70l roll up bag on the back of a CB500F

[motchen]

Hi there,

I have been planning a trip from London, UK, to somewhere on Great Britain this summer (given the pandemic I won't be going much further it seems). I am planning to do it on a CB500F, which obviously lacks anywhere for luggage. I have a 70l waterproof roll up bag which I have been using to carry some stuff to work on Mondays and home again on Fridays.

I strap it on to the back seat using ROK straps. It has a giant velcro thing on the bottom that I only recently discovered so now I'm wondering if I can strap that under the rear seat as well. It feels sturdy.

Since I live in London I never get over 20mph using this setup. I was wondering if this would be safe for long days on a motorway and for going down countryside lanes? The way it changes the handling on my bike is already very noticeable in London. Would that be exaggerated at higher speeds and on twisty roads?

Cheers!

[markharf]

"Safe" is a relative concept. I've put all sorts of miles on all sorts of bikes with 50-70 liter backpacks trussed up and strapped to the seat behind me; they're awkward, look funny, affect handling, and kind've ruin the "aggressive street fighter" mystique on the basis of which Honda wants to sell you this bike. If none of that bothers you excessively, you'll be fine.

For what it's worth, the bike's inertia becomes more of a factor (and the sack perched on the seat behind you correspondingly less) as you gain speed. At least, that's what I tell myself when I drop an unfamiliar, loaded bike at <1mph in a parking lot, but never at 70mph on the highway. Something about vectors, maybe. Same thing would be true if you were carrying a passenger--greater speed = more stability.

Hope that's helpful.

Mark

[Fishenough]

I like travelling just this way on short trips less than a week along more commonly traveled routes in Alaska and Northern Canada. I'm a backpacker, so camping gear, tools, and such all fit in a bag of such size tightly strapped to back rack/rear seat. I use heavy straps commonly used for securing kayaks to the roofs of cars. On some trips the bag contains my entire backpack for a ride and hike. At my destination I store my helmet and riding gear in the bag and hide it carefully a little way along the hiking trail.

For many years I would ride the Canol Road in the Yukon for a couple days, and I like the light weight of the single roll down bag. The Canol is at times twisty and being a well maintained dirt road its a fun ride. And easy to catch yourself exceeding the 60 kph speed limit, maintaining a good pace for your own safety not for fear of getting a speeding ticket. It's not uncommon to ride the entire length of the road without seeing a single person or other vehicle.

If it's more of a journey of several thousand kilometres or far from civization, I do have roll down side bags to spread out the weight of the extra gear.

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[backofbeyond]

70L is a big bag if you fill it up. And whatever you fill it with could well disappear from your life for ever if it falls off in the fast lane of the M4 without you noticing. And that's without worrying about what it hits when it comes loose. So my advice would be to make sure that whatever straps you use to fix it on the bike - the ROKs or any others you buy - are used sensibly to keep the thing in place. The velcro's good but use plenty of straps as well. For a bag that size I'll be looking at 4 straps minimum.

If you've just got the pillion seat to fix it to a 70L bag is going to be hard to keep in place as it'll flop over both sides. Even if it doesn't fall off you don't want it tipping so much it ends up in the wheel. What I tend to do when I'm not completely happy with luggage security (many many times during my bike travel life) is to position both you and the luggage on the bike in such a way that you can feel it against your back or your posterior. That way if it moves you'll know. Don't strap it to you though.

If it's heavy you will notice a difference in the handling but you'll quickly adapt to it. By the time you're out of London you won't notice it any more. That's when it's easy to lose it. Good luck - I dread to think how much stuff I've lost over the years through bags or other stuff vanishing off the back while I rode along oblivious.

[markharf]

Funny, I don't think I've ever lost any luggage off any vehicle, ever. That includes everything from ladders, planks and building materials piled high atop cars and trucks to the aforementioned giant backpacks on tiny motorcycles. Attachments--whether straps, bungies, ropes, cables--are always redundant so that if one fails it's not the end of the world.

To be perfectly honest, I suppose that's not quite 100% true. I've lost a water bottle or two over the years, a bucket of paint brushes in solvent I forgot to remove from the roof, and an occasional cup of to-go coffee set down absent-mindedly. But never anything tied down for transport.

Someone mentioned kayak straps, which I've found ideal--they're long, strong, have adequate buckles, and the good ones have high-friction surfaces so that wrapping one turn over preceding ones will secure them against untightening even if you don't get all the slack out. I also use heavy-duty, black rubber bungie cords, but never the cheap ones--crimp the hooks on tightly and watch out for UV/ozone degradation over time. I've never had bike-specific straps like rokstraps or BMW straps, so no basis for comparison, and I've never relied on velcro.

I'm answering at length because I'm trying to avoid the stuff I should be taking care of today. Hope that's helpful.

Mark

[Threewheelbonnie]

I take it you've found the straps under the seat? Take the pillion seat off with the key and look under the pointless pillion pad/hump lid thing. There will be two loops of webbing that can be pulled out of hooks in the plastic and left outside to lash things to.

Andy

[shu...]

I did this in Turkey . It handled fine, hardly noticed it most of the time.




70L is a big bag, but you don't have to fill it up all the way.

My roll top wasn't 70L: probably 50L. More than big enough for everything including some camping gear, if you have a good sized tank bag. The tank bag is for things you may want during the day: water, raingloves, etc.

Double up on the Rok Straps for peace of mind. You don't want things ending up tangled in your wheel or chain.

...........shu

[motchen]

This is all great advice thank you everyone.

My conclusion is it should be ok as long as I'm sensible. I've got 4 ROK straps and the velcro on the bottom of the bag is huge. If I can get that secured under the seat then I think it would really help. I've never heard of these webbing loops under the seat so I will get out and look for them. I've been strapping it to the rear foot pegs and some metal that the license plate holder and indicators are attached to, directly under the pillion seat.

There's no chance of putting this bag on the bike without it touching my back anyway. At least I'll know if it's starting to shift or I can wave goodbye to it when it comes off. It hasn't moved an inch in London but the big boy speeds out of the city are what I worry about. If the bike's more stable at higher speeds and 4 ROK straps should do the trick then that's perfect.

70l is definitely on the big side. I'm not really sure what I was thinking buying a bag like that for a skinny little streetfighter but it works great for my commute, saving me having to carry any bags at all the rest of the week.

I like having a single bag, it's a dead simple setup. It's roomy enough for a RTW trip as far as I can tell. As a test I loaded it up with my tent, sleeping bag, two sleeping mats (one of them being one of those old school closed cell foam ones), a bunch of clothes, my hiking boots, rain gear, and it was loosely packed. I still need to work out my electronics and tools since I don't actually know what I need but if it's secure enough then I'm dead happy.

Thanks again all