I have the R35 and its bloody brilliant....I got royally pissed on last year going to a TWO shoot in Leicester and it didn't leak at all. The outer pockets have waterproof zips?!?!
I actually now use this for ALL rucksack trips. Walking, travelling and cycling. The QuadLock system is brilliant to shift the weight and takes the stress of lower back and shoulders. Only comment I would make....if not adjusted properly the R35 can sit quite high on your back. And obviously on sports bikes (arse up head down) can restrict your helmet in a backward movement. I had this on a couple of trips and it gave me cronic neck/back ache. So make sure you use all the adjustments on it to get it sitting properly. Humps can make it sit funny too (no shit sherlock
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A great investment and simply brillant. I don't leave home on a long ride/trip without it.