DIY Alpkit drybag Panniers 431g

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ljamesbee
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DIY Alpkit drybag Panniers 431g

Postby ljamesbee » 18 Aug 2015, 8:51pm

I thought I would show my DIY panniers in case it comes in handy for anyone. I drew inspiration from some Ortlieb 'back roller classic' panniers, which I used for aaages touring and commuting. The no. 1 thing I loved about them was the clip system (especially while I was commuting in London). So easy to attach and remove them that you can do it with one hand while juggling other stuff. Made them out of:

-Ortlieb pannier spares,which you can buy. I cannibalised some ruined bags which used the 'QL1' system
-Corrugated plastic sheet sometimes called correx - I bought this from a framing wholesaler in Birmingham for like £3 or £4
-2 x Alpkit 20L dry bags. I Actually went to their factory/shop and they are really nice :)

All you do is 1) cut the correx sheet to the right shape to provide a backing for the bags. I calculated that 28cm wide for the backing would give the largest volume for 20L dry bags. The height of this is up to you. 2) Cut an oval shaped base - estimate from drybag dimensions 3) wrap sharp edges of correx in duct tape 4) determine best place for QL1 clips for your particular rack - as low and far forward as possible, but make sure to avoid heel strike 5) screw the QL1 clips through the backing and through the drybag material using ortlieb screws. Having someone to help you makes it much easier to get the bag positioning correct.

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Next to an Ortlieb bag
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Pair of bags. One filled, one empty and with a 'fiber flare' light on it.
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Weight of one bag
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On an electric bike ;)
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The base of one of them
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The backing when the bag has been assembled.

I've used them now for a couple of months and they they work. Don't really notice any difference between them and the Ortliebs. Only thing I might do at some point is to add a shoulder strap to them.

The final weight for each bag is 431g and 856g for both. A whopping 1050g saving over my Ortlieb bags :lol:.

Graham O
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Joined: 27 Jan 2007, 7:54am

Re: DIY Alpkit drybag Panniers 431g

Postby Graham O » 18 Aug 2015, 9:32pm

What a coincidence as I've been thinking of something very similar. Trying to design some lightweight panniers, I realised that those Drybags are ideal for for the task. Hadn't thought of using correx though; a good idea.

bainbridge
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Joined: 26 Oct 2014, 7:19pm

Re: DIY Alpkit drybag Panniers 431g

Postby bainbridge » 19 Aug 2015, 12:11am

Tidy job they look really good on the bike!

What would the total cost be if everything was purchased?

How do they stand up in a downpour?

It's midsummer :-)

ljamesbee
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Joined: 16 Aug 2015, 12:40am

Re: DIY Alpkit drybag Panniers 431g

Postby ljamesbee » 19 Aug 2015, 2:15am

Graham O wrote:What a coincidence as I've been thinking of something very similar. Trying to design some lightweight panniers, I realised that those Drybags are ideal for for the task. Hadn't thought of using correx though; a good idea.


The correx works well. I cut it so that the corrugated structure was horizontal so it has more strength in that direction. Had no problems with it, but it's possible the other way would have been better. Not sure really.

If anyone wants some, I have a bunch left and could post some at cost of postage. I bought a sail sized sheet on a particularly windy day and nearly got blown over carrying it to the car :lol:.

bainbridge wrote:What would the total cost be if everything was purchased?

How do they stand up in a downpour?

It's midsummer :-)


They're proper dry bags - you need to squeeze the air out of them when you close them! In light rain they were fine. I'm pretty confident they would be fine in heavy rain as well. You could always get some very light dry bags to use as a liner.

I think it would cost like £50 to buy the exact parts I used. (ortlieb parts from jejames). They work well enough that I would (very reluctantly :evil:) pay that much to make them if I didn't have the parts already.

-2 E170's - Upper rail
-2 E109 or E110's - Lower rail with hook
-2 E162's - rack hooks with strap

These places seem to sell the spares

jejames cycles - some things show as out of stock, but I'm pretty certain you can still order everything
sjs cycles
rose bikes (in germany)
ghyllside cycles
wiggle

You could also buy some of these Ortlieb bags, and some dry bags, then switch all the parts over. Would save the weight, and you would have the ortlieb shells to use at some point in the future.

To make them cheaper, I would probably buy some of these bikehut panniers, or something similar in order to get all the mounting hardware. I'd then buy buy a cheap ebay dry bag. Not gonna be as good as the alpkit bags, but you can always replace them later. That would let you make some (which would be even lighter than mine!), for like £23

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Heltor Chasca
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Location: Near Bath & The Mendips in Somerset

Re: DIY Alpkit drybag Panniers 431g

Postby Heltor Chasca » 19 Aug 2015, 7:29am

I'm dead impressed. Well done. The choices are limitless: you could go all military or fluro-orange. Lomo in Scotland make good, decently priced dry bags. I might try something similar for my Big Dummy one day when life calms down to a blur!

reohn2
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Re: DIY Alpkit drybag Panniers 431g

Postby reohn2 » 19 Aug 2015, 8:52am

I think they're a good idea,my reservations are the positioning could be a lot better on the rack,which in the photo is too far back.They'd be better much further forward or tilted to bring weight over the rear axle.I do understand about heel clearances.
And would they stand up to a spill 'n slide on say chip n seal tarmac?
If they were torn open they'd need a roll of gaffer tape to mend them.
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mjr
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Re: DIY Alpkit drybag Panniers 431g

Postby mjr » 19 Aug 2015, 8:58am

Blobs of glue to seal where the mounting hardware goes through the bag might be a good idea?
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
All the above is CC-By-SA and no other implied copyright license to Cycle magazine.

