which makes me think it's by design. This crank is off a '68 Huffy. With the bottom bracket adjusted it doesn't seem to affect operation, but when you take it apart it doesn't hold the sprocket on because there isn't any pressure.

Thoughts?

 

[Wildcat]

I remember having a bike like that years ago, the sprocket was held on by assembling the crankset. I thought it was a cost cutting measure by the manufacturer.

 

[deven_science]

New one to me, too.

 

[jamesdart]

That's weird

 

[Wildcat]

Does the race have threads? if so, it could be a replacement that didn't fit, so someone filed down the threads on the crank to make it work.

 

[deorman]

I have never seen such a piece...

Man, that's pathetic.

 

[CRASH]

Talking to the mucle bike guys, this has been seen on a number of Rails, but there isn't a specific year. I don't think it's a defect, I think it's something they tried, but didn't stick with. The reason I say that is the race has no way to tighten it at all, so it wasn't designed with threads or the ability to turn them.
I put it all back together and it works just fine.

 

[Wildcat]

The thing will work fine, but any play the cranks develop will loosen the sprocket also. That's the only advantage I see to having it threaded in the first place.

 

[Bicycle808]

I love RRB, not only b/c there threads on topics like this, but b/c threads like this will be active for a week, with several ppl commenting on it. It's goofy, but it's also awesome.

Personally, I've never seen a crank/BB set up like that. I can see how it will work, but I can also see that it has some gaping flaws**, not the least of which is the fact that you'll have trouble sourcing some parts, such as the DS cone, should you ever need to replace it. I imagine it'll take standard bearings, so just keep up on the maintenance, and I'm sure you'll be fine for a long while.....

**To be fair, Huffy could never have foreseen that a grown man would still be riding this bike almost half a century later, so no player-hatin' points on Huffy for this one.

 

[Jamie825]

The groove that is in the crank behind the sprocket is there a matching groove in the cone there could be a spring clip supposed to go in the groove that would hold the cone kinda like the axles on a front wheel drive they have a groove and clip at the end of the splines that snaps into place when installed? Just shooting in the dark don't really know anything about it just guessing

 

[Bicycle808]

The groove that is in the crank behind the sprocket is there a matching groove in the cone there could be a spring clip supposed to go in the groove that would hold the cone kinda like the axles on a front wheel drive they have a groove and clip at the end of the splines that snaps into place when installed? Just shooting in the dark don't really know anything about it just guessing

Yeah, I see that groove... There may very well have been a circlip holding the sprocket on.... like, as in sprocket, washer, circlip,cone. There wouldn't even need to be a groove or clip for the cone; once you adjust the NDS cone, the DS cone would be squared-up and in-place. But a circlip or similar doohickey could definitely have been in-play back when these Huffies were new. I'd be inclined to try a 7/8" external retainer clip, like this: http://www.zoro.com/i/G2462844/?utm...4fxk9NxX5Orn3wBxmlFkApJdZZXdrGfnE-RoCj1Hw_wcB , just to see if it works....

Good eye, Jamie825...

 

[Jamie825]

That's not really the type of ring I was thinking of what I was talking about would be a round ring kinda like a coat hanger sized wire wrapped around the groove with enough end gap to allow it to squeeze together to let cone slide over and the ring spring into an equal groove in the cone of course it would have to be spring steel and not a coat hanger

 

[Bicycle808]

That's not really the type of ring I was thinking of what I was talking about would be a round ring kinda like a coat hanger sized wire wrapped around the groove with enough end gap to allow it to squeeze together to let cone slide over and the ring spring into an equal groove in the cone of course it would have to be spring steel and not a coat hanger

Yeah, I see what you mean, but I'm thinking that with circlips being used on rear sprockets even back then, they might have tried a similar approach at the front, and it'd require a lot less from the hardware, as well as making it easy for the home mechanic.

Compare the groove on Crash's crank with the groove on this driver:

The only thing (possibly) missing are the dips for the 3 tabs in a typical modern coaster cog, but a front sprocket on an OPC wouldn't need those, on account of the drive-pin. With a washer of the appropriate thickness, a circlip would keep the sprocket flust up against the DS crankarm, and the drivepin would keep it from rotating. Sandwich the cone in there between the circlip and the bearings, install and tighten down the NDS guts, and you'd be rockin' pretty hard...

Your theory makes sense, but based on Crash's picture, the cone doesn't have a groove for that, plus it'd probably be pretty hard to cram the cone over the ring....

 

[schwinn boy]

I just ran across this same problem. Did you get it resolved?

 

[Wildcat]

Talking to the mucle bike guys, this has been seen on a number of Rails, but there isn't a specific year. I don't think it's a defect, I think it's something they tried, but didn't stick with. The reason I say that is the race has no way to tighten it at all, so it wasn't designed with threads or the ability to turn them.
I put it all back together and it works just fine.

I think it will be fine as long as you keep any play out of the cranks.

 

[CRASH]

I just ran across this same problem. Did you get it resolved?

I cleaned it up, greased it, and put it back together. It went together and adjusted fine and held without a problem. That bike sold, so I can't tell you about longevity of adjustments.

 

[c1run1]

i took one apart the other day the same thing

 

[chepe13]

My late 60s firestone has this same setup.

 

[CRASH]

This popped up again tonight. Took apart a crank from a '60's Huffy... not sure of the year yet... but found the threadless set up. This time I had to work off the race with a couple flatheads. But even though it was pressed on it was still a little loose for the sprocket.

 

[deorman]

So basically, you've got a sprocket, a spacing washer, and a couple of pounds of scrap metal.