We have a lot of downhill freeride sites in the UK, where stuff like this happens:

http://video.google.com/videoplay?do...1052421059027#

Not all of that is possible on a Brompton, or indeed a Jetstream, or possibly a Swissbike, but that isn't the point. My 26" Matrix was very capable on the downhill stuff, including riding it down flights of steps when naysayers poo-poo'd folding MTBs, but on loose downhill sections 20" tyres don't dig in, at speed there's enough bounce and slam to have the rider off the bike. I agree its possible, slowly, but for me it's just not pleasant.

I haven't ridden a Jetstream downhill, but I have taken a 20" Downtube downhill, and it is not an experience to be enjoyably repeated. Add in the short fork travel, designed for tarmac, smaller clearances between forks, rims and brakes; mud, rocks and ruts soon put a stop to 20" folding bike downhill freeriding.

The question is: is the Swissbike as good downhill as Montague say it is.? We wait with baited breff. The same question has to be asked of the new lockjaw Matrix, nobody seems to take them seriously offroad.


"You know degree-of-gnarly is directly proportional to the amount of broken/bent stuff in the middle of nowhere..."

Amen!

In the UK, finding a place to ride downhill usaually involves a drive, so carrying stuff around isn't a problem. It all goes in the car.