Stongest tandem ebike wheel build help

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Mar 20, 2016
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Location
Enid, oklahoma
I need help building a super strong 26 inch rear wheel. I know enough on every little thing to build a strong wheel. Im looking for a part or two to begin. I want to know if any one makes a steel 48 spoke bicycle rim?

I have come to the assumption steel is stronger to hold its shape from damage, breaking & cracking, but dont know when this is implied if it means single or double wall steel? My only available option right now is a neat triple wall 35mm wide aluminum wall rim i found in very low quantiy. So i dont if triple wall aluminum or if a steel rim is better. Im trying my best to avoid using another 21 inch motorcross rim becuase i loose gears with my mid drive cargo bike with chain to close to tire.

As for spokes ive heard it all. Yes if i go with 11ga then spokes stop breaking but tension need be high to prevent loosening of spokes. The smalest spokes size ill accept is 12ga, i dont care about those advising a smaller spoke size becuase of needed flex, i have a heavy monster bike, cargo, 110 pound lithium battery setup, etc, & ride every day in good weather on pot hole infested streets. Going for the record for most wheels disposed. Id prefer my 135- (142mm) disk brake hub with 14mm solid axle.

Which rim is better & can i find a steel 48 spoke rim in 26 inch.
 
I'll assume you already know about these and they will not fit your needs:

https://yubabikes.com/cargobikestore/rear-wheel-mundo
 
Raisedeyebrows said:
I'll assume you already know about these and they will not fit your needs:

https://yubabikes.com/cargobikestore/rear-wheel-mundo
I have been trying to get a yuba rear wheel for months, still no avail. Yes i need something stonger.
I could have wheel built & substitute for smaller axle & use adapters.
 
Can you lace 11ga spokes in a 48 spoke lace pattern. 3 cross. 12 ga at the minimum which i keep hearing people say break or fail? Tying to have wheel built pronto for work season.
 
What cross pattern you can lace in is determined by the rim diameter vs the hub flange diameter, and whether or not the rim has angled spoke holes to match the lacing pattern you want to do.

The bigger the hub flanges, and the smaller the rim, the less crossings you can do.



The main reason people report breakage of 12g is because they are too thick to tension sufficiently on typical hubmotor bicycle rims, without causing the rims themselves to crack and fail even without road-strain.

11g are even thicker, and would exacerbate that problem, unless you also use a rim that's designed for at least that size spoke, so the spokes can be tensioned sufficiently to pre-stretch them and keep them tight under rim loading.


Thinner spokes (or double- or triple- butted, with thick ends but a thin middle to allow sufficient tensioning) solve the problems of wheels coming apart / spokes breaking due to the problems above.


With potholey roads, and heavy loads/bikes, rims have to be strong enough to not deform too much when there is a hit, but tires have to be big enough and have enough air in them to spread the hit around the whole rim so it doens't end up impacting the rim. Otherwise the rim gets deformed and all teh spokes are then loose, and then stuff starts breaking that didn't break because of the hit itself. If the hit is bad enough it can cause the rim to cut into/thru the tire/tube, and/or to deform and to suddenly overstretch spokes and potentially snap them.


However, it takes quite a bit to do the spoke snapping. I recently nicked the edge of a deep sharp pothole (deeper than my outstreched hand from pinky to thumb) where asphalt was completely missing at a bus stop, and the edge collapsed under my right rear wheel and sucked me into the pothole, slowing me from almsot 20MPH to nearly 10MPH in an instant, and taking all that inertia into the impact spot on the rim.

20" 45mm wide doublewall aluminum rim, 70-something mm long radially laced 13g non-butted Sapim spokes from Grin http://ebikes.ca into an HSR3548 DD hubmotor, Shinko 2.5" wide 16" moped/mc tire. SB Cruiser trike is a few hundred pounds, probably nearing 500lbs with my 180lbs weight riding it, and most of that weight is in teh back, and with the ~40lb battery and ~8lb charger and ~10lb toolbag just in front of that right rear wheel.


No spokes broke. One head pulled thru it's washer most of the way thru the oversized spoke holes on the hubmotor, and a few others pulled thru their washers there but didn't pull thru the oversized holes, and a few of the nipples partially stripped threads.

