Parts for pair of steerable wheels?

[Galifer]

I'm thinking of making a 3 or 4 wheeled bike. Two wheels will be used for steering. Not sure if regular sized wheels or perhaps smaller wheels, with hub motor in one or both. No axle. What are lightweight and affordable parts I can use to attach the wheels to the chassis? I was thinking of maybe something like this:


Or with suspension something like this?


The load will be a total of around 100kg including human and bike. No fancy speeds, just casual cycling speeds.

Also is there anything special I need to do when attaching wheels in this way, i.e. not having them supported on both sides?

In case it makes a difference, I'm in the UK. Tips on where to buy such parts would be most helpful as I'm a total newb!

Many thanks!

 

[Chalo]

Sturmey Archer makes drum brake hubs designed for one sided use. (That's what the black trike in your picture has.) 15mm or 20mm through-axle front disc brake hubs also work for one-sided applications.

Grin Technologies' All Axle front hub motor can probably be used one sided, but it is certainly one of only a very few. Direct drive hub motors usually have bearings big enough to be used one sided, but that would require machining a new axle to do it.

Read up on Ackermann steering geometry. You'll need to understand this before you cut metal.

What is it you're trying to accomplish? Mostly when you switch from two to three or four wheels, you end up with a bike that weighs and costs more, does fewer things well, and is less pleasant to ride. Bumps in the surface can only affect a two wheeler in the pitch axis, but for a three or four wheeler they also work in the roll axis. It's only worth it if you have major balance issues or you're carrying very heavy loads.

 

[stan.distortion]

I've no experience with them but QS do their popular 205 50H in a single sided mounting variant. All the ones I've come across so far are for a stud mounted (regular car type) wheel but I'd be surprised if they don't do a spoked model and even more surprised if they wouldn't build a couple for you to spec. More expensive than the very popular generic 205 hubmotors and someone's probably doing a single sided variant of those and shipping can be expensive with QS China but apparently they've got a US dealer now and are close to having one in Europe.

https://www.aliexpress.com/af/qs-motor.html?d=y&origin=n&spm=a2g0o.productlist.0.0.26d03eb5yLeCpz&catId=200215591

EDIT: Maybe just what you're looking for but if the styling doesn't get you then the shipping will
https://www.aliexpress.com/item/1005003171166289.html?spm=a2g0o.productlist.0.0.6cf13eb5TsGRAJ&algo_pvid=d317e51e-cab8-4dfd-a874-71268fbffda7&algo_exp_id=d317e51e-cab8-4dfd-a874-71268fbffda7-46

 

[Galifer]

Sturmey Archer makes drum brake hubs designed for one sided use. (That's what the black trike in your picture has.) 15mm or 20mm through-axle front disc brake hubs also work for one-sided applications.

Thanks. I googled them but the ones I saw are not with any electric hub motor.

Grin Technologies' All Axle front hub motor can probably be used one sided, but it is certainly one of only a very few. Direct drive hub motors usually have bearings big enough to be used one sided, but that would require machining a new axle to do it.

They seem quite high price but more importantly, though I could not find an official watt rating for that, they look to be above the UK's 250W limit.

Read up on Ackermann steering geometry. You'll need to understand this before you cut metal.

Thanks yeah I had read up about that but great to put a name to it!

What is it you're trying to accomplish? Mostly when you switch from two to three or four wheels, you end up with a bike that weighs and costs more, does fewer things well, and is less pleasant to ride. Bumps in the surface can only affect a two wheeler in the pitch axis, but for a three or four wheeler they also work in the roll axis. It's only worth it if you have major balance issues or you're carrying very heavy loads.

A small 'bike house'. Basically a glorified insulated tent but rigid. Not the hard and heavy materials one might associate with a 'camper van' or the hard shelled cargo bikes. Light materials. But I'm rather new to working with metal and so the frame and battery are going to be the heavy items it seems.

 

[Galifer]

I've no experience with them but QS do their popular 205 50H in a single sided mounting variant.

Thanks. I googled that and it appears to be 3000W, so, over 10 times the legal limit here unfortunately.

