Sunrunner Cycles

[Tintaglia]

Has anybody seen or tried one of these bikes? I actually bought my Lafree Lite from the guy selling them so he should know what a good electric bike feels like

It seems to be offering an amazing 3 year guarantee on the battery (lithium iron phosphate) and motor and says the battery can be charged up to 5000 times. It also only weighs about 2kg but claims quite a good range from a 3.5Ah battery (option of a 5Ah).

They are being sold on eBay for £595.00 on this page:

THE LIGHTEST ELECTRIC BIKES IN THE WORLD on eBay, Bikes, Cycling, Sporting Goods (item 220145624406 end time 10-Sep-07 21:59:24 BST)

If you go to the website mentioned on the page there is quite a lot of extra detail and a pdf file that you can download.
http://www.sunrunnercycles.co.uk/

 

[flecc]

I can't see a PDF link anywhere there Tintaglia?

As for the claims, they're a joke.

Either they've been taken for a ride, or they are trying to do that to others.

The trouble is that most people just don't understand the facts of electrical physics and engineering. If they did, they'd know such claims are downright silly.
.

 

[Django]

Hi Flecc,

Click on the 'BIKES' link towards the top of the page.

Cheers,

Django

 

[flecc]

Thanks Django.

I can't see those LiFePO4 batteries giving anything like that number of charges in practice. They're very new and there's no experience of them in bikes other than the fact that several makers are experimenting with them, including eZee.

In addition, on their battery chart the power/weight ratio is described as acceptable, this also shown for li-ion manganese. Since they claim 30 miles range with a 2 kg battery, that's the same as eZee claiming about 66 miles on their latter type 4.4 kg battery. Any eZeebike owner getting 66 miles? I think not.
.

 

[Miles]

As for their claim to be the lightest:
Monty Electronic Bicycles. Bicycles.

 

[JohnInStockie]

I think I saw Flecc on his latest LiPo4 bike !!!

see this

 

[flecc]

I've already seen that John, but I packed in motorbikes three years ago! That sort of exercise is fun and interesting, but not really practical.

My 24 mph T bike is more than fast enough for a bit of fun now.
.

 

[flecc]

As for their claim to be the lightest:
Monty Electronic Bicycles. Bicycles.

Not a bad looking little bike Miles, and about 17 kilos is good.

There's no technical reason currently why one of these e-folders with a small Li-ion battery can't be as low as 15 kilos all in, or even less. Dahon got the bike weight down to 7.9 kilos on one model, and the rest is more than enough for motor/electrics/battery. Couldn't be done cheaply though.
.

 

[Miles]

Not a bad looking little bike Miles, and about 17 kilos is good.

There's no technical reason currently why one of these e-folders with a small Li-ion battery can't be as low as 15 kilos all in, or even less. Dahon got the bike weight down to 7.9 kilos on one model, and the rest is more than enough for motor/electrics/battery. Couldn't be done cheaply though.
.

Agreed. Less than 16 kilos is the target....

 

[flecc]

The cathodes in LiFePO4 are undoubtedly better than any existing type, and regarded as a little more than twice as good. Compared with current Li-ions with 500 charges claimed, that would indicate around 1000 to 1200 charges are theoretically possible. I've seen one claim of 2000.

But that claim of 5000 on this bike is going much too far on current knowledge.

It's patently a calculated laboratory figure if it has any basis at all, since a team of riders on these bikes running 24 hours a day on one battery would take well over three years on their mid size battery to achieve the 100,000 miles to prove the figure. These large cell batteries haven't been around anywhere near that long, mainly appearing in the last year.

Back on 10th November 2006, technical man Ken Ching of eZeebike said this:

"eZee is currently experimenting with Li Iron Phospate (LiFePO4) technology"

Since nearly a year has passed since then and we still have no indication of these batteries arriving, I conclude that there have been difficulties in realising the promise of this chemistry at an acceptable cost. That alone makes it difficult to believe it would be ready for the market at ebay prices.
.

 

[rooel]

As for their claim to be the lightest:
Monty Electronic Bicycles. Bicycles.

