OpenEMoto

trazor said:
...
At the end after all this research, i've a bike that has a plush rear suspension that everybody likes. I would liked to have more "progressivenes" (instead of the very linear curve) , but looks impossible with a standard shock and monopivot linkage.

...

I was looking old posts and I had a thought. So here it is:

Some time ago I watched YT video about motocross and enduro rear suspensions differences.
The person in that video explained and showed two motorcycles: Enduro and motorcorss.
Both bikes had progressive rear suspensions but atchived it in different ways.

Motocross had linkage sytem implemented outside rear shock. Endure bike had no linkage. He explained that enduro bike had no mechanical linkage installed to increase clearance to ride through obstacles like fallen trees, stones, railroad :eek:

Enduro bike had no linkage inside rear shock but progressive suspension was achieved by using progressive rear shock itself. In that particular enduro bike rear suspension progressiveness is implemented inside rear shock.

In summary:
Particular enduro bike had more complicated progressive rear shock but had no need for linkage due more sophisticated rear shock and therefore had better clearance.

Particular motocross bike had rear linkage to achieve progressive rear suspension and more simple rear shock but less clearance because linkage is sticking down the rear fork.

Enduro can be with linkage system but if one hits linkage in stone or tree it might brake.
 
minde28383 said:
trazor said:
...
At the end after all this research, i've a bike that has a plush rear suspension that everybody likes. I would liked to have more "progressivenes" (instead of the very linear curve) , but looks impossible with a standard shock and monopivot linkage.

...

I was looking old posts and I had a thought. So here it is:

Some time ago I watched YT video about motocross and enduro rear suspensions differences.
The person in that video explained and showed two motorcycles: Enduro and motorcorss.
Both bikes had progressive rear suspensions but atchived it in different ways.

Motocross had linkage sytem implemented outside rear shock. Endure bike had no linkage. He explained that enduro bike had no mechanical linkage installed to increase clearance to ride through obstacles like fallen trees, stones, railroad :eek:

Enduro bike had no linkage inside rear shock but progressive suspension was achieved by using progressive rear shock itself. In that particular enduro bike rear suspension progressiveness is implemented inside rear shock.

In summary:
Particular enduro bike had more complicated progressive rear shock but had no need for linkage due more sophisticated rear shock and therefore had better clearance.

Particular motocross bike had rear linkage to achieve progressive rear suspension and more simple rear shock but less clearance because linkage is sticking down the rear fork.

Enduro can be with linkage system but if one hits linkage in stone or tree it might brake.

I reached the same conclusion after reading this article https://dirtbikemagazine.com/ktm-suspension-shootout-pds-vs-linkage/

Now the problem is, where to find a cheap progressive or multi stage shock? Some user commented on using air shocks, since these shocks are progessive by nature, but usually expensive. Every shock has their own characteristics, If I change travel or lenght, it will require a new model in Linkage program and find new anchor points to frame and swingarm.
 
Most probably everyone knows but here is few words about DNM option.
Most popular bicycle air shock for hub driven ebikes are 'DNM RCP 2' and 'DNM RCP 3' models. '2' or '3' verions no difference. At least I found '2' is as good as '3'.
Lengths up to 240mm. Prices from 100 to 120. With light wheel they would be really good cheap rear shock.
They have metal spring and pressured air chamber so they are semi air or semi metal spring shocks.
I prefer them over solo air shocks because when solo air fails than it is done. When semi air shock brakes you still can ride. Also I had better experience with metal spring shocks. Ss here is my preference.

Solo air shock has weight benefit ie weights less.

The same goes with forks. New DNM forks are without metal springs. Previous models had metal spring in one leg. I prefer older model over newest. Difference between semi air and solo air model is few hundred grams.
 
minde28383 said:
Most probably everyone knows but here is few words about DNM option.
Most popular bicycle air shock for hub driven ebikes are 'DNM RCP 2' and 'DNM RCP 3' models. '2' or '3' verions no difference. At least I found '2' is as good as '3'.
Lengths up to 240mm. Prices from 100 to 120. With light wheel they would be really good cheap rear shock.

Kuberg freerider uses the dnm burner rc3 and that's a fairly decent feel for the price of shock it's no fox float x2 but it's not the price either but that's what I'll properly upgrade to in time the dorado front fork I have no complaints about it's awesome nice progesive feel highly tunable but it's fairly costly new I found a second hand bike and snapped it up.
 
Cross posting related repair

https://endless-sphere.com/forums/viewtopic.php?f=8&t=97572&p=1444177#p1444177

file.php
 
trazor said:
IMG_20190128_174433.jpg

Testing automotive paint. Silicone plugs in place. I'm fed up of rust.

Powder coating is the way to go. I got great results from a home powder coat kit I got from Eastwood Company.
 
Dogboy1200 said:
trazor said:
IMG_20190128_174433.jpg

Testing automotive paint. Silicone plugs in place. I'm fed up of rust.

Powder coating is the way to go. I got great results from a home powder coat kit I got from Eastwood Company.

I think you are right because after painting one of my moto with 3 layer automotive paint and riding in the forest two weekends the frame is full of scratches letting see the basecoat or base metal. If I understand correctly, the powder coating is much harder. The Eastwood home kit looks good and is cheap, the problem in my case is to find an oven that fits frame and swingarm.
My second frame will be painted with automotive paint because I already have a set of base,color(pearl blue),clear cans. These paints are of better quality but still I think it will not hold up very well to the usual abuse.
 
trazor said:
Dogboy1200 said:
trazor said:
IMG_20190128_174433.jpg

Testing automotive paint. Silicone plugs in place. I'm fed up of rust.

