Hevy Duty Wheel build advice needed

I also posted this on the Facebook group, but the more advice the better so here it is again.
The Bike is my Currie Ezip Trails as modified in my sig.
I need to build a new wheel for my bike, broke another spoke and I am looking for something a little stronger (I'm a really big guy: like 6'8" 350lbs).
I need to use the same hub, but I am looking for some recommendations for a rim and some spokes.
I seem to keep breaking them at the elbow. Any thoughts, or suggestions?
Should I use thicker gauge spokes, double butted spokes. The stronger rim is just because I'm a "Clydesdale".

Zen_Shenron said:

I also posted this on the Facebook group, but the more advice the better so here it is again.
The Bike is my Currie Ezip Trails as modified in my sig.
I need to build a new wheel for my bike, broke another spoke and I am looking for something a little stronger (I'm a really big guy: like 6'8" 350lbs).
I need to use the same hub, but I am looking for some recommendations for a rim and some spokes.
I seem to keep breaking them at the elbow. Any thoughts, or suggestions?
Should I use thicker gauge spokes, double butted spokes. The stronger rim is just because I'm a "Clydesdale".

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You need to talk to johnrobholmes on this forum. He is a very skilled wheel builder. My experience with regular bike shops for wheels with hubs is not very good. You need someone wo knows about hub motors.

The most likely reason for the spoke breaking at the flange is that the head of the spoke is not seated properly in the hole. This can be due to poor manufacturing of the flange, the hole being too large or not countersunk to match the spoke. Cheap spokes can also break because of work hardening caused when the head is formed and the elbow bent. The extra flexing of the elbow because of poor seating will eventually cause a fracture to occur.
Since I changed to DT spokes I have never had a failure.
Many think the answer is to go to heavier spokes. This may work if the new spokes seat properly and are well made. But the extra rigidity may then cause the rim to fail by cracking around the spoke holes. The cheap rims supplied on Crystalyte wheels are very prone to this.
It seems a bit counter intuative, but using good quality double butted or triple butted DT spokes makes a more resilient wheel. Just make sure that the spoke heads seat properly in the flange holes. The thinner spokes have a degree of elasticity in them that heavy spokes don't have. The higher tensile strength of stainless steel means that they can be really tight but still have some give due to the elasticity.
I now run double butted DT spokes on a semi-deep v Velocity rim. It's so smooth and tight that it feels like riding a precision instrument. 8)
Because of your weight, you are probably pushing the limits of what a bicycle wheel can do, so it means you'll have to get top quality parts and ensure that the build is flawless.
HTH.

I'm not heavy as you are, but I ride very hard in rough mountain trails, so I guess this can compare.

12 ga spokes are tough as nails, but very few bicycle rims can take the tension needed to lace this big. I have a Sun BFM that survived 12 ga spokes weekly trueing for a year, other than this one, you should go for a motorcycle rim or one of the wide rims that Methods offers in the sale section. I plan to try one myself for my next wheel build.

Butted spokes are the easy way to go, if you want a choice of bicycle rims to build with. Any top of the line DH rim will do, and using 14 ga nipples let you keep the eyelets. That makes for a clean looking wheel that is easy to maintain.

In any case, the secret of a tough wheel is regular maintenance: True it often, maintain a good and equal tension, and it will last. Of course, a fat tire helps alot, and suspension even more.

JohnRobHolmes can supply you with quality spokes of any lenght and size, his advice is good and I agree with the previous answer from Fractal.

I'm very happy with what I did, I wanted to build as bullet proof a wheel as I could have built, and I looked to what wheels are used in cargo bikes designed for the purpose of carrying loads in excess of 400lbs (this is not including the bike & rider, but the cargo added) and on the advice of people such as John Rob Holmes, I sought out a local wheel builder and have been very happy.

The issues you are having can be a number of things working together to cause the failure, but I would also recommend double butted spokes.

My first E-Bike was never subjected to anywhere near as high of loads my current bikes have been, and had overly large (12G) spokes that caused failures of the rim instead, been there done that!

You really need an expert that can merry the proper spoke to the hub you are using (mine had to use washers on the spoke heads to get the proper spacing at the hub) and I recently took a 287 mile trip with a bike loaded with about 300lbs of rider & camping gear, and I hit some nasty pot holes & a 4inch "curb" (45% ramp for a bridge) at about 23 MPH on a ridged frame bike with Scwalbe Big Apple 2.35 wide balloon tires, and I didn't even get a wheel out of true!

It cost me about $120 per wheel to have them built, but after struggling on my own, and tacoing wheels trying to keep them properly tensioned, I think it is a very worth-while investment.

I am using Sun Rynolite Rims and 14/13G double butted spokes made by Sapim, and I couldn't be happier with them.

MadRhino said:

I'm not heavy as you are, but I ride very hard in rough mountain trails, so I guess this can compare.

