Converting a "Fatty"

BrianP

Pedelecer
Jan 4, 2012
80
33
Here I am on the beach at Milford on Sea



On the shingle spit at Hurst Castle



Riding in the snow, not deep enough to trouble the Moonlander.



The Moonlander has a very curvy frame so it can still use standard 135mm hubs. The other approach is to use a non standard 170mm wide rear hub and straighter frame tubes.

One of the new internal gear hub with motor would be great if it could be engineered. here's a Moonlander with Alfine



Brian
 
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103Alex1

Esteemed Pedelecer
Sep 29, 2012
2,228
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Hub gears sound like a good option to explore. Wonder if the Nuvinci would be compatible ? Reckon with a higher powered motor Rohloff 14-sp also an option ... but they are so much more expensive than any other hub gears it's a hard pill to swallow.

I like the idea of a mid-drive motor like Spinalot linked earlier in the thread. Wonder if there's any way one of those could be integrated with this frame ?
 

flecc

Member
Oct 25, 2006
53,476
30,787
I like the idea of a mid-drive motor like Spinalot linked earlier in the thread. Wonder if there's any way one of those could be integrated with this frame ?
The Sunstar crank unit might fit ok, on the low powered side but that's not a problem off-road where speed isn't the main objective and using the lower gears is normal:

Sunstar SO3
 

jackhandy

Esteemed Pedelecer
May 20, 2012
1,820
323
the Cornish Alps
" Shingle Spit...."

First class Spoonerism :eek:

Right up there with "Smart Feller"

Sorry..... but that's made my day.
 

103Alex1

Esteemed Pedelecer
Sep 29, 2012
2,228
67
Still think the fatty bikes deserve a mid-mount hub motor. Like a Crystalite ?? Does that rules out hub gears ? But they won't fit the frame design I don't think.
 

stesteste

Pedelecer
May 2, 2012
106
1
bradford
the on one fatty would be nice for a small motor thee on one fatty is only £999, might have a look at one this weekend i wonder if my alien aroura motor could be laced into this what u guys think or something stronger


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103Alex1

Esteemed Pedelecer
Sep 29, 2012
2,228
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the on one fatty would be nice for a small motor thee on one fatty is only £999, might have a look at one this weekend i wonder if my alien aroura motor could be laced into this what u guys think or something stronger
It would probably do but if it were me and you want a rear hub motor I'd pop a low 201rpm bafang 500W motor on it due to the size of the rims. Ought to be a decent climber then I'd have thought. Only downside is having to swap out for a freewheel. It'd be far nicer with a CST if they came with lower rpm versions and you could keep your rear 10sp but go for an 11-42T (or larger outer front chainring setup). It should then be a decent bike to ride off the shingly hills too.

It's got an 11-36T stock setup I think - need to think about that. Not much info on the wheels or whether rims double-walled. Best going to take a look as you'd need to build the motor in to the supplied rims and make sure the replacement spokes were up to the job. Catsnapper could definitely supply some good ones that'd work well I'd have thought. You'd need a 15Ah+ battery and a suitable controller though.

It's an exciting idea.
 

BrianP

Pedelecer
Jan 4, 2012
80
33
Surly have 135mm front and rear spacing, so I would guess their frames could make a good basis for conversion.

Triton Cycles have a sale on SURLY Pugsley Frameset | £425.00 | Frames & Forks | Frames - XC Hardtail | Triton Cycles and appear to even have some stock.

The On-One Fatty would make a great conversion if the 170mm rear spacing can be solved? Front is 135mm so perhaps use front motor, just seems more logical to use a rear wheel motor for an off road bike.

Components such as wheels and tyres are a bit expensive as well.

I get the feeling having enjoyed riding a fat bike so much that an electric fatty would also be great fun.

Brian
 

jackhandy

Esteemed Pedelecer
May 20, 2012
1,820
323
the Cornish Alps
The On-One Fatty would make a great conversion if the 170mm rear spacing can be solved? Front is 135mm so perhaps use front motor, just seems more logical to use a rear wheel motor for an off road bike.

Brian
Even better - I'll bet d8veh could build a stonking 2wd beast!
 

BrianP

Pedelecer
Jan 4, 2012
80
33
I think you are right. I rather like my Kona Ute with front wheel drive, having both wheels driven feels nice through corners and makes great sense off road. So, what would be a good all off road no legal hold backs spec and what would be a nice on road within legal rules spec?

Brian
 

stesteste

Pedelecer
May 2, 2012
106
1
bradford
oooh well converted or not i went and bought the on o e fatty :) excited now

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103Alex1

Esteemed Pedelecer
Sep 29, 2012
2,228
67
I think you are right. I rather like my Kona Ute with front wheel drive, having both wheels driven feels nice through corners and makes great sense off road. So, what would be a good all off road no legal hold backs spec and what would be a nice on road within legal rules spec?

