Lacing motor into fat tire rims

Rifle

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Really thought there'd be something on this somewhere on the forum but the only time it even got mentioned in any of the fat tire threads I found was them mentioning paying someone to lace the motor into the fat tire rim as another added cost of going with a fat tire build. I'm currently wanting a second ebike mainly for exploring off-road / off-trail areas (sort of an off-road wheelchair) and that can go fast enough established off-road trails to get a bit of a flying sensation and I'm thinking a fat tire bike is the best way to do that. The only tricky part I see in building one is the rim lacing. And the price. There doesn't seem to be a cheap way to get a hold of a good fat tire bike w/ how much just the frame and rims go for.

Anyways, I plan on putting a rear 9c 2810 on and that seems tricky w/ the unusual rim and dishing. Anyone have experience?
 
I've got a Fatbike, 4" tires on 65mm wide rims. Lacing this beast up had only one minor issue. the spoke holes were drilled staggered for wide hubs, so a narrow hub would have more verticle spokes and less cross bracing. It also ment I had to do 1 extra step in calculating the spoke length, as they end up a few mm shorter depending on the stagger. It really wasn't a big deal. I built both wheels and had no troubles. JRH cut the spokes for the hub. Someone local did it for the front wheel. I prefer JRH's spokes. Even mail order, he was faster than the local shop.

When you pick your rim, talk to JRH. and/or post here what you pick. Others may have some ideas on how best to lace that rim.

You may find it's easier to lace the wheel your self. Finding a local shop that can and is willing, and is experianced enough with hub motors may be a chalange.
 
this is on my Salsa Mukluk with a 170 rear drop out been running it 8 months no problem. im 260lbs plus a 74.4 lbs bike mine is laced for an offset wheel
 

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Hmmm... so just as easy as following ebikes.ca instructions. Rims looked like they had all sorts of weird holes so I wasn't even sure if they used normal spoke nipples.
 
Those rims with the big holes are very light weight single wall rims. They aren't meant for any more abuse than a human powered bike traversing snow at 8mph. An Ebike can easily put 10 times the power through a rim, so you'll probably have better luck with a double walled Surly or one of the double walled rims from ChoppersUS.
 
I brand new to this forum. I have a Salsa Mukluk I want to run a rear hub motor like you have. I'm new to fat tire bikes and mountain biking in general. If you could give me all the details of the build that would be wonderful. The questions I have are many. What brand of motor did you use? Where did you get it from? How many watts and volts? Did you have to go to a 36h Darryl rim? Where did you mount the battery?
What hub and spokes did you use? Anything you would do different? Cost of your build? Did you do it yourself? Positives and negatives of the build. The only reason I've asking you is, I'm having a lot of trouble getting information from anyone. I've called a dozen local bike shops and no one has a clue. I've made some national calls also and have gotten very little info. I'd appreciate any details you can give. Thanks!
 
yep your going to get that cause what is the % of the people that have Fatbike period i think they said maybe 8000 in the us only out of how many bikes not sure on that one and let alone to put a motor in a Ti Mukluk like me.up here in alaska theres only 8 ti muks that i know of and im the only one with a motor in it :mrgreen:
 
My only fatbike has room for 3.5" tires at most (it is older than the fatbike phenomenon, so I designed it for 3.0 Nokian tires plus mud). I used Snow Cat rims, which are 45mm wide-- like the tires, the widest that were available at the turn of the millennium.

If I were building a fat e-bike today, I'd skip over the expensive, relatively lightweight Surly rims in favor of Weinmann DHL65, DHL80, or DHL100 rims. They all come in 36 hole drilling, they are all double-walled, and they retail for about $60. That's a deal. Just about any bike shop can special order them.

I'd use 14/15ga Sapim spokes from danscomp.com, because at $0.40 those are by far the the best deal around, and they will cut them to any length you like. Hub motors usually require some weird length. Go for cross-1 lacing. Don't let any bike shop guys tell you different, because they've probably never laced a giant diameter hub and had to figure it out for themselves.

I'm not fully up to date on the hubs these days. What I know from running hub motors on 700c and 29er wheels in the past is that you want a slow wind motor. If you get a fast wind, like something that promises 25mph or more at 36 volts, you'll bog it down with a big tall tire and get terrible efficiency. You can always add voltage to get higher speed (within reason), but you can't lower a motor's RPM sweet spot if it's too high.

For instance, the simulator at ebikes.ca says that the Nine Continent 2808 motor (the slowest wind listed there) will make over 1kW of power from 14 to 18mph with a 29" tall wheel, 48V battery, and 40A controller. It will top out on the flat at about 25mph, at 81% efficiency. It will climb an 8% grade at 16mph at 60% efficiency (which will overheat it in 5 minutes). These are good realistic performance benchmarks. You can use a faster wind and get a higher top speed, but you'll have more power consumption, slightly lower efficiency, and slightly faster overheating.

Something between few and none of the fatbike tires currently available are going to behave nicely at 30+mph on pavement. If you must go that fast, you do what you have to do-- but if you are content with below-30mph top speeds even with help from the pedals, you'll yield better range and efficiency that higher speeds would give you. And you'll lower the climbing speed at which the motor really bogs down and cooks itself.

I don't know what motors come with axles long enough to be adapted to your Mukluk's 170mm rear dropout spacing. Maybe others here can point you in the right direction.
 
hello
I just got my rim laced and I am wondering if it looks right or not as I am not sure it looks to me like the spokes are laced to far apart or to far down the hub from the rim holes is what I mean but as I have no idea how to build a rim it may be perfect and just look strange to me I need you guys to look at it and tell me if it will be ok or not thanks sincerely Jamesnew ebike rim.jpgnew ebike rim 3.jpgnew ebike rim 2.jpg
 
I think that is a three cross pattern. Looks odd with a big hub, but is supposed to give you a stronger wheel. Also looks like it wasn't easy to do. Those spokes have to be bent all over the place. You must have had an old school wheel builder.

Most ebike hub motors are laced with a single cross pattern, because the hubs are so large, multiple crosses are hard to do, and result in sharp spoke angles, as your pics show.

I don't have the experience to say whether yours is better or if it's OK.
 
That pattern is bad. The spokes will tend to break at the nipple. Whoever built that either doesn't understand big diameter hubs, or was working around spokes that were easy to get.

Cross-one, twisted radial, or radial. Those are your choices with hub motors.
 
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