12 ga spokes are tough as nails, but very few bicycle rims can take the tension needed to lace this big. I have a Sun BFM that survived 12 ga spokes weekly trueing for a year, other than this one, you should go for a motorcycle rim or one of the wide rims that Methods offers in the sale section. I plan to try one myself for my next wheel build.

Butted spokes are the easy way to go, if you want a choice of bicycle rims to build with. Any top of the line DH rim will do, and using 14 ga nipples let you keep the eyelets. That makes for a clean looking wheel that is easy to maintain.

In any case, the secret of a tough wheel is regular maintenance: True it often, maintain a good and equal tension, and it will last. Of course, a fat tire helps alot, and suspension even more.

JohnRobHolmes can supply you with quality spokes of any lenght and size, his advice is good and I agree with the previous answer from Fractal.

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This so true, 12 ga spokes are tough BUT : 1)they are hard to get, 2) harder to true and get good tension, 3)regular bicycle shops cannot cut 12 ga spokes because the regular cutting machines dont go that big. I have an x-lyte wheel with 12 ga sopkes and they keep snapping!!! I have to replace them with 13 ga and retrue the wheel evry few weeks. I will never ride with those cheap wheels again!!!!

After breaking many of the cheap Chinese spokes on my, so far bulletproof but inexpensive Weinmann DM 30 wheels I went with the Sapim 12 ga and have never looked back. The wheels are just a tad bit wider than the Rhinolites and don't have the inserts. These DM30s came out of Florida and were pre-drilled for 12Ga spokes. No broken spokes or bent rims in the last 6K and I seldom even have to true them anymore. Not that I take it easy on them or anything cuz I don't. Me I don't understand all of this thinner spokes are better stuff at all. Maybe for a road bike or something light duty that may be so. Mopeds are made for the speed many travel on their ebikes they are built heavier and have heavier spokes and wheels as do motorcycles. You don't see wimpy 14 ga spokes on either one. If you want something to last then overbuild it. Get some heavy rims and use some heavy spokes that actually fit, what they are installed on, or go find some moped stuff that will werq. You are talking about over 400lBS gross weight here. Johnrobholms has the spokes and likely can find a decent rim for you if you search him out.
Good luck

Good stuff guys, so for it looks like some double butted 13/14 spokes.
For the rim I am looking at maybe the Sun Rynolite or maybe some Alex DX32 or DM24 DH rims.
How does this sound?
Also I was going to do 36 spoke but would a 48 be better for me to spread the weight better? if so I was looking at these hubs http://www.staton-inc.com/store/pro...e_Hub_Left_and_right_hand_threads-880-27.html

Most motors are 36 hole although ebikes.ca does have a few with bunches of holes but for a front or something it should be stronger like the stuff they put on tandems. OOPS curry sorry yes 48 is better for both.

biohazardman said:

After breaking many of the cheap Chinese spokes on my, so far bulletproof but inexpensive Weinmann DM 30 wheels I went with the Sapim 12 ga and have never looked back. The wheels are just a tad bit wider than the Rhinolites and don't have the inserts. These DM30s came out of Florida and were pre-drilled for 12Ga spokes. No broken spokes or bent rims in the last 6K and I seldom even have to true them anymore. Not that I take it easy on them or anything cuz I don't. Me I don't understand all of this thinner spokes are better stuff at all. Maybe for a road bike or something light duty that may be so. Mopeds are made for the speed many travel on their ebikes they are built heavier and have heavier spokes and wheels as do motorcycles. You don't see wimpy 14 ga spokes on either one. If you want something to last then overbuild it. Get some heavy rims and use some heavy spokes that actually fit, what they are installed on, or go find some moped stuff that will werq. You are talking about over 400lBS gross weight here. Johnrobholms has the spokes and likely can find a decent rim for you if you search him out.
Good luck

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I understand your reasons, and I'm sure there are times that call for 12G spokes, however, given the fact that it's pretty hard to even get a decent spoke wrench from a typical bike shop much less spokes, they are much harder to come by.

I was prepared to go the 12G route myself when I was setting about to build my NuVinci wheel, but given the fact that most hubs aren't even designed to work with spokes that large, it can turn into some headaches.

I think you make a good point however, because if you ARE going to build a fast E-Bike, and approach motorcycle speeds, then 12G might be the place to start, and using moped/motorcycle rims makes sense for 40MPH+ applications.

I think the real question might be what is causing the failures in the first place, and from what I have been told, often broken spokes especially at the hub is often as much a symptom of the spoke not being able to flex and spring back properly as much as anything, and double butted spokes bend where others brake under the same loads.

