Hill climbing - Astro 3210

[Miles]

There have also been posts on this forum reporting high losses.

The "perfect ratio" thing is their marketing pitch.

There are no published figures on the efficiency of the NuVinci.

I think it's an amazing bit of engineering but for us to use an efficient lightweight motor and then add a relatively inefficient CVT, which weighs as much as some hub motors, doesn't make sense IMO.

Fallbrook produce a control unit which does exactly what you describe, Paul.
http://www.fallbrooktech.com/09_LEV_Kit.asp

 

[gunthn]

On efficiency and the nuvinci.

I used one in conjunction with a cyclone 500 at 36v(max 1500w of power). I had the same motor directly connected to the bb and found no difference in power, unless the nuts which adjust to the width of the frame dropouts had creeped in and tightened the hub up. The motor was mounted just above the hub on the rear frame members and this may have given a little overall advantage over the bb setup which was likely washed out by slight differences in eff in the nuvinci. If I had to guess there could have been no more than a 10% efficiency difference if at all.

Perhaps pushing the hub to 3k to 5k watts exposes slippage problems?

They seem to be somewhat at their limit at 3500k.

Weight is Nuvinci's Achille's heal.

 

[ChinaPhil]

After reading comments on the Nuvinci hub I went to view and ride a bike with a Rohloff Speedhub - great piece of engineering but I cannot see an obvious way to fit an additional sprocket or freewheel. So, after reading "Fitting freewheels to splined freehub drivers" (http://endless-sphere.com/forums/viewtopic.php?f=28&t=13532&start=90) I am on the Sram DualDrive, dual freewheel path. The first step was to try a DualDrive on the Fuji Cyclone to gain experience for the next build.

The Cyclone motor was sent back to Cyclone for repair - the Cyclone throttle's red light coming on at ¾ throttle was a motor problem, not a battery one.

So now the motor is back from Cyclone, a DualDrive II (weight 1kg) has been fitted to the rear wheel and the plastic idle roller has been replaced by an 8-tooth ball bearing idle wheel. The bike rides well and the DualDrive is proving really useful, especially its ability to change gears whilst stationary. Hill climbing ability is improved - I have just climbed a hill that used to be beyond the bike’s capabilities. The more I ride this bike the more I tend to rely on the 3 speeds of the DualDrive (0.73, 1.00 and 1.36).

I have bought a secondhand bike and will start fitting the Astro system to it whilst I wait for the outcome of the thread "Fitting freewheels to splined freehub drivers".

 

[recumpence]

Hey Phil,

I actually make a Rolhoff speed hub left side 130mm BCD adaptor. I have one in stock.

If you want to go that route, I can send you one.

Matt

 

[ChinaPhil]

I have now fitted the Astro system to another bike - rear wheel comes from my Fuji Cyclone bike which now uses a DualDrive II:

View attachment 1
The lower 2-stage drive clamp also serves as a seat post clamp. The Castle Creations HV110 and RC throttle interface system are in the water bottle – may have to vent later.


I wear a backpack containing the 12S 10Ah Zippy Flightmax LiPo batteries (in safe packs) - Deans Ultra connector is near the top of the water bottle.
Bike weight, as shown, is between 14kg and 15kg.
The DualDrive II works well on my other bike so I am looking forward to the outcome of the thread "Fitting freewheels to splined freehub drivers" – any update gentlemen?
Meanwhile I will go hill climbing and play with the acceleration!

 

[mud2005]

looks really good Phil any updates on performance/reliability?

 

[deecanio]

Hi Phil,

looking good there and invaluable testing on the dual drive.
Im waiting on getting a dual drive for myself, but im fairly confident that once Gary confirms their worth i'll have one and laced in no time at all, the recent thread on the SA failures has given me the jitters slightly but im confident that i'll get an sram imminently.
the dual freewheels idea is a go already?
Thud made a broaching tool to put the splines into threaded freewheels and Luke is broaching as i type - i think Miles has some and mine are due with luke any day to be broached.
i have a (dumb) question.
using left hand drive as you are, have you used the disk mount to mount the sprocket and does this mean that your motor drive is only single speed??
i will run the dual drive with the two splined freewheels, one mounting my 219 sprocket and the other going direct to the front chainring, this gives me 3spd otor and 3 spd pedals but total independance from each other - does your system work the same?

Cheers,

D

 

[ChinaPhil]

Hi Deecanio and Mud2005,

I use the rear wheel disc mount which gives a single speed of approximately 14mph ( I really must fit a speedo). The acceleration is impressive (front wheel lifting) as is the hill climbing ability (I live in a mountainous area with few flat roads).

I fitted a Dual Drive II to my Fuji bike, which uses a standard Cyclone 500W kit, in order to gain gearing experience (http://endless-sphere.com/forums/viewtopic.php?f=28&t=13145&p=217026&hilit=fuji#p217026).
I really like the Dual Drive and will fit one to this bike, probably using standard bicycle chain (only an Astro 3210!).

Now I always put batteries in a back pack, the bikes handle so much better.