# Problem with cassette cogs strength



## geckocycles (Sep 3, 2006)

I put this together for my wife to try out. 
I took a $200 Walmart bike and put on a BBSHD and a 24ah 52v battery to start. Freewheel was junk and chain came off constantly and limited on gearing. Tried another freewheel and it was no better so I figured the hub was ****. I put on a cassette hub on the old wheel with a 40t cassette. Not enough gear with the stock chainring for the steep hills at my house. I made steel 30t chainring. 








Brakes were **** so I put on a Hope disk on the rear and left the cable pull one on the front, at least for now.

Now I can't keep a cassette gear from tacoing. 








Even the 30t spaced in the middle of the cassette body will taco with perfect chainline. I even got the heaviest gears I could find with no luck. THey are all too thin, drilled out and not much to them for this power. I am at a loss unless I make my own more solid gears or silver solder smaller gears onto larger gears thus possibly damaging heat treat. I have tacoed 5 gears now. I really only need 3 or 4 usable gears in the back. I know this looks weird but I am trying everything I can imagine to keep a gear together for now.
I have Rohloff on my bike now without issues with a 32x18 and BBS02. The NuVinci finally started leaking oil.








Maybe I need to get the Rohloff for this Fat too? I have just not heard of this issue. I have worn out rear gears in no time on my bike, thus the NuVinci/Rohloff, but never broke them till the BBSHD.


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## BIke N Gear (Sep 27, 2004)

I'm guessing the life insurance is paid in full on the wife.


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## honkinunit (Aug 6, 2004)

SRAM makes the EX1 components with extra strength for ebikes. They use a reinforced 8-speed cassette. They are pricey components.

https://www.worldwidecyclery.com/blogs/worldwide-cyclery-blog/customer-review-sram-ex1-drivetrain

Your story is a great example of how building an good ebike is a lot harder than slapping a motor kit on a random bike. Purpose built ebikes are expensive for a reason.


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## WoodlandHills (Nov 18, 2015)

Dump the weight-weenie aluminum and buy cheap ass steel.


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## Sanchofula (Dec 30, 2007)

I think he meant "piece of crap" bike, but it's more polite to say random ?

So yeah, garbage bike, garbage parts, not surprising that s bike that would fail under heavy non ebike use would fail under ebike use.

Don't people realize that Walmart sells poor quality bikes ?



craigsj said:


> Not really. It's not a random bike, it's a $200 Walmart bike.
> 
> Converting a bike is not that hard nor does a BBSHD destroy common bike parts so readily. The problem here is poor choices, starting with thinking that a 30T/40T combination with a BBSHD and junk parts is a good idea.


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## geckocycles (Sep 3, 2006)

WoodlandHills said:


> Dump the weight-weenie aluminum and buy cheap ass steel.


Don't know where you came up with Al gears? The first set was off my Moots and is a $90 cassette. Second set not much heavier. THe last set looked solid in pictures and was an IRD cassette. When it arrived it was drilled out and only slightly thicker.

I didn't even know there is such a thing as AL cassette! I made my own 30T STEEL chainring. This bike has nothing to do with light weight anything. I was testing the HD and the programming of it more than anything.


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## geckocycles (Sep 3, 2006)

honkinunit said:


> SRAM makes the EX1 components with extra strength for ebikes. They use a reinforced 8-speed cassette. They are pricey components.
> 
> https://www.worldwidecyclery.com/blogs/worldwide-cyclery-blog/customer-review-sram-ex1-drivetrain
> 
> Your story is a great example of how building an good ebike is a lot harder than slapping a motor kit on a random bike. Purpose built ebikes are expensive for a reason.


THanks for the note. I am looking into it now. They are drilled out too but I hope there are pins of some kind to support the gears together further out on the gear close to the teeth.