The rim itself had it's bead seat flange bent inward almost all the way down to the inner surface on teh impact point on the outboard side (no damage on the inboard side), and teh whole thing warped from the side loading during impact. It's bad enough that it's now untruable, but it's not unrideable. I rode the rest of the way to work and then my ride home later with that, and though I could feel the looseness of the wheel, nothing else broke on the ~3.5-4 miles, without changing my riding style (which is probably pretty hard on the wheels even normally ;) ).

Later I re-rounded the rim via spoke tension/truing, after replacing the now-missing washers and the stripped spoke nipples, though I can't fix the side-to-side wobble. At some point I'll have to replace that rim.


Oh, and the same set of 13g spokes/motor/etc already survived a similar but not as bad hit on the previous (identical) rim.


I suspect but haven't tested that 14/15 butted spokes might have saved the most recent rim from all but the bead seat flange damage, as they would have been able to stretch more in impact, but having them longer (non-radial lacing) would have helped even more. (just not possible with the rim/hub I have to work with).


So you don't have to have thick spokes to have a wheel that can survive potholes under heavy loads.

You might have to have better *rims*, though. ;) If I ever run across some wide steel moped or motorcycle rims that will fit my Shinko tires, I'd give them a try (partly just because I can bend teh steel rim bead seat flange back in shape without cracking it, unlike the aluminum ones I have now, and partly because many of these wheels have angled nipple holes that would allow me to use longer spokes in at least a 1x pattern, which would let me have even more "suspension" in teh spokes that would help save teh rim in an impact like the ones that have so far destroyed two rims).

I have yet to find any steel rims that are anything other than single-wall, at least in the sizes I've looked at for the trike.


The bigger (larger diameter) the wheel is, the better it will ride over these holes, though, and the bigger (fatter) the tire is, the better, too. You may not be able to use a larger wheel on yours, but if you can, try that. Eventually I'll be rebuilding the back end of the SB Cruiser (or building a whole new one) to use at least 26" wheels back there, for those reasons, as the ~22" outer diameter I have now (16" Shinkos on 20" bike rims) gives a fairly harsh ride vs a comparable tire fatness on a 26" wheel.
 
11gauge is too thick for any bicycle rim made. You won't be able to get them tight enough, and that causes them to fatigue and break.

If you have any rim damage that isn't related to breaking spokes, then the problem isn't the rim, but the tire. A proper sized and inflated tire won't let the rim come in contact with the road, so flat spotting is impossible. If the rim is cracking, then the tire is too small for the weight, and impacts are causing an overpressure in the tire, cracking the rim.

Aluminum rims with 14g spokes can handle DH free rides down cliff faces with impacts from jumping 50 feet or more. They can handle a life time of being the rear wheel in pedicabs all over the world, hauling fat tourists through potholed city streets. They can take extreme beatings over and over and over without issue, when paired with the right tire.
So unless you're breaking rims on your loaded down cargo bike while jumping over school buses or something, then the problem isn't the rim.
 
I see. The limit to using 12ga, 11ga, or 10ga is to be reserved for strong motorcross rims. I knew this to some degree. 12ga is ok, its the limit for strong standard bicycle rims, but i myself like the idea of using a steel rim & make sure your nipples are reinforced with double washers. I know a couple pros who go as far as 10ga at times but they are all in wide fat bicycle rims wich may spread out the spoke tension, & going 70 to 80mph to boot!, they say not a problem one yet for back & front wheels, but i see where this is mostly applied to the idea of having ain wheel hub motor. I have a mid drive. I dont see how (lynn custom motor bicyles) gets away with 11ga but they are in steel rims. Local bike shop finished off my rear wheel by over tensioning the 48 spoke ,31mm wide, double wall rim, all spokes cracked and most broke through. I dont know how this triple wall rim will hold up with 12ga spokes. Vs a 36 spoke steel rim with 12 guage spokes. You make some greats points amberwolf. The tension would be maxed out on the rim with quality 12 guage spokes in order to make a good wheel. Thats a lot of tension!
Screenshot_2018-03-05-18-31-10.jpg
 
My 48 spoke hub with beefy 14mm axle. For fun i would mind a steel 48 spoke rim to stay true. Comes with disk brake holes so not very common. Drunk skunk you do know your wheels last i read. 👍

Ill be using this 48 hole hub or a 36 hole revoler hub with large solid axle when i have wheel built. 12ga 48 spoke looks beefy but hope it works under tension. Love your insight guys.
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orange streak said:
I dont see how (lynn custom motor bicyles) gets away with 11ga but they are in steel rims.
I'd guess they're probably motorcycle or moped rims, like the one in hte picture in your post appears to be.


