[Closed] Source for Closed Cell Foam - for Homemade Huck Norris

cheapo camping roll mat?

Here's who I used:

https://www.efoam.co.uk/closed-cell-polyethylene-foam.php?gclid=CjwKCAiA0IXQBRA2EiwAMODil0hA8bJHCp26KA9OPFCG7OuqPtqwYcYgdM1BQtWI8f6DXIdfmBjxthoCOQIQAvD_BwE

I ordered 15mm thick, 67mm wide strip by 2m (to go in 2.6" tyres) and then just cut a few notches in. I believe this is exactly the same as the new stuff from MarshGuard, but cost under a tenner 🙂

I've used this place for work stuff, before:

https://www.anyfoam.co.uk/sheet-foam.php

width 58cm, length 400cm, thickness 1.5cm

For two tyres, that site wants £49???

You need to do 58mm, 4000mm! At the moment you're sizing up a sheet 58cm X 400cm...... 😉

D'oh

If you want a simpler and easier alternative to a flat style Huck Norris, with the additional benefits of s****y pants Cushcore, watch this vid...

Only problem is 50mm backer rod isn't that easy to come by in UK; I've made do with 30mm (without having to split it down middle as video suggests) and it's done a fine job so far, costs about £1 an end and weighs about 40g per wheel (I'm #26forlife mind)

Pool noodles are another option, but not sure how they'll do on circumference for all you new fangled big wheel warriors.

Plastazote is a trade name for the material if you are googling

Thinking about it, it wasn't that I couldn't get hold of 50mm backer rod, it was more that I didn't realize until I'd already got the 30mm stuff off ebay.

If you have wide rims, probably worth the upgrade and it's still not gonna bankrupt you:

https://www.dortechdirect.co.uk/polyethylene-foam-backer-rod-50mm-circular.html

How's that worked for you then andyrm?

Are people finding these foam inserts allow the use of lighter "exo" type rear tyres on rocky trails? Or do they not really prevent holes?

I've found it good so far, on a 34mm internal rim and 2.6" Butcher Grid. You can see it's taken some whacks but no pinch flats yet - including a full day at BPW a couple of weeks back. That's at 78kg kitted up, 28psi rear.

Just bookmarking for reference

Thinking about it, it wasn't that I couldn't get hold of 50mm backer rod, it was more that I didn't realize until I'd already got the 30mm stuff off ebay.

If you have wide rims, probably worth the upgrade and it's still not gonna bankrupt you:

https://www.dortechdirect.co.uk/polyethylene-foam-backer-rod-50mm-circular.html

How did the 30mm work for you. I only run up to 2.3/2.4 tyres on not that wide rims. I'm thinking the 50 would be overkill.

The site you linked has it in all sizes but I guess the 30,40 and 50mm ones are the choice.

This is most excellent. I've just been umming and ahhing about what to do instead of procore, which has turned out to be just as much hassle as having inner tubes.

I wonder if there's value in keeping it full size in the tyre.

Given how cheap that stuff is I'm going to give it a go. Only need 2m cut in half for my 26er wheels

I've just ordered some 50mm, let's see how it does! I'm thinking that I'll leave it full circular like a flat tyre defender.

What do we think then? Backer rod vs flat foam cut with holes?

And what width for 25mm rims and 2.3-2.4 tyres?

How did the 30mm work for you. I only run up to 2.3/2.4 tyres on not that wide rims.

I'm running it on rims that are 23mm internal, 28mm external with 2.4 tyres...

Main reason I went for it is because I [s][b]always[/b][/s] used to burp tubeless, so wanted the extra bead support, but also fancied more rim protection after a summer in the alps dinging more rims than a colonic surgeon.

My burping issues are cured and although our local trails aren't that rocky, I've cased into tree stumps a few times and my rim is as pristine as if it'd been bleached...

That said, I'd reccomend going a bit wider if you regularly encounter mad rock and I'd like to try 40 or 50mm widths to see about the extra sidewall support.

How do u mount the tyres with the foam inside?

I've bought the 50mm for my 30mm IW rims.

Backer rod should be better at bead retention and over lapping the rim edge when the wheel is cranked over - I've seen Huck Norris fail in that scenario.

Basically as in the video...

