Hill climbing - Cyclone 500W

[ChinaPhil]

Cars and motorcycles are banned where I live, so bikes are a key form of transport. In summer the temperature is 33-35degC (90-95degF) with humidity in the range 70-99%, rust is a real problem. The majority of electric bikes look like this:


View attachment 4
My current bike, based on a Fuji Odessa, uses a Cyclone Taiwan, single chainring, 500W motor kit and a 24V 20Ah LiFePO4 battery – a straightforward installation. Gearing is:
14-tooth sprocket on the gearbox output shaft (internal reduction ratio 9.55:1) to,
44-tooth chainring (30:1 reduction ratio at the crank) to,
13 to 34-tooth cassette on an 8-speed rear-derailleur (26in / 660mm wheel).
[maximum crank speed is 80rpm to 90rpm so I can match the cadence - just].


The bike has now travelled more than 1,500km (950ml); recently I re-tightened the drive mounting bolts and removed 2 links from the chain. The bike weighs 25kg (55lb) and I weigh 100kg (220lb), in riding gear. The folding trolley is used for groceries, suitcases, scuba gear etc. Sometimes my wife travels, sitting sidesaddle, on the rear carrier – she is much lighter than I am.

The Cyclone battery is in the black bag suspended from the top tube by velcro straps.

View attachment 1
I ride daily and use a cheap bicycle computer to measure both speed and distance (checked by GPS). No pedal-assist top speed is about 35km/h (22mph); I normally ride at a more leisurely 25km/h (15mph). However, the bike struggles with steep mountain paths, where tight twists and turns prevent any sort of run up. The incline limit, with me onboard and pedaling, seems to be about 13%, but the paths I wish to take are much steeper. The photograph below was taken on one of my favourite routes, at the point where the bike could go no further:


So decision time,
either
modify this bike by fitting a 3 piece chainwheel or 3 speed SRAM dual drive or
build another one?
I decided to build another bike with the aim of better hill climbing ability. After reading many threads (contributors, thank you) and seeking recumpence’s advice (Matt, thank you) I ordered an Astro 3210 brushless motor (10 turn), a Matt 2-stage drive, a Castle Creations HV110 and a 12S 10Ah Zippy Flightmax LiPo pack.
OK, I really wanted to try an RC motor!
The complete drive system weighs approximately 7kg (15lb), so I have set myself a target of loosing 7kg – no more cheesecake for a while!

I will start a separate thread “Hill climbing - Astro 3210” for the new build.

 

[StinkyGoalieGuy]

ChinaPhil,

I currently have a Cyclone 500W also. I drive the front chain rings, and keep the 3 chain rings up front (4 total including the driven ring). The cyclone 14T freewheel gear drives a 44T or 42T (can't remember off the top of my head) chain ring up front. For max hill climbing, I shift to my granny gear, and then use my 34T on the rear cogs. So (44/14) * (34/22) = 4.85. So I'm getting an additional 4.85 reduction after the Cyclone's 1:9.55 reduction. With this setup, I have climbed a 28.6% grade (according to city calculations) starting from a standstill, with no pedaling. This is using 30lbs of lead acid. Of course I only go 4MPH in this gear combo.

So you can definitely climb some steep hills if you make use of the front chain rings, or put an SRAM Dual Drive on the rear. You just won't be going too fast.

With that said, I eventually want to build an RC motor drive too. I also heard the 500Watt motor is exactly the same as the 1200, except for the internal controller. At some point, I'm considering bypassing the internal controller and trying to use my CC HV110 to drive the motor at 48 Volts, and if I can climb that hill any faster.

I'm interested to see how your Astro 3210 Hill climbing turns out.

 

[Miles]

Welcome Phil,

Some wonderful photos on your website

 

[ChinaPhil]

Thought that I should update this thread.

I have been riding the Fuji Cyclone, with a DualDrive II (0.73, 1.00 and 1.36), for some time now.

View attachment 2
The DualDrive click box can be seen just above the chain tensioner.

Typically I select a speed on the rear-derailleur to suite the anticipated terrain, for example:
1 for hill climbing,
3 for mixed terrain,
6 to 8 on the flat.
and then use the DualDrive’s 3 speeds when riding because:
it is possible to change gears when stationary,
gear changes are faster than the rear-derailleur.


The derailleur and DualDrive controls are very close to each other.

To make the bike easier to handle, batteries are now in backpacks; I use 2 options, both with Deans Ultra connectors:
24V 20Ah LiFePO4, and
6S 20Ah Zippy Flightmax LiPo (batteries in safe packs).


This is the smaller 6S 20Ah pack.

The result is good hill climbing ability, guesstimating 15% to 20% inclines at 5 to 6mph. For a typical ride please see the video:

http://www.youtube.com/watch?v=HjlcAAa4aKA

where I am hanging over the handlebars to stop the front wheel lifting.

Now onto a second Astro build and hopefully better hill climbing ability!