I dont know how this triple wall rim will hold up with 12ga spokes.

Since the nipples are only supported by a single wall (the innermost), it doesnt really matter how many walls a rim has, regarding spoke size and tension. It is the strength of the area immediately surrounding the hole that matters. Rims with reinforcing eyelets on the holes are likely to be less prone to cracking and pulling thru than those without, but using spokes that don't require such high tension in the first place is a better idea. ;)


Vs a 36 spoke steel rim with 12 guage spokes.
Regarding spoke size/tension, it doesnt matter how many spokes there are--the tension on any single spoke still has to be a certain amount to pretension it to stretch it enough so it doesn't come loose and fatigue (usually at the elbow).

48 spokes vs 36 just helps distribute the vehicle load a bit more evenly around the entire rim, after teh spokes are all correctly tensioned.


orange streak said:
For fun i would mind a steel 48 spoke rim to stay true.
The rim material itself has very little or nothing to directly do with staying true. it's up to having the spokes correctly tensioned for the chosen rim and spokes.

A wider rim with stiffer internal structure (doublewall, etc) might have a better chance of staying true in the event of a single-spot sideloading event (sideways skid hitting something, etc) that impacts the rim itself, but if it's all tensioned correctly that'll be less of an issue anyway.


If your wheels won't stay true, then most likely the spokes aren't tensioned sufficiently, or they were overtensioned and the rim is damaged around the nipple holes, so that now they are too low a tension and impossible to retension.

Or the tires aren't big enough with enough air in them to prevent impacts to the rim itself, and/or to help distribute the vehicle load around the whole rim and instead are point-loading the rim, distorting it and loosening spokes just long enough to allow the rim to relax / distort whlie teh spoks reseat as the wheel turns.


The main advantage to a steel rim is you can bend it back into shape without cracking it after you have an impact sufficient to get past the tire and damage the rim, whereas an aluminum rim in that state is probably just going to need replacing.


Comes with disk brake holes so not very common.
Not sure what you mean--many hubs (rear or front) come with disc brake mounts, both with thru-axles and with the various sizes of standard ones.

It might actually be less common to find large-axle hubs without them; I'm not sure.
 
I have come to a better decision. I will get to making my rear wheel with quality 12ga spokes at the absolute largest. My decision has been made much easier for me. Admittedly i cant go wrong with these mc wheels. I can make the best decision very soon. Yes a triple wall rim has much input for being much stronger & stays straight, but the wall is not stronger for the spoke tension, & must be supported by washers & nipple. This will be the new front rim to be fitted in a new fork with 3 inch street tire,since i mentioned it earlier. I will make my next wheel even later also a 21 x 1.6 mc if things dont work out, at the expence of loosing a couple shift gears with chain clearance. I believe i need a wider tire or rim to support the massive load stress i put it through.
 

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orange streak said:
I have come to a better decision. I will get to making my rear wheel with quality 12ga spokes at the absolute largest. My decision has been made much easier for me. Admittedly i cant go wrong with these mc wheels.
I'm a bit confused. Are you building the rear wheel with MC rims and hubs, or bicycle rims and hubs?

If MC parts, you should use what the rims and hubs were built to take.

If bicycle parts, then use the parts those were built to take--I'd go with 13g at the most, and realistically 13/14 butted should work.

Make sure you also use quality brand of spokes, from a known-trusted source, so you don't end up with unpredictable spokes.


I will make my next wheel even later also a 21 x 1.6 mc if things dont work out, at the expence of loosing a couple shift gears with chain clearance.

1.6" doesn't sound very wide; I'm using 2.5" wide tires on my SB Cruiser, and they aren't all that wide on 45mm wide rims.