Wrap foam around tyreless rim, cut to length, secure with zip tie, then remove from rim

Fit one bead of tyre

Insert insert, can be a bit of a faff feeding it around the rim and making sure the gap lines up with the valve, but it's pretty simple really.

Pour in tubeless sealant of your choice.

Insert other bead of tyre, grimacing at how white your knuckles are as you manoeuvre the final portion into place.

Inflate and dance merrily at the combined achievements of saving money and weight in comparison to the commercial products on the market, whilst ensuring your rim is ready for a solid pounding.

ensuring your rim is ready for a solid pounding

Sign me up!

Doub-entres aside, I thought I'd follow this up.

The packer rod arrived earlier in the week and I've spent part of today on general bike up keep including the inserts.

First up, the packer rod foam is less dense than the Huck Norris foam. A 2m section weights 110g, so cut in half to mirror a Cushcore insert would reduce this to 55g. THats 4-5x less dense. It's not sufficiently dense IMO to successfully mitigate against impacts if cut in half to be like cushcore.

At this point, I decided to put the entire packer rod in un-cut, which is more akin to the banger insert from Mr. Wolf.

I measured up and cut the extra length needed for my 29er wheels and attached it together with two cable ties looping through both ends.

Putting the insert in was a bit more involved than regular tubeless, but un-eventful and not excessively long. maybe an additional 5-10 minutes per tyre.

The technique of pushing the tyre bead under the insert into the rim well with a tyre lever to get enough slack absolutely must be applied otherwise you're never going to get the tyre on the rim without breaking something.

Pushing the tyre bead down and in like this does result in the bead sitting on the top of the valve and allows air to short-circuit when trying to inflate, so be aware of that. Its a simple matter to drag the bead back over the base of the valve, but its not obvious at first.

Otherwise, inflation was uneventful, as was topping up the spooge which I did via the valve and the bead.

Its clear that the insert is compressed by the tyre pressure. I did two today, and one rattles in the tyre where is circumference has reduced and is no longer tight on the rim. After I noted this, I made the second insert a tighter fit and that one is fine.

Its obvious that I need less pressure to get them feeling the same. I'm hopeful, given my preference for low pressures that the higher volume insert will behave a bit like a rockshox air token and increase the progressiveness of the tyre compression as well as providing physical bottom out resistance. Air volume in the tyre must be reduced by at least 60% I'd have thought.

Proof will be in the pudding. First ride out tomorrow, but on the soft soggy Mendips, I'm doubtful the riding its going to test it that much.

Details are:

LB 35mm 29er carbon rims
50mm packer rod
Schwalbe Nobby Nics 2.35.

[img] [/img]

According to teh data sheet for the high density foam @andyrm linked to, it compresses by 50% at 170 kPa, which is about 24 psi. So it's going to get half the size. But can't do that circumferentially so it may get even thinner than half size because it is being kind of stretched. But then @Scienceofficer says the round stuff rattles, so that appears to be compressing in two dimensions but not in the third. Which is a bit weird.

I am not sure tbh, what this stuff does when in the tyre. If you pinch, will it spread teh load out a bit? Not much, I'd have thought. If it is acting as a "tyre within a tyre" then perhaps.

I'm going to try the 50mm packer rod a bit later too, arrived yesterday.

So far, the high density foam I've used has been all good, I run 28-30psi rear anyway, so probably pinch less than others.

Greyspoke - cheers for the actual numbers, that helps. Wonder if I can now go searching for foam by compression figure??

Given that the rod is very long and very narrow, I'm not really surprised to see it get baggy under a bit of pressure. It'll be more subject to compression changes in its shorter dimensions. Given the relative differences of OD/ID over its 50mm width, it wouldn't need to reduce its sectional area much before becoming loose. The material is a bit stretchy and its under slight tension to make it a close fit on the rim. The second one I made tighter was only about 40mm shorter and its remained tight enough on the rim to not rattle.

Bear in mind that the backer rod is also a different product from the one andyrm linked to. Density is 35kg per m3, but I can't find any expression of compression under pressure.

Any of these inserts should behave along the same lines as the products actually sold to prevent puncture and provide rim protection. The question in my mind is whether they will work sufficiently well to reduce pinch punctures and help protect rims for a fraction of the cost.

