(Full sus) Fat bike frames for smaller/lighter motors than M620

[El Topo]

The more I think about it, the more I come to the conclusion that I want a fat *trail* bike and no 3kW monster truck, weighing north of 30kg, meaning an E23 doesn't seem very attractive to me at the moment.

It has been mentioned by @Neeko DeVinchi here that the E10 and the E22 share the same rear triangle. Therefore it *should* be possible to marry the E23 (fat) rear triangle to the E10 front triangle.
Dengfu says "it is not ok", which is understandable, because they can't sell a front/rear triangle combination that is not tested/approved by their engineers.

Since I can't afford to just order frame parts worth 1000$ just to see if they fit, I would like to have some assurance that such a build would work and is not in danger of cracking or what ever else could happen.

I would really appreciate anyone's input on this!
TIA!

 

[TeoElFeo]

I doubt anybody can provide you here such assurance Even if a person would have 2 bikes, how would they be able to assure you? I guess it's only the trial and error method. Firstly, are you even sure that the pivot points will match to assemble thus together? And also, why do you need a fat bike? Not much advantage unless riding sand or snow. However the tires are heavier and more prone to cuts and punctures, squirm.. Maybe the plus size tyres would do?

 

[El Topo]

Thank you for the reply, TeoElFeo.

I doubt anybody can provide you here such assurance Even if a person would have 2 bikes, how would they be able to assure you? I guess it's only the trial and error method.

There are quite a few knowledgeable people here, that might be able to confirm or disprove that marrying the E10 front with the E23 rear should work, that is what I am hoping for in this thread.
If someone would explain why he doesn't see an issue why it should work, I would be happy to take the risk. I am a casual rider and wouldn't attempt big drops or anything like that, I just want the suspension for a comfortable ride, that is a bit more forgiving if I am again lacking in technique.

Firstly, are you even sure that the pivot points will match to assemble thus together?

I don't.
But if the E10 and E22 rear triangle are the same, and the E23 fat rear triangle can be bolted onto the E22 front triangle (which is obviously the case), then the pivot points of the E23 rear should match those of the E10 front. But I might be mistaken on this, and there is something I overlook.
I don't know anything about suspension kinematics, but again, if the two frames share the same non-fat rear triangle, the kinematics should also be the same, right? At least they seem to do on the the comparison photo here And if that is the case, then the E23 rear should work the same (almost because the chainstay and therefore axle is a bit more far out.

And also, why do you need a fat bike? Not much advantage unless riding sand or snow. However the tires are heavier and more prone to cuts and punctures, squirm.. Maybe the plus size tyres would do?

I know it is common to tell people who want a fat bike that "normal" MTBs are superior, but I would prefer to to not have that discussion in this thread. Let me just say that I prefer how they ride, for what I want to ride with it.

 

[Waynemarlow]

Let me just say that I prefer how they ride, for what I want to ride with it.

So you are saying you only ride in sand or snow ?

 

[El Topo]

Can we please stay on topic and focus on the question, instead of discussing what tire width I should ride?

 

[Waynemarlow]

Can we please stay on topic and focus on the question, instead of discussing what tire width I should ride?

But tyre width is the reason you are going for a Fat Bike.

I'm not sure you really understand the full repercussions of the extra width on the rear. Things like needing 100 - 120mm width on the bottom bracket so that the cranks clear the rear stays, what motor has that width, very few. There's a few adaptors out there but again they are expensive, the motors expensive and mostly not torque based. I'm not sure on a M600 motor there are cranks available to get enough Q factor to clear the stays, which immediately rules out the E10 front end.

Its a lot of years ago but I built a frame that took the then Fat tyres all of 3.0", the front was pretty easy to sort but the rear posed all sorts of difficulties with feet clipping the over width rear hub and cassette. The full suspension I had was soon made rigid as with both suspension and big soft tyres it was like riding in porridge all of the time. Drag in the dry was horrendous from the very soft shell constantly maximising grip which also means maximum friction, you end up fitting bigger and heavier batteries to get any sort of range. It all becomes a bit of a spiral of needing extra which makes it all heavier, which makes needing a bigger and more powerful motor.

I shelved the frame in the end as the benefits were really limited to only the few times we had snow around, where you want to cut down to very low PSI figures of the tyre footprint to prevent burying, then it was good. Equally I've done some riding in sand on a rigid Fat Bike and that was a lot of fun. Not knocking Fat Bikes as they are fun but the E10 already takes a 2.8 x 27.5 using standard boost components, standard cranks and standard motor, at low pressures in the UK mud its very very good, has supple suspension enabling the rider to load up the tyre momentarily to gain maximum grip, has clearance for the gloop and rides in my view better than a hard tail 4" tyred Fat Bike without all the expense.

