Mid drive vs hub for new build

Hi guys,

Question. I like to start a new build. I have a mid drive bike, but i like to have more power and less noise.
Is a hub the only way to go? I am running my gng on 3500w. I like to have 5000w.
I am using my bike for offroad and freeriding in the city.

Mid battery and mid-motor will have a better balance. a big hub-motor on the rear will be heavier on the rear (obviously).

5,000W will likely require LiPo batteries to be able to fit enough C-rate onto a bike frame. One of the benefits of a mid-drive is that it broadens the performance range of the system while drawing lower peak-amps from the battery. If you do NOT want LiPo, then a mid-drive will provide the best performance from the available C-rate of your NON-LiPo pack.

If LiPo is acceptable to you, then 5,000W from a rear hub is possible. Rodgah was able to get very high performance from a rear hub, and it ran fairly quietly, but once you max out the amps the motor can take, you have to raise the volts to get more power. Rodgah used roughly 100V, 24S-LiPo. He used a Crystalyte HT35XX series. http://www.electricbike.com/big-hit-fsr/

There is a third option...get a big non-hub motor and run a single-stage chain drive to the left side of the rear wheel. This is because 3,000W is somewhere near when bicycle chain will break occasionally, or at least wear out much faster. On a left-side-drive, a 5:1 reduction means the fat motor can spin 5 times faster than the wheel. I recommend a wide 20-inch wheel, with a 22-inch moped tire (if you decide to go with a LSD). I'd recommend #219 chain for a high reduction (using a 13T minimum drive sprocket to keep the noise down), and to be able to hold 5,000W.

John in CR sells a $285 mini-monster, and LightningRods has a "big block GNG".

"Moped Tires"
http://endless-sphere.com/forums/viewtopic.php?f=3&t=40123

"93% Peak efficiency 2-speed hubmotor $285"
http://endless-sphere.com/forums/viewtopic.php?f=31&t=40859

"LightningRods big block motor, 115mm dia X 100mm (4.5 dia X 4-inches)"
http://endless-sphere.com/forums/viewtopic.php?f=28&t=42785&start=2650#p808885

Secret1511 said:

Is a hub the only way to go? I am running my gng on 3500w. I like to have 5000w.
I am using my bike for offroad and freeriding in the city.

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Do you have videos of you putting 3.5kW mid drive to use?
Also wondering what kind of things you can't do with that much mid drive power?
What kind of rear wheel gearing/shifting do you have?
Videos would be entertaining, and probably help more 'no' answers to wheel hub motor for urban free-riding.
Avoiding the noise as highest priority could lose you a lot of other strengths in what you already have... but if you must be quieter at all cost, then hub.

deepfraught said:

Secret1511 said:

Is a hub the only way to go? I am running my gng on 3500w. I like to have 5000w.
I am using my bike for offroad and freeriding in the city.

Click to expand...

Do you have videos of you putting 3.5kW mid drive to use?
Also wondering what kind of things you can't do with that much mid drive power?
What kind of rear wheel gearing/shifting do you have?
Videos would be entertaining, and probably help more 'no' answers to wheel hub motor for urban free-riding.
Avoiding the noise as highest priority could lose you a lot of other strengths in what you already have... but if you must be quieter at all cost, then hub.

Click to expand...

Yes i will post some video's soon.
3.5kw is nice, but i keep replacing stuff. To much power chain and sprokets are to weak. I am running shimano XT and that should be quality. Even broke some #25 chains on the primairy drive. Thats the big disadvange of high power middrive.
I thought of a 3540 clyte with 5kw. The 3540 is also light isn't it?

Hub motor in the wheel is crap for any kind of aggressive off-roading. They turn into space heaters whenever you are scrambling through rock gardens, climbing rock stairs, crawling up steep windeys. They feel like total boat anchors compared to the free feel of a mid-drive.

That being said, I think hubs are the way to go for everything else; commuting, romping around the neighborhood, riding urban bike paths ect... because of how quiet, simple and reliable they are.

Matt Schumaker drives are relatively quiet for the weight and power they produce. Mid-hub is also a quiet albeit weightier option. I make the change from GNG to mid-hub and I like it so far.

parajared said:

Mid-hub is also a quiet albeit weightier option. I make the change from GNG to mid-hub and I like it so far.

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This sounds like the best answer

Do you run single speed chain/sprocket?

parajared said:

Hub motor in the wheel is crap for any kind of aggressive off-roading.

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Funny, because never anyone had succeeded following me more than a few hundred feet in the mountain with a mid drive build, and very often broke their bike trying. A GNG fed 3.5 KW doesn't even come close, and is failing so often that you spend more time in repair than riding. Those mid drive kits are only good for low power.

Hub builds are reliable, my Demo has seen 30,000 Km to date and still going after many crashes.
If you like to build, build a mid drive. If you like to ride, build with a hub. Don't dream, you will temper a lot with a hub build to make it ride fine in the mountain, but it will ride reliably day after day, and you can decide when and where you want to spend time working to improve your bike.

