Rocker suspension to replace rear wheel

[Balor]

Basically, by replacing rear wheel with two smaller ones IN LINE (unlike iLean that was experimented with by Cruzbike) on a rocker we can have an EXCELLENT suspension that needs to springs or dampers and works by virtually increasing wheel size 4 times roughtly speaking (would not work on a 'drop to flat' though)

So, replacing a rear wheel with a rocker of two 12" wheels we'll have an equivalent of 48" wheel!

Inspired by a Martian Rover:
https://en.wikipedia.org/wiki/Rocker-bogie


A scetch of my MBB, before:

After:

Given that wheels are small and in line with each other, it may actually result in better aerodynamics, especially if one is to add an airfoil-shaped fender around the tops of the wheels (where there most of wheel aerodynamic losses take place).

I can attest that such a rocker suspension is GREAT in practice.

Unlike iLean, one should be able to fit brake on this system (even a single brake on one wheel) I suppose, because 'asymmetric' braking action will not cause the bike to lean because wheels are in line... but may cause it to rotate around the axis... that needs some further thought.

There are kiddie balance bike wheels that are pretty strong and light, but unfortunately finding well-rolling 12" tires is likely to be a pain. Designing a bike for 16" racing tires (like Scorchers) from scratch would likely work better both from suspension performance AND rolling resistance.

There might be some wheel scrub when turning though.

Definitely worth experimenting with!

 

[super slim]

Basically, by replacing rear wheel with two smaller ones IN LINE (unlike iLean that was experimented with by Cruzbike) on a rocker we can have an EXCELLENT suspension that needs to springs or dampers and works by virtually increasing wheel size 4 times roughtly speaking (would not work on a 'drop to flat' though)

So, replacing a rear wheel with a rocker of two 12" wheels we'll have an equivalent of 48" wheel!

Inspired by a Martian Rover:
https://en.wikipedia.org/wiki/Rocker-bogie


A scetch of my MBB, before:

After:

Given that wheels are small and in line with each other, it may actually result in better aerodynamics, especially if one is to add an airfoil-shaped fender around the tops of the wheels (where there most of wheel aerodynamic losses take place).

I can attest that such a rocker suspension is GREAT in practice.

Unlike iLean, one should be able to fit brake on this system (even a single brake on one wheel) I suppose, because 'asymmetric' braking action will not cause the bike to lean because wheels are in line... but may cause it to rotate around the axis... that needs some further thought.

There are kiddie balance bike wheels that are pretty strong and light, but unfortunately finding well-rolling 12" tires is likely to be a pain. Designing a bike for 16" racing tires (like Scorchers) from scratch would likely work better both from suspension performance AND rolling resistance.

There might be some wheel scrub when turning though.

Definitely worth experimenting with!

There will be tyre scrub, as the bike will turn around the front rear wheel! All iLean rear tyres are bald!!!
Only put a brake on the rear wheel!

 

[Balor]

Yea, it will scrub most likely, but how bad that is in practice needs ascertaining.
I think you'll be able to put a brake on one rear (leading) wheel and it will work, unlike on iLean.

 

[bladderhead]

In the UK the refuse lorries have two back axles. On the rearmost one the wheels steer. Should not be that hard to implement on non-drive wheels.

 

[3bs]

other than the fun of it (which is really enough of a justification) , i don't really see the value advantage over the weight complexity and cost disadvantages.

isnt your bike currently an outrigger quad?

 

[super slim]

In Australia, most 40 ft (12 M) trailer have Triaxles of 20T total capacity, as there a lot of big LONG straight roads here!!!
4,00 km (2,500 miles) from Perth WA to Sydney NSW!
But if they do a 180 degree tight turn to get into a fuel loading station, then the rear tyres HOWL as they are dragged sideways!!!!!

 

[Balor]

other than the fun of it (which is really enough of a justification) , i don't really see the value advantage over the weight complexity and cost disadvantages.

isnt your bike currently an outrigger quad?

As for weight, and complexity/costs... in fact, it should be simpler than conventional suspesion and almost zero maintenance - only one pivot on a rocker and two wheels, no springs/dampers/zero brake drive and pedal bob.
Two 12" kiddie runbike wheels weight half a kg PAIR, and should actually be quite strong enough because the smaller the wheel is - the stronger it gets and you get two instead of one. 12" tires can be had in 150 gr, and I don't intend to run ultra light componentry anyway.
If you want brakes though - that's different, yea... will likely need something custom or otherwise think of something, maybe a disk brake kickbike hub - they ARE heavy though.

Quad - currently - no. I've just did a few test runs to test viability and it works *wonderfully* - much better than I've expected, really! To be fair, I've used 26" wheels, effect will be much less with 16 or 12 wheels obviously.
That is for a 'tilt plus' leaning velo. My goals are comfort and safety first, and speed second (provided pursuit of safety and comfort does not eliminate speed benefits entirely), and I'm way past saving on weight front, so I'll just enjoy my speed on the flats and crawl uphill anyway.

Our roads can be BAD. I need ALL suspension I can get my hands on - what works for a martian rover, might just work for our roads
And bogie suspenion is excellent in wheel keeping traction - and on a bent, once traction is lost you are going down fast - cause low CG and almost no body english is possible... while having such a 'rocker bogie' as a front wheel is doubtful, if it will work, it should be GREAT for offroading.
Bonus points for looks you will get, bent or no bent. I mean, I kind of got tired of endless "Is this thing comfortable' questions, so I'm looking forward to 'Why do you need this many wheels' instead

But if they do a 180 degree tight turn to get into a fuel loading station, then the rear tyres HOWL as they are dragged sideways!!!!!

Good point. Fortunately, my goals are long-distance travel most in straight lines, not criterium or track races. Obviously, with small wheels you RR will take a hit as well. How bad that will be in practice - again, we'll see. It may be slower, but it might be worth it.