Nuvinci IGH users: Is my hub working normally?

Nirve

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Joined
Jun 12, 2020
Messages
56
I am not sure if I use all the range that the Nuvinci N380 has to offer.
According to my math, my range caps out at about 1.4 and not 1.9. Nuvinci claims the hub has a range from 0.5 to 1.9.

My gearing:
Grubee 1:4 gearbox > 9/17 left side, 10/44 right side, 30/20 drive chain to hub sprocket.
At the highest gear of 1.9 with my 26" wheel I "should reach" 45mph. But at 6800rpm my max speed is around 33mph which equals a gear of 1.4.
The engine could propel me faster but I don't want to go higher in RPM: I'd need to shift more.

Does anyone (@gary55, @GreasyChris) have a clue? Is my math wrong or my IGH?

Thanks!
 

GreasyChris

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Joined
Jan 3, 2019
Messages
1,664
I am not sure if I use all the range that the Nuvinci N380 has to offer.
According to my math, my range caps out at about 1.4 and not 1.9. Nuvinci claims the hub has a range from 0.5 to 1.9.

My gearing:
Grubee 1:4 gearbox > 9/17 left side, 10/44 right side, 30/20 drive chain to hub sprocket.
At the highest gear of 1.9 with my 26" wheel I "should reach" 45mph. But at 6800rpm my max speed is around 33mph which equals a gear of 1.4.
The engine could propel me faster but I don't want to go higher in RPM: I'd need to shift more.

Does anyone (@gary55, @GreasyChris) have a clue? Is my math wrong or my IGH?

Thanks!
I think your gearing may be off a little. Unfortunately my nuvinci hub didn't last very long. My gearing was engine 4:1 then a 10t to a 17t then 10t to 44t then a 40t to a 20t. This gives a 14.96:1 ratio when the hub is at a 1:1 ratio.
This ratio will take you to 33mph at a 1:1 ratio on the rear hub. Hope that helps.
 

Nirve

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Joined
Jun 12, 2020
Messages
56
I think your gearing may be off a little. Unfortunately my nuvinci hub didn't last very long. My gearing was engine 4:1 then a 10t to a 17t then 10t to 44t then a 40t to a 20t. This gives a 14.96:1 ratio when the hub is at a 1:1 ratio.
This ratio will take you to 33mph at a 1:1 ratio on the rear hub. Hope that helps.
Thanks for chiming in!
How do I know my hub is 1:1 without any indication on the interface?
I geared mine so the upper end is at 6800rpm or a little over 32mph which is my engines max anyway. But on some cold mornings without wind it really could go faster, but I’m topped out at my RPM

Edit: @GreasyChris I did math on your gearings and at max overdrive (1.9), at 6800RPM on a 26" bicycle, you would go 66MPH. Is that not geared way too high? I think it makes most sense to be a little over the max speed at highest gearing of what your engine is capable of.. thoughts?
 

Street Ryderz

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Oct 14, 2016
Messages
4,444
I think your gearing may be off a little. Unfortunately my nuvinci hub didn't last very long. My gearing was engine 4:1 then a 10t to a 17t then 10t to 44t then a 40t to a 20t. This gives a 14.96:1 ratio when the hub is at a 1:1 ratio.
This ratio will take you to 33mph at a 1:1 ratio on the rear hub. Hope that helps.
That's a shame yours didn't last, I was always Leary about going that route but then Gary had great results and had me thinking about it, then I saw one of your video's shifting under power or slight lift and was very impressed, do you think that if easier on the shifts it would have lasted ?
 

Nirve

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Joined
Jun 12, 2020
Messages
56
That's a shame yours didn't last, I was always Leary about going that route but then Gary had great results and had me thinking about it, then I saw one of your video's shifting under power or slight lift and was very impressed, do you think that if easier on the shifts it would have lasted ?
Not greasychris but I’m trying to be gentle to my Nuvinci. That means when going off, I wait until everything "catches" before I throttle any further. Don't want to move 300lbs jerky on that hub. Same thing when I start throttling from coasting.
I do enjoy myself going from a dead stop though as well shifting while accelerating. I have more than 500 miles on it so far without issues, but I know it can fail any time (knock on wood).
I don't know which Nuvinci GreasyChris used but I got the strongest that I could get.
Do you know how many miles your hub lasted, GreasyChris?
 

gary55

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Nov 27, 2012
Messages
4,031
My chime in on this is that Chris is a better engine builder than I am. He produces more power from his builds, and he puts more emphasis on hard core performance. Put it to the wood and see how it eats. I am calmer in my expectations. The reason my nuvinci has lasted so long is I seldom force it to the max. My engines are moderate. Some porting, a little decking to a good squish, and a moderate pipe. For a all around bike that gets me A to B with not much wear on the engine and cruises at 30 effortlessly it's a good match. You guys remember how long ago I went with this hub. I just got groceries with it yesterday. Chris builds bikes that can force that small single gear to move at the low end and have enough torque left at the top end to fly. If you go to a large carburated reed intake with a well tuned pipe and the porting and the squishing and the balancing, a drive train that works with moderate power might not be the best choice.
 

Nirve

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Joined
Jun 12, 2020
Messages
56
My chime in on this is that Chris is a better engine builder than I am. He produces more power from his builds, and he puts more emphasis on hard core performance. Put it to the wood and see how it eats. I am calmer in my expectations. The reason my nuvinci has lasted so long is I seldom force it to the max. My engines are moderate. Some porting, a little decking to a good squish, and a moderate pipe. For a all around bike that gets me A to B with not much wear on the engine and cruises at 30 effortlessly it's a good match. You guys remember how long ago I went with this hub. I just got groceries with it yesterday. Chris builds bikes that can force that small single gear to move at the low end and have enough torque left at the top end to fly. If you go to a large carburated reed intake with a well tuned pipe and the porting and the squishing and the balancing, a drive train that works with moderate power might not be the best choice.
That would make sense then why his gearing is quite high... because he might actually hit 60mph 😅
I am doing what you are doing. I go a solid 30, rarely faster. Commute most weekdays to work with it. Hope it lasts me a long time.
Have you upgraded to the one turn shift interface yet? I will soon, if I get hands on the parts!
How many miles/hours do you have on yours?
 

gary55

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Nov 27, 2012
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I wish I could say miles/hours, but it's went through so many winters and rain showers that the speedo just can't keep up. Malfunctions is it the mag on the wheel, is it the pick up, is it the battery, did I f*** up the wire? Funny thing is I screw around with these things and it starts working again so I just go with it. best I can tell you is a time stamp when I started building it. about 4 years and 4 months ago. Same hub, 1 new top end. top end wasn't due to failure. Just preventive maintenance.
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Nirve

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Joined
Jun 12, 2020
Messages
56
Thanks for sharing @gary55 , looks really clean! I have this GPS speedometer for 30 bucks and it is working just fine, comes with an odometer and everything. May want to check it out.

Is that a suspension fork in a 1" steerer tube?
 
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