Two rims, one tire? Hubless Wheel Feasibility

[BartRidesEternal]

Hi Ratters,

For a feasibility check in regards to a rad project I'm working on (on paper) I have a question. I could not find it on the interwebs or this forum:

A:
Did anyone ever put two rims, side-by-side together and put one tire on it?

B:
If yes; were there two inner tubes involved or just one?

C:
Aside from spoke holes and lacing. Is this possible?


Like this, but with two rims and one tire:

Thanks in advance!!

 

[Captain Awesome]

Didn’t @Wildcat have something like this on his radar?

 

[Wildcat]

I had two rims bolted together and used one 3" tire and tube. The vave stem wasn't in the middle, I used one of the rims stem hole. That didn't work well, I was going to drill a hole in the middle but went to two tires.
I laced up the two rims to the one hub using the standard 3 cross pattern, but it couldn't be trued up like that. The shop guys laced it up in a weird way that worked, and the rims didn't need to be bolted together, the spokes held it together.
The two tires on the two rims used two tubes. I had to air each side up a little at a time so one side wouldn't be larger, as the inner sidewalls touched.
While riding, if one side went flat, you could still ride with one tube aired up. But it never was even enough. I think the tires need to be separated so the sidewalls don't touch.

 

[twojs.bike]

Ha! Of course wildcat already tried this. Not surprised at all!

 

[Wildcat]

Ha! Of course wildcat already tried this. Not surprised at all!

After all that work, I think just getting wide rims is the way to go and probably more reliable.

Two rims attached together here are 60mm almost the same as 57mm.

 

[BartRidesEternal]

I had two rims bolted together and used one 3" tire and tube. The vave stem wasn't in the middle, I used one of the rims stem hole. That didn't work well, I was going to drill a hole in the middle but went to two tires.
I laced up the two rims to the one hub using the standard 3 cross pattern, but it couldn't be trued up like that. The shop guys laced it up in a weird way that worked, and the rims didn't need to be bolted together, the spokes held it together.
The two tires on the two rims used two tubes. I had to air each side up a little at a time so one side wouldn't be larger, as the inner sidewalls touched.
While riding, if one side went flat, you could still ride with one tube aired up. But it never was even enough. I think the tires need to be separated so the sidewalls don't touch.


View attachment 288365View attachment 288366View attachment 288367View attachment 288368

After all that work, I think just getting wide rims is the way to go and probably more reliable.

Two rims attached together here are 60mm almost the same as 57mm.

View attachment 288377View attachment 288378

Thanks Wildcat and the rest!

Wow that was quite an experience.

I'm not looking for a wider rim perse, just a very strong solution.

I want to use a bicycle rim non-laced in a constructional manner.
Normally the spokes equally distribute the load over a large section of the rim. If you'll use much less spokes as it were, then everything changes. So I'll have to keep all that in mind.

I might use "Ryde Andra 29" 26 inch rims which are one of the strongest available right now. Think about a plan from there.

Thanks again for that information!

 

[Irontri]

Thanks Wildcat and the rest!

Wow that was quite an experience.

I'm not looking for a wider rim perse, just a very strong solution.

I want to use a bicycle rim non-laced in a constructional manner.
Normally the spokes equally distribute the load over a large section of the rim. If you'll use much less spokes as it were, that everything changes. So I'll have to keep all that in mind.

I might use "Ryde Andra 29" 26 inch rims which are one of the strongest available right now. Think about a plan from there.

Thanks again for that information!

A guy in Poland has 2 rims and 2 tires laced to 1 hub, I guess like in your pic.

 

[Dizzle Problems]

I've seen this one in person. Two tubes were used. Pretty awesome!

 

[BartRidesEternal]

I've seen this one in person. Two tubes were used. Pretty awesome!

View attachment 288383

Thanks again guys!

In this case, if you do not use more spokes, then this solution isn't necessarily stronger. It is handy when one nipple blows through the rim hole. Then you have spare holes


I think I have the solution. I ordered the "Ryde Andra 29" rim which can hold loads up to 150kg (one rim).

When I'm designing functional art, I'm taking the f from functional very serious
Unfortunately I can't show you my design just yet, I might use it for a buildoff. We'll see.

But now I have all my options on the table, so thank you forum!

 

[Wildcat]

Thanks again guys!