Graham O
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Re: DIY Alpkit drybag Panniers 431g

Postby Graham O » 19 Aug 2015, 8:59am

reohn2 wrote:And would they stand up to a spill 'n slide on say chip n seal tarmac?
If they were torn open they'd need a roll of gaffer tape to mend them.


I, too, was wondering about their durability and was considering having a ballistic nylon mesh surround them which would also provide additional "pocketing". But the easiest solution is to carry a spare drybag which could be used if one was damaged. It would still be cheaper and lighter than a pair of Ortliebs.

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simonineaston
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Re: DIY Alpkit drybag Panniers 431g

Postby simonineaston » 19 Aug 2015, 9:46am

Top Job, reporting on this for us James - thnx :-)
At one stage I was trying to work out how to make the panniers out of mesh, and simply pop individual dry-bags in the mesh 'pannier' but I'm thinking your way could be better. Am tempted to give 'em a go.
(rides: Brompton nano & ever-changing Moultons)

beardy
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Re: DIY Alpkit drybag Panniers 431g

Postby beardy » 19 Aug 2015, 11:19am

I like the general idea a lot, I have seen Correx reinforced panniers weighing about 450g each.
I would much prefer to use a drybag with a box shape, even with a box shape the Correx soon curls, with a cylinder I can see that happening even more rapidly.
The cylinders also strike me as being less aerodynamic which is more of a concern for a road rider.

Any box shaped dry bags out there?

Graham O
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Re: DIY Alpkit drybag Panniers 431g

Postby Graham O » 19 Aug 2015, 11:44am

beardy wrote:Any box shaped dry bags out there?


The problem with a box shape is that it is harder to make waterproof. Whether taped or welded seams, it's not easy, so the usual solution is to make the outer box shaped and fit a loose dry bag inside.

I can make drybags and tape the seams, but the prices from Alpkit are such that it's not worthwhile. This thread has motivated me to pursue the project and see what I can come up with.

ljamesbee
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Re: DIY Alpkit drybag Panniers 431g

Postby ljamesbee » 19 Aug 2015, 4:44pm

reohn2 wrote:I think they're a good idea,my reservations are the positioning could be a lot better on the rack,which in the photo is too far back.They'd be better much further forward or tilted to bring weight over the rear axle?


The positioning is because of heel strike. I had considered making them so they could be mounted at an angle, but wanted to keep them as simple as possible.

mjr wrote:Blobs of glue to seal where the mounting hardware goes through the bag might be a good idea?


Couldn't hurt. Worth saying that Ortlieb don't do that. I think it's just the design of their screws they use that keeps water out. One thing you could also do in addition to your suggestion is put a couple of iron-on nylon patches to reinforce the areas where the screws go. That or some 'tuff tape' or something similar.

beardy wrote:I like the general idea a lot, I have seen Correx reinforced panniers weighing about 450g each.
I would much prefer to use a drybag with a box shape, even with a box shape the Correx soon curls, with a cylinder I can see that happening even more rapidly.
The cylinders also strike me as being less aerodynamic which is more of a concern for a road rider.

Any box shaped dry bags out there?


Not quite sure what you mean about the correx 'curling up'. I put the corrugated structure horizontally so they won't curl up that way I don't think. The weight of the contents seems to keep the bag straight in the vertical direction. If I recall correctly, I used 4 or 5mm correx which may have been thick enough to prevent what you are describing.

As for durability, they are good as new after a few months use. There are definitely tougher bags out there, but the drybags are not too expensive so can always be replaced. I researched the dry bags quite carefully as I wanted them to be as tough as possible, with a high denier count fabric, but still low weight. The alpkit ones were basically the best I could find and I think they're really well priced for what they are. The loops on the side are really useful as well.

The bags themselves are an oval shape (as the baseplate photo demonstrates). I cut the oval baseplate asymmetrically (flatter back), and the horizontal correx structure keeps the back of the bags relatively flat. The resulting shape is quite aerodynamic (I think), as it's more like a semi-circle. The width that the correx backing is cut to goes some of the way to determining the resulting shape of the bag. If I had the backing narrower, there would be slightly more volume, but a less aerodynamic shape. 28cm seems to be the best width (for the alpkit bags)

ljamesbee
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Re: DIY Alpkit drybag Panniers 431g

Postby ljamesbee » 19 Aug 2015, 4:50pm

Graham O wrote:This thread has motivated me to pursue the project and see what I can come up with.


Look forward to seeing how they turn out :)

iandriver
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Re: DIY Alpkit drybag Panniers 431g

Postby iandriver » 19 Aug 2015, 5:14pm

Interesting idea.

I've heard of nylon chopping boards being used to make the back plate:

http://www.ikea.com/gb/en/catalog/products/90202268/
Supporter of the A10 corridor cycling campaign serving Royston to Cambridge http://a10corridorcycle.com. Never knew gardening secateurs were an essential part of the on bike tool kit until I took up campaigning.....

ljamesbee
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Re: DIY Alpkit drybag Panniers 431g

Postby ljamesbee » 19 Aug 2015, 5:34pm

iandriver wrote:Interesting idea.

I've heard of nylon chopping boards being used to make the back plate:

http://www.ikea.com/gb/en/catalog/products/90202268/


VERY good idea. Useful multi-use item as well for chopping board while touring, provided it's not screwed in. I think this type is lighter.

You could perhaps use much thinner correx to screw the mounting components into to provide a permanent backing, but then use one of those chopping boards as a removable backplate. I do a similar thing when hiking with my sleeping mat to give my bag more structure and it works for me.