Also remember that the smaller the outside tire diameter, teh harsher the ride can be, and the harder it is to clear the potholes.

If you need the chain to clear, you could use a wider hub, to push the lower gears out past the rim/tire.

Or you can take the gear cluster apart, and decide which intermediate gears you can live without, so you don't lose either low or high gears. Then move the gears you dont' need inboard of the lowest gears you do need, so the ones you do need will all clear the tire/rim.

I believe i need a wider tire or rim to support the massive load stress i put it through.
Bigger tougher tires definitely make a difference in what a wheel can handle, but also making sure you have enough air in them. If you keep pressures low the tire flexes a lot, and can't prevent a pothole's edge from whacking the rim on impact. If the tire is aired up sufficiently, it can distribute that impact around the whole wheel, and prevent the impact point from damaging the rim at that location.

There can still be impacts that can get past that adn destroy the wheel anyway, but they'll be rarer....
 
If you're using bicycle rims, 14ga should be considered a maximum. 14-15ga butted spokes work well for most applications, 14-17 for low tension uses (like the left side of a rear wheel), and straight 15ga for an economical front wheel.
 
To clear it up better. 21 x 1.6 is the rim size of the mc wheel. With the tire it is 3 inches wide. The current bicycle wheel & tire are 2 inches wide in a 48 spoke rim with 14ga spokes. Ive gone through so many wheels, perhaps i should be taking a factory wheel to be retensioned by a mechanic before use. Can not get the back wheel to last very long before either broken spokes, bending it, even snaping it at a time, & a couple complete collapses. In fact i should be running lower tire pressures since i over inflate by a few percent, good for flat protection. I realy like the idea of fitting a 7-10mm wider hub to. help build a sronger wheel if steel frame can be stretched with no problems. My tire is 1/16 next to the chain, very close. A 3 inch tire would be another half inch protruding outward, but i really like the idea of figuring how to move the lower gears outward for chain clearance & keep torque. I could make the sacrifice of the highend 40mph speed & drop it to 30mph max, as long as i keep my climbing gears. A special 7-8 speed freewheel or customised one would do the trick. The hard part, See that shaft and sprocket.... I believe i would need widen the kit just to move that chain line away from the tire, i can do that but nothing comes easy. Oh i have a quarter inch if i take out most of the spacer washers on shaft, then the pedal crank chain needs realigned. Once its all in place its very reliable.
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I'm not sure if you read the part of my post about tire pressures; you don't want to lower pressures if you're already getting rim strikes. That will just make the problem worse.

If your wheels are coming apart while you ride normally, there's probably something wrong with them to start with. If it's only the potholes doing it, then the best thing is to avoid them, or get a suspension that can deal with them, or get wheels designed to survive them without suspension.

Since your local bike shop doesn't know how to tension wheels, and destroys them, you don't want to take them there, so you should try learning to do it yourself. It's pretty easy, though it takes practice. You can experiment on wheels you already have that aren't in use for whatever reason, or on junk bikes or wheels from a thrift store, etc.

If you get the specific tools for doing it, like tension meters and truing stands, it could cost a bit, but when youv'e learned it and have the tools you are no longer dependent n anyone else to fix or build your wheels, and most likely you'll have less problems to start with. :)

YOu can build your own truing stands for cheap (lots of DIY articles about it in a google search), or even just do it on the bike itself with zipties, or a laser pointer, or any number of methods.
 
If anybody still comes across this post. I am eager to make a wider hub to solve & equal out the chain clearance front & back to run wider tires. Im using bicycle hubs. I need to widen my hub to 140mm to 160mm wide to get the clearance & make wheel a little stronger. All i can find cheap right now is 170mm wide. How far can widen my 135mm dropout width safely??? I would love to fit a motorcycle tire back thers. Destroyed another tandem wheel. 😟
 
Could you post a photo of the bike and how the weight/cargo is distributed on it? I'd enjoy seeing it, most of us like seeing bikes that can carry a lot of weight.
 
orange streak said:
Destroyed another tandem wheel. 😟

What was the failure? What rim and spokes did you use?

