Are a Hub and Mid Drive comparable by power?

[Deleted member 4366]

Something like this would be better. It has hydraulic brakes and semi-decent forks. More importantly, it has 27 speed gears so you can use a freewheel hub-motor if you want.
https://www.ebay.co.uk/itm/carrera-kraken/192500100241?hash=item2cd1e66c91:g:QDYAAOSwLahav7p6

 

[Blunderbuss]

The Kraken fits the bill perfectly and i like the look of it, i have found one in Ipswich which is about 1 hour away from me (Cambridge) so will see how that does over the the next 36 hours. Thanks for your help .

 

[Deleted member 4366]

Not all Krakens are the same. Most don't have hydraulic brakes, and there were various different forks and gears, so look at the spec of what you're getting.

 

[Blunderbuss]

I have taken off the 20AH battery and bike rack (total of 8.5KG) and have used cable ties, insulation tape and a bin liner to get a 10AH (3KG) battery to fit onto the down tube with the controller so I could see what it is like. WOW, it is a world apart - it felt like a bike , i could even pedal it up an incline with no assist. Before i do anything else i am going to do some runs in this configuration to see how the 10AH battery lasts.

 

[Deleted member 4366]

I love your thinking. that was a great idea.

Roughly, each KG you take off means that you get the same performance with 1% less combined power. A modern 40-cell Samsung 30Q battery gives 12Ah and only weighs 3kg, so that would be a 5.5kg saving. a Q128C would save another 1kg and a medium quality donor bike with a couple of light weight mods could save another 2kg, giving you a total saving of 8.5kg, which would mean that the 12Ah would be equivalent to 13Ah compared to your old setup. Hill-climbing with the Q128C at 20A would therefore be 8.5% better too.

 

[Blunderbuss]

I have just completed a 24 mile ride and the 10Ah battery was only just down to two bars (47.8V) - so the pursuit of less weight has made a massive difference (i have reduced the weight of the bike by 12KG from the first incarnation which had a 20Ah battery and 1000W D/D). And from the handling/enjoyment having the battery on the downtube is such a great change, popping in and out of the tractor tracks to keep a smoother line does not mean fighting a tank slapper anymore.

Thinking of my donor bike for the next project I went into Halfords to have a look at the Carrera range and the frames all seemed to be the same, when you check their website they all weigh almost the same 14 or 15kg. As d8veh said they don't all have the hydraulic brakes the Vulcan (which is down to £279 with the current sale/discount) and Krakken do. So i will keep my eye out for those variants on ebay, gumtree and local facebook groups.

 

[Deleted member 4366]

I have just completed a 24 mile ride and the 10Ah battery was only just down to two bars (47.8V) - so the pursuit of less weight has made a massive difference (i have reduced the weight of the bike by 12KG from the first incarnation which had a 20Ah battery and 1000W D/D). And from the handling/enjoyment having the battery on the downtube is such a great change, popping in and out of the tractor tracks to keep a smoother line does not mean fighting a tank slapper anymore.

We need to sticky that for all the guys that come on here asking about those cheap DD kits that they've seen on Ebay.