But note, only one gear ratio! No derailleur or hub gears.

 

[Miles]

But note, only one gear ratio! No derailleur or hub gears.

The weight comparison still stands. Taking the hub gear out of the Sunrunner bike, advertised on ebay, won't reduce its weight by 2kg .......

 

[flecc]

They are good weights, but not enough to make big claims about. There's at least one other production folder at under 18 kilos, and with full gears too, and some full size bikes under 20 kilos, Wisper 905e for example.

If those bikes used Lithium Iron batteries they'd be lighter than the Sunrunners.
.

 

[rooel]

If those bikes used Lithium Iron batteries they'd be lighter than the Sunrunners.
.

Yes, put Lithium cells in a Roo El battery pack and its usual 18kgs weight will come down to 17kgs, with five gear ratios in the hub, and the only electric folder acknowledged by A to B magazine as worth buying (until they reviewed the nano Brompton, but that has 16 inch wheels.)

 

[flecc]

Indeed Rooel, and true also of the Biketec folder with Panasonic's latest unit. An LiFePO4 battery in that instead of the Li-ion manganese and it would also be 17 kilos. A to B haven't tested that, and I think they'd like it, it's highly rated elsewhere.

As I remarked to Miles, I look forward to even lighter folders though. It's clear to see where more weight could be saved even on existing designs like yours, more expensive high tech materials in particular could make a big difference to both bikes and motors.

Carbon fibre, kevlar and titanium with an imaginative approach could produce a real surprise at a price.
.

 

[flecc]

Well Tintaglia, we might not be too impressed with the Sunrunners claims, but you've certainly instigated a lively little thread, livening up what has been a rather quiet period in here. So thanks for the information and links.
.

 

[Miles]

As I remarked to Miles, I look forward to even lighter folders though. It's clear to see where more weight could be saved even on existing designs like yours, more expensive high tech materials in particular could make a big difference to both bikes and motors.
.

I guess you could start with one of these...... Dahon Launch "lightest Ever" Folder | BikeRadar.com

 

[flecc]

Nice one Miles, 0.4 kilos lighter than their previous best, and that was a 20" wheel folder.

That sort of approach with the lighter beam frame 20" folder should get a weight down into the sixes, say 6.8 kilo. Than a magnesium shelled motor like the Nano, but with lighter nylon drive gears like the Quandos, bringing that to around 9.5 kilos at most. Add a decent size LiFePO4 and we'd have a 12 kilo e-folder! That would really get the sparks flying.
.

 

[Tintaglia]

Well Tintaglia, we might not be too impressed with the Sunrunners claims, but you've certainly instigated a lively little thread, livening up what has been a rather quiet period in here. So thanks for the information and links.
.

I didn't really expect anyone would be impressed by the claims but thanks for your opinions. It's always interesting to see a new entry into the market. I would still be interested to try a test ride and will suggest that he supplies A to B with bike to review.

For what it's worth, of the bikes I've tried recently I liked the black Izip with the batteries in the frame the best, but was put off by the range and difficulty in adding an extra battery and not being able to charge the battery off the bike. I also liked the look of the Sparta Ion but didn't get to try a test ride and don't like the sound of having to take it to the dealer for re-setting. I'm looking forward to seeing the new Whisper but for the time being I'll just keep trying to buy a second Lafree at a reasonable price (I keep getting outbid on eBay)

 

[flecc]

Yes, I'd like to see A to B test it, though only time will tell with the battery life. Months ago I tried to get Wisper to submit a 905e to A to B and they indicated they would, but it seems courage apparently departed.

The Lafree prices are daft when the realities are considered. The latest situation is that Giant are no longer supplying motor drive sprockets. These little 14 tooth sprockets wear first, and now a number of owners are stuck with sprockets on their last legs. The promised 9 Ah batteries have now disappeared and only the old 6.5 Ah will be supplied in future, still at the excessive £250. While their chargers are still available they remain at a silly £120, but fortunately I have other sources at much lower prices. No other spares are available.

I'm currently trying to solve the sprocket problem, but there's no doubt that the second hand prices should be very much lower with such poor prospects for keeping them on the road.
.