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

From Em3ev.com
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The basics are this is a proven design and quality from a trusted vender, for a good price.

I found this thread very informative so far but it's true much was non-issue; most 'bikes' adding the common substantial weight of 'E' will be interested and will likely find benefit in the durability/longevity/reliability gained from an decent steel frame with battery space, with a best all around design for the largest range of functions. . . .

quality is hinted at by general basic characteristics of steel and it's construction, and is evidenced by vendor rapport, customer feedback, and personal inspection/test. Design success is evidenced by dirbikes, enduros, and motorcycles everywhere.

Now lets focus on getting the power and control of a 125cc MX bike into this thing and available to the masses :D :D
 
Without going back to review the whole thread, I think it's noteworthy that this frame doesn't have the wild suspension-related chain takeup of others, e.g. Qulbix Raptor.

I mean, if pedal bob isn't a critical issue, why not make the swingarm coaxial to the cranks and dodge the problem entirely? But this frame is at least a step in the right direction.
 
It's not finished, but the photos of my project may help someone who is considering this frame. I am no expert on ebikes, which is why it's important to have a reputable dealer behind you (like Paul). Once I get a battery I will be able to see how it holds up to an adaptto, Cromotor powered EM3EV Ebike
 

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Grand!

66-67 degree headtube is spot on for all terrain handling, like downhill bikes from 2003-2010. the newer DH bikes have 63-65 degrees, wich only really works , going downhill. this frame will work great with a standard 200mm fork.

If you want make the newest DH frames work on the flats and going uphill, you need a fork with the axle further in front of the steering axis, to keep the trail distance low.

The DNM gear, I know nothing about. But let's face it, on a single pivot, moderately rising rate bike , the shock does not need to be too fancy. oil volume will be more important than fancy features. Because of the weight of the hub , the compression damping has to be firm. A linear damper works just fine, a little bottom out control would be nice though.

Being a unified rear triangle , the bike will feel softer when riding in the saddle , firmer when standing on the pedals. No disadvantage here, methinks'.

edit: I might have mixed falling/rising rate. I've used rising rate when the damping gets firmer trough the stroke, shock compresses faster, while te leverage ratio is actually falling from 4:1 to 3,5:1
.manitu
 
Quokka said:
It's not finished, but the photos of my project may help someone who is considering this frame. I am no expert on ebikes, which is why it's important to have a reputable dealer behind you (like Paul). Once I get a battery I will be able to see how it holds up to an adaptto, Cromotor powered EM3EV Ebikehttps://endless-sphere.com/forums/download/file.php?id=188717
file.php
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Wow ! :shock: Corona power !.......or is that one of those new "Flow" electrolyte cells ?
Or a Cargo bike ?
Nice neat way of demonstrating the battery compartment to us common folk ! :wink:
 
Sorry, I've been quite busy just recently and didn't have much of a chance to check in on this thread.

I'd like to ask for an opinion on the frame and more specifically, the location of the BB in relation to the seat. I personally find that I really want the seat as low as possible on this bike, when its running a descent power level (5KW plus). If the seats high, the bike doesn't feel stable to me. There is quite a lot of travel on this bike, more than is really needed on the road IMPO. Firstly, the bike is pretty tall, so you don't want the seat too high (I'm 6 feet, 1.83m and I find it ok, but less than 5 feet 10" and you might find the bike a bit tall, at least until you are up and moving). I also find the BB is really quite high off the ground, which puts it quite close to the seat. Together, it doesn't make for a great bike to pedal, kind of BMX style, with very bent knees.

If we were to do a new swingarm (I've been thinking about a specially designed swing arm for a middle motor), do people think it might be an idea to bring the BB a little lower than it currently is? If yes, any approx figures? Would that have any implications if we did this? I'm guessing you don't want to have the pedals hitting the ground when the suspension is fully compressed. Are DH bikes typically setup so that the pedals will never touch down, no matter what? (excuse my ignorance, I'm not an expert on DH bikes)

BTW, there is a moto style seat coming. I should have 1 to try very soon and should be able to start offering them for sale soon. Also, I must apologise that we haven't offered full frame packages with motors, battery etc. so far. I'll get that corrected soon.

I must go back and read over some of the posts made recently and read up some more on suspension technology. Also, I do appreciate some of the comments made, thanks :D
 
I asked the same question a while ago and Chalo provided the following information:

Bottom bracket height is always relative to the ground. Wheels vary in height, but the ground does not. The lowest bottom brackets on mass market bikes for adults were about 260mm to the center. Riding a bike that low with normal length cranks requires a little bit of discipline about not pedaling through turns. The highest BBs on unsuspended mass market bikes were about 330mm high. If you are using dual suspension, it wouldn't be a bad idea to shoot for a value in the 300 to 350mm range, depending on your height, your habits, and how long your suspension travel is.

