Is the rear wheel on your motorized bicycle strong enough

GoldenMotor.com

reb1

New Member
Aug 15, 2010
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CALIFORNIA
If you have not noticed the trend in parts for Planes, Trains, Cars and Bicycles is to under engineer as much as possible. If you are popping spokes, bending axles and needing to bring out the spoke wrench allot then you probably need a stronger wheel at least on the rear of your motorized bicycle.
Some manufactures make the flanges on there hubs to thin. This thin flange can act like a knife on the spokes, especially if they are not properly tensioned. If a hub flange is below .050" it is to thin. A good example of this is my pops old wheel chair. The steel hubs were made of a very thin steel and they used 10 gauge spokes to compensate for the bad engineering. This works up to a point. When pop got over 250lbs this engineering technique failed. I am guessing the company who did this had issues like the cost of the product and the price of the machinery to make the product. I had the same problem on the original wheels that came on my tandem. The flanges were two thin and the spokes broke at the hub. I fixed both these problems by purchasing hubs with thicker flanges. The flanges on the replacement hubs are .100".
Spoke quality can be a problem also. A cheap spoke will have excessive stretch. Even if you properly tension the wheel when you build it, you will end up truing the wheel at an annoying rate and eventually have broken spokes. I use 14gage spokes made of SS. I use DT, Phil Wood, Wheel Smith and Union spokes. As we go with heavier spokes we also create a tendency for cracking the rim. If you build a wheel with double butted spokes the wheel can last longer. They do make 13/14ga double butted. The largest straight gauge that I would use is 13ga and I would be very careful on the overall spoke tension so the rim does not crack.
Rims can be purchased for racing touring and tandem use. I would say racing is out for MB purposes. Some companies weld their rims together and some glue and pin. Some rims that are designed for disk use will have a very rough or uneven spot at the joint and would be undesirable for use with rim brakes. I like rims with machined side walls for rim brake use.
The manufactures started using machines to build wheels a while back. The machinery is very expensive. They engineered around some problems and reduced cost on there end by deciding on using less spokes in mass production wheels. To compensate for this they first used a heavier rim. The difference between 36 and 32 spokes is enough to decrease the lateral strength of a wheel considerably. They told everybody that they had figured out how to make the wheel as strong with less spokes. They also spread the word that it was lighter. The old standard was 36 spokes. In England it was 40 on the rear and 36 on the front. I like 40 or 48 for a Tandem or heavy loaded touring bicycle. 36 for general use with riders not over 180 lbs. I consider 36 spokes on a quality wheel with properly engineered parts to be the minimum for The kind of use a person on a MB will give it.
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
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38
Ridin' inSane Diego, CA.
Re: Is the rear wheel on your MB strong enough

And that is why I use 32 flat-blade spokes on the front with machined rims and a v-brake, disc brake combo.......and 36 12gauge stainless steel spokes on a double wall alloy rim and a heavy duty hub on the rear. No probs.



brnot
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
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northeastern Minnesota
Re: Is the rear wheel on your MB strong enough

I've been thinking about using vintage Schwinn rims (1940's in excellent condition) and re lacing them with 12 gauge spokes. I realize that I'd need to drill out the holes larger. Is this a bad idea? Money enters into the equation, and wanting to stay pretty much true to the original bike, but at the same time beefing it up to make it stronger as a motorbike. Partly I'm attracted to learning how to lace wheels. Also, I could use whatever hubs I wanted. I know Worksman are super and have used them. Husky wheels are very good. Weinman I wasn't too impressed with and the chrome on the cheaper ones is poor and subject to rust. I'm not looking for the ultimate wheel, but want good ones appropriate to an old cruiser/motored bike.
SB
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,266
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Los Angeles, CA.
Re: Is the rear wheel on your MB strong enough

I've never had any real problems with using the stock aluminum wheels that come on modern chinese bikes, but I also make sure to install the new drive sprocket as carefully as possible, because if the chain comes off into the spokes, the spokes are done!!
I prefer to use the heavy steel cruiser wheels with the 12 gauge spokes when I have a choice.
 

