Singlespeed & Fixed Gear - Track Hub design

I am studying engineering and have access to lots of machines(cnc) in my university workshop. I was vondering is it possible to build your own track hubs from a block of aluminium. The only thing I need is any blueprints, measurements or any full dimensions of a sealed track hub. Does anybody of you know a link for such drawings? Or maybe somebody has expirience in such activities and could help me?

sure you could do it

just because i just registered in this forum means I am not able to do anything? I have restored cars, built bicycles, robots etc. I think i am able to use tools to get thing done. Why not a hub. It's just an aluminium piece with 37 holes and some thread. Just need the drawings.

If you're really an engineering student and have done the things you say yet can't come up with a basic hub design using CAD software then you should rethink your major.

Edit:

With the negativity out of the way, I'd love to see your eventual design utilizing 37 spokes.

Perhaps you can call it the "Veronica" as a reference to one of Kevin Smiths characters in the film "Clerks".

With the negativity out of the way, I'd love to see your eventual design utilizing 37 spokes.

Perhaps you can call it the "Veronica" as a reference to one of Kevin Smiths characters in the film "Clerks".

Not positive but I'm assuming the OP meant 36 holes for spokes and 1 for the bearings/axle. Not 37 spoke holes...

Any whoooo.... Yeah as long as you plan to make the hub yourself why don't you design it yourself to? As a engineering student I'm sure you have access to CAD software.

Here's some custom tandem hubs made by Canadian mechanic and racer, Doc Morten, back in the 30's out of solid alloy. The hard part will be machining steel races to fit methinks.

http://lh5.ggpht.com/__0sZkBzxvxs/TH1dnSFi3LI/AAAAAAAAA4o/gZ3b2BG03z4/s800/DM1..jpg

http://lh5.ggpht.com/__0sZkBzxvxs/TH1dnYU-orI/AAAAAAAAA4s/K_FlHblL3y8/s800/dm2..jpg

I'm guessing these were turned on some sort of milling machine?

uh... are you studying to be a machinist or an engineer? If the latter, design your own damn hub. It's not that hard.

If you're looking to find dimensions for an existing hub, then copy it, just buy an existing hub.

This is about as basic of a design problem as you'll find. If you can't handle it, I highly suggest finding a different carreer path. The last thing the world needs is another engineer who can't design his way out of a box.

- An Engineer

I have access to CAD software. I'm using Solid Edge v20 and N6 for CNC machining. I could design a hub myself, but i need some information about thread sizes, sprocket/lockring spacing and bearing placement. Since I don't have a sealed bearing hub close to me, I can't just measure this. The idea is to create just the hub body - all the other parts will be bought.

Whoah. Post pix when done, I'm interested in seeing this. Sounds cool

http://pardo.net/bike/pic/fail-024/000.html


Look about halfway down the page. They have dimensions of a track hub. Not a technical drawing so I'm not sure if it will be very helpful but maybe.

I understand Dinaars' problem, and he doesn't deserve the harsh and biting criticism he's getting (then again, I shouldn't forget what forum this is).

If the design problem were to design a hub in a requirements vacuum, then no problem. In that case, it truly is an easy problem and any engineer worth his salt (or future salt if he's a student) should come up with an answer easily.

But we live in the real world where such a design is constrained by convention, arbitrary historical precedent, and the interactions with other components. If the guy needs info on thread sizes so his hub will take standard axle nuts and cogs, it's an acceptable question. If he needs inner diameters so he can use off-the-shelf bearings (a valid design choice), then so be it. Those kinds of things are important if he ever plans to put this hub on a bike that won't also have to be design from the ground up.

Sorry I don't have your answers...but ignore the surly members of our "community" and keep working at it.

-- Another Engineer

If the guy needs info on thread sizes so his hub will take standard axle nuts and cogs, it's an acceptable question. If he needs inner diameters so he can use off-the-shelf bearings (a valid design choice), then so be it. Those kinds of things are important if he ever plans to put this hub on a bike that won't also have to be design from the ground up.

All he needs to do is some basic research and all this information is readily available on the internet. He's just being intellectually lazy, expecting us to spoon feed him the answers. The most important part of engineering education is learning to gather relevant information and then process it into a viable result. I'm really disappointed with the current crop of engineers that expect others to do their thinking for them.

-- An engineer from another era

All he needs to do is some basic research and all this information is readily available on the internet. He's just being intellectually lazy, expecting us to spoon feed him the answers. The most important part of engineering education is learning to gather relevant information and then process it into a viable result. I'm really disappointed with the current crop of engineers that expect others to do their thinking for them.

-- An engineer from another era

This.

I find it weird that with information so readily available people in my generation still expect to be spoon fed. Google is a wonderful thing.

-- An engineering student turned computer science student (not for lack of intelligence, just lack of interest)

And I like cats.

-- Not an engineer at all but I like messing around with my bike.

http://pardo.net/bike/pic/fail-024/000.html


Look about halfway down the page. They have dimensions of a track hub. Not a technical drawing so I'm not sure if it will be very helpful but maybe.