I'm hoping my experiment will provide some cut resistance via sacrificial damage to the insert like Huck Norris (and cushcore, and Banger in fact), as well as function as a damper due to its thickness providing physical resistance to tyre compression, and ramping up air pressures in the air chamber under larger tyre deformations.

Given that the insert is squishy and the tyre carcass is stretchy, I don't know how well its going to be work or what behaviours I'll see, but the point is, if it does, its £2 per tyre, not £35 in the case of Huck Norris, £75 in the case of cushcore or £95 in the case of Banger.

Actually thinking about it, I've no idea if the quoted figure is linear compression or all round compression, and I'd have to purchase a copy of BS ISO 7214 to find out. Zote say they do [url= http://www.zotefoams.com/downloads-category/plastazote-property-data-sheets/ ]harder and denser grades[/url] thant he LD45, but they may not be available in small quantities.

any update thoughts on this.  I've been playing around with tyre pressures and likely to get some the dortechdirect rod either 40mm or 50mm for 30mm OD rims

Just switched rear tyre at the weekend - 50mm backer rod all good! Few little nicks in it suggest it's done it's job properly but no pinch flats, burps or bashed up rims so for the tiny price, I'd say it's a resounding success 👍👍👍

Actually, yes.

The backer rod has been pretty effective, but it's certainly susceptible to damage. I'm not really surprised, since it's less dense than either the Huck Norris or Cush Core and I've been running 20 psi on 2,35 tyres.

<span style="font-size: 0.8rem;">Now the drier weather is here, I've just whipped mine out to see how it's doing. It's riddled with cuts and slices, but my carbon rims are both fine. I was pretty sure it was doing something after hearing some funny popping noises on some heavy hits over the duration.</span></span>

Interestingly, the one ride I had without the insert at the weekend made the tyre feel really pingy and I thumped through to the rim twice on roots.

The up shot is I'll be continuing to use it, but it seems like it needs replacing every 6 months for my riding preferences and low pressures. Still, it works out at about £3 a year as an insurance policy for my rims, and I prefer the way the tyres feel too.

.

Those are the most severe cuts by the way, plenty of other minor cuts around the circumference.

Awesome stuff, thanks for the update.

I found some 75 kg/m3 foam to use.

hi , im struggling to get hold of this stuff in sweden. any ebay link or alternatives to dortechdirect?

ooh, poah, got a link?

http://www.easycomposites.co.uk/#!/core-materials/closed-cell-foam-and-3dcore/easycell75-closed-cell-pvc-foam-core.html

will need to cut and shape but should do the same job as huck norris

What thickness were you thinking? I note the 10 and 25mm thickness ones are stated as being 'difficult to bend by hand'

Book marked as this might be useful for an upcoming Morzine  trip.

i ordered the 10mm one.  heat gun and cut outs will sort the bending.

All told, I've found backer rod inserts to be nigh on miraculous... not only do they protect the rim and prevent burping, they also let you ride with a flat tyre... couple of months ago got a flat on the front towards the end of the ride and after a few tentative moments, learnt that in a stituation where I'd normally get off and push back to the van, there was still plenty of grip to be had; that was with 30mm, so I'd imagine if you go full girth with the 50mm, it'd be better still.

Might even start marketing them~ just need to come up with a name;

Foameo's rim jobs seems pretty catchy

that stuff I found isn't suitable.  I'd go with the backer rod

Pound land has some 50mm diameter pool noodles at the moment. I bought two with the intention of giving it a go.

Why not suitable Paoh?

They do a version with cuts in already that would bend better!

Was just about to buy that stuff from Poah's link - have to put it on hold till we find out why it's no use.

So with the 50mm packing foam stuff. How well does the stans get round the wheel.or does it get trapped?

I wonder how much it actually spreads out the load of a whack to the rim from a rock. Obviously it will do so a bit, but it doesn't appear to be that strong.

On the back of putting a hole in the 2.5" DHF I'm running on the rear of my BFe, I ordered 2x approx. 2M of the 50mm rod a few days ago from Dortech.

One of the 2M lengths now resides in that wheel - a 26" Flow Mk1 - and it fits perfectly.  Just!  The big volume tyre helps (wouldn't want to try 50mm dia on a 2.3" Maxxis), and the length is exactly right for 26".  Might need two shorter sections for 650b or 29".