The only Fat EBike production full suspension I know is the Lamere Summit, perhaps some of your questions could be answered there.

The eSummit! World's Best Electric Full Suspension Fat Bike | LaMere Cycles

LaMere eSummit is world's only full suspension, full carbon electric fat bike with Shimano E8000 motor and internal battery. Can be turned into regular eMTB for non-snow season. Fits biggest 27.5x4.5" and 26x5" fat tires. Custom built any way you like here in Minneapolis, MN.

www.lamerecycles.com

Equally I think Light Carbon does a frame based around the M620 engine which you will probably need the extra power of. From memory I think you have to fit a wider bottom bracket to the engine but do check.

New LightCarbon Full Suspension Electric Fat Bike Frame Fit Bafang M620 Motor Suppliers,Manufacturers,Factories

We are the professional manufacturer for Full Suspension Electric Fat Bike Frame. Inquiry now about more New LightCarbon Full Suspension Electric Fat Bike Frame Fit Bafang M620 Motor information.

www.lightcarbon.com

 

[Mabman]

Wayne is correct, Fat Bikes have wider bb's for the very reasons he states and is most likely why the OP's idea of mating a narrower bb front triangle to a wider spaced rear triangle won't work.

Not to poke the bear but I also fail to see the advantage of wider than 3.0 tires for trail riding and even in sand for the most part as I ride both frequently on a 2.4/2.8 combo on my locals. But to each their own.

 

[MadZoom]

I agree with Waynemarlow's points. Earlier this year, I rode my friend's carbon ultra with a Maxxis FBR 26x4.8 for about 30+ miles (trail/road). The drag in dry conditions was a big surprise to me. Ultimately, I went with a bike that used a 27.5x2.8 in the rear which was a good thing because when it came time to replacing it, I had a lot more tire choices. The tire choices for fat tires are very limited along with higher prices. If you are still want a fat tire setup, the Maxxis FBR would be the choice ranging from 27.5x3.8 to 26x4.0-4.8.

 

[Neeko DeVinchi]

I think we need to add some perspective here, in an effort to address the issue.

For reference, the above is the E23. Built up by one of the members on the Dengfu Frame Facebook community.

This is a shot of the rear wheel of the bike however, pay close attention to the way the upper linkage is connected to the bridge which forms the upper seat stays. In addition, note that the seat stays expands outwards to allow for more clearance for a bigger circumference wheel.

Compared to either the E10 or E22, where the bridge / seat stays don't need as much clearance to support a 29x2.4 tyre on a 30mm internal rim.

@El Topo as I've explained before, it's not simply a case of combining two sections of two bikes together.

I've already explained that the M620 motor can support fatbike cranks and chainrings. Hence, why Dengfu built a fatbike platform around the M620 motor.

@Waynemarlow is correct by stating that neither the M500/M600/M510 have provisions to support fatbike cranks.

Part of the reason why the E22 can work as a 15x110 & 12x148 full 29er

27.5 front and rear (or mullet), is due to the proportions of the frame in conjunction with stack height & wheelbase per each respective frame size. Bare in mind that (with the exception of some downhill-esk styled fatbike novelty forks from Alibaba), I have yet to have come across a fatbike fork which exceeds 120mm of travel.

The testimonials of riders who have brought/built E23's is positive. Which suggests that the platform (as it is) is built, in accordance with the application fatbikes relish in.

The E10 (v1 or v2) is a platform, designed for a different application in mind. Granted, some may have opinions as to the specific applications within the emtb world the bike favors (trail, Allmountain, enduro, Freeride, adventure/touring etc). Myself, I have already gone on record stating that "it can be, whatever you want it to be". And I still stand by that.

The point being, the E10 frameset, lends itself nicely to being built up in vast configurations which favors quick handling, speed and agility. Coupled with its acceptable weight (within the full-fat emtb world) and generous frame size options compared to other ebike frame options from the far east, even I am left asking the question "why would someone choose to take away traits which makes the E10, what it is?"

The E22's platform (whilst heavier and more gurfy), is also built to serve a particular application and purpose as well. Similar in some ways to the E10, the E22 however takes full advantage of its extra mass by prioritizing stability and traction at higher speeds. Whilst ensuring that the rider retains control of the bike, thereby inspiring confidence.

