Source for Closed Cell Foam – for Homemade Huck Norris

I’ll give the spare rod a try.  The original one had a fer holes drilled through it to allow the sealant to pass easier – didn’t work, it seems!

Latest update from me…

This weekend I survived yet another biblically wet 24/12, and used it as an opportunity to try the inserts on a longer event in an XC setting.

Setup was thus:

– 19mm internal Rim

– 2.0inch TR tyre

– 30mm backer rod (complete)

– On a MK1 Scalpel with a whopping 67mm of rear travel

I’ve ridden this setup briefly before as a test and already worked out I could either lose 5psi or run as normal and have extra support and protection. During the dry laps in the morning I opted for the normal setup and ran at about 28-30psi and just got on with it. Newnham isn’t that technical but there are lots of roots and pointy rocks that can easily cause a pinch if you’re going full gas and get sloppy and I was (attempting) to nail the descents, quickest lap was a smidge over 31 mins and I wasn’t holding back, no issues whatsoever despite thumping the rim a couple of times to the point where I winced but got away with it, who knows if the rod saved me or not….?

When the bad weather came in over night my rather optimistic tyre choice was causing me a few issues losing traction so I dropped the pressure down to about ~23-25psi and regained some composure on the slippy bits. I stopped mid lap to let a bit more out, can’t be sure but probably down to about 19-20psi which felt pretty soft to the thumb test for a measly 2.0 inch tyre, but when riding felt like it was firmer, so probably the volume compensation thing kicking in there and it felt more stable than that kind of pressure ever has with those tyres on that rim.

At the lower pressure I was regularly feeling muted contact on some of the faster rooty sections and was happy that I didn’t have to be quite as careful as I would normally. Also felt a bit more contact on the rocky descents but tyre felt nice and stable and again no issues, this time I’m convinced the backer rod helped as there’s no way I’d have got away with that pressure and that amount of contact without it.

So to conclude, I’ll be continuing to use them as there seems to be literally no downside, the weight is negligible and effects all positive. I’ll probably experiment a bit more with the bigger rods in bigger tyres to work out the volume thing a bit more, I might even try a 3/4 cut 40mm in the 2.0 inch tyres at some point.

I’m toying with the idea of trying one of these cut in half in the rear, on a 2.6″ tyre to see how it compares to 50mm rod in the same tyre:

https://amzn.to/2As6yD5

Will report back!

My 2p’s worth after a month or so running the 40mm backer rod. Its in a Maxxis Aggressor 2.5 WT on a Hope 650b DH Tech rim on the rear and it definitely works. I pulled the rod together to make a hoop round the rim and trimmed off an additional 40mm or so, meaning it was short of joining up if wrapped round the rim. So,  off the rim I joined it with 2x zip ties and a short wrap of tape. Fitting it onto the rim I had to stretch it on a little but this ensured that it sat in the rim well and wasn’t floppy inside the tyre. Tyre seated 1st time with a track pump and minimal effort. Cutting a small cross in the valve aids inflation too.

Running 26-28psi, (feels firmer) its stable at speed over a wide range of surfaces, I’ve not had any fitting issues, doesn’t seem to soak up the Stans, although I guess this would change if it was cut length-ways. When pressing on you do get the occasional “oh shit!!… I’ve got a flat” feeling but so far, touch wood its just that.. a feeling. I’ve cased a couple of rocks and roots round the Peak that would have probably pinch flatted had the rod not been fitted and its taken the hits without issue.

I’ve got a 50mm rod still in the garage and plan to try this next time. I think fitting the tyre might prove a bit tricky though due to the volume it takes up.

All in all I’m pretty impressed for just over a tenner

Carlos

would 50mm backer rod be Ok in a 3.0 plus tyre on a 45mm rim Or will i need something bigger? and is bigger available?

@lawmanmx have a look at my link a couple of posts above, that’s 65mm so probably a better bet I reckon, should do a better job supporting sidewalls on that setup. I’m using 50mm in a 2.6″ tyre on a 33mm internal rim so that seems a sensible step up 👍

mmmmmhhh? they look a bit ‘flimsy’ compared to the solid backer rod stuff tho Andy, have you got yours yet? if so, what is it like in comparison?

Should be here tomorrow so I’ll report back!

Soooo, has anyone tried a 50mm backer rod in a 3.0 plus tyre yet?