Thanks guys for pointing out the motor itself needs to be special. Anyone know of 250W rated motors? (I don't mind if they're more powerful, just as long as the *official* rating is 250W).

And for the parts that actually connect the wheel to the frame... anyone?

Or if we have to scrap the 'single side' hurdle and just support the wheel on both sides, if anyone has any nice links of that, and/or parts for me to be able to make that happen, would be much appreciated! I even wondered about cutting off the front of two old scrap bikes, employing the turning phenomenon of those but cutting off the handle bars... if that might be a cheaper way and be a reasonable thing to do?

 

[Chalo]

Technically, it will be much easier to use unpowered front wheels, and motorize the one or two fixed wheels.

 

[MadRhino]

All hub motor manufacturers in Asia are making some side mount motors. Yet I too, would prefer the motor on the rear. Still, 2 motors on the front is interesting for some applications.

If you are ready to go into welding and fabrication of your own front end, make it leaning, with quality shocks. Very satisfying and well worth the trouble. Many different leaning trikes can be found online, helping to choose your design.

 

[Galifer]

Technically, it will be much easier to use unpowered front wheels, and motorize the one or two fixed wheels.

Ok I will consider that, thanks. If I did that, I still need to find out what parts I need and where such things are available to actually fix them to the chassis. Do you have any ideas about that?

Also just to mention though it might make y'all think I'm crazy - what I have actually been considering is to have it 3 wheeled, and to have the chain power the front wheel. Unusual I know but could maybe make things a bit easier by hacking of the back of a regular bike and using that (angled differently) for the front wheel, with all the chain and everything already lined up and useable, and that saves also having the long chain going to the back and the axle and all that jazz that that would require. Plus I have another reason for wanting to keep the underside of the vehicle clear but that's probably too much info to go into that, for this thread. So my intention was actually to have these two steering wheels as the back wheels. I know this is very abnormal but so far I see no reason against it.

 

[Galifer]

All hub motor manufacturers in Asia are making some side mount motors. Yet I too, would prefer the motor on the rear. Still, 2 motors on the front is interesting for some applications.

My reasons may be more apparent from my last comment now. But yeah I was thinking even just installing a motor on one of the two. I heard that shouldn't be a problem. I was thinking for the option of doing 2 of them partly so can switch to one as backup if needed. But also potentially for more power where circumstances allow.

If you are ready to go into welding and fabrication of your own front end, make it leaning, with quality shocks. Very satisfying and well worth the trouble. Many different leaning trikes can be found online, helping to choose your design.

I haven't found anywhere to buy actual parts for DIY build. Do you know of any? And on the cheap side how much cash might we be looking at? Budget is a little tight since who knows with a first build, it might not even work! So have to be careful with cash.

Oh and... I hadn't even thought of just looking for a motor. Is putting that together ... easy enough? And save money? Rather than just buying a wheel with motor installed already?

 

[Chalo]

Rear steering is notoriously unstable. There's a reason you never see it on any roadgoing vehicle, whether motorized or muscle powered. The only rear steering trike I can remember was the German half-tilting, rear-steering Culty, and it was famously difficult to learn to ride.

Because a hub motor can be mounted on the side of a chassis, with the floor well below the axle, it makes sense for the motors to be on the rear wheels and the pedal drive to be on a steerable front wheel, like a Cruzbike:

Or you can use a rear hub motor in front, and simplify the rear wheels.

I still need to find out what parts I need and where such things are available to actually fix them to the chassis. Do you have any ideas about that?

Every time I've made single sided wheels, I either machined an axle on the lathe or adapted a bolt or round bar to serve as one. The simplest stub axle I ever made was a 5/8" rod with shaft collars clamped inside and outside of the wheel hub.

Kingpins you can make from bicycle head tubes.

 

[999zip999]

Two wheels up front one motor in the rear.

 

[Galifer]

Rear steering is notoriously unstable. There's a reason you never see it on any roadgoing vehicle, whether motorized or muscle powered. The only rear steering trike I can remember was the German half-tilting, rear-steering Culty, and it was famously difficult to learn to ride.

That's very useful to know, thanks!