Again similar to the E10 (depending on how someone chooses to spec one), the platform can be utilized in ways such as a trail, Allmountain, high powered off road vehicle, etc.

The overall point I'm trying to make is that, each respective Dengfu frame owner has tailored their chosen bike, in accordance with which platform would best suit/serve/cater/adhere to their respective requirements 'WITHIN THE CONFINES OF EACH RESPECTIVE PLATFORMS STRENGTHS.

A fatbike (ebike or regular) by design, serves a particular purpose within the world of mountain biking. Nowadays, more associated with the 'outback offroad / hunting / touring / beach cruiser' applications. But clearly distinguishable by its design and purpose.

I see no gains to be made by canabalising two purpose built ebike frames which already serve respectable purposes,

to create something which........'remains unclear' whether it would.........work!!!

This is my opinion of course. But I am aware that Dengfu have also chimed in concerning this proposal. So I'll refrain from outlining my opinions further, for fear that it's not contributing towards answering this threads topic.

 

[El Topo]

I was hoping for more of an actual DIY-spirit in the DIY-forum, but apparently fat tires evoke the same strong feelings here, like they do in most other places.
Time to move on then...

 

[Paulquattro]

I was hoping for more of an actual DIY-spirit in the DIY-forum, but apparently fat tires evoke the same strong feelings here, like they do in most other places.
Time to move on then...

I think reading through this most of the replys are pretty clear it cant be done
As for DIY spirit
With these sort of comments from you i think DIY is your best bet .

 

[Waynemarlow]

I was hoping for more of an actual DIY-spirit in the DIY-forum, but apparently fat tires evoke the same strong feelings here, like they do in most other places.
Time to move on then...

Not sure but I'm reading that we all like Fat tyres, in the right place and useage.

On a full suspension bike are they really necessary ? If your'e not riding in snow or sand are they really an advantage, convince us.

 

[TeoElFeo]

I was hoping for more of an actual DIY-spirit in the DIY-forum, but apparently fat tires evoke the same strong feelings here, like they do in most other places.
Time to move on then...

Or maybe you were just hoping that somebody would give you a ready solution with assurance and not question your questionable ideas? Real world, so disappointing

 

[bram.biesiekierski]

I reckon it would work. Obviously I have no way to prove this. But looking at the e10, e22, and e23. I think I you could bolt it together. You would have to address the chain line issue ofcoarse.

Why you would want to do this is another question, and I have no answers for that one.

And you would ofcoarse need to buy 2 frames. Then build the Frankenstein fat e10, and a regular e22 out of the left overs. Probs not a bad idea. As once you get sick of fat bikes, you will still have a e22 frame to build up.

 

[Tilt]

Plus j'y pense, plus j'en viens à la conclusion que je veux un gros vélo *trail* et pas de camion monstre de 5 kW, pesant au nord de 30 kg, ce qui signifie qu'un E23 ne me semble pas très attrayant pour le moment.

@Neeko DeVinchi a mentionné ici que le E10 et le E22 partagent le même triangle arrière. Par conséquent, il * devrait * être possible de marier le triangle arrière E23 (gras) au triangle avant E10.
Dengfu dit "ce n'est pas ok", ce qui est compréhensible, car ils ne peuvent pas vendre une combinaison de triangle avant/arrière qui n'est pas testée/approuvée par leurs ingénieurs.

Étant donné que je ne peux pas me permettre de commander des pièces de cadre d'une valeur de 1000 $ juste pour voir si elles conviennent, j'aimerais avoir l'assurance qu'une telle construction fonctionnerait et ne risquerait pas de se fissurer ou quoi que ce soit d'autre pourrait arriver.

J'apprécierais vraiment la contribution de quiconque à ce sujet

 

[Tilt]

moi aussi je voulais un montage E10 avec le moteur M600 et l'arrière E23 négatif pour dengfu donc je l'ai pris chez lightcarbon mais pas le e10

 

[Jon A]

moi aussi je voulais un montage E10 avec le moteur M600 et l'arrière E23 négatif pour dengfu donc je l'ai pris chez lightcarbon mais pas le e10

Nice looking bike! I wasn't aware Light Carbon was making E-fatbikes now. If they had been a couple of years ago I may have gone with one of theirs. I'll have to look into their offerings a bit more.

