Dropped in to say Hi

Footie

Esteemed Pedelecer
Jun 16, 2007
549
10
Cornwall. PL27
Hi all, just dropped in to say hello.
Been a good while since I posted or visited the forum.
My electric bike battery died a few years ago and with a replacement costing several hundred pounds I just couldn't justify the high cost for leisure cycling, so the bike has been shed bound and gathering dust.
Not been keeping up with the world of electric bikes but it seems the batteries are still as expensive as they were.
I finally decided that I would convert my bike back to SLA but the battery case was too short for the present day batteries, so I have had to modify the battery case to fit the standard 12V 9Ah SLA batteries.
Today I finally got around to getting things sorted and the bike has been out on the road testing the new battery pack.
With the test run OK I then recharged the pack, which also worked OK.
This afternoon I have carried out the finishing touches to the pack (sealing, smoothing edges, etc) and it is now ready to go, although it does need a quick spray of paint to make it look a bit there after.
Due to work it is unlikely I will be able to test it any more until next weekend but looking forward to being back out on the road on my nine year old electric bike :)
 

flecc

Member
Oct 25, 2006
46,322
23,081
Hi Footie, welcome back, good to learn your bike is going to be back on the road again.

Once the casing is finished it'll be time for a new photo of it.
.
 

Footie

Esteemed Pedelecer
Jun 16, 2007
549
10
Cornwall. PL27
Hi Flecc, Thanks for the welcome back ;)
I had a quick look but couldn't find a Gallery, possibly not looking hard enough.
Is there a thread for showing off ones pride and joy?
If not then here is a picture of my Cougar Mountain Electric Bike.
I am aware the seat post it now very close to the top of the battery, it is wound right up to stop the seat hitting it , only when I get to ride it will I know if there is a problem.
I may have to modify the bike (a little) and remove the spring suspension altogether, still very much work in progress :)
 
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Footie

Esteemed Pedelecer
Jun 16, 2007
549
10
Cornwall. PL27
Managed to test out my new SLA 9Ahr battery today.
Nothing serious, just a short (close to home) run.
Rode it (gently) into town and back (2 mile round trip), handled the steep hills without a hitch.
I am still able to ride it on the flat without power, pleased about that, as I had a worry the added weight might make it too heavy.
Battery took 50 minutes to charge back up and the charged voltage was 39.9v.
I will now start increasing the range to see what I have.
Seems everything is working fine with my rejuvenated E-bike, so far :)
 
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flecc

Member
Oct 25, 2006
46,322
23,081
Looks good, I think you'll probably just about get away with that tall battery, just so long as you don't do any stunt jumping! :)
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Footie

Esteemed Pedelecer
Jun 16, 2007
549
10
Cornwall. PL27
Tested my electric bike at a slightly greater distance last Sunday but I had some problems with "pulsing" power. It started after about 2 miles out. The entire trip was only 6 miles (in total) but the last 2 miles were a nightmare, I was down to a crawl, I even had to change right down to first gear to be able to keep moving.
The battery was at 37.5 volts when I got home, it was 39.5 volts at the start.
Searched on the internet and found someone with similar problems, which was caused by the sensors in the brakes intermittently cutting power. I did adjust the breaks before the second trip, so I have checked them over and readjusted them, even fitted a new cable adjuster.
I am Hoping to try the bike again over the weekend. Fingers crossed it will work OK.
 

Footie

Esteemed Pedelecer
Jun 16, 2007
549
10
Cornwall. PL27
Tested my electric bike today, on a circular route of 2.5 miles, twice.
Unfortunately, on the second trip the pulsing started at about 1/2 mile from home. So for some unknown reason I have a range limit of about 4.5 miles. Battery was reading 37.7 volts when I got home.
I hate to admit it but this seems to point to a power loss under load and likely an issue with the batteries in the pack.
After some thought I have decided, if I am going to fork out another £100 for three SLA batteries then I might as well spend a further £75 and buy myself a 36v 10Ahr lithium-ion bottle battery. So one is now on order :)
 

Footie

Esteemed Pedelecer
Jun 16, 2007
549
10
Cornwall. PL27
My new bottle battery arrived yesterday, so today I set to work fitting it to my electric bike.
I opted to fit the battery behind the seat, as it was before.
Clearance is tight, so I have had to remove the original rear battery rail, as it was taking up valuable space needed for getting the new bottle battery in and out.
In it's place I have fitted a narrow length of aluminum sheet, which is the full width of the frame.
This will serve three purposes, firstly, it allows me to use the original fixing holes of the battery rail (so no new holes).
Secondly, it gives me a good fixing surface for the battery, allowing higher fitment, which is necessary for the required clearance under the battery to access the plug and switch.
Thirdly, it will act as a deflecting shield to help protect the battery against the wet and crud being thrown up by the back wheel.
I was reluctant to disturb the original wiring, so I have used some semi soft rubble disks to attach the battery wires to the original SLA battery connecting pins, that stick out of the bottom frame.
I have then hot-glued some plastic caps over the pins, then hot-glued all around them to seal tight to keep out the wet, dirt, etc.
I carried out a short test run up the road and all works OK.
Battery is now on it's first full charge.
Weather permitting, I will test it out properly tomorrow :)

 
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flecc

Member
Oct 25, 2006
46,322
23,081
Neat adaptation Footie, hope tomorrow's trial goes well.

P.S. Just noticed how long the crank arms appear on your bike, they look 180 mm or more?
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Footie

Esteemed Pedelecer
Jun 16, 2007
549
10
Cornwall. PL27
Had a successful test of my new battery today, cycled 9 miles with no power cut-outs and I still had power in the battery when I got home. Admittedly, I could have gone further but my legs are a bit weak at cycling at moment, as I have not cycled for well over 18 months. Hopefully, now I have a decent battery on my electric bike that will improve. My goal was to have a working range of about 10 miles (5 miles there & 5 miles back), it would seem I now have that ... Just what I wanted ;)

Neat adaptation Footie, hope tomorrow's trial goes well.
P.S. Just noticed how long the crank arms appear on your bike, they look 180 mm or more?
.
The cranks are 170mm (center to center), as originally supplied.
Why do you ask?
 

flecc

Member
Oct 25, 2006
46,322
23,081
The cranks are 170mm (center to center), as originally supplied.
Why do you ask?
That's perfectly normal then, I just got the impression from the photo they were longer.

It's a subject that interests me since there's lots of expert discussion on the efficiencies or otherwise of differing crank arm lengths and cadences. A very few use crank arms only 100 mm long with high cadences, even in competition.
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Footie

Esteemed Pedelecer
Jun 16, 2007
549
10
Cornwall. PL27
I see.
Just did a quick search on the Internet and found a site that suggested the ideal crank size for someone my height (5ft 8inch) is 167.5mm to 170mm.
Having a normal body length but short legs, I have difficulty setting the seat height to the optimum height, so I have to compromise by setting it slightly higher.
This is so I get good power for climbing hills ... which I have plenty of here :(
Only problem is, I am on tip-toe when stopped at traffic lights and junctions, unless I get out of the seat.
In truth, I think a slightly shorter crank would help to reduce the problem, giving me a good leg length on the bike while allowing more foot contact with the ground (due to a reduced seat height).
I can see why these things can fuel interest and become thought provoking :)