Remember that your effective BB height will be affected by suspension sag.
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So 300-350mm from BB centre to the ground when the suspension is compressed by ~25% (normal riding position) as a guideline. Seat height above BB depends on the length of the rider's legs (if you want to pedal it like a bicycle).
 
cell_man said:
I'd like to ask for an opinion on the frame and more specifically, the location of the BB in relation to the seat. Together, it doesn't make for a great bike to pedal, kind of BMX style, with very bent knees.
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This is good to know. I am about the same height, and will report back after I've got mine built up enough to ride. Currently working on battery pack harness.

cell_man said:
BTW, there is a moto style seat coming. I should have 1 to try very soon and should be able to start offering them for sale soon. Also, I must apologise that we haven't offered full frame packages with motors, battery etc. so far. I'll get that corrected soon.
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Excited about this! Any idea of price on the moto style seat?
 
So 300-350mm from BB centre to the ground when the suspension is compressed by ~25% (normal riding position) as a guideline. Seat height above BB depends on the length of the rider's legs (if you want to pedal it like a bicycle).
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This sounds right and is nicely simplified imo.

Not being an owner of this frame at this juncture, my simple single feedback is I'd find benefit in adjustability up to 13" height (330mm) to bb center with rear susp >50% compress. Top of bike seat adj from 25- 31" above that for full pedal stroke or best control/comfort. This would possibly be the highest settings I'd ever consider reasonable in accomodation of a majority.

I like the idea of a mid motor capable arm, and wonder what type would be considered for this app. The moto seat would also likely be desirable for many users, likely with a goal standover of greatest adjustability +/- ~5" from a 34" median?

You would think there'd be a guide/dataset somewhere to draw good baseline to best accomodate the widest range of bicycle types/uses/users/conditions from intitial bike geometry to adjustability of crank and wheel size, and shock length and placement?
 
Quokka said:
It's not finished, but the photos of my project may help someone who is considering this frame. I am no expert on ebikes, which is why it's important to have a reputable dealer behind you (like Paul). Once I get a battery I will be able to see how it holds up to an adaptto, Cromotor powered EM3EV Ebike
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I like the CF style side covers. Were those DIY?
 
Hey guys sorry about some of those pics being upside down. I have now idea why the orientation was changed when I attached them to my post.
 
Yeah, there should be two threads protruding through a nut to ensure proper engagement (the first thread on a bolt isn't fully formed). In this case the nylon locking insert hasn't a hope of doing its job ;)
 
Punx0r said:
Yeah, there should be two threads protruding through a nut to ensure proper engagement (the first thread on a bolt isn't fully formed). In this case the nylon locking insert hasn't a hope of doing its job ;)
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Yeah I was afraid of that. I'll have to apply some lock-tite before I really crank them down. I suppose worst case scenario I could find some thinner lock-nuts or nut/washer combo to use. To me it almost seems as if they didn't account for the thickness of the plastic housing around the triangle and foam padding between the plastic and steel tubing when choosing the length for these bolts.
 
That's probably what happened. Are the bolts removable? If so the obvious solution would be to replace them for ones 5mm longer. Or are they welded in to form studs? If so, I'd do what you suggest and just add a dab of Loctite if you're concerned about vibration. The physical strength should still be sufficient.
 
Punx0r said:
That's probably what happened. Are the bolts removable? If so the obvious solution would be to replace them for ones 5mm longer. Or are they welded in to form studs? If so, I'd do what you suggest and just add a dab of Loctite if you're concerned about vibration. The physical strength should still be sufficient.
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Yes, they are welded on as studs. I'll definitely be adding the Loctite for final assembly. I'll have to keep a close eye on these for a while.
 
I'm growing fond of this frame, I might actually order a couple frames for rentals. (750w avg, 40kmh)

BB height on DH bikes goes from 340mm static and up to around 420mm . I dont know if they even go that high today. So the earlier estimate (300-350mm/25%compressed) is spot on. Even the Specialized Demo8 has a 343mm BB height, and that frame is known for being low.

Here is a design study of the 2015 Demo8 frame.
http://www.vitalmtb.com/product/fea...st-Look-2015-Specialized-Demo-Carbon-650b,276
I would not make a lower bike than this , nor one with less headtube angle.This is not a freeride bike , but an all out downhill racer.