The only Fat EBike production full suspension I know is the Lamere Summit, perhaps some of your questions could be answered there.

The eSummit! World's Best Electric Full Suspension Fat Bike | LaMere Cycles

LaMere eSummit is world's only full suspension, full carbon electric fat bike with Shimano E8000 motor and internal battery. Can be turned into regular eMTB for non-snow season. Fits biggest 27.5x4.5" and 26x5" fat tires. Custom built any way you like here in Minneapolis, MN.

www.lamerecycles.com

The Lamere is basically the Shimano version of the Dengfu E06--the E06 rear coupled to the E04 front. A very nice bike to be sure, but it wouldn't be my choice (in the US) vs. the E06 for a couple reasons: Cost!!!, Lack of power, lack of battery size, lack of a throttle.

Bare in mind that (with the exception of some downhill-esk styled fatbike novelty forks from Alibaba), I have yet to have come across a fatbike fork which exceeds 120mm of travel.

The fork widely regarded as the absolute best fatbike fork available--the Manitou Mastodon--is available up to 150mm travel:

I've got two of them, running at 140mm travel on my bikes.

As for the usual "discussion" about fatbikes by those with little or no experience with them, I won't bore you all with the very long list of reasons to like them year round but the OP specifically mentioned wanting a smooth ride.

Those who don't have much time on a good full suspension fatbike with good wheels and tires aren't going to have any idea. The small bump compliance and ability to smooth trail chatter just can't be matched with smaller tires running at two or three times the pressure, no matter how expensive a shock and fork you run. And if you don't like how it feels, this is where the versatility comes into play.

While in conditions like this:

The giant, monster-truck 5" wide winter tires are something to behold, and work fantastically well (especially when paired with Bafang Ultra power!) but it's quite likely they won't giving you the handling you want in more tame conditions. For general trail use, a good set of 27.5X4" tires ("mid-fat") on lightweight wheels will change the handling dramatically:

And I mean dramatically. It feels like a completely different bike. If one hasn't ridden a good bike with good tires of this size on a lightweight wheelset, he has no idea how well fat tires can handle for general trail riding. Very much more MTB with + tires feel than "fatbike" feel. And they still offer a much smoother ride than MTB width tires, along with superior traction and rollover that allows me to go places offroad I simply couldn't on my 29er. And yes, they can still handle a good amount of snow. A shot of Daxxie's (much prettier) E06 with the same tires, which he likes very much for the same reasons:

And if you want something even more nimble, you can take it a step farther. A set of 29+ wheels is a very, very, common accessory for fatbike owners, as seen here on Surly's (most beautiful) build:

Those are all Dengfu E06's, just as an example of how a guy can basically have three different bikes with a 2 minute wheel swap and how one frame can be so versatile. Ebikes, even DIY ones, aren't cheap when built with quality parts and take quite a bit of space to store. One bike with a couple different wheelsets to suit the conditions or his mood on a given day is an attractive option to a lot of people.

In any case, my advice to the OP:

While there clearly is some swap-ability between the rear triangles of some Dengfu frames (as Lamere has done, Wattwagons even offered their E22 for sale with E23 rear ends as an accessory for a while for users who want to switch back and forth and I'm guessing with the right linkages the same would be possible with the E55/E56), those are all within the same "frame family." What you're talking about crosses from one "frame family" to another, and even if the rear triangles may look the same, there may be some subtle differences that make it a no-go. Sorry I can't confirm one way or the other if it would work or not.

But the good news is now there are enough choices, I don't think you really need to re-invent the wheel. With Dengfu's excellent E06, E23 and now E56 and the Light Carbon offerings, my advice is to weigh the plusses and minuses of each frame depending upon the attributes that you're looking for the most and buy the complete frame so you know everything will work together as intended. And spend the money on a set (at least one, more if you're picky about having the best setup for a particular set of conditions) of carbon wheels, use well regarded tires in the fatbike community for the conditions you're interested in and set them up tubeless (fatbike tubes are extremely heavy and detrimental to handling).

If you do that, I think you'll be very happy with whatever you end up with.

 

[Tilt]

Je Pense avec le nouveau moteur m610 beaucoup voudront un cadre fatbike leger, puissant , batterie de 600watt et batterie additionnelle et pneu tubeless et certainement un poids de 24 kg sur la balance

 

[Tilt]

Le m610 sera disponible en juillet je pense me procurer un nouveau fat ultra léger avec cet objectif moteur en dessous de 24kg sans la batterie 330w supplémentaireThe m610 will be available in July I'm thinking of getting myself a new ultra-light fat with this objective motor below 24kg without the additional 330w battery

 

[El Topo]

.....

