Frame too light for conversion?

[Rickidoodah]

Hi, I'm thinking of converting an old bike to electric and am looking at either the 8Fun 750 watt mid drive or a 500-100 watt hub motor, so both require a substantial battery. I'm looking at the 48v frame batteries which I think are 4-5kg.
I have two bikes which I can use, a 1998 Kona Roast or a 2004 Gary Fisher Big Sur.
My question is which do you think s most suitable given the weight of the battery etc?

Kona Roast
(Good)

• Strong Frame.

(Bad)

• Heavy Frame - 2.3kg

Gary Fisher
(Good)

• Very light and nimble.
• Light weight frame - 1.5kg

(Bad)

• Frame may be too weak to hold the battery.

 

[Deleted member 4366]

Best to show photos of them. Avoid whichever one doesn't have disc brakes.

 

[D8ve]

From your comments.
Electric assist negates an extra Kg of frame weight.
A split frame will realy ruin your day.

From D8veh and others.
Disk brakes a must. Rim works for 99% of time but even 1% of oh **** is too much for me.

 

[Rickidoodah]

Good point about the split frame.
I think I'll convert the Kona (it's v strong as it's made for jumping) and I'll sell the Gary Fisher Big Sur as it doesn't get used anymore.

Thanks for the advice.
Rick