In this case, if you do not use more spokes, then this solution isn't necessarily stronger. It is handy when one nipple blows through the rim hole. Then you have spare holes


I think I have the solution. I ordered the "Ryde Andra 29" rim which can hold loads up to 150kg (one rim).

When I'm designing functional art, I'm taking the f from functional very serious
Unfortunately I can't show you my design just yet, I might use it for a buildoff. We'll see.

But now I have all my options on the table, so thank you forum!

What I found is stronger with two rims is the two extra rim walls, 4 all total that give the rim more rigidness. Laterally and horizontally. That's why my shop guys couldn't true them as I had laced them up regular 3 cross.

 

[BartRidesEternal]

Alright, I'm going to be open about what I'm working on here.

The past month or so I'm thinking about building a bicycle with an hubless wheel. A non-driven wheel.
I'm really looking forward to the main buildoff (and enjoying the current one!) and looking at various projects/bicycles to build.
This is the first year where I really invested in my tools to build some serious bikes.

The process in regards to building such a wheel is pretty intense, lots of stuff to think about:
The points below are a 'fraction' of the choice process.

• Going for a principle where 'smaller wheels' rotate on the larger bicycle rim. Like a rollercoaster track.
• Affordable! Everything is easy with a big budget
• 26 inch bicycle rim?
  • Yes: Without spokes, are the rims going to be strong/stiff enough?
  • What type of rollers are we going to use? How many and where?
  • Use a strong rim or a high rim? High rims are stiffer generally because stiffness is: I=WxH^3.
  • Stabilization? How are the wheels not going off track?
  • No: Not use a bicycle rim: What rim is large enough and suitable? Moped?
• Rollers:
  • Standardized has my preference. If don't like bicycles that are made to sit on a show or a museum. We need to roll fast!
  • Diabolo rollers (rollers for tubes). Standardized options? Are the bearings suitable in regards to RPM and conditions?
  • Skateboard rollers? Multiple under an angle.
  • Custom rollers?
  • 3D printed rollers? Material? UV resistant, high impact suitable. ABS or PETG? Nylon?
  • How to distribute the load, so road bumps won't bend or crack the bicycle rim?

This is my first inspiration. I found it on instagram. Altough this is a well executed design, I still have something else in mind. Less heavy, less rollers and more efficiency.

This is my Ryde Andra 29 rim. This is 26inch (559) size. It is one of the strongest affordable rims out there, up to 150kg.

This is a 3D CAD model with the Andra 29 rim (cross-section) and a 'standardized' roller for 50mm tubes. I am hesitant about this Nylon roller since I don't want the rim to wobble left- to right.

Some of my concept drawings. All cross-sections.
What am I looking for here:

• Distribute the load on a part of the rim where the wall is thicker.
• Make sure the rollers provide guidance and stability on the rim.
• Ensure that the rollers don't eat the sidewalls of the rim too much.
• Think about the strength of the rollers and don't crack them in half. The V-shape is more critical in that regard.

Checking bearing RPM with small rollers (I had to check, I had no idea!).

And one wheel concept with rollers. I did not put rollers all around the wheel, like the first inspirational picture. because I am not aiming to build a ring all around the wheel which provide a base for the rollers.

So here the rim with tire must follow the smaller rollers.

• The top roller D is there to provide stability to the rim so that it does not topple sideways. Ideally these are two rollers that are positioned under an angle to keep the rim round and provide sideways stability.
• There are 3 or 4 lower rollers (A, B and C) to distribute the load. Sometimes you can hit a bump or pothole in the road. Then the impact is not always from 90 degree bottom point. X is a distance of the rollers depending on a assumption on 'bump' height and rim strength. I already calculated the rim strength.
• Small wheels E are there to guide the rim in its path. Depending on the rollers these might not be necessary.

Currently the engineering project is halting on a few questions regarding the 3D printed wheels (with standardized skateboard bearings).

One thing I am certain of: The original bicycle wheel with spokes is a marvelous invention on many engineering aspects! A hubless wheel is not going to topple that position! It is a nice-to-have
I would call it an 'open wheel' instead of a hubless wheel.

Anyway, if you are still reading... this was a fraction of the thought process in my head. I need some rest now...

Happy #Engineering !!!

 

[Captain Awesome]

Alright, I'm going to be open about what I'm working on here.

The past month or so I'm thinking about building a bicycle with an hubless wheel. A non-driven wheel.
I'm really looking forward to the main buildoff (and enjoying the current one!) and looking at various projects/bicycles to build.
This is the first year where I really invested in my tools to build some serious bikes.