Because a hub motor can be mounted on the side of a chassis, with the floor well below the axle, it makes sense for the motors to be on the rear wheels and the pedal drive to be on a steerable front wheel, like a Cruzbike:

I had pondered on that idea but assumed it would be too hard to steer and pedal. I was hypothesising two things:
1) That it would be too awkward to pedel while turning, but for example going slow or going up hill, we would need to pedal steering.
2) That when pressing down on one pedal, that would put a turning force on the wheel due to being on one side. Thus making pedal action less efficient (I imagined that that force would have to be counterbalanced with the arm on the same side as the depressing foot, having to pull with equal force as the sidewards force. And making steering difficult and swervy.

Are those factors not an issue with the one you showed? If not, that's awesome, since it would seem way easier to steer the front wheel! Including by lessening the overall width.

Every time I've made single sided wheels, I either machined an axle on the lathe or adapted a bolt or round bar to serve as one. The simplest stub axle I ever made was a 5/8" rod with shaft collars clamped inside and outside of the wheel hub.

Kingpins you can make from bicycle head tubes.

Cool. So then if I buy let's say a wheel that has a hub motor, I still need to make an axle? And, would this be for regular wheels that are normally supported both sides, but by making this axle it allows us to use them like this, supported only on one side?

 

[ZeroEm]

 

[Chalo]

Are those factors not an issue with the one you showed? If not, that's awesome, since it would seem way easier to steer the front wheel! Including by lessening the overall width.

I don't know; I haven't ridden one of those or the roughly similar Atomic Zombie Spin Cycle. I do have a giant sized Big Wheel trike with pedals on the steered assembly. It's neither difficult nor tricky to pedal, but at sharp steering angles the "uphill" foot has to get off the pedal and out of the way.

So then if I buy let's say a wheel that has a hub motor, I still need to make an axle?

If you find a hub motor for single sided use, it will have the axle stub integrated. Like this one, with a 25mm axle:

https://www.leafbike.com/products/diy-bike-conversion-kit/single-shaft-24-inch-36v-750w-hub-motor-bike-conversion-kit-1004.html

And, would this be for regular wheels that are normally supported both sides, but by making this axle it allows us to use them like this, supported only on one side?

That's the idea. A typical direct drive hub motor has 20mm bearings on the sides, but the axle is cut down to a smaller diameter where it passes through the freewheel, and then down again to 10x12mm or 10x14mm to sit in the bike's dropout slots. By duplicating the axle except for the part that sticks out, you can have up to a 20mm diameter rod or thread by which to hold the wheel on one side.

 

[Galifer]

FWD.jpg

What's that? Is it 2 universal joints?

I don't know; I haven't ridden one of those or the roughly similar Atomic Zombie Spin Cycle. I do have a giant sized Big Wheel trike with pedals on the steered assembly. It's neither difficult nor tricky to pedal, but at sharp steering angles the "uphill" foot has to get off the pedal and out of the way.

Cool. I would love to see pics! Also I ended up finding some videos of that bike and seems fine to steer once you get the hang of it.

If you find a hub motor for single sided use, it will have the axle stub integrated. Like this one, with a 25mm axle:

Cool, thanks. Does anyone know of any 250W versions worth buying from the UK (I mean, could be from outside the UK but hopefully with reasonable postage etc.)? And regarding searching for them, is there a particular search term I should be using? Like for that one, is it the "Single Shaft" part of the title that is relevant? Or...?

"And, would this be for regular wheels that are normally supported both sides, but by making this axle it allows us to use them like this, supported only on one side?"

That's the idea. A typical direct drive hub motor has 20mm bearings on the sides, but the axle is cut down to a smaller diameter where it passes through the freewheel, and then down again to 10x12mm or 10x14mm to sit in the bike's dropout slots. By duplicating the axle except for the part that sticks out, you can have up to a 20mm diameter rod or thread by which to hold the wheel on one side.

Ah sorry... maybe this answers the above question? So basically any hub motor wheel is ok? Or, just direct drive ones? I had the sense that the geared hubs are more normal for 250W... are they no good for single side application?

 

[ZeroEm]

by Galifer » Sep 02 2021 7:33am

What's that? Is it 2 universal joints?

