Red ones might be too kinky for your stem, no way to tell without trying, though. Silver ones look like they'd be a piece of cake. I've got risers like those through a stem with a 4cm clamp with ease.



As to the flexibility of bars, someone really needs to do some testing and release results to the public. Maybe I'll apply for a grant

I don't think risers as a style are designed to provide shock absorption, they're "risey" just to provide a certain bar height, IMO.

I have some steel flat bars that feel just fine. Infact I've only had one pair of bars that felt harsh and those were some PricePoint Sette Flat aluminum bars. But it's really hit or miss from bar to bar. The bike's going to feel better with most Al bars because they'll be lighter, so worth a shot to get Al anyways.

Oh, and wider bars will generally help lessen harshness also. If your old steel flats are like 22" you've got a lot of room to go wider. The widest I run is 25" but a lot of people go wider these days. The widest I've seen for sale are 31". I bet there are even wider.