MadRhino said:

parajared said:

Hub motor in the wheel is crap for any kind of aggressive off-roading.

Click to expand...

Funny, because never anyone had succeeded following me more than a few hundred feet in the mountain with a mid drive build, and very often broke their bike trying. A GNG fed 3.5 KW doesn't even come close, and is failing so often that you spend more time in repair than riding. Those mid drive kits are only good for low power.

Hub builds are reliable, my Demo has seen 30,000 Km to date and still going after many crashes.
If you like to build, build a mid drive. If you like to ride, build with a hub. Don't dream, you will temper a lot with a hub build to make it ride fine in the mountain, but it will ride reliably day after day, and you can decide when and where you want to spend time working to improve your bike.

Click to expand...

Yes i like to ride, but i am sick of breaking things. I also love to build. I have a middrive. The main question is. Am i going for a better middrive or to a good hub?
Is a 3540 suitable enough? I like to keep it as light as possible.

If you are determined to use a DD rear hub, I'd recommend putting it in a smaller wheel, like 24-inch or 20-inch. A 20-inch rim with a moped tire is about 22-inches diameter. then, feed it high volts, while restricting the amps. Make sure you install a temp sensor, and then slowly raise the amp-limit when you are on the hardest section that you like riding. After a while, you will find the highest amp-setting that you can use without frying the motor.

Several builders have tried oil-cooling to be able to pump more amps through their hub-motor, maybe that's an option? I believe Lyen's controllers when coupled with a CycleAnalyst makes it easy to change to several power settings. High amps for fairly flat land, since the motor spends a lot of time at cruise speed (shedding what little heat that accumulated during the short acceleration)...and then using a lower amp-cap when you hit a slow and steep uphill trail.

H motors are light weight, but they are also very quick to overheat. Cool it down or build with a big hub, I prefer the second solution and think of it as a light weight motorcycle. Sub 80 Lbs build powered 20 Kw makes a beast, most will find it is too light for the power that it has.

2 weeks ago I had a friend following me with a powerful mid drive, much lighter bike. I took a trail that is technical, with drops and jumps and lots of big rocks. I figured I was giving him some advantage on that trail, yet after only 2 hard turns and a 5 ft drop I looked back as soon as the trail got nicer, and had lost him already.

24" with a 3" tire is OK if you are willing to spend on custom tuned suspension, I have 2 bikes built with cromotor in 24". A 26" with a 3" tire is best for the mountain, I use a 5404 with large wheel size on my V 10. A 20" wheel is only good for the nice streets, in the mountain it is a rodeo.

Funny, because never anyone had succeeded following me more than a few hundred feet in the mountain with a mid drive build, and very often broke their bike trying. A GNG fed 3.5 KW doesn't even come close, and is failing so often that you spend more time in repair than riding. Those mid drive kits are only good for low power.

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I have read several reports of members having good results with large motors, crystalyte 4 series, cromotor ect.. paired with lots of power. These builds sound to me like little motorbikes, and to that effect it seems as though that an actual motorbike frame with the transmission, big chain, extra cargo space for batteries and shocks pre-built to handle heavy loads would be superior.

Little hub motors in the wheel (9c, GM, MXUS, Crystalye H ect..) do not work for off-roading; when the flow of the track is fast they work great, and they climb right up the side of some pretty steep stuff too, but when trails get rocky, and it’s a steep slow grind they peg the 110 Celsius mark faster than you can say holy maloney sack of baloney! The advantage of a mid-drive going to your gears is that you can downshift and prevent your motor from getting too toasty on you.

I agree about the GNG breaking a lot, I have had a lot of trouble with the belt system, but continued to have problems even after chain mod. Eventually the el-cheapo BB spindle bent, and ultimately my freewheeling crankset and sprocket got mangled on a rock, causing me more grief than I wanted to fix.

MadRhino said:

H motors are light weight, but they are also very quick to overheat. Cool it down or build with a big hub, I prefer the second solution and think of it as a light weight motorcycle. Sub 80 Lbs build powered 20 Kw makes a beast, most will find it is too light for the power that it has.

2 weeks ago I had a friend following me with a powerful mid drive, much lighter bike. I took a trail that is technical, with drops and jumps and lots of big rocks. I figured I was giving him some advantage on that trail, yet after only 2 hard turns and a 5 ft drop I looked back as soon as the trail got nicer, and had lost him already.

24" with a 3" tire is OK if you are willing to spend on custom tuned suspension, I have 2 bikes built with cromotor in 24". A 26" with a 3" tire is best for the mountain, I use a 5404 with large wheel size on my V 10. A 20" wheel is only good for the nice streets, in the mountain it is a rodeo.

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The problem is i have a dropout off 135mm a cromotor won't fit.
What is a other option? 24 inch rims would be nice. Here in the netherlands we got no hills.
It's flat. Highest point in my city is 60 meters

In the Netherlands you don't need to build for the mountain of course. If you build with a H motor, I suggest that you use the HT in a 26" wheel, feed it 10 KW and this will make a good off road bike for the terrain that you have.