Zen_Shenron said:

Good stuff guys, so for it looks like some double butted 13/14 spokes.
For the rim I am looking at maybe the Sun Rynolite or maybe some Alex DX32 or DM24 DH rims.
How does this sound?
Also I was going to do 36 spoke but would a 48 be better for me to spread the weight better? if so I was looking at these hubs http://www.staton-inc.com/store/pro...e_Hub_Left_and_right_hand_threads-880-27.html

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You can't go wrong going bigger!

I would go for the 48 spoke wheels sure, especially since that would allow you to use more common sized spokes (13/14 double butted) with increased strength, with out sacrificing logistics.

A friend of mine doesn't have an E-Bike, but has gone through a few different rim/spoke designs, is self taught in wheel-building (with a lot of reading on-line) and is a larger guy too, and he has recently switched to a 40 spoke rim, and went on a camping tour with his wife and two friends, and carried the bulk of the camping gear and had no problems (up until using the 40 spoke rear wheel, he has regularly broke spokes after 4 - 6 months use).

Zen_Shenron said:

The Bike is my Currie Ezip Trails as modified in my sig.
I need to build a new wheel for my bike, broke another spoke and I am looking for something a little stronger (I'm a really big guy: like 6'8" 350lbs).

I need to use the same hub, but I am looking for some recommendations for a rim and some spokes.

Click to expand...

That's my size. I'm 6'8" and down to 340 lbs. from a high of about 415. I'm a veteran bike mechanic, and I have built plenty of bike wheels that hold up nicely for me. Good strong e-bike wheels are harder, but still feasible. I used to ride an e-bike that weighed over 500 lbs all-up, with 700c wheels.

The Alex DM24 is an excellent rim, especially for the price. With a careful and methodical build, it should be adequate for your use. Velocity's Psycho is stronger because it is heavier-- it's almost exactly the same shape and size as the Alex rim. Velocity's Chukker is a super strong rim, and the only one I know of that's narrow enough for skinny tires like 26x1.25" if you want that option. (For what it's worth, a fatter tire makes your wheel more durable, all else equal.)

If you can find a Sun Mammoth or BFR, try that. It's stronger than the DM24 and not expensive, but it seems to be out of production.

Surly's Large Marge is humongous and ungodly strong, but at 65mm wide, it does not fit in all frames. It's expensive-- over $150 retail. This one appears to be a clone of the Large Marge with a lower price tag:
http://www.choppersus.com/store/product/786/Rim-Only-26-x-2.5-Silver/

I seem to keep breaking them at the elbow. Any thoughts, or suggestions?
Should I use thicker gauge spokes, double butted spokes.

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Spoke breakages at the elbow are most often from omitting important steps at the time the wheel is built. A skillful professional wheelbuilder can make a more reliable wheel, given the same components, than a manufacturer can. You can too, if you get yourself a copy of Jobst Brant's The Bicycle Wheel, read it, and follow the directions closely. A spoke tensiometer helps. In your case, you want up to about 150kg of tension on each spoke.

13-14ga single-butted spokes from Wheelsmith, Sapim, or Phil Wood are a little more resistant to elbow breaks than straight gauge 14ga spokes, but there's more benefit to be had in a careful build than in thicker spokes. As long as you use lots of tension, 13ga straight gauge spokes (those from ebikes.ca for instance) are likely to be reliable, but thicker spokes than that will give you chronic problems with loosening. They don't have enough elasticity to stay tight at tensions bicycle rims can withstand.

That elasticity is the point of double-butted spokes. A 14-15ga spoke, for instance, has the break resistance of a 14ga spoke because that's the thickness of its elbow and thread. But it has the stretch of a 15ga spoke because that's the diameter for most of its length. By the same token, a 13-14ga spoke is as strong as a straight 13ga spoke, but with the elasticity of a 14ga spoke. The more elastic a spoke is, the longer it can continue to support the rim as load is increased.

48 spoke lacing makes a wheel that is more reliable and easier to true up after some beating, but the wheel's strength is mainly in the rim. Don't bother with 48 spokes if you can find a stronger rim in 36 hole (and these days, you probably can). Your rear hub has only 36 holes in it, so that one choice is made for you already.

Best of luck with your project.

Chalo

biohazardman said:

Me I don't understand all of this thinner spokes are better stuff at all. Maybe for a road bike or something light duty that may be so. Mopeds are made for the speed many travel on their ebikes they are built heavier and have heavier spokes and wheels as do motorcycles. You don't see wimpy 14 ga spokes on either one. If you want something to last then overbuild it. [/img]

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Wheels are a system. There has to be a balance between the size and number of spokes, their tension, and the rim's strength and ability to withstand tension, or you get problems. Motorcycle-like spokes go with motorcycle rims. If you use bicycle rims, you're better off with bicycle spokes.

If you use too heavy a spoke, you might cure occasional spoke breakage, but at the cost of wheel stability, reliability, and load capacity (really!). Unwanted side effects include chronic unwinding, cracking around the rim holes, slackening under load with resulting wheel sway, and breakage at the spoke threads (when the spokes depart the nipples at an angle because the nipples are too fat to tilt in the rim holes).

