drj0n bagworks

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drjon
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drj0n bagworks

Post by drjon » Sat Jun 08, 2019 10:20 am

so, feel like this is as good a place as any to put this up...id love some feedback on the ideas I hope to bring to this thread...

I've been working on a way to have a quick on/off mount that will allow 4 point mounting of a bar harness for a wee bit now.

why? if you have ever used 4 point mounting then you will know - instead of being a wobbly, rattly nightmare, the harness becomes rock solid.

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Now various manufacturers allow for this sort of system. the primary one being Bar Yak - I have an ultra and would thoroughly recommend them.

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the other is Rockgist who sell a bar clamp based system designed to tension around the fork crown meaning it doesn't need to mount to the handlebars at all.

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factors that are important: rigidity of mounts or tension if using straps - some harnesses use straps and buckles that easily loosen. number of mounts - 4 is better than 3. position of mounts spread is preferred. then there is position of load - narrow trumps wide, lower and closer to head tube is best when riding.

so.... initially I made a harness and bag that works with the Bar Yak and jones loops. it is bomber stable and holds my sleep system and some cosies no problem.

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but - I have an interest in different handlebar set ups - Groovy Luv and Watson Parkarinos - and there is not enough room with a wide stem clamp to mount a Bar Yak neatly and parallel. I was also interested in using a carbon bar from a German manufacturer and as seems increasingly common, it uses a metal web integrated into the weave for strength at the bar clamp - the manufacturer advised me not to clamp anywhere but on this - precluding a bar clamp.

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https://www.flickr.com/photos/drj0n/478 ... ateposted/

hence proto one: it has a 20mm, close tolerance steerer mount to remove any likelihood of damage, and the acetal forward prongs are pretty rigid, the carbon tube is 10mm diameter and with the bar gives 4 points of mounting. but its pretty ugly eh?

so I got to thinking of a more refined option...

this will be 'dynamic' and use straps between the bar and the forward carbon tube to create the required rigid 'back mount' for the bag. im undecided on the strut design. I had good luck with the harness I made slipping a carbon fibre tube into a webbing envelope for lateral rigidity, so may use some 3mm carbon strip sewn into straps, which would mount onto the tubes with velcro, or I may use aluminium pieces I will either make or buy. there will be a carbon fibre tube running parallel to the bar and there will be straps to the bar and then i'll probably use voile straps for the front to hold the bag, due the stretch and thus tension.

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thoughts?

if (and its a big if) the steerer clamp ad other parts are viably easy/cheap -ish to make, I *might* be able to sell it.

of course, with rick hunter's Cow Catcher, this may well become redundant. Ive known rick for a long time and he is always highly innovative - using his kit in extremis helps drive them to be highly effective!

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Bearbonesnorm
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Re: drj0n bagworks

Post by Bearbonesnorm » Sat Jun 08, 2019 12:01 pm

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Looking at the above pic Jon. The arms only appear to be secured by way of 2 bolts (each) and they're in shear. There's potentially quite a bit of weight hanging off the front of the arms and obviously quite a lot of leverage acting on those bolts ... would it be possible to machine a groove / step into the alloy steerer top that the arms can slide into before being bolted to it? The bolts would then simply retain it while the physical 'joint' took most of the load.

Nice work :wink:
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drjon
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Re: drj0n bagworks

Post by drjon » Sat Jun 08, 2019 12:52 pm

yep- they are in shear. I reckoned 4xM6 bolts would probably be tough enough to take the weight, even in shear, but it would be a risk. if I pursued this, I would make it keyed in to the steerer part just as you suggest. I actually made this to fit under a stem, but on the bike in the photos there isn't room under the stem really. the idea was the lower tube would just be for stabilisation, the bars would take most of the weight. orientated as in the pics, you're right! but still, its probably not ideal.

aaaaaand when mounted under the 2cm height of the steerer unit is an issue... folk might not necessarily have this much space....

tbh, this proto is going to be shelved without being used: in making it the idea developed and so proto 2 will hopefully make everything better! thanks for the input! its great to access a hive mind!

lune ranger
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Re: drj0n bagworks

Post by lune ranger » Thu Jun 13, 2019 11:54 pm

Great work drjOn. Always interested to see the stuff you are working on.
Don’t want to rain on your parade but have you seen these:

https://www.sjscycles.co.uk/accessories ... -mm-0-deg/

Other lengths available as well.
I’ve used one to mount a trad bar bag on a trad tourer on a long tour. Also used one in a similar way to which you are proposing, for making a four point strapping structure for a dry bag.

