Chassis development versus power development......

[recumpence]

Hey Guys,

With my new trike being finished, I have discovered how critically important chassis setup is. I mean, I have always known that is important (good brakes, proper CG, etc). However, I never realized just HOW important it was untill I finished my latest trike. This thing has more power than I have ever put in a pedal powered chassis before, yet it is the best behaved bike I have ever built. That is purely due to the proper chassis setup for the power I am making.

Now, the questions is;

With the limited R&D time I have available for projects, should I continue pursuing more and more power, or should I move toward better chassis development? I am already looking at a TIG and making a decent chassis/frame jig to make my own frames. But, I want your input on this. I have a bunch of two and three wheel chassis ideas rolling around in my head. But, I also have my own proprietary motor design we are building.

Where should I focus my time?

Matt

 

[damcard]

Hmm, I don't understand why you cant do both. I would think better chassis design is a must to add more power. Instead of choosing just one, focus on both but half as much. Just a thought. -David

 

[amberwolf]

I'd personally like to see more frame development, even though I myself wouldn't benefit from it (unless you post enough pics of the right viewing angles for me to get all the intersection angles and measurements from ).

There are a lot of trikes out there, but not many maneuverable and stable-at-high-speed ones, and almost none designed for power assist or full power drive. There are more bikes in that category, but still not enough of those, either.

 

[etard]

Where are you guys driving these high powered trikes? I mean , here in America bicycles are kinda a hobby thing, making Ebikes a real niche market, while trikes are cool, to me they just seem like a novelty item that adapts itself well to component mounting and placement but the last time I actually saw one on the road was years ago and I had to wince as cars passed him by at that level. Yes, there are huge advantages regarding the law and power delivery, yada yada yada, but there is no way you are ever going to take these things off road or zip through city traffic. If you are going to pursue the trikes, you might as well sell them as motorcycles and take all the pedal nonsense off, get down to brass tacks and design a frame built for best body position and weight distribution. Yes, it's cool that you can pedal it home, but who the hell wants to pedal around a $10,000 boutique piece of art that goes 0-60 mph in 3 seconds? Cmon Matt, make a Zero beater. That's were all the fun and recognition will come, once you can dominate a 125cc motocross bike and offer a 40 mile range, you can say goodbye to appliances for good and provide the world with a usable commodity. Sorry to all the Trike owners, but they will always remain a tiny piece of the pie as far as I am concerned. Then again, the Electric dirtbike market is kinda flooded, the electric chopper market is wide open for you to build the machine that will put you on the cover of PopSci or Motorcyclist magazine. I love seeing your builds progress here on ES, but lets be honest, your latest trike is far from what I would categorize as bicycle. If you want to keep making Ebikes, maybe make your next bike as stealth as possible, something where people ask, "Where are the batteries?" " Where is the motor?" You say you have investors lined up, maybe use those connects to get that motor built and marketed, while you focus on your frame building. Either way, I'm sure the divine hand of fate has many great things in store for you.

 

[AussieJester]

I would definitely like to see some of your custom frame ideas turned into reality Matt, perhaps focus on this yourself and leave the motor side for -->insert whomever is building them for you here <---

I think the trikes are great myself although i can see where etard is coming from. I think if you came out with an equivalent to the Stealth Bomber it would be a bigger seller than the trikes, that said i doubt theres any lack of buyers after your builds, so if the trikes are what you like doing stick with that and keep improving the frame side of things, easy enough to bolt on more H.P not as easy to make major changes to a frame once its complete.../my 2 cents

Best of luck which ever route you do take Matt i know i wont
be alone excitedly following your projects.

KiM

 

[deecanio]

Hi Matt,

Though for slightly selfish reasons i would like to someone come forth and produce a full suss frame.
Just bare bones is the route with the ability to add motor and batts and components of choice to build up.
I also see where etard is coming from as far as markets go, there are plenty of forum members who would love a bike frame that eliminates chain growth/mounting woes to make things easier, indeed with all due to respect to forum members i don't think we have nailed bikes to the degree you've nailed the kmx's and i dont think we will until someone produces a frame.
I've mentioned it to HAL and to Kim who have made their own frame to great effect and tbh i would easily pay £1k for the right frame.
Collectively we have all the knowledge we need to make this happen and i strongly agree with etard that this is the market to hit, ive said this amny times but again the first person to make a decent full suss with some good power will be a rich man
Anyway thats where my vote goes, tbh im still waiting for you to convert your mtb
I don't think this will happen anytime soon so in the interim im going to try and find the best ally welder i can and see if i can mod something - let us know your plans and save me some money!!!


D

 

[liveforphysics]

There all ready is a next stage in chassis development.

Extremely low center of gravity.

Smaller wheels with very wide tires, and extremely sticky tires availale.

Monster internally vented disk brakes on each front wheel, and a 10" disk on the rear axle. Simply don't have brake fade, no matter how hard you push them.

Weight reduction refined to a science.

Engineered chassis flex at critical points to serve as suspension.

Chassis that will out-handle anything short of an F1 or GT1 class racecar.


They are of course, shifter karts. You will find taking a trike design, and looking to improve the handleing and power handleing will lead you to arriving at a shifter kart, which is the result of >50+years of lightweight racing chassis evolution.

Perhaps to make it legally an electric bicycle (3-wheels), you could start from a shifterkart chassis, keep the front end the same, and convert the rear axle to run a single very wide tire, and fit recumbent type pedals onto it somehow to meet the legal requirements of being a bicycle.

I can't imagine any configuration of a trike that could offer better chassis performance or power handleing. Maybe make the pedals just spin a little useless generator that re-charges the batteries. Just something that weigh's 1-2lbs, but can make it meet the "functional pedals" requirement of the law to be an E-bicycle.

 

[recumpence]

E,

I see your point. This is the input I was looking for. I totally agree the new trike is a touch over-the-top. That is pretty obvious to me. I just wanted to see how far this could be taken. I also agree trikes are truely a niche that will probably never be a huge hit. I have a Catrike 700 that I LOVE! But, I am pretty much invisible on that thing. So, I stay off the busy roads and assume I cannot be seen and I am OK. The high powered trikes I have been building have been sold mainly to private pilots who drive them at the airports they frequent. You haven't lived untill you have ridden a (Hmm, can I say this?) "Street-Legal" go-kart. These things are addictive! Again, I totally agree they are impractical for in traffic driving. They also stick out like a sore thumb. When you ride a trike, you are asking to be looked at. It is a total "Hey officer, pull me over" kind of thing. In those respects, you are right on the money.

One idea I have been wanting to build is a 20 inch, full suspension, "Urban Assault" bike. It would be almost a small Motard type bike. That bike would have 6 or 7kw (just enough to wheelie, but not to flip unexpectedly), it would have a trellis or enclosed frame, be light enough to easily lift with a much longer than standard BMX wheelbase. I have never likes full size mountainbikes. This might be a good option to pursue. I also would love to build a full suspension trike. But, we have already covered that. It would be fun and I would truely love using it. But, that is a limited use type of thing.

Anyway, I really need to figure out what is most beneficial to pursue. I am not looking at making a fortune on this. I am not a money worshipper. But, I do want to devote my time to what would advance the hobby and EVs the most.

Matt

 

[recumpence]

There all ready is a next stage in chassis development.

Extremely low center of gravity.

Smaller wheels with very wide tires, and extremely sticky tires availale.

Monster internally vented disk brakes on each front wheel, and a 10" disk on the rear axle. Simply don't have brake fade, no matter how hard you push them.

Weight reduction refined to a science.

Engineered chassis flex at critical points to serve as suspension.

Chassis that will out-handle anything short of an F1 or GT1 class racecar.


They are of course, shifter karts. You will find taking a trike design, and looking to improve the handleing and power handleing will lead you to arriving at a shifter kart, which is the result of >50+years of lightweight racing chassis evolution.

Perhaps to make it legally an electric bicycle (3-wheels), you could start from a shifterkart chassis, keep the front end the same, and convert the rear axle to run a single very wide tire, and fit recumbent type pedals onto it somehow to meet the legal requirements of being a bicycle.

I can't imagine any configuration of a trike that could offer better chassis performance or power handleing. Maybe make the pedals just spin a little useless generator that re-charges the batteries. Just something that weigh's 1-2lbs, but can make it meet the "functional pedals" requirement of the law to be an E-bicycle.

Yup, I am with ya on that!

Matt

 

[AussieJester]

One idea I have been wanting to build is a 20 inch, full suspension, "Urban Assault" bike.

Matt, have you seen these? Something like this (electrified) with your pro twist on it would be a goer IMHO.

KiM

 

[deecanio]

i hadn't seen them Kim, but im bloody glad you showed me, possible rolling chassis - do you know the price?
Thats the kind of thing that would stomp ass with a good electrical setup, mmmmm.
Bang on the money IMHO, at least as far as the chain growth solution goes, also could be much lighter


**EDIT** Sheeeeet frame and swing arm only 770$ - you bugger Kim, thats the new car out of the window!!!!
somebody stop me!!!!!

D

 

[AussieJester]

**EDIT** Sheeeeet frame and swing arm only 770$ - you bugger Kim, thats the new car out of the window!!!!
somebody stop me!!!!!

D

Yes theres full price list there Deec ;-P Also some videos of the bike gets thrown around well under pedal power alone considering it has a 50cc ICE motor on it. Matt could make one alot better IMHO, the rear is good the front needs improving for electric, the ICE motor is a structual part of the bike without it the frame strength is gone. Set of 20in rims and BIG fat slicks and you have a supermotard stylin bicycle.

KiM

 

[deecanio]

Expect a new thread very soon mate :wink:
ice replaced by batts would steady up the frame no?
i would also chop off the mountings i dont need, make the moto seat normal mtb too, i dont want an electric moto after all.
watch this space buddy

D

 

[AussieJester]

ice replaced by batts would steady up the frame no?

No...batteries alone can't be used for structural support Deec, the frame would need additional bracing.

KiM

 

[deecanio]

sorry i meant in a structure not just loose - shouldn't be too difficult to brace and box in one hit ?
i need Miles to bring his spanners as i'm hovering over the buy button
maybe i'll need another 3220 to go lol - i'll have a MUCH closer look when i get home from work

D

 

[snath]

**EDIT** Sheeeeet frame and swing arm only 770$ - you bugger Kim, thats the new car out of the window!!!!
somebody stop me!!!!!

D

Yes theres full price list there Deec ;-P Also some videos of the bike gets thrown around well under pedal power alone considering it has a 50cc ICE motor on it. Matt could make one alot better IMHO, the rear is good the front needs improving for electric, the ICE motor is a structual part of the bike without it the frame strength is gone. Set of 20in rims and BIG fat slicks and you have a supermotard stylin bicycle.

KiM

IMHO, I don't believe the engine is much of a structural component. To reassure my self, I consulted my copy of Tony Foale's and Vic Willougbhy's Motorcycle Chassis Design: the Theory and Practice and, to me, most of the examples of a tubular backbone do not use the engine to stiffen the frame.

 

[spinningmagnets]

The Wright brothers are very famous to this day for their pioneering work getting an airplane to fly, but they never made much money building planes, Curtiss was the first to really make money building and selling planes.

If you want to be famous for being a milestone guy, follow your passion. If you want to make money, develop the thing thats missing for the coming E-bike growth phase in the US. Your RC-drives don't need any more development, they are already cutting edge (honestly, is any other bicycle RC-drive even close?), what THEY need is a plug-and-play packager for entire kits. IMHO, the thing thats missing is good E-bike frames,...if you agree....

Chinese companies will always quickly come out with a cheap heavy steel copy of whatever is selling, so stick with the mid-range prices that have some upscale features. Your top-of-the-line prototypes will draw interest and help sell the money making mid-range line.

I think there's plenty of choices when it comes to E-bike motor kits, and dedicated E-bike frames (like the Panasonic pedelec) are proprietary and hard to upgrade or replace a specific component for a repair.

There needs to be frames for sale that will accept any generic E-bike kit option. Some added length between the seat-post and rear tire creates the space for a variety of motor options, whether its a cheap TNC, or a high-end RC-drive. Motor location there can drive the BB or the rear wheel, and clearly ANY bike configuration can accept the hub-motor choices.

If you only talking about trikes, I'm guessing that they are more of a weekend-rider market, since trikes are too wide to ride on the sidewalk and too low to ride in 35-MPH traffic safely (cars can't see them). I think the thing that weekend E-trike frames need most is a light folding model (single-stage RC-drive/LiPo). That would make it easier to transport in a car to scenic weekend destinations, and easier to put back into the garage on Sunday night.

That may sound like a PITA to design and make, but thats exactly why I don't know of anybody that's doing that. Just some thoughts...

 

[REdiculous]

Get that motor together w/ a gearbox and you could sell quite a few I think.

Design a neat tadpole frame and...?

I think you should keep working on the power side of the problem. I think that'll give you the most 'bang for your buck' and will push the hobby farther than a new frame design. have a good one!

 

[johnrobholmes]

Design a two wheel moped frame. I need some local competition to feed off of :lol:


I see it like this, if you try to push any bigger/faster you are going to run into an exponentially increasing cost to keep up with ICE power to weight ratios with a decent range. I say go back to your "roots" and see what you can fab up for a superlight 5kw or less vehicle. Maybe play with a hybrid. Maybe get rid of the pedals. Maybe try a little folding bike. Do something different from your last builds, but don't try and chase the power and speed too far - electric just can't realistically compete with ICE beyond a certain point without spending 5x the money.

 

[etard]

Great post Kim!! The motoped is kinda how I pictured Hal's original frame design to be used, but I wouldn't call it a motorized vehicle. It's a moped and those are real cool, EXCEPT they need licensing, registering, and possibly insuring to be legal in most states. Check your local laws (not you John, we already know about your lil loophole :wink: ) The motor/ gearbox is great for us backyard tinkerers that can strap it to a bicycle and be proud of the thing. But it will rarely illicit more than WTF looks from the bicycle community at large. Matt, your talents are clearly marked for clean, tidy lines, proper components, and rocksolid design. I feel like most people are coming to the conclusion as you stated earlier, that you overbuild on power (will that be one 3220 or two?), keep the drivetrain simple and solid, and start with a good base vehicle. That's where we need a frame slightly bigger and heavier than the current DH mt bike designs, that can house the rats nest hidden away from prying eyes, and built to withstand a beating without epic failures and weakspots. What happened to the Ripper, we never did get to see a video of that thing throwing your ass over the back??!! :lol: I like your idea of an urban assault video, EXCEPT one day I might find myself trying to outrun a cop on one of your contraptions. Then there will be heavy curses, along with some technical gibberish about how I told you to build that thing, and the cop should be thanking ME for the ability to catch commie bastards such as myself on it! :lol:

Are you not satisfied with the Astros? They seem to be good motors, what kind of power to weight ratio will your motor design entail?

 

[flyinmonkie]

Matt,

I have to agree with Etard, Kim, and D about the mtb or full sus frame and for the same reasons. It kind of comes down to where you want to take your "hobby". The practicality of a 2 wheeled bike that can be ridden every day and carry grocceries will help push light EV's for daily use. A sceaming dirt ripping full sus mtb will draw attention to the fact that ebikes do not need to be cheap chinese scootor or moped looking things that dont hold a charge or can't go up a hill. As we push the ability of ebikes further, people accept them more, laws will adapt to what the people want.

A frame that is built with motor placement in mind and allows for several options of motors as well as hides or hold batteries would help the hobby market. Drives and motors are fairly sussed as it seams for the average ebike builder. A frame to put it all on is where all the trouble is. That and getting controllers and throttle reponse sorted easily.