Powder coating is the way to go. I got great results from a home powder coat kit I got from Eastwood Company.

I think you are right because after painting one of my moto with 3 layer automotive paint and riding in the forest two weekends the frame is full of scratches letting see the basecoat or base metal. If I understand correctly, the powder coating is much harder. The Eastwood home kit looks good and is cheap, the problem in my case is to find an oven that fits frame and swingarm.
My second frame will be painted with automotive paint because I already have a set of base,color(pearl blue),clear cans. These paints are of better quality but still I think it will not hold up very well to the usual abuse.

If you want to give it the kicking of it's life best finish is galvanised then powder coated, expect to pay around £20 for a frame to be galvanised them dame for powder coating.

Only thing with galving is the frame must have drain holes on every tube or expect an explosion guy lost half his face local to me.
 
parabellum said:
trazor said:
take some build techniques that don't require expensive tooling.
Amazing performance with such simple hand tools! Your video definitively is a source of inspiration to me. Thanks for taking time!

Thank you!

I've edited lot more hours, this time making the Emoto frame: [youtube]nFmHWTzSU_E[/youtube].
 
fantastic! thanks for taking the time to document that.
 
New video of old footage (I don't even live in that place anymore). I think this presents some novel ideas on how to make a strong, lightweight and watertight LiPo battery (with BMS).

[youtube]dQg4E43aYaw[/youtube]

I've been using the battery for 5 months and works really well. When stored wet has a tendency to grow some mold in the surface :confused:

file.php
 
Barely any better than a hub motor, the swing arm weight needs to be light as possible to have fast damping reaction over bumps if the swing arm has the motor weight it will be lazy and start to bounce about.

The fabrication looks sweet and it's a good effort but a little frame design knowledge would have seen it be a beast. Cradle the motor and build the swing arm off that like a normal dirtbike.

The new kuberg challenger has a good design to copy cat.
 
Ianhill said:
Barely any better than a hub motor, the swing arm weight needs to be light as possible to have fast damping reaction over bumps if the swing arm has the motor weight it will be lazy and start to bounce about.

The fabrication looks sweet and it's a good effort but a little frame design knowledge would have seen it be a beast. Cradle the motor and build the swing arm off that like a normal dirtbike.

The new kuberg challenger has a good design to copy cat.

Except the motor is mounted very close to the pivot of the swing arm... so the unsprung weight wont have the same impact on handling as a hub motor. The ideal would be to have the swing-arm and motor axle be concentric - that way the motor weight is as close to sprung as possible (and probably negligible at that point) but this isn't too bad, certainly way better than a hub of equal torque/power handling.
 
Ianhill said:
Barely any better than a hub motor, the swing arm weight needs to be light as possible to have fast damping reaction over bumps if the swing arm has the motor weight it will be lazy and start to bounce about.

The fabrication looks sweet and it's a good effort but a little frame design knowledge would have seen it be a beast. Cradle the motor and build the swing arm off that like a normal dirtbike.

The new kuberg challenger has a good design to copy cat.

Although my physics knowledge is elementary and never read a Tony Foale book, I'm pretty sure of what my legs feel and this new swingarm and motor are MUCH better than the MXUS3K setup. The overall center of gravity, the reduced weight from 13 to 7Kg. Not to mention the advantage of using the motor as structural part, the nonexistant problem of chain slack/swingarm travel, the space saved for batteries/clearance, the reduced fabrication complexity, the open choice of mid/hub motor.

Someday I will create a sprung motor frame. I appreciate your candor :D
 
I can see the motor is not at the end of the lever(swing arm) and much closer to the fulcrum point so it adds much less force to the swing arm than say double the weight hub motor.

It's by no means a death trap and won't be the first or last to try the idea there's stuff being sold that's worse so for a diy project it's a very good effort that will progress if a version 2.0 is made just keep chucking a few ideas in the pot for food for thought and the overall design and ride feel will benefit.

I got an a2b metro and that has an extended swing arm and a hub the weight of a mxus from factory and that is the ultimate in lazy rear end feel ok to peddle along on tarmac fairly smooth but gravel roads it's funny almost reacting delayed and pogoing me about still a cracking ride mind and same for yours didn't mean to offend.
 
Ian,

Trazor has been flying scratch built ebikes for years now, and this is far from version 1.0 of his ebike builds. The effect of his motor placement on unsprung weight is negligible. The ideal would be to mount the motor concentric to the swingarm pivot, but I don't see the complexity to be worth the effort.

I believe the bigger issue is whether the motor is anchored to the frame or the swingarm, because that will more directly affect the rear suspension. To date there's been too little discussion of those effects. The most I've gotten out of Toolman2 on the subject is that he felt a "jacking" of the rear (opposite of squat) that seemed to make the tire dig in better with motor on the swingarm. The effect became more pronounced with a higher pivot point, because the wheel would more easily dig in under and lift the pivot point. At this point I don't think we can call it a problem, just a difference.

Once I finally source a pair of controllers capable of 28s and 200A ea battery side, I'll build my own silent trail beast. I'll mount a HubMonster trimmed down to 13.5kg on the swingarm as close to the pivot point as possible. I'll mount the motor on top of the swingarm in order to lower the pivot point for a given clearance for obstacles, and lessen the suspension effect of motor anchored on the swingarm.

As far as hubbies being so bad on the bumps, we could all probably use some lessons from MadRhino about how to tune the rear suspension with a hubmotor, because he's still loving his hubbies on his local downhill single tracks up in Canada and probably more years of experience with that kind of riding than any of us.
 
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