The tyre was a bit harder to get on, as the rod pushed the bead into the rim hooks, so a screwdriver was used as a tyre lever to get the last 15cm of bead on.  The tyre inflated with a compressor with ease (it's a non-TR DHF) and seems to have stayed up. It also feels somewhat like I guess a runflat does without any air in it.

It'll get a run out in Chopwell on Sunday over some rocks and roots, but hoping it'll be good.  Since the Spitfire snapped I've been using my spare BFe and my riding style still isn't acclimatised to hard tail riding just yet, and getting the air pressure in the rear tyre is more of a guess than knowing the exact number.

As for the fluid, I'm using Oko diluted about 50:50 with water for now, so hope it'll still seal.  However, if I was to repeat I'd cut channels out of the upper and lower edges of the rod, and possibly drill a lot of 10mm holes as well so that the fluid can migrate.  In fact, I'll be trying it on the HB160 when it eventually arrives!

Can't find any 2" backer rod out here in Canada. Do we think taking two 1" rods and taping them together would work? You'd the width but lose out on the height. Maybe it would set too well in the tire?

Edit: Another option looks like this stuff:  http://foamzone.ca/rv-marine/closed-cell/xpe-closed-cell-charcoal.html

A couple of strips of that for ghetto huck norris style insert?

So this backer rod stuff sounds like it’s the pick, are people cutting it flat or leaving the whose sausage in the wheel?

I’m also debating whether to put this in both wheels or just the rear. Rear gets the abuse but if it helps to run lower pressures in the front that’d be pretty sweet too. Any thoughts from people who have tried it?

So this backer rod stuff sounds like it’s the pick, are people cutting it flat or leaving the whose sausage in the wheel?

Today I've setup 4 rear wheels thusly:

- 30mm 'whole sausage' with 2.0in tyre on 19mm internal (XC race setup)

- 40mm sliced in half with 2.0in tyre on 19mm internal (alt XC setup)

- 40mm sliced to 2/3rds thickness (ie: 1/3 removed) with 2.3in tyre on 26mm internal (trail)

- 50mm sliced in half with 2.4in tyre on 30mm internal (alt trail)

Not ridden any of them yet but planning to test them out as and when I have the time and on appropriate rides, curious to see what the difference, if any, in feel and protection there is between the different thicknesses.

I've still got some unmolested 40mm and 50mm rods and pondering whether to wang a complete one into my 2.8in +tyre wheels...

40mm backer rod in 28mm rim and 2.4 tires

No rim strikes today coming down heartbreaker ridge at pace nor mastermind

I'm sold for now. Will monitor

i bought two huck norris (norrisi?) for 50 euros. couldnt be bothered with the faff.😀

The 50mm backing rod proved it's worth in Ae today coming down Omega Man when the back wheel impacted rather hard on a pointy rock - was convinced the tyre was going to go down, but it held, and only because of the bodge.

Out of the 6 of us there, 2 had snakebites - one Fx1 & Rx2 running tubes, one 2xR tubeless then tubed.

I'm sold on it, especially on the hard tail.

Was that a whole 50mm rod or cut down/in half? What size tyre wa that in? I have a couple of uncut 50mm rods here but can’t see them realistically fitting in anything smaller than 2.8 or more without pretty much filling the tyre.

EDIT - ignore me, just spotted your earlier post with all that info in 🙂

I'm running 50mm rod as a full rod in Specialized 2.6" tyre (rear only) on a 33mm inner width LB rim.

Seems to work a treat, carries some marks now where it's done it's job, but held up brilliantly.

"bought two huck norris (norrisi?) for 50 euros. couldnt be bothered with the faff."

Who was faffing ?

5whole pounds and 10 minutes work .

No faffing happened. Beer did though

Top work everyone. This is some premium forum. 🙂

I have a Huck Norris on the bike and a Mr Wolf Banger in the cupboard because I'm very gullible. I must get around to actually trying the Mr Wolf...

I'd be very interested in how you find the Mr wolf banger.

I'm interested in how it moderates the tyres compression and rebound. It was the inspiration for me to try the full fat 50mm backer rod.

@trail rat. I was faffing. I can't get hold of these things in Sweden without significant postage and/or searching.  Good luck to you guys though. Top bodging!