Could not fined the one I was looking for. I followed a project years ago. Trike was turned into FWD. makes for a short chain.
I think some type of CV would be better.
I would like that but he little front wheels would make for a big chainring.

 

[stan.distortion]

That 250w rule... obviously the law should be obeyed but some laws are just plain stupid. When was the last time you saw a bail of hay in a taxi? UK law requires they carry one at all times for the horse (may have been dropped now, they had a clearout of those kind of laws a few years back). A 250w hub is fine if you live somewhere as flat as Holland and just want to go from the retirement home to the bingo hall but you're planning on lugging around a lot more weight than the typical bicycle and besides, that's two 125w hubs you're looking for if you're planning on two wheel drive.

There's the letter of the law and the intention of the law, often two very different things and I've never heard of UK police testing ebike power outputs, they'd probably end up booking more than half the ebikes in the UK if they did so maybe don't get too hung up on it and focus on the intention of the law instead, act like a tarearse hooligan and they'll pull you.

EDIT: Oh, and that font wheel drive setup is seriously sweet! You'd park that thing in the living room so you could admire it all evening

 

[MadRhino]

Obey the trafic laws, and they won’t start searching legal reasons to get you off the streets. Mostly never run red lights and don’t enter conflicts with the other users of the street. Usually you can allow yourself some excess speed and hard accelerations without problems, probably because you are silent, since gassers are not getting that kind of free pass.

Its been some 15 years that I ride illegal bikes. Yet in all this time and lots of mileage I’ve been ticketed only for mandatory helmet. When they passed the helmet law for ebikes, I resisted at first but I soon realized its been added to the trafic law code, not the ebike law. The police doesn’t care for the specific rules of vehicles, they focus on trafic flow and behavior.

 

[ZeroEm]

Don't forget to put the 250w stickers on. 8)

 

[MadRhino]

Don't forget to put the 250w stickers on. 8)

Too complicated to train cops to check the conformity of ebike, and they don’t want to.
If they want you off the streets, they will send your bike to inspection, where they will find a list of reasons to forbid it.

I can imagine the vehicle inspector checking the bike, plugging the obvious big red and black battery connectors, trying the throttle and OOOPS!!!
The bike had gone flying alone in a backflip and crashes upside down in the garage door after breaking the office window with a pedal bump. Sure it’s gonna be the fault of the bike.

 

[ZeroEm]

by MadRhino » Sep 02 2021 11:22pm

ZeroEm wrote: ↑Sep 02 2021 6:32pm
Don't forget to put the 250w stickers on. 8)

Too complicated to train cops to check the conformity of ebike, and they don’t want to.
If they want you off the streets, they will send your bike to inspection, where they will find a list of reasons to forbid it.

I can imagine the vehicle inspector checking the bike, plugging the obvious big red and black battery connectors, trying the throttle and OOOPS!!!
The bike had gone flying alone in a backflip and crashes upside down in the garage door after breaking the office window with a pedal bump. Sure it’s gonna be the fault of the bike.

My battery cables coming out are 4 AWG that might be a giveaway. For the OOPS!!! last year I set the CA so you need a speed of .5 kph before the throttle will work.

 

[Chalo]

My battery cables coming out are 4 AWG that might be a giveaway.

I bet the average cop understands the technical principles about as well as the average dog.

 

[ZeroEm]

:lol:

by Chalo » Sep 02 2021 11:49pm

ZeroEm wrote: ↑Sep 02 2021 11:33pm
My battery cables coming out are 4 AWG that might be a giveaway.

I bet the average cop understands the technical principles about as well as the average dog.

When the dogs can not keep up then they take notice.
I'm sure they can figure out if your going to fast but here in SA there is no way they have a clue about the power. I have a big hub motor and some people ask if its electric. The rest can't tell.

I joined a group to greenway ride (figure it would get me out more). the last ride was 20 miles, 10 is sorta down hill going back it sort up for 10 miles. Try not to stand out so rode in the middle of the group that spread out over a mile or two. the half that came up behind kept looking :lol: and asked if I have assist on the trike. I forget i'm over weight and they are thin and they could not keep up with me. :lol: