Custom frame production reaserch... (updated on pg 1)

[Ariane]

Hi Bzhwindtalker,

Thank you, of course yes a bit heavy about 50 Kg with a 2 KW/h Konions packs and an Xlyte 5304, motocross fork (CR80), and I have done many mistakes in my desing, it's great to keep your frame lighter and love you draft. :wink:

My ebike is not the lighter one but it can take everything, and will try it next summer with the new Cromotor I'm planning to buy next month , good day!
Black Arrow

 

[farmkid4]

My only "recommendation" is about the battery compartment, you need to open it on the opposite side of "the crankset and chain" I have done this mistake on my Black Arrow so please don't do the same.
Black Arrow

I think he meant to have the side panel opposite the crank drive side to open to make it easy to charge bats etc.

I like the design idea. What size tires do you use?

 

[Tench]

Rear suspension does not need to be complicated to be good and effective. I used to build motorcycle frames for racing and could achieve a rising rate system with the shock mounted directly to the swing arm and frame with no linkages. because the angle of the swing arm changes in relation to the shock absorber the leverage ratio also changes. Use this to your advantage and position the shock so that the angle between it and the swing arm becomes closer to 90 deg as the suspension is compressed. maximum travel at the shock would happen if it where at 90 deg to the swing arm and minimum or next to zero travel would happen if it where at 180 deg to the swing arm so you can see that positioning the shocks connection to the frame and swing arm correctly in relation to the swing arm pivot and angle to have a large change in the angle between them between full extension and full compression can create a progressive rising rate system. Many motorcycles are done like this nowadays inc all the KTM dirt bikes, it is sometimes advantagous to use a linkage purely to package the suspension in a more compact way while keeping a progessive system but on a new blank paper design of an Ebike direct mounting will be easy to fit into the design.

Simon.

 

[Ariane]

I think he meant to have the side panel opposite the crank drive side to open to make it easy to charge bats etc.

I like the design idea. What size tires do you think you design for?

Farmkid4 correct thank you i use 24" rim on my ebike and will probably use 17" moped rim on it next summer, with the new motor, good day
Black Arrow

 

[bzhwindtalker]

Ah I did not get the fact you had 2kwh Black Arrow! In the end your bike is the same weigth as a S bomber with almost double battery and a bombproof frame good job

I updated first page with a scale draft that I'm quite happy about, the head tube angle is still to define more precisely (66-67°)

I have a 32mm stator dd hub (9c clone) that I will probably use to test this bike, paired with either a 48v sensorless 12 fet or a hua tong 72v. I will clean and paint it, do a phase upgrade and I will get that spoked onto a strong 24' rim. I never cooked a hub yet

 

[MadRhino]

exemple : this is so complicated!

Yep, it is, but it rides real good. I'm not talking about pedaling here, just freeriding as a gravity bike, or riding the mountain powered with a hub motor.

I have experimented with the same battery-controller-motor on both the Demo 8 that you show, and the A-line below. The Demo is such a smooth ride in comparison to the A-line, it is just miles ahead. Every one who tried them agreed, building with the Demo was a huge improvement of handling and suspension quality. The Demo is a better ride than the A-line as a freeride, but with a hub motor this difference is amplified. I've done some mods on both, and tried many shocks, it is a no contest. The Demo is a winner as an Ebike as it was as a gravity bike, and you feel the difference instantly when you ride them fast in the rough.

I'm not saying it has to be that complicated to ride good. I have tried many other and some are real good with simpler designs. Norco have changed their suspension design radically this year with the Aurum, and it is a much better ride now. The new Santa Cruz V 10 is a close match with the Demo.

The Transition TR 450 rides just as good as the Demo with a much simpler design:

 

[Lenk42602]

I am looking into starting a production of full suspention custom cro-mo & aluminium frames, I will in this thread post some CAD and prototype testing results.

I plan on making a first frame from scratch just to define geometry, that will be powered with either a Mac on 16s headway or a turnigy 80-85 with single stage #219 on 8s. The bike is designed with 24 or even 20 inch wheels, but will fit 26 too.

feel free to comment
Adam

BZ, your target weight will be challenging even with lipo and a MAC hubbie. Better chance with a Turnigy, and you should make provisions in your designs to allow for use of either drive system. Consider mounting that turnigy on the underside of your swingarm. Couple of additional design considerations - make sure that you establish your bottom bracket height early in the design based on 20 -24 wheels in conjunction with your head tube angle & length, and rear suspension eye to eye length/pivot point mounting locations. All of these are affected by the other. Use the a software package like www.bikechecker.com to make sure that your plans will work. Additionally, utilizing removable brackets for upper and lower rear shock mounting point allows one to go back and change shock length if need be (i.e. different wheel size, different fork, etc). Also make sure your design incoproates the axle to crown length you anticpate utilizing on your front fork. In my experience, the pit bike shock mentioned above on the bomber has been the answer over puny bicycle shocks, as it is tuned with a 1000 pound spring with 5 - ish inches of additional travel after sag.

My set up has been working beautifully since completion last fall - due to the simplicity and robustness of the design (lack of mutli link pivot points, etc), I have done nothing but ride it....

Contrary to the masses of folks retro-fitting full sus mountain bikes with batteries and motors and espousing the advantages of multi link bicycle suspension designs over single pivot moto designs, take a look at all of the bikes that have made it to actual production thus far - Stealth Fighter,Bomber, soon to be Phazor Cycle, heck even the Opti for that matter.

All have single pivots for a reason.

http://endless-sphere.com/forums/viewtopic.php?f=6&t=23143

Len

 

[Ariane]

MadRhino,

I have seen many posts from you, about how fast you ride with those DH ebike on a mountain, but I didn't see any videos or I have miss them. Those DH bike looks very good and they probably handle technical trails better than everything on earth, with their light package components. But when you add batteries, motor controller it's a different story.

And none of those designs have enough spare room to put the battery in the frame. Of course you can place Lipo's battery pack on each side of those frame and it's not an heavy task and you can put the controller somewhere easily, but by doing it you don't need an ebike frame that look's a Stealth Bomber or Stealth fighter.

The only remaining question is how you can build something like those DH bike frame with enough spare room to put the batteries in the frame with the same handling? For me its impossible task that's it, building an ebike is always a source of compromises.

Good day!
Black Arrow

 

[Ariane]

Ah I did not get the fact you had 2kwh Black Arrow! In the end your bike is the same weight as an S bomber with almost double battery and a bombproof frame good job

HI Adam,

Thank you your design look's good to me but I will short the swing arm a bit it's seem too long. In the mean time if you change the length of the shock you also change the rack angle :wink:

Good day!
Black Arrow

 

[MadRhino]

MadRhino,

I have seen many posts from you, about how fast you ride with those DH ebike on a mountain, but I didn't see any videos or I have miss them. Those DH bike looks very good and they probably handle technical trails better than everything on earth, with their light package components. But when you add batteries, motor controller it's a different story.

And none of those designs have enough spare room to put the battery in the frame. Of course you can place Lipo's battery pack on each side of those frame and it's not an heavy task and you can put the controller somewhere easily, but by doing it you don't need an ebike frame that look's a Stealth Bomber or Stealth fighter.

The only remaining question is how you can build something like those DH bike frame with enough spare room to put the batteries in the frame with the same handling? For me its impossible task that's it, building an ebike is always a source of compromises.

Good day!
Black Arrow

You're right, batteries can't go in frame, only the controller can and it's tight. I don't like big batteries each side, they make the frame too wide and interfere with freedom of posture. I carry another 24s 1p in a small frame bag and that's it. The frame bag is on the top tube at the junction of the seat tube, when I need little range, it can carry tools instead.

A specific frame would have to be designed for DH riders to carry batteries, but it's too much investment in time right now, so I work on an alternative solution. I want to make an alu battery box to fit under the down tube near the crank, shaped as the rock bumper that you can see on some trial motor bikes. That would clear the top tube and make the setup near perfect, and could be fitted to almost any DH bike. Yet it could only carry 24s 1p, but with the fork mounted 4 bricks pack, this is enough for my need.

I am trying to keep the bike as lean as possible, and stealth. A frame that can carry a lot of batteries inside is not stealth, even if it is very practical and offers a long range. You're right, it has to be a compromise, mine is range. The mountain is at the door step, and most of my trails are 10 to 15 Km. The Norco has big bags on fork and tail, and can carry a lot of batteries, but it is not a DH ride anymore. I use it very little now, mostly on the road or "flat" off road.