Brian
Get d8veh on to this, Brian - If I get a car again in a few months time, I may well swap one of my bikes for a converted fatty to use for fun times as I won't need two. If the power supply to a dual drive can be sorted out to adequately service an affordable no holds barred setup with a sensible range that could be a really great bike build.

The Moonlander's my top pick for a donor bike frame ... if I can get my hands on a frame and adequate rims, would like to build it from that with the setup / drivetrain etc. I really want from the ground up and all the workings built in.

I bet you could go for a really decent 72v setup on that bike. Thinking about the end result and working backwards though (finish / everything working like a dream being just as important as the guts on a special build), it's managing LiPos that's the off-putting issue at the moment - part inexperience / ignorance but also how to keep the bike really neat whilst being able to charge without removing batteries from the bike. I'm thinking that's a no-go but we'll see, so be interesting to look at what lower voltage (36V - 48V) Li-Ion battery powered solutions would work also.

If you're up for converting yours will be taking a very keen interest :)
 

103Alex1

Esteemed Pedelecer
Sep 29, 2012
2,228
67
oooh well converted or not i went and bought the on o e fatty excited now
Congratulations :) ... a new home for the Durite horn in due course ? ;) ... Your thread on that inspired me and I got one lol. Gonna try to rig it up behind the seatpost on the Trek though, as I've had to accept that the front of the bike is already like something out of Star Wars :eek: !

Full riding reports soon as you can for us ? :cool:
 

stesteste

Pedelecer
May 2, 2012
106
1
bradford
Congratulations :) ... a new home for the Durite horn in due course ? ;) ... Your thread on that inspired me and I got one lol. Gonna try to rig it up behind the seatpost on the Trek though, as I've had to accept that the front of the bike is already like something out of Star Wars :eek: !

Full riding reports soon as you can for us ? :cool:
the horn i use daily and is very effective. more funds needed for conversion this diagram looks good for battery placement and crank drive what u think

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103Alex1

Esteemed Pedelecer
Sep 29, 2012
2,228
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more funds needed for conversion this diagram looks good for battery placement and crank drive what u think
Are you thinking about doing a GNG kit on it then ? Not sure about having the battery sat high like that on the top tube. You might be able to get a LiPo pack built into the triangle or else a long thin battery boxed off in there but it looks a bit tight for any sort of larger battery on account of the frame geometry :confused:
 

stesteste

Pedelecer
May 2, 2012
106
1
bradford
just looking at different options at the moment, will have a good measure up when bike arrives this is the only pic i found for measure so far, done on my phone so small pic
oooh i got the 20 inch

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BrianP

Pedelecer
Jan 4, 2012
80
33
oooh well converted or not i went and bought the on o e fatty :) excited now
You will love it. Just had another great ride out to Hurst Castle. Yesterday I had a ride on a normal tyred bike for the first time for a month. Scary narrow tyres were actually 2.1"!

Lots of great riding off road in the Dales. I am originally from Bradford and still miss the Dales so much.

Not quite sure why fat bikes are so much fun, but they are. The wide bottom bracket makes loads of room for batteries within the frame.

Have fun.

Brian
 

BrianP

Pedelecer
Jan 4, 2012
80
33
The Moonlander's my top pick for a donor bike frame ... if I can get my hands on a frame and adequate rims, would like to build it from that with the setup / drivetrain etc. I really want from the ground up and all the workings built in.
Triton Cycles have a sale on on Salsa and Surly bikes and frames. A number of fat bike frames included.

OFFERS | Frames & Forks | Triton Cycles

Best reduction, Mukluk at £319 SALSA Mukluk Frameset | £319.99 | Frames & Forks | Frames - XC Hardtail | Triton Cycles

Brian
 
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103Alex1

Esteemed Pedelecer
Sep 29, 2012
2,228
67
Thanks - very interesting and I've had a look at the sale ones. The two main features which keep bringing me back to the Moonlander are the 135mm spaced, 28mm offset rear-loading dropouts which are flexible as far as hubs are concerned and which easily accommodates the BFL 4.7 tyres without winding up with other issues to overcome. Plus the bottom bracket height.

The price is way over what I want to pay at the moment as the bike is fetching "new model markups" so think I'll need to wait and buy a used frame if one ever comes along or until I can get a second hand bike for under a grand. Would rather have a 1-3 year old used bike in reasonable nick than a brand new bike at a dealer markup. More money available for motors, batteries and component upgrading :).