Who has bought EM3EV's bicycle frames and how do you like it

[WoodlandHills]

I've seen two up close in Melb Lurkin - one from Croydon and the other from Werribee.
On both the welds were ok - although the gauge of the drops themselves looked a bit thin and the headsets are still oldschool narrow tube so not ideal for big drops.

Woodlands, the geometry of the rear linkage determines the rate at which the suspension is loaded and unloaded. Yep I'm pretty confident I know what I am talking about.
The title of the thread reads bicycle frame. I don't a 125cc four bar would hold up very well.

If you can't get your hands on a good 3kw light (sub 25kg) eMTB you're looking in the wrong places. There's tonnes here.

Actually, I've gone back and read your stuff and as someone whose suspension and geometry knowledge has won AMA national Superbike/Supersport races and Supersport national championships, I can say with even greater confidence that you do not. But do go on and continue to pontificate, I won't interrupt again. :lol:

 

[Lurkin]

Easy, easy.

We're all friends here, even if we disagree at times. There's nothing wrong with challenging understood concepts, it reinforces whether the current understanding is correct or whether there is a possibility of something new arising from an old idea. Let's leave the personal stuff out, its the internet and we could all be rocket scientists for all I actually know about the other people on here.

In any case, it's a pretty moot point unless someone is willing to actually explain what is wrong with this frame, with a view to getting a decent design together for getting someone else to produce it and sell it at a reasonable price. Yes, the frame producer gets the benefit of the design, but afterward, everyone else gets the benefit of cheap, well designed frames being available. I would do it, but I don't have the knowledge or skill.

 

[Punx0r]

I do find myself wondering how much of current MTB suspension tech (4 bar linkages et al) is genuine improvement Vs. theoretical improvement or just marketing hype. The obvious comparison being that ICE bikes (almost?) invariably use a single pivot suspension.

Maybe the answer is that they aren't comparable vehicles and so justify the different suspensions. IDK.

 

[Samd]

You read my threads and dismissed them because, Um ,just because. Base an argument on fact or give up dismissing me via the Argument from Incredulity.

In the words of MC Hammer, you can't touch this.
Your pal,
The pontiff.

And see this Demo 8? Sam Hill (look him up) won the world championships on it in 2008. The signatures on the downtube hang proudly on my shed wall.
There are discerning riders here.

Suggest you don't bring a knife to a gunfight.

 

[nutnspecial]

Hi sam, I'm sorry if I came across as vindictive. Maybe it'd have been best to keep it strictly a question without the corresponding opinion. I did want to be civil, but perfectly clear I was calling you out on bullsh!t, which gets spread thick too often and of course not just from one individual; so I'm sorry don't take it too personally.

When it comes to frame geom, suspensions, and 'offroad', it's very interesting and also constructive to use facts when comparing single pivot vs multilink characteristics and benefits on pedal/gravity bikes, and consider also light dirtbikes/enduro and motocross/supercross bikes.

Let's not forget to specify what 'offroad' means also. It becomes hard imo to make such broad but absolute general claims such as yours seem non-inflamatory in this venue or actually stick in real life.

Ps: providing a close factual conclusion, which would likely come down to 'split decisions' in bike use and ride weight anyway, I would also consider material benefit for specified use (steel or aluminum), maintenance, environmental impact, longevity, and cost too.

 

[Samd]

Material is a good point. I have a couple of dozen aluminium modded frames under my belt and have moved onto carbon mods. CrMo (4130) has nice harmonics and any stooge can weld it but you don't get the hydro formed look.

But even Walbikes can now be found in newer materials. Just because it's cheap at Walmart doesn't make it an offroad bike.
No sense putting lipstick on a pig.

This bike is a commuter.

 

[cheekybloke]

Having ridden many mtbs for the last 20 plus years i would have to say there is really no comparison between a single pivot pogo stick type frame and one with a patented rear suspension linkage for off road riding.
Even for commuting there is way less pedal bob with a real rear end.
The em3ev frames are a box with a steerer tube and nothing else,which is fine if thats what you are wanting but not for me thanks, i will stick with my chopped up DH Comp.

 

[Samd]

Now that's a delicious rear end right there.

 

[markz]

i will stick with my chopped up DH Comp.

What type of frame did you chop up and is there much selection for DH, XC, All Mountain full suspension frames that leave a lot of room in the triangle?

GT's seem to take up most of that space. Giant Glory 0, Kona Supreme Operator, Trek Session 9.9
Norco Sight Alloy, Revolver 7 and 9, Fluid, Range

I need to start hunting for a decent fs frame, I think I can snatch one up for around a hundred bucks easily. Cheaper if it doesnt have the suspension components.

 

[Punx0r]

It makes sense that a multi-link suspension could have advantages like reduction of pedal-bob, but what about for ride quality when not pedalling?

there is really no comparison between a single pivot pogo stick type frame and one with a patented rear suspension linkage for off road riding.

I don't doubt it! But how much of the difference is just due to huge general difference in quality? A cheesey pogo-stick fork pivots and slides in the same places as the latest high-tech one.