Sorry for the vids, it's been in my plans for a while, but I'm not lucky with cameras. I had bought a 32Gb POV camera that was busted in a crash after only 2 days, and I couldn't recover the vids from the mico USB card. Another chep POV bought on Ebay was received defective, and I never found the time to try and fix it. I broke my HTC phone into pieces when it fell out of my poket in a rough trail and exploded on a maple tree, and although it had little vid in, there were a lot of pics that I still hope to recover some day. I carry nothing anymore on my bikes, not even the CA after breaking 2. A friend of mine has some footage that he shot following me last summer, but has yet to make a montage of the clear parts. He didn't have a motor and couldn't keep up, he could only follow me in steep DH sections where he had the advantage of light weight. So his vid has to be cut to assemble the few good parts that he managed to shoot. I hassled him a few times about it, still waiting.

Next summer, I'll be done with building hub motor setups, and I plan to make a vid weekend with friends. We'll ride 4 DH Ebikes with cameras and try to make something neat with the footage.

 

[Ariane]

Hi MadRhino,

Well I will be happy to ride with you next summer. I never ride on DH bike or ebike, except my Black Arrow. My back ground came from my motocross past but it can be fun if we have the chance to ride together or with a groups of ebiker. I'm also planning to buy a Go pro cam for next summer.

I really like Adams approach because you can fit the components you need on this frame to build your own ebike like you want and budget. I think that a 1 KW/hours pack is the best comprise between range and lightness and you can charge a pack like this in a hurry. With (2) batteries pack you can also swap them and you are ready to go again.

So Adam's frame in my mind is perfect for 85 to about 90 % of the ebike people and you can use this frame everywhere.

Good day!
Black Arrow

 

[MadRhino]

Yep, we must ride together, you're not so far after all. I'll be happy to let you ride one of my bikes, and to show you the trails that we have here. They are not so technical, we can ride some of them very fast when the weather is dry.

Back to the topic, I'd like a frame that retains the looks and feel of a freeride bike. It is not stealth enough to obstruct the triangle to make a battery container. I would prefer to have the top and down tube made bigger with battery compartment, and leave an open space in the triangle. I believe it is not that hard to design a frame that could hold 8 Lipo bricks, without filling the triangle opening and making the shock axis to push in the rider's arse. Make it bigger and wider in the front of the top tube, and deeper at the bottom of the down tube. Then you can use the open triangle space for the piggy back end shock mount, and I would be glad to fit a 24 fet controller on the fork instead of batteries.

Sorry for the rough drawing, only to give an idea.

 

[RallySTX]

That drawing looks like it was done by me! It also has a very good layout, in my opinion. Would it have a side cover like the Stealth, for battery access?
Brian L.

 

[farmkid4]

Sorry for the rough drawing, only to give an idea.

I like that design although it would be more difficult to design and build. It would def look quite nice tho

 

[John in CR]

Hey MadRhino,

What about something similar a lot of ways to the Cannondale SuperV, original AL version? How's it pass your tests ridewise? That huge main/down tube could be made to fit lots of batts if made more rectangle than round. Straight is so much better for fitting batts.

 

[MadRhino]

...Straight is so much better for fitting batts.

Yep, but curves are so much better to build stiffness with lighter weight. A sphere and a box made the same volume, with the same weight of the same material, think of which is stronger...

For performance in general, and mountain riding handling in particular, weight is a very important factor. I see this design, something shaped similar, made as an exoframe with small diameter Ti tubing, with appropriate triangulation reinforcement for stiffness, and enclosed with 2 CF halves that could be quickly removed.

I have someone who is willing to make it. He is a specialist with composite CF and Ti bicycle frames fabrication, and can use his employer's facilities off season. Yet, he's asking an obscene amount of money to engineer and make a single prototype, that could be justified only with the production of a large series.

 

[John in CR]

Here's another one for you MadRhino. How far below the center of the BB is useful territory? ie How much ground clearance is really necessary? Can the battery compartment or shield for the controller extend close to the reach of the cranks, or are your pedals always parallel to the ground for the big hits or clearing big obstacles, so its only ok to go to radius of those typical small sprockets?

 

[MadRhino]

Too bad I don't have a camera, for I'd show you the bash guard that's been on my chainring for the last season. To make it short, my 36T chain ring can hit the ground and rocks many times a day, and if I didn't have this 1/2 in thick bashguard, It wouldn't last one hour.

I use something like this

After one season, it is eroded almost flush to the chain ring and need to be replaced. It protects the ring, but sometimes a hit can break the crank set. Those DH cranks are really tough, yet they don't last more than 2 seasons, if you are lucky. My BB ground clearance is 14 1/2 in, but it is way less when the suspension is compressed.

