Northern Ireland Outdoors Forum - Hiking, camping and more

General => General Chat => Topic started by: RedLeader on October 04, 2011

Title: Rucksacks and Back Measuring
Post by: RedLeader on October 04, 2011

Despite knowing that rucksacks come in a variety of back sizes I still had a slight brain fart and bought one off the shelf without getting measured or even being aware what size it was, it felt comfy so I was happy.

Once I got home I realised that I should have got measured. I've since checked the bag and it's listed as a small. I'm a pretty short dude so I reckoned it would be spot on but after some nerdy measuring for interest, according to Osprey I'm actually the top end of a medium or low end of a large which makes little sense.

Ospreys measuring instructions are here (http://www.ospreypacks.com/en/web/sizing_and_fitting), the pack is a Mutant 38 and my back measurement was around 52cm, although working out exactly where to measure from and too was a bit random.

Aside from back measuring curiosity I have a few issues. The first is the bag feels quite comfy so I'm reluctant to return it but at the same time I can't really tell if it's any good until it's done a few miles and by that stage it can't go back. Also, it was on offer at half price and was the last on the shelf so if I wanted to swap it for a different size I'd be unlikely to have much success.

(http://www.ospreypacks.com/images_pages/torso_measurement.jpg)

Title: Re: Rucksacks and Back Measuring
Post by: LandyLiam on October 04, 2011

if it doesn't suit after a few miles stick on on ebay and hopefully make a few pounds on it  ;)

p.s. you look like a girl in that pic  ;D

Title: Re: Rucksacks and Back Measuring
Post by: RedLeader on October 04, 2011

I didn't think I needed to mention that was me in the pic  ;D

It did cross my mind that it would probably sell on being such a highly regarded bag.

Quote from: LandyLiam on October 04, 2011

if it doesn't suit after a few miles stick on on ebay and hopefully make a few pounds on it  ;)

p.s. you look like a girl in that pic  ;D

Title: Re: Rucksacks and Back Measuring
Post by: twentyclicks on October 04, 2011

It's not too hard to measure compared to trying to do bike-fit measurements... the knobbly bit at the back of your neck is easy to find, and use your trousers to create a ring around your waist at the top of the hips to measure from. I'm usually a medium (50cm) as my back is slightly short for my height.

Tried the mutant before, but it was a large they had at the time. I fastened the hip belt at the right level and the straps were sitting off my shoulders - definitely too big!

Title: Re: Rucksacks and Back Measuring
Post by: suspectmonkey on October 04, 2011

I got a bit hung up about sizing when I was buying my rucksack, although I was taking an extra chance as I was ordering it off the internet so couldn't try before buy.  I found the measurement info (http://backpackinglight.co.uk/page47.asp#) on the Backpacking Light website very useful, but also this PDF from Gregory packs (http://www.gregorypacks.com/files/pack_fit.pdf) was really helpful in figuring out what I was looking for with the fit.  If you print out that sheet then you will have something to help judge the fit by.  Probably best not to adopt The Crane position wearing a rucksack when other folks are about the house though... :)

Just a final note - make sure you are measuring to the top of your hip shelf.  An easy way to find this is to stand with your "hands on your hips" and slide them up/down until you feel them resting on the hip bone.  Chances are unless you are Simon Cowell this will be higher than where the waist band of your jeans normally sit.

Unfortunately physical height has little bearing on your back length.  I was convinced that being 6ft I would need a large pack but no matter what way I measured myself I kept coming out as medium.  As it turns out the Golite medium is perfect for me.  Despite our difference in height Kat and I have very similar back lengths, so she also takes a Golite medium. 

Title: Re: Rucksacks and Back Measuring
Post by: RedLeader on October 05, 2011

Interesting, so how can you tell if a bag is a good fit, discounting the measuring science?

I have quite sloped shoulders and the way the straps sit makes a huge difference. Unless the straps are nicely flat it's very uncomfortable and with the sloping it's a hard thing to find. Sometimes I think if I get a bag that sits on my hips okay then the shoulders don't feel so good.

The straps on the Mutant curve inwards which I'm hoping will help the shoulder issue.
(http://www.snowshoemag.com/media/content/691_3.jpg)

Title: Re: Rucksacks and Back Measuring
Post by: twentyclicks on October 05, 2011

Load it up with 10kg of stuff. If the hipbelt sits correctly on your hips, and you can have the straps comfortably on your shoulders, then it is ok. Loosen up the straps so you can get the weight sitting right on the hips, then adjust them back just-so. It could be, that despite your longer back, because of how you like the bag on your shoulders, the smaller size is ok. Because the straps originate lower than they should, they may be curving more in line with your slopey shoulders  :D

Title: Re: Rucksacks and Back Measuring
Post by: RedLeader on October 05, 2011

That sounds sensible enough. I did wonder if having a longer back would mean you could make a smaller bag fit nicely by loosening the straps so the bag drops to your hips.

Is 10kg the maximum recommended for a bag of this style?

Quote from: twentyclicks on October 05, 2011

Load it up with 10kg of stuff. If the hipbelt sits correctly on your hips, and you can have the straps comfortably on your shoulders, then it is ok. Loosen up the straps so you can get the weight sitting right on the hips, then adjust them back just-so. It could be, that despite your longer back, because of how you like the bag on your shoulders, the smaller size is ok. Because the straps originate lower than they should, they may be curving more in line with your slopey shoulders  :D

Title: Re: Rucksacks and Back Measuring
Post by: twentyclicks on October 05, 2011

You'll barely notice 10kg with it - but it's enough to make the bag 'sit' on your hips. With the framesheet I'd say 20kg would be around the maximum, but you'd need 2 ropes, lots of water and climbing hardware to approach that!

My wee BCB pack is very small, but it sits great with the straps loosened all the way. I also discovered with my own pack that, without a load-bearing hipbelt, the lifter straps are pointless and should just be loosened right up to let the bag pendulum onto the back of your pelvis... I think this is a lower position than if using a hipbelt.

Title: Re: Rucksacks and Back Measuring
Post by: RedLeader on October 05, 2011

I did a nerdy test pack last night and was excited to see I could defo do sub 10kg. I've never been out with less than 14kg   :o

Title: Re: Rucksacks and Back Measuring
Post by: twentyclicks on October 05, 2011

Bring on the 22nd - all this extra capacity for firelogs /medicinal tonic ;)