 

[SlowCo]

It makes sense that a multi-link suspension could have advantages like reduction of pedal-bob, but what about for ride quality when not pedalling?

there is really no comparison between a single pivot pogo stick type frame and one with a patented rear suspension linkage for off road riding.

I don't doubt it! But how much of the difference is just due to huge general difference in quality? A cheesey pogo-stick fork pivots and slides in the same places as the latest high-tech one.

I think the focus is more on the (multi link) rising rate rear suspension design. The very basic design of the EM3EV rear swing arm vs the advanced design of most modern down hill bicycles (like cheekyblokes) and off road motorcycles. Especially the damping of the front fork and rear shock is a price/quality choice.

 

[cheekybloke]

i will stick with my chopped up DH Comp.

What type of frame did you chop up and is there much selection for DH, XC, All Mountain full suspension frames that leave a lot of room in the triangle?

GT's seem to take up most of that space. Giant Glory 0, Kona Supreme Operator, Trek Session 9.9
Norco Sight Alloy, Revolver 7 and 9, Fluid, Range

I need to start hunting for a decent fs frame, I think I can snatch one up for around a hundred bucks easily. Cheaper if it doesnt have the suspension components.

The donor frame was a Giant dh comp and it was chopped by Sam D.
These frames are from 2003 ish onwards and are quite cheap if you can find one.
i got 2 from Ebay for 80 gbp for the pair, no shocks on them but well worth it.

 

[Punx0r]

I did a bit of reading earlier about the various designs: single pivot Vs. multi-link/pivot. It seems the rising/falling rate is a red herring, especially since air shocks are inherently rising-rate. Basically, any of the available options can be rising/falling or approximately linear. There seems no clear advantage to axle-path, either. This seems borne out by there being some good quality bikes with single pivot suspension capable of winning competitions (or at least in the recent past). IIRC all Orange’s bikes are single pivot.

Some of the multi-link designs reduce pedal bob, brake dive, pedal squat or other unpleasant-sounding things. All well above my riding capabilities

In summary, it seems most designs are capable of giving good results if they’re implemented correctly as part of a good overall frame/suspension package.

That’s not to say the EM3EV frame is necessarily brilliant, just that it seems overly-simplistic to assume it must be no good because it’s a single-pivot. I doubt it helps that single pivot is also the cheapest design to produce so gets used on a lot of junk bikes…

 

[ecycler]

I do not wish to enter the single pivot vs. multi-link debate, but I do want to point out how similar the DH Comp rear geometry is to the Suzuki Hayabusa. Kind of interesting:

 

[Punx0r]

That's an interesting comparison If nothing else, it's a clever way to package a long shock into a small space. Once comment I read earlier was how motorcycles can often make better use of a single-pivot design because they have more space available and don't need to accommodate (pedal) cranks.

 

[Hillhater]

Have we all got the same terminology ?
...because to me, both those pics above show a single pivot swing arm.!
The other linkages are simply to alter the shock/Spring travel relative to the swing arm.
There are other designs of swing arm which do have multiple pivot points for multiple lineages which make up the swing arm......but there have been no pictures of those in this thread !

 

[Lurkin]

Eh been searching to the referred to thread earlier without success. The guts of it was that rear suspension on bicycles typically is to keep the wheels to the ground whilst avoiding pedal bob with minimal force being applied other than from the legs.

Particularly higher power ebikes differ as there is the force applied at the hub which reduces the need to avoid pedal bob (assuming throttle not torque sensing PAS) thus changing the rear suspension dynamic and makes the set up more appropriate to be more like a dirt bikes. I can't remember or brain the exact logic, but there was also an argument that due to the driving force coming from the rear wheel (think hub motor) rather than from the legs, it would have a differnet effect on how the single pivot reacted when under load and on the throttle.

Of course, this all goes out the window when you want to pedal! :lol:

 

[GmagNeato]

I think it's been fairly well established that, for off-road purposes, mid-drive systems are the best way to go. The EM3EV frame is not designed for a mid drive system, but rather a mid-high powered hub motor. Therefore, pointing to it's swing-arm design as inferior to any DH, FR, AM or other such bike frame design doesn't really make sense. The best of those frames were brilliantly designed for and around completely different mechanical/physical conditions. All the arguments of the swing-arm rise/fall - pedal bob efficiency, etc are pretty moot once you lace a 25lb 10kw hub monster into the rear wheel . I can't see going into a build with a frame like this ever expecting the kind of performance or experience you would get out of a mid-drive setup for that use/style of riding.

However, I wouldn't call this frame solely a "commuter" either. Although from a design aspect it should perform very well in that application.

A more apple to apple comparison, in my opinion, would be MX, which are decidedly NOT strictly commuter bikes, but ALL use a very similar swing-arm design.

If the quality of these frames pans out, with a warranty and some decent components I think it could be a pretty sweet ride - for the right applications. Looking forward to some more first hand use thoughts / opinions on this frame.

 

[GmagNeato]

Having ridden many mtbs for the last 20 plus years i would have to say there is really no comparison between a single pivot pogo stick type frame and one with a patented rear suspension linkage for off road riding.