The pedicab market embraced e-assist a couple of years ago, so now they want six-passenger trikes that can weigh 2000 pounds all up. It's really stupid, but so far they are sort of getting by with regular 48 spoke pedicab wheels. It makes me wonder what's the matter with your wheels, or with what you're doing with them.
 
I messaged 8 people toaday looking for a nipple washer to fit my 12guage spoke nipples??? and my last experimental bicycle wheel is in the shop waiting to be finished. After the season i will switch to motorcross rim in back. I dont want anymore yuba mundo rear wheels i have broke like 10 so far. There are 4 cracks in rim & a complete rim ripout, trash. 😟
I found a cheap 160mm hub for later to use with a wider rear tire this fall. Looks like it will turn out to have a screw on adapter disk brake mount.

48 spokes, 14ga, 3 cross lace pattern, the 31mm wide yuba rims can not take the toll any more. That like 55 pounds lbs. of batteries on each of the side loaders. I used a mix of heavy duty aluminum footboard plates & i welded a flat bar underneath to prevent side loads from bending a snapping again. 👍

I just want to spread my frame dropouts from 135 to 160mm, is it safe?
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12ga spokes reduce the load carrying capacity of your wheels, compared to the 14 or 15ga spokes your bicycle rims were designed for. When your spokes are too thick, they unscrew in normal use, which leaves the rim unsupported and subject to bending. Also, thick spokes promote cracking around spoke nipples because they lack elasticity.

The strength of the wheel is in the rim, not the spokes. The spokes' job is to support the rim and connect it to the hub, and to carry a preload tension. Thinner spokes do a better job of these things, and help distribute stresses evenly around the rim. So paradoxically, it's thin spokes that allow a rim to carry the heaviest load it's capable of carrying.

It's a more complicated to widen the spacing of your longtail bike than it would be for a normal bike frame. The important thing is to use a hub that is as symmetrical as possible, in terms of flange spacing from the center of the axle. If it's symmetrical, it doesn't have to be wide. And if it's equally asymmetrical, then adding width won't help much. Using, say, a minimum amount freewheel spacing for 6 speed, and transferring the extra spacing to the other side of the axle, might get you a more or less dishless rear wheel.

But first, you have to use thin spokes. 14-15ga on the right side and 14-17ga on the left side of a normal dished rear wheel is an optimal setup. 14-15ga on both sides for a symmetrical wheel.

The strongest 48 hole rim for 26 inch wheels that I'm aware of is the Halo SAS. It's a heavy double walled rim with stainless double eyelets (sockets) that provide a lot of reinforcement to the spoke holes. It is not compatible with 12ga spokes.
 
Halo SAS rims look interesting, disc brakes not V-brake.
Chain Reaction Cycle is out of stock at $65

http://www.treefortbikes.com/product/333222410018/1485/Halo-SAS-26-Disc-Rim.html

I am still going with moto rims myself.
 
Halo SAS seem to have enough sidewall to use rim brakes-- at least as much as many rims up into the '90s.

The problem with moto rims is moto tires. They are very slow and very heavy. And they are hard to remove and replace.
 
Chalo, this is one area where even your critics have had to reluctantly admit to your expertise, so...I have a related question that you might be able to help with.

For this example, let us imagine we are standing on the right side of a bicycle path with a vicious pothole near us. As we look to our left, a bike is riding from our left to our right. The front wheel is lightly loaded and the rider pulls up to get the front wheel over, but the rear wheel takes a firm hit.

It's easy to imagine that the rear wheel rim is so fully tensioned that it retains a round shape. However, the rim experiences the "hit" mostly at the 5:00 O'clock position. The spokes neat 5 are temporarily unloaded a small amount, and the spokes near 11:00 O'clock experience a spike in tension-loading.

If several spokes near 11 are loose, then that one spoke that is near 11 and still properly tensioned will experience a much higher load. I think that much so far is something we can all agree on. But now...imagine that all the spokes are properly adjusted to the same tension...

My question is...if the rim takes a hit at the 5:00 O'clock position, does the rim slightly deform into an egg-shape...which would apply forces to every spoke from 8, 9, 10, 11, 12, 1, 2?

I thought that over the years, I would find the answer from reading. No luck so far...
 
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