BarelyAWake

New Member
Jul 21, 2009
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Maine
Re: Is the rear wheel on your MB strong enough

I've been thinking about using vintage Schwinn rims (1940's in excellent condition) and re lacing them with 12 gauge spokes. I realize that I'd need to drill out the holes larger. Is this a bad idea?

...I'm not looking for the ultimate wheel, but want good ones appropriate to an old cruiser/motored bike.
SB
This is the same method I used for my Rollfast as I really liked the original steel rims, I liked their shape - most particularly the lack of flat sides for rim brakes, inevitable with modern rims even if included on a bike with disks.

I didn't actually need to drill out the holes as they were somewhat large to begin with and while I did upgrade the spokes, they're not quite as heavy as 12g. Even should you need to enlarge to fit, it's such a slight modification it'd have no adverse effect.

The 70yo+ steel rims themselves have proven incredibly durable, our roads here aren't known for their good condition & I hit holes, dropoffs and road debris of all shapes and sizes frequently and at speed - a few times with such force that I know I'd have staved up the (cheap) alloys on my Schwinn. While I'll not say they're superior to a quality modern double walled alloy rim - I will say they're so tough as to make it a bit of a moot point.

The only downside I've noticed at all is on a prolonged (very) high speed but gentle turn I seem to be suffering from some minor (rear) wheel flex... I could be mistaken & it may be tracking, or even my spokes not being quite as heavy a gauge as they could be... it could even just be my balloon tires messing w/my brain... in any case I don't think this would prove to be a problem for you as I was going seriously pants-on-head stupid fast, downhill on our twisty & rough roads :p

I just broke 4000 miles on that bike BTW, the rear wheel could use a (minor) truing and that's about it *shrug*
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
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living the dream in southern california
Re: Is the rear wheel on your MB strong enough

Silverbear, i drilled these rims and the rear New Departure Hub for Worksman spokes. the rims and hub were from that 1938 Colson Vogue, and they're still straight and true with no issues at all. i don't ride the bike much, but it's got a few hundred miles on it.

it's always been common practice to drill out rims and hubs. rims are easy, and the only real issue with the hub is how big the spoke flange is. if it's too small, you'll drill right to the edge, and sacrifice some strength. the other "problem" with older, hardened steel hubs, is it'll destroy every drill bit you have.

the best part about older hubs, though, is they're machined in one piece. they don't have press-on flanges, so there's one less thing to worry about.

 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
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northeastern Minnesota
Re: Is the rear wheel on your MB strong enough

Barely & Bairdco,
Thank you both for your input on this. I recall each of you using your original rims and it is what got me thinking along these lines in the first place. I like the idea of using the Worksman spokes and I'm guessing in the case of Bairdco that you also purchased a drum brake axle from Worksman, is that right? Did you purchase these parts directly from Worksman or is there another outlet? I think I'll also check in to Husky to see if they sell hub and spokes separately. This is for a winter project. While I have a great set of 1942 Schwinn rims I think instead I would use a set of 52 Schwinn rims also in nice shape, with the exception of the coaster brake not working. If I use those rims then I have in mind to use the Bendix three speed coaster brake hub from a Schwinn Corvette step through I found at the dump this summer. I have the shifter for it, but would need to replace the cable. That wheel is a middleweight, but it wouldn't matter since I would be using just the hub from it with the rim from the 52. Should make an awesome wheel. I'll have to go back to your build thread to see more clearly what you did. I understand the spoke pattern is different on a Worksman than other wheels, but don't understand lacing well enough to just look and see. Did you lace it like the Worksman or the way it was as a Colson?
Barely, as I recall you had a shop do the lacing on yours and your front hub is a Sturmey Archer with the built in generator. I'll have to go back to the rustoration thread to find the links for that.
I think I see more straight bar Schwinns in my future and would like to become proficient at re lacing the original wheels for them if they are in good enough shape, making copper gas tanks for them (once I've done one I will have a pattern) and the third thing is to come up with a pattern for turning a leaf spring from a snowmobile into a leaf suspension front fork. Once I have a pattern and know the leaf is the right thickness I can come up with plenty of dead snowmobiles as donors and have a local Indian welder friend to enlist for the welding. What I have in mind is one like Louie McMan made for his Monroe... just right. Bairdco, I had hoped the coaster brake conversion to front hub brake would work out for you for very selfish reasons of course. Has that turned into a dead end? Thank you guys. It seems I'm always learning from you, two. My mentors...
SB
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
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living the dream in southern california
Re: Is the rear wheel on your MB strong enough