As for the usual "discussion" about fatbikes by those with little or no experience with them, I won't bore you all with the very long list of reasons to like them year round but the OP specifically mentioned wanting a smooth ride.

Those who don't have much time on a good full suspension fatbike with good wheels and tires aren't going to have any idea. The small bump compliance and ability to smooth trail chatter just can't be matched with smaller tires running at two or three times the pressure, no matter how expensive a shock and fork you run. And if you don't like how it feels, this is where the versatility comes into play.
....

While I am *a bit* late, thank you very much for this excellent write up, why one would choose a fat bike over a regular one. I couldn't have put it any better, no matter how hard I would have tried.

And spend the money on a set (at least one, more if you're picky about having the best setup for a particular set of conditions) of carbon wheels, use well regarded tires in the fatbike community for the conditions you're interested in and set them up tubeless (fatbike tubes are extremely heavy and detrimental to handling).

Thanks for the advice, I am already running a Nextie 90mm wheelset with a silent Onyx hub, and Schwalbe Al Mighty (tubeless) on my (non-electric) HT fat bike, and am quite happy with it! I also got Mulefut 27.5" 80mm rims with Gnarwhals on top of that.

Next purchase will be be a 29" wheelset, but carbon and Onyx hubs are expensive!

 

[El Topo]

There is this frame, but I am unable to find out who is actually producing them.
Does anyone know who manufactures it?
The geometry is quite old school, but it seems like the only fat bike frame for the M5/600 class of motors.

Before I actually bite the bullet and get a M620 based frame like the E56, is there anyone with new ideas on how to build a lighter fat bike in 2023?
I looked at the adapters by @Tomblarom, to run a M500 motor in a M620 frame, but am unsure if would be happy with such a solution.

 

[Tilt]

the topo here is

 

[El Topo]

Thanks, for the reply.

Looking at the shots of that 4leaf bike again, it looks like they use an adaptor to mount the smaller M5/600 motors.
I wonder if they got a sleek solution, and if someone else is selling that too. They surely must have solved the spider and chainline issue with the smaller motors. Maybe there are off the shelf parts that fit.

If that is the case, one might also use an E56 frame...

 

[Tilt]

no adapter for the motor

 

[El Topo]

They actually seem to have two different versions of that frame:

Still, who makes that frame, and where can it be bought?

Checking that video again, it seems like larger diameter fat tires like 27.5x4.5" will be a very tight fit, or will not fit at all.

 

[Tilt]

They actually seem to have two different versions of that frame:

Still, who makes that frame, and where can it be bought?

Checking that video again, it seems like larger diameter fat tires like 27.5x4.5" will be a very tight fit, or will not fit at all.

26x4 80 goes very well no problem the lightcarbon lc 39 frame with wider rear triangle at my request very good frame since the video it's 2 bikes are at my house

 

[Tilt]

The dengfu e10 can have a similar assembly on this forum a guy does it

 

[Tilt]

26x4 80 goes very well no problem the lightcarbon lc 39 frame with wider rear triangle at my request very good frame since the video it's 2 bikes are at my house

27.5 ×4.50 does not fit on this fat maxi 26x5.00 or 27×3.80

 

[El Topo]

Thank you so much for the replies, @Tilt !

27.5 ×4.50 does not fit on this fat maxi 26x5.00 or 27×3.80

Bummer, thanks for the info though.

The dengfu e10 can have a similar assembly on this forum a guy does it
View attachment 127897

So someone actually did, what I only theoretized about?

Can you give me a link to this build, please? I can't find anything with my meager search skills.

Given this presumably the E23 rear, I would just need to know the cranks and spider this specific build uses, if I am not missing anything. And of course how to get those different front and rear triangles, without having to purchase two framesets.

 

[Tilt]

Thank you so much for the replies, @Tilt !


Bummer, thanks for the info though.



So someone actually did, what I only theoretized about?

Can you give me a link to this build, please? I can't find anything with my meager search skills.

Given this presumably the E23 rear, I would just need to know the cranks and spider this specific build uses, if I am not missing anything. And of course how to get those different front and rear triangles, without having to purchase two framesets.

for the lightcarbon 4leaf frame (firon woo) can provide you with the frame and cranks you want and for the dengfu e10 frame he buy it in Chile shen