Rear bike hub idea.

You as well as I know how much of a pain in the butt it is to properly replace the rear axle in your hub when it breaks or bends or when the bearings fall apart. I've noticed when you throw motors into the mix, your hub has a tendency to come loose and your wheel jiggles. Well I have an idea of how to avoid this if it doesn't already exist. This would be a new product. Female thread the outside edges of the hub to except male threaded, sealed bearings. In the middle of each bearing is a threaded hole to run the axle through. Mark the axle with a stop point on one side of it so that you don't thread it through too far or short. Put a washer and nut on each side of the axle making sure not to over tighten it causing the bearings to seize. Use a good amount of thread lock to help hold everything in place. There should be no problem with the axle shifting in its threads as long as the bearings allow the hub to spin freely over it. The hub itself would have to be a little bit bigger and beefier than the norm so that everything would fit properly. The bearings themselves need to be wider, I'd say maybe .5" to make a nice strong and stable fit --->I___I<--- like that wide. You should be able to hold the bearings in place with your fingers while you're threading the axle through; it might require 2 people, I would say don't clamp anything down on the bearings during this process. The same thing with the axle just hold it in place with your fingers while you thread the nuts on. It would probably need a set of varying size spacers to fit in the dropouts correctly depending on the needs of the cyclist. Just a thought.

What about the Stator? It needs to be fixed in the middle of the axle, will it have threads and bolts holding it in place?

Gary

that won't work, for the above stated reason, but Why do they use such crude axles and small bearings on hub motors? the only parts that need to turn(other than the freewheel) are much larger in diameter, yet the axles are smaller than most high qhality bicycle hubs. If someone were to design a larger diameter freewheel or freehub then you could make hub motore with very large axles, and angular contact ball bearings, at the expense of the smaller cogs, which can be made up for with larger front sprockets. You could have a drum shaped 50mm axle that bolts on with multiple bolts to the dropouts, leaving plenty of room for wires to go in. Most current dropouts could be modified to work, but purpose buit frames could even better take advantage of this.

I'm sorry I should have explained better. It's not for a hub motor just a regular bike hub. I was leaning more towards mid drives and motors that run by belt or chain to the rear hub or just regular bike hubs in general. I figured this belonged in this part of the forum because it is a mechanical issue and it's a generalization across the broad spectrum of rear bicycle hub issues. I placed it here because I wanted more members/guests to see it as opposed to people just interested in non hub motor drive topics. It just seems odd to me the way that the axles are mounted in bike hubs and how unnecessarily over complicated it is.

I think you're going to have to post some images of what you are intending, as I don't understand how it could help based on the description alone. I just don't get what adding a bearing (when the hub already has them) will do? If you want to have wider spaced bearings, to better support the hub against the axle, there's not room for them on the right side (see further below in this post), and even on the left side the hub itself would have to be wider to rest on the bearing in order to have any effect.

As far as replacing the axle or bearings or whatever in a regular rear bike hub, it's actually very easy to do--easier than changing the tire/tube in some cases (with very tight-fitting tires).

If it requires a second person to help install the modified hub/wheel, it sounds much more complex to do than the usual. It also means that if it did take two people to install the wheel because of the bearings, you'd be unable to take the wheel off to change tires or tubes while on the side of the road, without flagging someone down to help you.

Also, if you have to use a bigger / beefier hub than normal to start with in order to use your modification, then you probably would not have to do the mod to prevent the issues described.

As for cost: having to add threads to hubs and bearing races is going to be quite difficult and expensive for an individual to do, as they'll have to buy (probably expensive) specialized tools for the purpose, or else send them out to a place that does this stuff (whcih probably also isn't cheap). The race (the outside of the bearing) is typically very hard material, and is not likely to be easy to cut threads in.

A consideration: How would you deal with the lack of space for adding anything at all on the right side of most rear wheels, where the freewheel, cassette, etc. face is usually within a mm or two of the bike frame? None of the bikes I've had or worked on have enough space to put half an inch of bearing or anything else between those two.




Regarding causing bearngs to seize from side pressure: if you use correctly sized spacers, so that they only contact the appropriate race (usually the inner one), and thus don't put inappropriate loading on teh bearing.

Regarding regular-hubbed wheels' axles coming loose at the dropouts because of motors pulling on them, perhaps it would be easier to just add the equivalent of torque plates to the dropouts, to keep it from moving in them?

I'm going to attempt to draw a picture either with my computer or by hand and take a picture. I was thinking more of a mass produced hub to replace current hub styles and such. You know how some hubs are wider on the outside and taper to the middle? Well I was thinking of increasing the width of the outer edges of the hub, make the metal thicker to accept threading and making the taper to the middle shorter this way you have room to install "sealed" bearings. The bearing would have a flange kind of like the lock ring on a bottom bracket so that you would be able to screw it into the hub and it would also make replacing a broken one easier. What I meant by holding the bearing in place to thread the axle through would be to just squeeze the spinning part of the bearing with you fingers to keep it from turning while you thread the axle through.

How many rear hubs have you had come apart?

A cheap walmart hub might fail, but the basic design of the hub has been refined and tested to work well in over 2 billion bicycles over the last 150 years. They are well designed for the job they do if quality parts are used.

If you have a hub failing, I'd question the quality of the build, not the design.

Currently the hub on my Skyline keeps coming loose. I already had my local bike shop fix it and it's still coming loose. I've had axles break on GT mountain and bmx bikes in the past. I was just trying to think of a way to simplify the axle assembly of a hub. This forum is a testament to the fact that just because it works doesn't mean that it can't be improved upon. My idea only requires 8 basic parts: 1 hub, 2 bearings, 1 axle, 2 washers and 2 nuts.

Okay how about this then. Make a cartridge that works similar to a sealed bottom bracket. All you'd have to do is replace the whole thing when it gets worn out. You just unscrew and slide the worn cartridge out and then slide the new one in and screw it into place in the hub.

http://www.endless-sphere.com/forums/viewtopic.php?p=682812#p682812

Chalo said:

I found BMX hubs that had huge 17mm cartridge bearings, so I took the axles out and built 17mm stub axles into the frame.

Click to expand...

id gsuees that meanss these alreayd esxist.

well that's cool now I know.