Hubless Wheel Feasibility Project

[Captain Awesome]

Been awhile since I’ve dabbled in polymers but PA6 has a relatively low friction coefficient and a decently high melt point, yes?

 

[BartRidesEternal]

Start making your “prototypes” and doing mock ups. You’ll still have plenty of work left to do even by May

Plus you still have the rest of the bike to deal with

Following along!!

Thanks cap! I'll build a "working" prototype then!

Been awhile since I’ve dabbled in polymers but PA6 has a relatively low friction coefficient and a decently high melt point, yes?

I also had to look up the properties of Nylon again to be honest. In our workshop, at my employer we also utilize Nylon wheels.
They are tough, wear-resistant, sound dampening. But having seen the incredible wear resistance of these wheels being used on rough, street/tile like surfaces, this was my first choice.

 

[BartRidesEternal]

I was focussing on this term 'hubless wheel' which I would like to call an 'open wheel'.

But I just realized the principle I'm working with is more like a monowheel:

Check the rail (wheel) and rollers.

 

[BartRidesEternal]

Found this via pinterest:
Except being just beautiful and/or interesting, someone found a use for it

Now I have to put this on my 'to build' list too.

 

[BartRidesEternal]

So at this point I wanted to show you guys the direction I'm heading with this wheel prototype:

Years ago, I read a 'recumbent' topic here on Ratrodbikes. There I saw the #flowroller from 'Rohorne'.
I never lost sight of that front wheel driven and steered custom cycle. Its so obvious, genius and cool at the same time.

Seeing that rear wheel, hanging and doing nothing (taildragger?), I thought, this is a perfect opportunity for some Bartrideseternal sauce.

Alright, below some pictures of the flowroller and then some of my ideas on CADboard scale 1:1.

I plucked these pictures from the internet.

My first sketch.
Details are flawed, but its pretty cool!

[EDIT] I don't know if I will build again with a shaft drive. Dimensions and alignment with my current tools is an absolute nightmare. The shaft drive klunker from the ORBO build this year will turn out great, but I'll leave the shafts for a little while.

 

[us56456712]

How does the chain line work? Looks to me when you turn the chain will bind and get thrown.

 

[kchurch86]

Oh I gotta follow this one...

 

[BartRidesEternal]

How does the chain line work? Looks to me when you turn the chain will bind and get thrown.

If I understand correctly; your question is about the sketch on cardboard?
The cardboard sketch has a shaft drive sketched. And the downtube is too low to effectively make turns.

On the pictures the complete bottom bracket and chain turns in corners. The extreme headtube angle is (I'm thinking) to mitigate the forces on the bars by pedalling.

Check out this youtube video:
Imagine that with an hubless/open wheel
That wheel flop due to the crazy headtube angle... maybe I can think of something when the build arrises.

Oh I gotta follow this one...

Thanks, I won't start building the bike till the main buildoff. This is a little feasibility check if the 'open wheel' is manageable for a buildoff bike. + I'm not sure if I'll build this bike for the buildoff either.
I am going to build such a bike someday!

 

[BartRidesEternal]

Rollers rolled in!
Next: base sketches and ideas! Lets do this!

 

[BartRidesEternal]

I thought long about the wheel-to-frame connections.
I want one bottom "base" wheel and the rest adjustable. If ever, for whatever reason a different 26" rim is used, all wheels should still carry the load.

So one hole and the rest are dropouts.

I had quite some notes and sketches, but I'll just give you guys THE JUICE:

480mm diameter is the base diameter for the wheel. The rest is a 'simulation' to take smaller rims (inner diameter) into account.

Rough concept based on steel plate. 100mm dropout width because I like fat tires.
I am aware this isn't stiff enough in the sideways direction.

More soon!

 

[Wayne]

I have been thinking about a hub-less wheel also. Using two lazy susan bearings, preloaded against each other.

16" outer diameter for a 20" tire. Maybe some year I'll get it figured out.

 

[Captain Awesome]

I have been thinking about a hub-less wheel also. Using two lazy susan bearings, preloaded against each other.

View attachment 290199

16" outer diameter for a 20" tire. Maybe some year I'll get it figured out.

Wow. Never even thought about that

 

[Wayne]

Wow. Never even thought about that

Will definitely have a higher rolling resistance with many more ball bearing, so not a hill climber, just for cruising.

 

[The Renaissance Man]

Subscribed!

 

[Captain Awesome]

Will definitely have a higher rolling resistance with many more ball bearing, so not a hill climber, just for cruising.

That’s what I was thinking. Slow rolling conversation piece

 

[BartRidesEternal]

I have been thinking about a hub-less wheel also. Using two lazy susan bearings, preloaded against each other.

View attachment 290199

16" outer diameter for a 20" tire. Maybe some year I'll get it figured out.

Wow! That is a great size indeed! I never thought about utilizing those bearings though.

Will definitely have a higher rolling resistance with many more ball bearing, so not a hill climber, just for cruising.

Oil lubricated an option?

Subscribed!

Thanks!

That’s what I was thinking. Slow rolling conversation piece

Yes well... speed, weight, price, coolness, maintainability etcetera....

 

[Wayne]

Oil lubricated an option?

The balls are loaded through a hole in the outer race. I can see at the load plug, they were loaded with grease. I don't think they were meant to be serviced. Probably riding thought standing water would not be good.

 

[The Renaissance Man]

That’s what I was thinking. Slow rolling conversation piece

Two words: Women's shoes.

Practicality is way down the list.