As for the trikes, they fairly impractical as a commuter or more than a toy, but they a re a logical step to a light EV. They wrok well to test drive trians, motors, gearing, and components. They could be the launching step to a 1 or 2 person light EV for commuting to work. That would require a new frame concept and probably an enclosure, but with the power you have demonstrated, it could lead to a concept vehical that could get you to work and back with a 25 mile round trip. I know it is a huge jump to something that could be road legal and registerable, but it could be a proof of concept.

The other option for the trikes is to come up with a full sus frame and a little more ground clearence, wider tires, and you have a kicking beach runner. MAke a wide paddle tire fit the rear and you could take it to the dunes. That would be fun.

Clay

 

[coln72]

Unless you plan to develope in a totally new direction from trikes, I would stck to getting your new motor design up and running. From my experience with racing trikes, the frame design has become standardised. It has become a formular. You make this frame to this design, fit these cmponents and you will go fast. The new development in trike racing in Australia at least is composite monocoques. Composite chassis are a common feature. One school has the ability to produce their own carbon wheel hubs etc. (bastards :x).

While I feel trikes are cool, they will always be a nique market, and you will never get the economy of scale to justify your own frames. I have a mate who makes trikes for schools, and he only does a few a year, but his quality is brilliant. What he makes of his trikes is pocket money to spend on his car

 

[kfong]

Wow, first time I've seen the motoped. That frame even has me excited. I was thinking of chopping up a razor ebike at one time but even the 650 model looked too small. This one has great potential as an ebike frame. Very solid and from the looks of it, the motor isn’t integral for the strength as motorcycles are designed. I would feel comfortable taking this one at high speeds. Plenty of area under the bike for batts and motor and all the mounting points are already there for you. Like Deecanio said, throw on a bike seat and you have yourself a burly ebike meant to take some serious power. Pick up a high end triple front fork and you have yourself a motocross chassis that’s very light in comparison. It would look enough like a bike that it won’t draw much attention. Even classifying it as an electric moped would be cool, since you would have no problem riding it in fast traffic with an overpowered setup. This to me would be an great way to build a DIY Zero contender, yet stealthy enough to pass for a bike. Someone needs to build this! Matt with your talents, I bet it would be sold as soon as it gets finished, or even before. Pre-orders anyone?

Specs. look great

Chassis/Suspension / Brakes

Frame 4130 Chromoly CRF50/Pit Bike Style frame
Swing Arm 6061 Aluminum hand TIG welded in Santa Cruz, CA
Body/Seat /Fenders CRF50/Pit Bike
Front Suspension 8" travel, Downhill mountain bike 1-1/8" headset
Rear Suspension 8" travel, 10.5"-11" ItoI Pitbike shock
Front Brake Downhill mountain bike hydraulic Disc 8" rotor
Rear Brake Downhill mountain bike hydraulic Disc 8" rotor
Front Rim & Tire 26" downhill mountain bike
Rear Rim & Tire 24" downhill mountain bike (Lots of torque with an hub style motor! but let's see an RC setup on this!)

Dimensions
Rake 24 degrees
Wheelbase 54 inches
Seat Height 36 inches
Bottom Bracket Height 14.75 inches
Ground Clearance 12 inches
Curb Weight 107 pounds-Dry, 115-ready to ride (I wonder what the actual frame weighs?)

 

[deecanio]

^^^^^^^^

yes,yes, and yes.
the only thing stopping me from ordering a frame today is that i dont have the skills to make the missing battery and motor/s carrier with any degree of Matts skills.
870 for frame and suspension is not too rude imo, how about it Matt?????? could, no, no WOULD you make a carrier for cells and motor/s if we had 10 pre orders?


D

 

[AussieJester]

^^^^^^^^

i dont have the skills to make the missing battery and motor/s carrier

I can see this starting up the needs to be annealed or heat treated argument after its welded seeing the frame is made from 4130 chromo. Grab a few rolls of duct tape and strap the A123s to the top tube Deec sheel be right least then you wont miss another summer of biking

KiM