Looks like your design is sufficiently different and could be adjustable and lighter than the Thorn one.

Are your harnesses available for sale? Looks good.

drjon
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Re: drj0n bagworks

Post by drjon » Fri Jun 14, 2019 7:14 pm

thanks for that! I knew about an older product very similar called a Fred Bar. I'm not surprised you've had good luck with it. the solidity over rough ground is SO much better eh?

the idea is this is as small and light as functionally possible and is also detachable easily. I received a couple of bits I need and now I just need to decide on the front strut. will keep this up to date!

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drjon
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Re: drj0n bagworks

Post by drjon » Sat Jun 15, 2019 6:30 pm

welp, got some time on the lathe this afternoon and finished off the harness stand off.

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https://vimeo.com/342468667

lune ranger
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Re: drj0n bagworks

Post by lune ranger » Sat Jun 15, 2019 9:04 pm

:-bd

Scud
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Re: drj0n bagworks

Post by Scud » Mon Jun 17, 2019 2:56 pm

Thats ace, looking for some sort of front support for my gravel bike for Torino Nice - kept having front bag rub tyre.

BreninBeener
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Re: drj0n bagworks

Post by BreninBeener » Fri Jun 28, 2019 6:53 pm

im loving it! will it be for sale? or do you need a beta tester?

drjon
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Re: drj0n bagworks

Post by drjon » Fri Jun 28, 2019 8:30 pm

maybe for sale. id need to have a way to make it MUCH more reasonably. the side parts are from a riser for a PRO dh direct mount stem, and are 23 quid alone...(for the kit, there are 2 thinner riser plates in the kit too) and there's a lot of work in the spacer. But if it is proven in terms of concept, ill work on how to actually 'make' it.

3D printing, as per the DeWidget, Strap Deck and Dangler is great until things start to take on a more x y and z shape. for plates and flat parts its reasonable - but as things get more 'depth' the cost goes up and up...thats why Strap Decks cost a bit, I decided to not compromise and put a curve on them to help cradle the load more than a dead flat plate would...

thanks for the stoke !

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Alpinum
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Re: drj0n bagworks

Post by Alpinum » Mon Jul 01, 2019 5:11 pm

Really like your work, be it fabric or alloys.

Or plastics...

Lovely when creativity has space to evolve. Eventually turn into usable things makes it even more worthwhile

Keep it up :-bd

drjon
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Re: drj0n bagworks

Post by drjon » Sat Jul 06, 2019 9:06 am

thanks dude! appreciate that - id recommend anyone who has ideas of making to try! I was wary of how my efforts would turn out for so long and with youtube and backpacking myog forums etc you can self teach pretty easily these days!
Last edited by drjon on Sat Dec 21, 2019 6:40 pm, edited 1 time in total.

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Bearbonesnorm
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Re: drj0n bagworks

Post by Bearbonesnorm » Sat Jul 06, 2019 6:25 pm

I think I'm being a bit dim here but what stops the whole thing from pivoting on the bolts? Is it simply the friction generated by the bolt or is there a mechanical means that locks it all in place?
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drjon
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Re: drj0n bagworks

Post by drjon » Sat Jul 06, 2019 9:40 pm

there is a strap that is of fixed length from the bar to the auxiliary bar, then the strap that cinches down on the dry bag goes from bar, round the dry bag to the auxiliary bar. that means tension in *that* strap stops the auxiliary bar rotating back up towards the handlebar and the fixed length strap from the handlebar to the auxiliary stops the auxiliary from being able to move away from the handlebar. sort of dynamic tension.

i'm going to make a harness that incorporates the fixed length strap, that way I just use side lock buckles on the front part.

in essence all the auxiliary needs to achieve is stand off from the head tube.

hope that makes sense!