Mounting batteries on the lower part of the down tube, would require them to be protected with a rock bumper or skid plate like those that are on Trial Motorcycles.

 

[bzhwindtalker]

I machined the head tube to fit 41mm 45° bearings. I made it 150mm long and i shaved 1mm of the outer skin to save some weigt. I still need to make the pivot bearing holding tube. I was really busy this week with exams, but hopefully I will have more time for the next 4 weeks, and i hope to get the prototype runing quite soon (2-3 weeks)

 

[Timma2500]

Back to the topic, I'd like a frame that retains the looks and feel of a freeride bike. It is not stealth enough to obstruct the triangle to make a battery container. I would prefer to have the top and down tube made bigger with battery compartment, and leave an open space in the triangle. I believe it is not that hard to design a frame that could hold 8 Lipo bricks, without filling the triangle opening and making the shock axis to push in the rider's arse. Make it bigger and wider in the front of the top tube, and deeper at the bottom of the down tube. Then you can use the open triangle space for the piggy back end shock mount, and I would be glad to fit a 24 fet controller on the fork instead of batteries.Sorry for the rough drawing, only to give an idea.

MH, your idea is similar to what i'm working on for an ES member at the moment, though its not a FR or DH frame, just a normal mtb frame.
It holds 6 x 6s 5ah lipo packs in the downtube. Top tube could hold a further 2 or 3 packs if desired.
Downtube dimensions are: 70mm high x 120mm wide:


*Battery access hole hadn't been cut in the top of the downtube at the time of pictures taken.
*Original frame needs final trimming before welding to the new downtube in these pictures.
*Shock mount yet to be re-welded on either.

Paul

 

[MadRhino]

I like it. It's a tad rough now, but has the potential to make a very stealth bike, and the weight distribution will be very good too.

 

[migueralliart]

I like it. It's a tad rough now, but has the potential to make a very stealth bike, and the weight distribution will be very good too.

Plus the added protection of having the batteries inside the tube. If something burns then it is not your legs.

 

[Phoebus]

I think that 66-67 head angle is way too high for this kind of bike.

63-64 would be much better. I run 63 exactly on my own electric DH bicycle.

Another thing to look into is the fact that you may have such an overwhelming amount of space for battery storage, that it may be possible to split the center chasis into two pieces with a gap between them, somewhat similar to MadRhino's beautiful sketch. Take a look at the Intense M3 downhill (non-electric) bike. The gaps really scream "I'm not electric!" to the average Joe.

M3 chassis photo link: http://endless-sphere.com/forums/download/file.php?id=71918

Separately, you may want to look at (thinning / sharpening / rounding out) the frame at the "top tube." Without thinning, the top tube is massive and square - the Stealth Bomber and most similar designs share this problem: The observers' eye is drawn to this massive square top, something which looks quite unnatural on a bike. I suspect that merely rounding off the top tube would much reduce the obviousness of the bikes' girth. An example of what I mean here can be seen on the Optibikes' top tube.

Overall I much like the direction that your frame is going.

 

[RWP]

Very nice work so far!

via Hangdog98...
There's less BS in motorcycle suspension designs because they're designed by engineers and not graphic artists.

Since I have been using Alibre, a less expensive more fun 3D modeling software than Solidworks, I know why we are seeing all those weird shaped aluminum bike frames...I think it's because bike designers are going hog wild...because they can and NOT because it's better. It's Mass Marketing!

In a couple of months I will be starting a new thread on a cr-mo frame build for mid drive motors. Probably .049 or .035 - 1" tubing. Only because I have not found anything better from the bike world.
Soon as I get Photoshop going on my new Mac I will post the Turnigy motor mount solutions I am working on for your comments and suggestions...just a few more days now I hope. They are designed to clamp to round tubing - 1.25" and 1.5" diameters and shims to fit smaller diameters and a motor plate for the Turnigy motors to bolt onto. Sorry for the non thread comments...

Has anyone found a Moto bike light enough to be considered for an E conversion?
I keep looking but come up empty. I think it needs to be less than 100# with a motor(s) and batteries. Maybe not a bicycle anymore...

 

[sn0wchyld]

....
Has anyone found a Moto bike light enough to be considered for an E conversion?
I keep looking but come up empty. I think it needs to be less than 100# with a motor(s) and batteries. Maybe not a bicycle anymore...

I've been looking at trials bike frames for a long time for this exact purpose... the ICE versions weigh in at around 60kg for the lighter ones, and ive heard of a few that have been converted at around the same weight.