To do these angles sucsessfully on an ebike, it would need a mid motor and a bit longer chainstays. It would be a wicked downhill toy for those who go fast , but it would not be great uphill , wich is much of the fun with mx bikes. But as a list of extremes, as in do not go beyond these angles or lower...


BB fore/aft. Again , The demo 8.. It, is absolutely pedal-able. the effective seat tube angle (76deg) is actually steeper than the stumpjumper hardtail mountainbike (75deg). Downhillers need to be able to get their ass behind the seat for the really steep sections. The actual seattube is less steep at 67deg.
The Footpegs to deepest point on the saddle on my suzuki RMX looks to be about 75deg too. I guess I'll sit 5-8 inces behind this point on level road.

I guess I would have the BB on your frame a bit forward, or the seat a bit back , combined with the longer swingarm. edit: I see your seatpost angle is 67deg. would not go much lower than this if pedaling performance is key.

Then again , I would maybe make a new model with frame mounted mid motor, mx rear swingarm , pedals just as an option , where the footpegs go. (and not on the swingarm)

Back to reality. Go for a telescopic seatpost , down for offroad , up for pedaling.
if you could make something work like that with the saddle , it would be great.


You should however , on all designs get space for a bigger and longer shock (note to self: check spelling) maybe one of DNM's pitbike shocks,http://www.dnmshock.com/products.php?func=p_list&pc_parent=3 wich several people have bought for their pitbikes , and work great with a good shimstack tune.http://planetminis.com/forums/chine...elka-basic-shock-valving-all-shocks-pics.html If you sell it with a decent tune for the frame/motor, that would be a BIG plus, and put you ahead of several producers.

I forgot your wheelbase , but if you could get away with a longer swingarm , go for it. on the hub version too ,to get a bigger shock in there.

Anyway , I salute you for actually designing and producing the next era of transportation , not just reading about it like most of us.


Oh, another thing , if you feel you have to much travel , sag more. 30-35% is the downhill standard , 40%? no roblem!
.manitu
 
To the chap with the Fox setup: Great looking bike! Wich motor?

The fork is a great performer , stiff leggs, plush suspension , good adjustments and a lot of aftermarket internals available. Great shock too, but soft for a hubmotor. The compression adjuster is only low speed , so it could use a shim tune. however , it is a real pain in the a** to service. You can do it yourself , but it requires special nitrogen/ air filling tools , or machining the piggyback botton cap for a scraeder valve.

.manitu
 
manitu said:
To the chap with the Fox setup: Great looking bike! Wich motor?

The fork is a great performer , stiff leggs, plush suspension , good adjustments and a lot of aftermarket internals available. Great shock too, but soft for a hubmotor. The compression adjuster is only low speed , so it could use a shim tune. however , it is a real pain in the a** to service. You can do it yourself , but it requires special nitrogen/ air filling tools , or machining the piggyback botton cap for a scraeder valve.

.manitu
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Thanks Manitu. And thanks for all the great info you've shared regarding frame geometry, etc. etc. Great stuff! For now I'll be running a 1500w leaf motor (5T) with a tuned down Adaptto Max-E. I want to ease into things regarding performance and tolerances with this frame. Plus I want to test out the reversible dropouts and fitment requirement of a 135mm hubmotor. If all goes well I plan to upgrade soon to a more hefty hub, model TBD but lately I've had my eye on the QS V3.

Rgd the 40, yes those are precisely the reasons I chose this fork. I'm expecting to need the 650lb spring for the rear shock, but want to at least see how it feels with the 450 first as I won't be doing much off-road for now. I may need to get some pointers from you along the way on suspension adjustments! :)
 
Received my frame yesterday from EM3EV. Early birthday present :)
Overall, very impressed, quality, packaging, attention to detail, etc.
Except for one thing: one of pivots, which connects swing arm to the frame is slightly bent in, and now won't fit in.
I've tried filing off paint on connecting surface, but it didn't do much.
Anyone else had this problem, and how did you fix it?
Thanks in advance!
 
It's been a while but I've finally found the time (and funds) to make some progress on my build. I did end up going with the QS 205 V3 Extra (3.5T) motor, and so far it has paired well with Adaptto Max-E controller. Should be a sufficiently powerful build to determine frame durability. Did my first spin up today. Still doing some testing and tweaking some settings and after some road testing I will post some updates.
 
Mine came very dirty, which was disconcerting, and the paintjob on the seatpost assembly wasn't great. But EM3ev refunded me to have it painted and all is good. Panel fitment isn't very good with very sloppy tolerances, but the more cool parts I add onto my bike, the more I like the frame. It's a bit shoddy, but for $499 what can you expect?
 
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