[Radfahrer]

Hi,
Since there bikes suspension was not really an issue. Bikes weigh 13Kg or so and can be deemed as the vehicles unsprung weight. The human being riding it can weigh 80Kg but is really sprung weight. This would be achieved through the natural ability of a human to absorb shock loading and the sprung saddle of the bike. This would give the vehicle a total weight of 93 Kg with 14% unsprung weight. This doesn't seem too bad in comparison with some older cars. Ebikes has driven up this unsprung weight considerably to circa 30% unsprung weight mainly from battery weight. Lead acid batteries supply1ng most of the weight increase.I use sla batteries are not going to disappear due to their reliability, high level of development and low cost. They are also recyclable(in Ireland). As a change in direction to ever lower battery weights(NiMh etc) has anyone ever looked at springing and damping the battery pack within the bike frame. I cringe sometimes when my SLA bike goes over traffic calming bumps. I'm affraid I'll break an axle due to shock load caused by my battery weight. I worry also about my battery casing being shattered by the same shock load. I'm strongly thinking of designing in some battery internal suspension with damping. i would be interested in comment on this from other ebikers.