i purchased a set of wheels from worksman, unlaced, with raw steel-unchromed rims. i used the drum brake and the spokes for those old rims i posted above.

the raw rims got laced up with 11g. Husky spokes, and i just switched the shimano hub to an old NOS Fichtel/Sachs hub with a skiptooth, and the front coaster brake experiment.

the front coaster brake just doesn't work right. there's not enough leverage, which i could probably fix with a bigger pulley set-up, but it just seems impractical. it slows the bike down enough for a pedaler, but add a motor and it'd be pretty useless.

i haven't motorized this bike yet, just 'cause i need a cool cruiser to pedal around the beach. as soon as it cools down, i'll probably set it up.

Worksman sells everything seperately, and i think Husky does, too, so you can mix and match to get the best price.

 

KCvale

Well-Known Member
Feb 28, 2010
3,966
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Phoenix,AZ
Re: Is the rear wheel on your MB strong enough

Nice looking strong wheels bairdco.
If you were building a new extreme power NuVinci hub what would you recommend as it is just the developers kit and hub?

By extreme power, I mean a jackshafted 2010 skyhawk with X-Chamber, and about a dozen or so programed in shift points to keep the 'sweet spot' of the motor at optimum, and the hub shifting to keep it there itself.

I'd like to replace the rear wheel on whatever bike I mount it on since the hub needs replacing anyway.
I figure I better make it sturdy as the goal is to take on a 125cc stock street bike in some friendly competition.

This isn't a pipe dream either, some of the parts will be here this month, but I have 3 more customer bikes to build before I get to it so I have time to research that crucial back wheel part.

I don't know what bike yet, but it will a quality beach cruiser with front shocks.
That's just the way I roll and going to let my 3-speed Suede go to do it and make it my new ride.
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
264
63
living the dream in southern california
Re: Is the rear wheel on your MB strong enough

for liability and personal reasons, i won't recommend anything to anyone who doesn't understand basic bicycle construction, has limited mechanical ability, and shows total disregard for his own safety and the safety of others.
 

azbill

Active Member
May 18, 2008
3,358
5
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Fountain Hills, Arizona
Re: Is the rear wheel on your MB strong enough

bairdco,,,
agreed, I have turned down many teens that I felt were too immature to sell to
I try to only deal with people who are responsible enough to understand that their actions reflect on ALL motorbicyclists
 

BarelyAWake

New Member
Jul 21, 2009
7,194
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0
Maine
Re: Is the rear wheel on your MB strong enough

Yeppers Silver - I did indeed cheat and have a shop lace up mine wheels, I'm fortunate enough to have a good bikeshop w/excellent techs in the area whom not only take great pride in their work, but are open minded enough to welcome the unusual :D (links provided are frm their catalog BTW);


http://motorbicycling.com/f38/rustoration-build-off-13144-33.html

Here are the links to the hubs I have;
X-FDD Dynamo Drum Brake Front Hub
S30-XRD3 3 Spd Internal Drum Brake Hub

Here are the links to the hubs I'd now want;
XL-FDD 36h 90mm Dynamo Drum Brake Hub
S80-XRD8 8 Spd Internal Drum Brake Hub

At the time there was still much debate as to whether or not an internally geared hub would stand the abuses of a shift kit, I decided I'd go for it regardless as it seemed the problems reported all came from used, older 3 speeds that may not have been in the best of shape to begin with. Additionally, there were some concerns that the dyno wouldn't hold up to the constant high speed use. As a result I considered them "experimental" and as such "disposable" if need be...