I think this will do. Thanks!

The thing is that it's easy and possible to find thread sizes, but try to find the information about how many turns it has to have. What is the needed distance from sprocket to flange so the spokes don't touch. How thick the flanges need to be, what is the needed wall thicknes in the middle of the hub? There are lot of questions and a googles link to wikipedias flip/flop hub just doesn't do good enough..

I want to do this.

-- Engineering student

I think this will do. Thanks!

The thing is that it's easy and possible to find thread sizes, but try to find the information about how many turns it has to have. What is the needed distance from sprocket to flange so the spokes don't touch. How thick the flanges need to be, what is the needed wall thicknes in the middle of the hub? There are lot of questions and a googles link to wikipedias flip/flop hub just doesn't do good enough..

Great hope that works out. Once you get something modeled up you should post a screen shot. And if you ever go through with machining it, post some pictures of that.

BTW, I found that link on the second page of a Google search.

Don't take any rudeness personally. It's the internet, people (including myself) are obligated to give others a hard time.

Edit: Also, if you are going to be machining from a solid block of aluminum you won't want flanges as large as the ones in the link I posted. That will not be very cost effective.

take a caliper to ur current hub?

I'm gonna suggest that if you're going to make your own hub, why make a standard track hub? One of these would be much cooler. (http://www.whiteind.com/trackhubset.html) Not to much more work either.

This seems like a cool idea.

-A sociology student

just put lots of holes in it

-an art student

just put lots of holes in it

-an art student

37 of them...or 41...or 33...or...

225

The most important part of engineering education is learning to gather relevant information and then process it into a viable result.

I completely agree. Though I'm not sure how personally asking people who are somewhat likely to possess the knowledge isn't a viable way of gathering relevant information. If someone comes to me and says "What airfoil section does the C-130 use?" I'm not gonna say "Go look it up...and F- you for being lazy". I'm going to provide the answer if I have it because appealing to expertise is a great way of gathering information. It's not spoon-feeding, and there's nothing inherently honorable about arriving by an answer in a harder way than necessary.

But in any case, I'm glad the OP appears to have gotten some of what he needs.

3's enough for me.

Though I'm not sure how personally asking people who are somewhat likely to possess the knowledge isn't a viable way of gathering relevant information. If someone comes to me and says "What airfoil section does the C-130 use?" I'm not gonna say "Go look it up...and F- you for being lazy". I'm going to provide the answer if I have it because appealing to expertise is a great way of gathering information. It's not spoon-feeding, and there's nothing inherently honorable about arriving by an answer in a harder way than necessary.

First off, I did not tell the OP to F-whatever nor was I in any way rude. Was I curt and to the point, yes. My objection was that the OP appeared to make no preliminary attempt to seek out as much information as possible before posting on this forum. No doubt the forum member who replied with the link to the drawing found it by "googling", so why couldn't the OP do the same? Also, most of the information the OP is seeking is common knowledge, and not in the same realm as "What airfoil section does the C-130 use?", which may be proprietary or even classified. As a practicing engineer, I often sought the advice of my colleages in areas where I lacked expertise, but I did the basic leg work myself rather rely on them to do all my work for me. Had the OP posted that he or she had already done the basic research, and was now seeking specific detailed information to complete the task, then I would have been more receptive to providing assistance. Finally, the OP is an engineering student in the learning phase, rather than an engineering professional in the practicing phase. As a practicing engineer, I was under tight schedule constraints to obtain results in the most expeditious manner and did not have the liberty to spend time engaged in research or "reinventing the wheel." OTOH, the OP is a student who needs to spend the time to learn design, and perhaps waste some time in order to learn the design process and how to evaluate the issues that are relevant. Simply copying a design drawing into a CNC machine is not engineering design.

I think this will do. Thanks!

The thing is that it's easy and possible to find thread sizes, but try to find the information about how many turns it has to have. What is the needed distance from sprocket to flange so the spokes don't touch. How thick the flanges need to be, what is the needed wall thicknes in the middle of the hub? There are lot of questions and a googles link to wikipedias flip/flop hub just doesn't do good enough..


I'm going to jump in and add the opinion of another engineer. Some of your questions your questions relate to specifications and some are design questions.

My advice is to first buy the off-the-shelf parts you plan to use such as the axle, cartridge bearings, spacers/locknuts, cog and lock ring. Take your calipers and get the measurements you need. Once you have the dimensions laid out, it's pretty trivial to design a hub shell around the parts.

If you want a hub that is going to be as light as possible instead of just looking cool, you task will be a bit more involved.

As for flange thickness, wall thickness, and chain clearance, these are just part of the design exercise. Take a look at some of the hubs on the bikes you've built and work out the flange thickness from there. Wall thickness of the hub shell will depend on material and geometry and you should work that out on your own as you sketch out your design.

Have fun, make a few so you can keep a set for a memento and ride the heck out of the rest.