How is this foam backer any different to pipe insulation? (comes in various sizes and is easily available) except for the obvious core removed for the pipe.

Good thread this.

20 metres of 50mm winging it's way to me now.

4 bikes to do.

£23 posted.

Could anyone give me an idea of the size needed for 2.35 tyres on 25mm ID rims?

Great thread by the way guys!

I was really sold on the idea of the huck norris and cushcore when I first heard and read about them, but the price kinda put me off. I've just ordered 2 x 2m lengths of the 50mm backer rod, and going to set the capra up with it.

Is it important to get a fairly close fit around the rim with the backer rod?

Tested again  last night on a trail call rim pinger.

Running low pressures (you can see the wear lines round the sidewalls) I didn't have any new dings/burp my tire nor did I hear any rim pinging......

My mates managed to ding and burp . We were all going hell for leather though 🙂

They are off to get some backer rod now.

"How is this foam backer any different to pipe insulation? (comes in various sizes and is easily available) except for the obvious core removed for the pipe."

It's more dense and the core isn't removed so it's even more dense for a given od.

that stuff I got couldn't be bent and it was quite brittle TBH.

the 40mm rod looks a good plan for my 25mm rims and baron tyres.

Fitted some 50mm backer Rod on my rear 30mm ID rim last night which is running a 2.5 WT Exo maxxis aggressor

Cut in half as can't see how you can get a full Rod in there.

One half of a 2m Rod fitted almost perfectly.

What kind of pressures have you been running on the rear with this in?

I'm a serial rim dinger riding mainly in the peak.

Also I went overboard and bought 20m of the stuff which will last for years so if anyone in Sheffield (S10) wants a of 2m section for the measly cost of £2.50 let me know.

I also bought 20 m, because there's always R&D required with the DIY approach, and I also have two bikes.

If you watch the Cush Core installation video and apply the same principles, you can get the whole thing in, but IMO having the whole thing present has a deleterious effect on slow speed mid size hits. I ended up cutting about 1cm off the height. I'd rather have a 60mm insert for the width too.

Nearly all the cuts are on the outer radius, further out than the rim bead. This tells me that I'm picking up most of my impacts when the bike is leant over. It'd be nice to have the insert contact and support the sidewalls of the tyre with a wider insert, and have more material at the margins.

92kgs, 2.4 29er tyres on 30mm internal rims. 18psi front, 21 rear.

how does the extra weight effect peddling?

Generally I don't try hawking my wares when I'm riding, so I don't know.

...all the cuts are on the outer radius, further out than the rim bead....

@scienceofficer - this would alternatively support the theory that when in a tyre under pressure, the whole thing shrinks.

Aye. It undoubtedly does.

Following this with interest,

Just a thought, would slicing say 15mm equally off the the top and bottom of a larger diameter backer rod be easier, so it is a, say 50mm wide strip 20mm thick (or whatever it needs to be) with curved edges, that would float between the tyre walls, as per Huck?

The material spec appears to be there or thereabouts, it’s just the shape that’s the issue?

It's not like anything like a similar spec. It's at least 3 times less dense., Which is why you need a greater thickness.

how does the extra weight effect peddling?

50mm insert cut in half is 60-70g on my scales so basically irrelevant, doubly so if it lets you get away with lighter tyres as a result

Cheers SO, I tried mine down a rocky trail (cavedale) with the same pressures as you noted tonight and everything felt great.

Just need to test it out on Potatoe Alley and Cut Gate to really test it out as these two trails are usually the source of my rim denting.

Set up a 2.6 with the full 50mm on the front with the usual amount of stans. Realised I'd put the tyre on the wrong way so had to undo it all. Usually there'd be a pool of fluid in the tyre but on this set up there were dry patches. Are people putting in a lot more fluid?

Been testing out the 50mm backer rod. I've still had some pinches when fairly hammering it, at lower pressures. however I think I've gotten  away with more than I would have done without (obvs. Just an opinion can't back it up scientifically).

The complete uncut backer rod seems to absorb a lot less sealant. When I cut it in half it seemed to take a lot more, so I doubt there is any weight saving whole thing vs. halved.

30 mm Id rims, 80kg. Maybe 30psi in rear but I do hammer through rocky trails