The process in regards to building such a wheel is pretty intense, lots of stuff to think about:
The points below are a 'fraction' of the choice process.

• Going for a principle where 'smaller wheels' rotate on the larger bicycle rim. Like a rollercoaster track.
• Affordable! Everything is easy with a big budget
• 26 inch bicycle rim?
  • Yes: Without spokes, are the rims going to be strong/stiff enough?
  • What type of rollers are we going to use? How many and where?
  • Use a strong rim or a high rim? High rims are stiffer generally because stiffness is: I=WxH^3.
  • Stabilization? How are the wheels not going off track?
  • No: Not use a bicycle rim: What rim is large enough and suitable? Moped?
• Rollers:
  • Standardized has my preference. If don't like bicycles that are made to sit on a show or a museum. We need to roll fast!
  • Diabolo rollers (rollers for tubes). Standardized options? Are the bearings suitable in regards to RPM and conditions?
  • Skateboard rollers? Multiple under an angle.
  • Custom rollers?
  • 3D printed rollers? Material? UV resistant, high impact suitable. ABS or PETG? Nylon?
  • How to distribute the load, so road bumps won't bend or crack the bicycle rim?

View attachment 288635
This is my first inspiration. I found it on instagram. Altough this is a well executed design, I still have something else in mind. Less heavy, less rollers and more efficiency.

View attachment 288638
View attachment 288639
View attachment 288640View attachment 288641
This is my Ryde Andra 29 rim. This is 26inch (559) size. It is one of the strongest affordable rims out there, up to 150kg.

View attachment 288643
This is a 3D CAD model with the Andra 29 rim (cross-section) and a 'standardized' roller for 50mm tubes. I am hesitant about this Nylon roller since I don't want the rim to wobble left- to right.


View attachment 288636
Some of my concept drawings. All cross-sections.
What am I looking for here:

• Distribute the load on a part of the rim where the wall is thicker.
• Make sure the rollers provide guidance and stability on the rim.
• Ensure that the rollers don't eat the sidewalls of the rim too much.
• Think about the strength of the rollers and don't crack them in half. The V-shape is more critical in that regard.

View attachment 288637
Checking bearing RPM with small rollers (I had to check, I had no idea!).

And one wheel concept with rollers. I did not put rollers all around the wheel, like the first inspirational picture. because I am not aiming to build a ring all around the wheel which provide a base for the rollers.

So here the rim with tire must follow the smaller rollers.

• The top roller D is there to provide stability to the rim so that it does not topple sideways. Ideally these are two rollers that are positioned under an angle to keep the rim round and provide sideways stability.
• There are 3 or 4 lower rollers (A, B and C) to distribute the load. Sometimes you can hit a bump or pothole in the road. Then the impact is not always from 90 degree bottom point. X is a distance of the rollers depending on a assumption on 'bump' height and rim strength. I already calculated the rim strength.
• Small wheels E are there to guide the rim in its path. Depending on the rollers these might not be necessary.

Currently the engineering project is halting on a few questions regarding the 3D printed wheels (with standardized skateboard bearings).

One thing I am certain of: The original bicycle wheel with spokes is a marvelous invention on many engineering aspects! A hubless wheel is not going to topple that position! It is a nice-to-have
I would call it an 'open wheel' instead of a hubless wheel.

Anyway, if you are still reading... this was a fraction of the thought process in my head. I need some rest now...

Happy #Engineering !!!

Absolutely subscribing to follow this! Always something in the back of my head to

 

[BartRidesEternal]

3D printed a 'half' of a wheel. Reason to test it like this is the idea that both sides of the wheel are nice and flat, since that part lays on the glass plate.
+ you'll need way less filler/support material, cutting in costs.
I can glue the two halves together and press a bush in the center.

Made for Skateboard bearings.

Pretty neat!

 

[BartRidesEternal]

Hi guys,

3D printing is pretty expensive, so I keep checking concepts and ideas:

Flange wheels. Positioned left/right for axial stability.
6 shafts, 12 external bearings on a shaft. Skateboards have 8.

Locations are chosen in regard to rim strength. Left is ride direction (so most impacts on potholes etcetera).

-See the flanges positioned left/right?
-The first, most left, wheel is positioned 60mm higher. I can't imagine hitting a higher obstable riding a custom cruiser.
-I could position the bottom centre wheel a little more to the right for better guidance.....