I weigh 340 lbs and ride a bike everywhere I go. I have some reliable, trouble-free wheels with 15-16ga spokes and others with 14-17ga spokes. Thin spokes (and careful matching of spokes and rims) are actually part of the reason these wheels are reliable. With the stout, hefty mountain bike rims the OP is discussing, there is no real point in using spokes as thin as 16 or 17 gauge (and they are more expensive and more difficult to build with). But if he did use 14-17ga spokes in a painstaking build, I would expect his elbow breakage problems to diminish or disappear entirely.

Chalo

Zen_Shenron said:

Good stuff guys, so for it looks like some double butted 13/14 spokes.
For the rim I am looking at maybe the Sun Rynolite or maybe some Alex DX32 or DM24 DH rims.
How does this sound?
Also I was going to do 36 spoke but would a 48 be better for me to spread the weight better? if so I was looking at these hubs http://www.staton-inc.com/store/pro...e_Hub_Left_and_right_hand_threads-880-27.html

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Alex DM24 is substantially stronger than Sun Rhyno LIte. Alex DX32 is not enough stronger to justify the extra cost, in my opinion.

DO NOT use the Staton hub. Staton makes a lot of good stuff, but that hub is fatally flawed in two ways. The axle is grooved for snap rings at the points of highest stress, and sooner or later will snap off there. (Sooner, if you are as big as you and me.) But mostly, the shoulder of the Staton hub axle that meets up to the frame is so narrow that it will gouge your frame and permanently damage it when the axle nuts are tightened. If you use snug-fitting washers to protect your dropouts, the axle shoulders will dig in as you ride and the wheel will loosen and slip.

I thought you were committed to your existing rear hub. Aren't you?

Chalo

Well the only reason I was committed is because the Currie setup uses a left side drive freewheel for the motor.
It is really hard to find any kind of hub with left side drive with left hand threads period.
The Staton were the only ones I was able to find that had that configuration, also I was only considering using one if I had decided to go with 48 spoke so I guess I will stick to the stock hub.
It just seems poorly manufactured to me, looks to be stamped steel construction.

Zen_Shenron said:

Well the only reason I was committed is because the Currie setup uses a left side drive freewheel for the motor.
It is really hard to find any kind of hub with left side drive with left hand threads period.
The Staton were the only ones I was able to find that had that configuration, also I was only considering using one if I had decided to go with 48 spoke so I guess I will stick to the stock hub.
It just seems poorly manufactured to me, looks to be stamped steel construction.

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Chalo is definitely the guy with the expert knowledge on wheel building, glad he chimed in!

I can't speak to the specifics of the curry rear wheel hub's design quality, the only one I have seen came into the LBS in a terrible state, hard to say how much was just operator error though, but from what I have seen of the stuff used to build their wheels, frankly you get what you pay for, and they are very cheaply made.

The shop rebuilt the wheel with new stuff from the manufacturer and it wasn't cheap to do, but personally I would find something better if you can, but there are some guys who have modified curry drive stuff, so maybe there are some replacement hubs out there that are compatible with your drive of better quality?

Ok I have decided to go with the DM24, it is ordered from http://www.jensonusa.com/store/product/RI308A05-Alex+Dm24+Rim.aspx for 23 bucks, not a bad deal. I am in the process of ordering some spokes from http://holmeshobbies.com/product.php?productid=406&cat=0&page=1, hopefully some 14/15 spokes will do the trick.

Zen_Shenron said:

Well the only reason I was committed is because the Currie setup uses a left side drive freewheel for the motor.
It is really hard to find any kind of hub with left side drive with left hand threads period.
The Staton were the only ones I was able to find that had that configuration, also I was only considering using one if I had decided to go with 48 spoke so I guess I will stick to the stock hub.
It just seems poorly manufactured to me, looks to be stamped steel construction.

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During the time period ten to fifteen years ago now, there were BMX hubs with LH threading on the left side. If you could find one of those out-of-production hubs (called "LHD" for left hand drive or "LSD" for left side drive), you might be able to set it up with 135mm spacing and room for a 7-speed freewheel. (Avoid left-side cassette hubs or freecoaster hubs, because they are worthless for your application and almost worthless for anything else.)

Chalo

Well I actually did find a supplier for the LHD hubs for the Currie wheel, here is a link for any who are interested in getting one http://www.evdeals.com/USPD Drive Parts.htm
lol I just realized looking at the contact info he is based in Plainville Mass, which is very close to me, a couple towns away.

Almost done trueing up my first wheel build and I must say I am very pleased with how it is comming out so far.
The lacing was easier than I thought it was going to be, trueing is taking a little longer but comming along very well.