This project was a test on the HD motor, not the bike. I fully expected to have to upgrade components, which I have, to test the BBSHD more than anything. The programming is totally different than the old BBS02. I don't know why they changed it so much. Even the new 02 controllers had program change on the firmware side. I have spent well over 20 hrs programming and countless hours researching and email support with MFG's and distributors and finally just turned off the pedal assist completely. Have 10% power on start up and after trying the 3 types that are available with these kits, I upgraded the throttle to a real one ($90) so it is more progressive and predictable. I have 2 controllers for it now, one stock and the other has the PAS resistor mod. This is not my first rodeo.
I will share my program with anyone if they want to try it.

Cheap walmart bikes are cheap for many reasons. To start it is the components. Get rid of all that matters and upgrade which I have done here. Frames are all made by the same few companies. Cheap frames are made from mild surprise tubing but there is little wrong with this outside of weight. They way over build the frames because of the production time they are willing to spend on those frames. The stays are 7/8" to 1" and probably .049 or heavier wall. I do not suspect frame flex. Most issues with cheap frames are the brazeons on every level. THey have thickened up the tubing so few failures if any are happening at the dropouts especially. I see NO frame repairs or even get calls these days on cheap bikes. Way more on expensive light weight bikes. I used to repair tons of mild surprise frames and now none are being brought in. Maybe they are just disposable and not being repaired anymore?

A little note: I was hired by the Derby Corp. as a production consultant to go to the Raleigh factories and evaluate production and to cut costs even more. Number crunching A-Holes get in the way of quality products and sound production techniques. They were happy with a 2% failure rate back in the day, so off I went.

Little things like DO and hanger alignment are suspect but easily checked and fixed. I don't suspect the stamped steel vertical drop outs (which are insanely thick) but more so the QR axle. The hub spacing is a whopping 192mm so chainline is much better than most.. Together with the width and 10mm QR axle in this hub, the problem maybe there. I feel that a 10mm axle this length is the issue although it is staying in adjustment fine. I should of got a bolt on axle. The derailleur is off of my Moots so nothing cheap there, XTR. Shifter is cheap but works fine.


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## geckocycles (Sep 3, 2006)

BIke N Gear said:


> I'm guessing the life insurance is paid in full on the wife.


NiCE!!!!
She won't even ride it around the lot till I get it working better. She is smarter than me! She has a pricey store bought ebike but wanted to go on the long rides I do. They no longer make a battery for her bike to upgrade or even one to carry as a spare. We got the biggest battery available at the time for it. It is way under powered Bosch at 350w and no throttle which she wanted. 5 yrs later and her $4000 bike is now waiting for the junk yard because of battery.

It is one thing to toss a cordless drill because they discontinued a battery for it, but a $4000 bike because of it! Realy? 10.5Ah is just not large enough.


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## geckocycles (Sep 3, 2006)

honkinunit said:


> SRAM makes the EX1 components with extra strength for ebikes. They use a reinforced 8-speed cassette. They are pricey components.
> 
> https://www.worldwidecyclery.com/blogs/worldwide-cyclery-blog/customer-review-sram-ex1-drivetrain
> 
> Your story is a great example of how building an good ebike is a lot harder than slapping a motor kit on a random bike. Purpose built ebikes are expensive for a reason.


Pricey is an understatement! Forged gears YEA!!! 48 too big but I don't have to use it.

I think I will make my own to test and then I can use a BMX chain too. The Rohloff is looking better all the time at $1700. Just hurts to spend that much on a proto to try this motor which so far I don't like the programming of it or the lack of being able to reprogram it to my liking. I like to be able to PA and use the throttle to override the PA.


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## geckocycles (Sep 3, 2006)

I'm thinking the QR skewer is stretching under load and allowing the wheel to torque sideways. Has nothing to do with the frame except for the rear width.

Now how to test this hypothesis? Can I replace the axle with a solid bolt on? Is 10mm axle just too small dia for the 192 spacing and the power?


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## WoodlandHills (Nov 18, 2015)

You could also just lace a Nexus 3 IGH into the wheel. Then you can use a single speed chain. I made my own sprockets by buying cheap nexus sprockets and welding steel chainrings to them. My bike was a singlespeed $300 Bikes Direct fatty that had horizontal dropouts which made chain adjustments easy. You could use a tensioner to keep it aligned and tight.


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