The wheels are standardized and affordable.

I'll ponder on this for a while.... feel free to express your ideas or criticism!

 

[BartRidesEternal]

Hi guys,

3D printing is pretty expensive, so I keep checking concepts and ideas:

Flange wheels. Positioned left/right for axial stability.
6 shafts, 12 external bearings on a shaft. Skateboards have 8.

Locations are chosen in regard to rim strength. Left is ride direction (so most impacts on potholes etcetera).

View attachment 289224View attachment 289225
View attachment 289226
-See the flanges positioned left/right?
-The first, most left, wheel is positioned 60mm higher. I can't imagine hitting a higher obstable riding a custom cruiser.
-I could position the bottom centre wheel a little more to the right for better guidance.....

The wheels are standardized and affordable.

I'll ponder on this for a while.... feel free to express your ideas or criticism!

Another positive thing about these wheels, slided/pressed on an shaft with external bearings is that it is easier to adjust to a different rim (in regards to width).

 

[BartRidesEternal]

Better images with an 26x3.0 inch tire

 

[Captain Awesome]

Impressed by the thought process. Never considered the roller spacing like that and the inputs behind it

Most would just naturally default to full circumference rollers when it’s not actually needed

 

[BartRidesEternal]

Impressed by the thought process. Never considered the roller spacing like that and the inputs behind it

Most would just naturally default to full circumference rollers when it’s not actually needed

Thanks Cap!
This is somewhat of a tryout for me too. Full circumference rollers are logical since they keep the wheel round (like spokes).
Rims arent designed for a 'bending' force. More to spread the load among manymany spoke holes.
That is also the risk with my current rim: Its not high. Its load limit is 150 kilograms, but it could have to do with the spoke points instead of the general rim....

High rims would be better, but then again, they are narrow at the spoke holes and you can't run a wheel over them, then you'll need a wide rim with some surface.

Its difficult putting the proces into words

 

[BartRidesEternal]

I made a choice. It is a fine balance in costs, practicality, strength, stability, low rolling resistance and fun.

Since my last post, I decided to go for larger wheels (=lower RPM =better reliability), standardized and less bearings.

One concept had 7 shafts and a bearing on each side on the frame. So thats 14 bearings total.

An skateboard has 8 bearings.

If I were to use an 'diabolo wheel' I still needed 6 wheels: 4 to spread the load on the rim and 2 for guidance. And 12 bearings.

Now I decided to go for flange wheels. 7 in total and strategically placed left/right (like my previous post) to guide the rim properly.
These are 'larger' wheels than the previous post and have an straight rolling surface, instead of the previous 3 degrees sloped wheels. The straight rolling surface is better in spreading the load over the flat surface of the rim.
Larger wheels are a bit more ugly, but I really want this to work on all levels!

Bearings.
Strategically placing the bearings nearly centered on the surface of the rim, I only need 1 bearing per wheel. 7 in total.
Bearings are standard sizing (32mm od. 10mm id. and 9mm width).
The bearings have a ZZ marking, which means they have two metal dust caps which do not scrape the bearings inner ring, so drag is minimized. (for example: 2RS bearings have two seals which seal the bearing pretty good, but they 'drag' a bit more).

Combined.
Combining the flanged wheels and bearings

I already ordered the wheels so I can start designing the base and after that I'll leave it so I can choose to build the bike for the buildoff this year. I don't want to push the limits of the rules, but also don't want to start too ambitiously and get stressed What are your thoughts on that @Captain Awesome ?

Pictures!!!

White Nylon wheels.

Modeled and I made a cross section with the standard wheels.

Top view, cross section.

Complete view.

Cross section with a bearing chamber machined in the nylon wheel.
The chamber is purposely made from the outside, so if the tire + rim wants to go bye, they don't push the Nylon flanged wheel off the bearing.
The chamber is also deep (24mm) so the bearing is properly loaded and therefore more reliable.

Whats next doc?

10mm shafts, adjustable in axial and radial direction, so various rims can be utilized (if that is necessary). Also, you can adjust the sideways play, so the rim runs smoothly between the rollers.

A base that can accommodate the shafts, remove play between the wheels and that I can weld/braze to the bike's frame.

I need to keep in mind that the top rollers need some form of 'prestress' or little bit of tension to keep the wheel in check and vibration free.

That's enough for now. More pictures when the wheels are here.

 

[Captain Awesome]

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!!