Thinner steel/Ti tubing with foam injection

[feds127]

My curiosity has me wondering the result of using thinner steel/Ti tubing and injecting with foam vs a traditional non-foam injected steel/Ti frame. I seem pretty common to foam inject a car frame to add stiffness. I would think that injecting foam into a bike frame would allow the use of thinner steel and help dampen vibrations. Anyone have any info on this?

[tv_vt]

Weren't there some carbon forks that were foam cored? Seems like there was also a bike with foam-injected tubing, but can't recall who it was.

[mandasol]

Bianchi has a proprietary tubing called Boron XL (which is essentially Deda EOM 16.5) they use in a frame called the Pinella. When they first released it they had problems with cracking, so they reinforced the tubing with structural foam in later models. I believe the frame is still offered with the same reinforced tubing.

[Lifelover]

Seems like a very expensive answer looking for a question.


I suspect in other applications, the weight savings is significant.

[tv_vt]

http://www.bicycling.com/gear/detail/0%2C7989%2Cs1-16-156-1559-0%2C00.html

"But all Sampson frames come with an injected polymer foam called Sampson Attenuation System (SAS), which damps vibration. "

[Ahneida Ride]

The Serotta F1 fork was foam injected.

[AndrewS]

The barrier to making a very light steel frames is the "beer can problem". The steel might be structurally strong enough to do the job with oversized diameter tubes, but the tube walls become so thin that they dent or puncture easily.

The use of a foam or some sort of light interior coating might make it possible to get under 3 pounds per frame with modern air hardening steel.


I don't think less dense materials, like Ti and aluminum, would benefit from this idea their relative strength compared to steel precludes really thin wall tubing.

[peanutgallery]

Bianchi XL EV2 was foam injected (later ones), they still broke...a lot. I had 3, I think.

Bianchi has a proprietary tubing called Boron XL (which is essentially Deda EOM 16.5) they use in a frame called the Pinella. When they first released it they had problems with cracking, so they reinforced the tubing with structural foam in later models. I believe the frame is still offered with the same reinforced tubing.

[mflaherty37]

I think that could do a lot for keeping steel down tubes from buckeling in a crash. It would be easy to try and see what it rides like. After you are finished experementing, the foam could be disolved out with acetone.

[thwart]

Bianchi XL EV2... broke...a lot That one was aluminum. The Pinella Boron XL was the one with foam injected steel tubes.

I have a predecessor, the Boron XL. Great frame.