I would tend to agree. But what about for hub motor builds used for say 80% commuting / 20% offroad use? The benefits of rear linkage design become less pronounced in this scenario. There are actually some drawbacks. #1 being less room available for more batteries to increase top speed and distance capacity. The single pivot design allows MASSIVE space in the triangle, while still providing a solid platform for suspension that, with the right components, could be more than sufficient.

Even for commuting there is way less pedal bob with a real rear end.

This is a non-issue with the right rear shock.

The em3ev frames are a box with a steerer tube and nothing else,which is fine if thats what you are wanting but not for me thanks,

Do you have any actual experience with this frame or one like it? In either of the applications you are commenting on?

i will stick with my chopped up DH Comp.

I don't blame you. That is a sick build. But some may not have the means to do as you've done. Should they just concede to going with overpriced, under powered, ready-made ebikes?

 

[Quokka]

I Have one of these frames. It's pretty good value for money but has a few drawbacks. The thing that annoys me is that the top plastic shroud is held on with double sided masking tape. When it gets hot the damn thing comes loose (talking 40 degree c). Also the frame is not very water proof. Welds are good and it's easy to assemble.

 

[spinningmagnets]

Thanks Quokka, that's the kind of information people come to endless-sphere for. This frame isn't my cup of tea (I'm a street ebike guy), but...I'm sure its appropriate for certain applications and budgets.

 

[cheekybloke]

Having ridden many mtbs for the last 20 plus years i would have to say there is really no comparison between a single pivot pogo stick type frame and one with a patented rear suspension linkage for off road riding.

I would tend to agree. But what about for hub motor builds used for say 80% commuting / 20% offroad use? The benefits of rear linkage design become less pronounced in this scenario. There are actually some drawbacks. #1 being less room available for more batteries to increase top speed and distance capacity. The single pivot design allows MASSIVE space in the triangle, while still providing a solid platform for suspension that, with the right components, could be more than sufficient.

Even for commuting there is way less pedal bob with a real rear end.

This is a non-issue with the right rear shock.

The em3ev frames are a box with a steerer tube and nothing else,which is fine if thats what you are wanting but not for me thanks,

Do you have any actual experience with this frame or one like it? In either of the applications you are commenting on?

i will stick with my chopped up DH Comp.

I don't blame you. That is a sick build. But some may not have the means to do as you've done. Should they just concede to going with overpriced, under powered, ready-made ebikes?

The giant dh comp frame has more batt space than most dh frames due to the shock being behind the seat tube, which is why it is chosen for a great donor for any e bike.
Most of the builds on here with theses frames are hub driven.
I have not ridden on of the em3ev frames but have ridden many single pivot bikes in the past and did not like them as much as my current bike.

Realistically these frames are fine for anyone wanting a decent looking shop bought frame with plenty of batt. storage.
As for the rear shock comment you cant put a tiara on a dog poo and call it a princess, it is more about the rising/falling rate.
Darren

 

[GmagNeato]

I Have one of these frames. It's pretty good value for money but has a few drawbacks. The thing that annoys me is that the top plastic shroud is held on with double sided masking tape. When it gets hot the damn thing comes loose (talking 40 degree c). Also the frame is not very water proof. Welds are good and it's easy to assemble.

Thanks Quokka. Glad to hear about the welds and trouble free assembly. I can def see that being annoying regarding the top plastic. However, that as well as the waterproofing ought to be fairly easy to remedy - but only worthwhile if it's well built otherwise.

 

[markz]

I am liking the Giant DH Comp bike more and more as an alternative.
https://www.flickr.com/photos/34052411@N07/3916293679/in/album-72157622359244408/
I just cant find any bare frames, or frames with shocks on them for a decent price.
I found a great website pinkbike.com that has tons of bikes, I also use Kijiji.com.

 

[GmagNeato]

The giant dh comp frame has more batt space than most dh frames due to the shock being behind the seat tube, which is why it is chosen for a great donor for any e bike.
Most of the builds on here with theses frames are hub driven.
I have not ridden on of the em3ev frames but have ridden many single pivot bikes in the past and did not like them as much as my current bike.

I've seen several excellent builds here on ES with the DH Comp frame, now including yours. I can understand what makes this great donor bike. I love the whole concept. But it is still not being used for the exact purpose in which it was designed. It is essentially a really good mountain bike trying (and succeeding obviously) to be an ebike. In order to get a high quality, high capacity battery compartment in this great frame, from what I've seen, a lot of fabrication is required. Some don't have the means for this, whether it be skill-set or equipment related.

Realistically these frames are fine for anyone wanting a decent looking shop bought frame with plenty of batt. storage.

Not sure how you would consider this frame more "shop bought" than a donor bicycle frame? I would say it's actually more purpose built for the application.

As for the rear shock comment you cant put a tiara on a dog poo and call it a princess, it is more about the rising/falling rate.
Darren

:lol: This gave me a good laugh! Hope you don't mind if I borrow this phrase sometime. I am by far no expert in frame design and do not claim to be. But from my understanding the type of shock (air, coil, travel distance, etc) has a huge effect on rise/fall rate. Am I incorrect in this understanding? Please explain. A shock with lockout would eliminate pedal bob for those times when pedaling efficiency matter that much.