As it turns out "reports of their imminent demise were greatly exaggerated" lol, I've not had even the slightest problem at all with either of them, my only minor complaints would be wishing for a touch more stopping power (fast, but very heavy bike) and just one more gear to use as an "overdrive" as I regeared for improved acceleration (again, heavy bike lol) by using a 10t & 48t combo on the SBP shiftkit. As they don't seem to have a 4sp hub w/drum brake, I've included the link for the 8sp instead (untested to my knowledge) & the dyno drum front hub w/larger brake.

.wee.
 

BarelyAWake

New Member
Jul 21, 2009
7,194
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0
Maine
Re: Is the rear wheel on your MB strong enough

It's both far better and not quite as good as I'd hoped lol - it's proved to be simple, reliable and durable with it's sealed bearings and dyno holding up to my constant use & abuse w/o even needing any attention at all... yet there's not quite as much power output as I had hoped, easily solved by using an LED for my taillight & running light (obv always on) and an incandescent for my headlight (maximum brightness). Initially I tried for all incandescents... but there just wasn't enough juice to go around :(
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
113
northeastern Minnesota
Re: Is the rear wheel on your MB strong enough

Barely,
Thank you for the detailed response with links. I'm sure others are looking things over closely, adding up costs, etc. I hear what you're saying about a heavy bike at speed needing good brakes. The difference in price on the the bigger front brake is certainly worth the small price jump. I'd have to swallow hard regarding the 8 speed and wonder if I would ever actually need it. The price difference is considerable, almost double over the three speed hub, but it would give a world of options with an sbp shift kit. I was surprised that the output for the dynamo wasn't more. It puts out pretty much the same as a standard sidewall 6v. generator. If it were me I think I'd power the LED running lights off the magneto white wire and keep the drum dynamo for the headlight, going for as powerful a bulb as I could. 3 watts isn't a whole lot, but as you say it is trouble free and always works if the bike is rolling. On this upcoming 50 Schwinn build (actually I'm already working on it as I wait for parts for the Worksman) I'm using two sidewall generators I have sitting on the shelf. Since the engine will be four stroke I don't have anything coming from the engine itself, so I'm using an old Schwinn 6 v. 3 watt sidewall generator to power LED front and rear running likes and a brake light. A newer 12 v 6 watt generator will be for the headlight alone. The sidewall generators will be on opposite sides of the rear wheel. Under the seat is battery backup for the running lights in case of a night time side of the road breakdown... still need to be seen. Hope it works out. My front wheel, by the way, is a Husky and uses the same Sturmey Archer drum brake minus the dynamo feature. Looks like a really nice hub and wheel. On the Husky site I did not see spokes or hubs sold separately, but maybe I wasn't looking in the right place. Have not yet priced Worksman spokes.
Thank you guys. It helps in planning out strategies for the winter. The thought of building wheels is both intriguing and daunting at the same time.
SB
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
113
northeastern Minnesota
Re: Is the rear wheel on your MB strong enough

So will all of those lights run off a 3 watt power source? I only noticed wattage on the first ones. Some nice lights, but most are way expensive for my budget. I guess it depends on a person's needs... riding conditions, speed of night time travel, etc. Compared to an emergency room visit they seem a little less expensive. Funny how these motored bikes are so attractive initially because they are so affordable. Walmart bike plus China girl motor for low bucks. Then reality sets in and we start upgrading this that and everything else to where it really adds up. But again, there is a wide range of use and need. If a person is riding around the neighborhood at 15 or 20mph on a cheap bike it is probably fine. If the bike pretty much replaces a car and is used for commuting, keeping up with traffic, sharing the road with cars and trucks then everything gets more serious. First we think in terms of how fast can we go. Later on we think about how fast can we stop and how well can we see where we're going. Pretty important stuff. I know for sure I can't afford a stay in the hospital.
SB