I had to look crash mushrooms up. I'd never heard of them referred to as that. I've seen them on smaller/lighter sport bikes. For the Tenere I chose crash bars. I found these two snippets of info. They claim the opposite of what I would have expected. We have some guys on here that have tested the hell out of their crash bars. . . . which worked as advertised. Both of my kids have Canyon Cages on their bikes; FJR, and a R6.
Crash protectors (sometimes called “bobbins”, “bungs” or “mushrooms”) are bolted-on protrusions, engine casings, and crash bars, designed to minimize or eliminate damage to your faring, tank, and engine should you go down and your bike slide on the road.Dec 17, 2020
Researchers said that many crash bars are “too flimsy” or “too poorly designed” to protect riders in an accident. ... Another study, known as The Hurt Report, found that “crash bars are not an effective injury countermeasure.” However, researchers did concede that crash bars did reduce injuries to the lower legs.Aug 26, 2019