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Bearbonesnorm
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Re: drj0n bagworks

Post by Bearbonesnorm » Sun Jul 07, 2019 6:25 am

With you Jon, ta. :wink:
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belugabob
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Re: drj0n bagworks

Post by belugabob » Mon Jul 08, 2019 9:06 pm

drjon wrote:
Sat Jul 06, 2019 9:40 pm
there is a strap that is of fixed length from the bar to the auxiliary bar, then the strap that cinches down on the dry bag goes from bar, round the dry bag to the auxiliary bar. that means tension in *that* strap stops the auxiliary bar rotating back up towards the handlebar and the fixed length strap from the handlebar to the auxiliary stops the auxiliary from being able to move away from the handlebar. sort of dynamic tension.

i'm going to make a harness that incorporates the fixed length strap, that way I just use side lock buckles on the front part.

in essence all the auxiliary needs to achieve is stand off from the head tube.

hope that makes sense!
The knee bone's connected to the leg bone - I've obviously had too much wine to have the faintest idea what all of that means - pictures, please...

drjon
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Re: drj0n bagworks

Post by drjon » Sat Dec 21, 2019 6:29 pm

https://vimeo.com/379577482

Well, ive progressed things a bit....

https://vimeo.com/380914152

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The original design used the TwinFix face plates for the Syntace stems. Admittedly a spendy stem, but they are real nice and the plates are available for retrofit separately.

They are designed for a mobile phone deck, or lights, computers or combos. Although the bolted on plate looks relatively flimsy in some ways, it will take a static load of 25kg. Actually a decent M5 bolt, if the mating surfaces are aligned well and there is reasonable threaded insertion, will probably take that and more in shear, but impacts in riding may increase the acceleration of weight to a degree that could cause damage on the simple forward mounted Strap Deck version, where straps do not go around the bar as well.

I'm in two minds whether to even try this out as the roll ends up being higher and further forward than ideal on test fitting. The second version remedies this and allows straps to go around the bar as well as through the Strap Deck. What this achieves is guidance for the straps, (id recommend voile) and a rock solid bar roll harness mount.

It weighs 70g in total and will hold a 5 1/2" roll absolutely rock solid. what's not to like? The bag here is a DCF hybrid bag I made that is waterproof and light.

I'll obviously need to put some miles on it and keep my fingers crossed that the TwinFix type attachment takes off (I think it should!) but I might add it to the line up in time...

Alright - merry Crimbo and here's to a good 2020.

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Bearbonesnorm
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Re: drj0n bagworks

Post by Bearbonesnorm » Sat Dec 21, 2019 8:58 pm

Looks very neat does that Jon :-bd
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pistonbroke
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Re: drj0n bagworks

Post by pistonbroke » Sun Dec 22, 2019 9:55 am

Very neat, perfect for clearing snow as well.
What is the name of those Syntace stems? Are they readily available and from where?
Edit, doh! I suppose Twinfix is the model.

drjon
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Re: drj0n bagworks

Post by drjon » Sun Dec 22, 2019 11:20 am

yep! twinfix versions of the megaforce and lightforce available at the synthase website, bike24, r2 bike or some other German shops...tend to be generally pretty good. also check out bike-discount.de as they sometimes have them for a deal.

thanks for the kind words chaps!

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Zippy
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Re: drj0n bagworks

Post by Zippy » Tue Dec 24, 2019 12:34 pm

That is a real life version of what's been floating around in my head for years. Nice work! :-bd I mean, I was gonna mount the clamp off the bars rather than the stem, but otherwise that's basically my imagination in reality :cool:

Nice work!

belugabob
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Re: drj0n bagworks

Post by belugabob » Tue Dec 24, 2019 4:18 pm

What is the distance between the bolt hole centres, on the twinfix clamps?

drjon
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Re: drj0n bagworks

Post by drjon » Tue Dec 24, 2019 7:18 pm

60mm

belugabob
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Re: drj0n bagworks

Post by belugabob » Thu Dec 26, 2019 1:29 pm

drjon wrote:
Tue Dec 24, 2019 7:18 pm
60mm
Thanks - will do some measuring, later.

That is between the upper and lower bolts, which mount the faceplate to the stem, isn't it? (Should have been more specific)

drjon
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Re: drj0n bagworks

Post by drjon » Thu Dec 26, 2019 1:46 pm

oh! sorry, no that is the c-c for the twin fix bolt holes - the face plate plates are pretty much 40mm - c-c( they are separate l and r sides) but I have some transfer punches coming to get a bang on 100% measurement, because a number of folk have asked if the face plates may work with other brand stems - can't condone it obvs, but If the c-c is the same I dont really see why not....stay tuned!

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