I Ordered from ratbite as it was a last minute decision before Alps trip.

Bit of a ballache getting the tyre mounted. 29er hope rim, 2.35 SG Schwalbe tyres. Had to cable tie the tyre as I worked round as the thick side walls plus the insert kept pushing the tyre back off. Got there in the end though and as I found out later it’s easier with two people.

Probably ran my pressures to high as I wanted to avoid problems so can’t comment on feel or effectiveness…….. Last day though a broken spoke pushed through the rim tape resulting in total air loss. Scratched my head over what to do exactly as I couldn’t be bothered to pull the insert out to run with a tube as it was nearly the end of the trip. So balls to it….. Rolled down quite a long rough trail for 5/10 mins on just the insert only. I was being carefull obviously but was surprised how good the insert coped. Started super slow but kept getting a bit quicker as the tyre kept its shape, just felt like low pressure.

Insert is wrecked now though. Got me thinking it would be good for races where it would get you to the end of a stage quicker than fixing.

Think I’ll order a big roll of backer rod and experiment with size and pressures.

As mentioned the ratbite stuff is cleanly cut in half 50mm with radius edges and a channel down the middle.

Backer rod after a weeks Alps riding, I was aware of a few hard strikes on the rim on some descents. No damage to either the tyre or the rim.

I’m happy with how its performed for a couple of £

What size wheel,tyre and rod Bruneep?

27.5   DT swiss E1700 25mm / Maxxis Minion SS 2.3  and 40mm rod

First puncture for a while yesterday, three rides into my backer rod trial. To be honest one leak was the tyre tread (so a cut from a rock etc) and one was what I assume an existing dent. It was ok doing the 1km back but certainly wouldn’t run it flat for long periods of time out of choice!

I did notice the rod was now a bit rattly inside the wheel, didn’t pop the bead so off as the sealant worked so hoping the cable tie join hasn’t failed and its just compressed a bit.

Ride feel is definitely different, actually feels worse at higher pressures as its draggy/damp feeling. Once you drop the pressure it feels better. This is 50mm backer complete in a 2.35 aggressor on 32mm internal (perhaps right on the border of the smallest tyre this rim would suit..)

I bought some of this to try in my rear wheel, it was a new setup a couple of weeks ago, I filled the tyre with 100ml of Muc Off sealant.

I removed the tyre this weekend out of curiosity and noticed that all bar around 30ml of the sealant had been absorbed by the backer rod. Needless to say I haven’t put it back in…..

it was a new setup

New as in new tyre? I only ask as I always find I lose a fair bit of sealant up in just sealing a tyre when it’s brand new, porous sidewalls and all that. I invariably have to top up again after a week or so with a new tyre, but then after that it’s stable.

I’ve not noticed the backer rods I’ve been using absorbing much, 20-30ml maybe at worst after a month or so. It’s closed cell so shouldn’t soak up much at all.

When I fitted the backer rod it wasn’t a new tyre, it had been on the wheel for a month or so before. With the Muc Off sealant being pink, the backer rod is now also very pink!

Re:  backer rod absorbing stuff – if it was absorbing it all through it would absorb more than those amounts possibly, Have you tried slicing it through to see?  Maybe that is the absorption into the surface layer where there are some open-ended pores?

Yeah, I can understand it getting a light coating of sealant but it really shouldn’t absorb it seeing as it’s closed cell. Mine certainly aren’t wet through, even the ones I sliced in half lengthways before fitting, they have a layer of sealant on the cut face, but nothing more and have only gained ~10g in weight so can’t have sucked up much.

I inspected my set-up whilst changing tyres at the weekend.

I have run a full diameter 50mm backer rod in a 29 x 2.4 Maxxis Ardent on a 30mm internal DT rim.

I have been experimenting with tyre pressures, some of which have been too low, and I have felt the foam rod saving my rims a couple of times. The rod had a few slits like those shown in bruneep’s photos. Because the slits are only just at the very edge I think that there is actually minimal protection of the rim sidewall. I think the main protection is offered by the height of the full rod. Because the foam is much lower density than a Huck Norris, and because the rod is only just wider than the rim, I would suggest that a sliced rod would offer little or no protection on rims this wide. There was no liquid sealant in the tyre after 6 weeks.

I re-fitted the rod with a 29 x 2.25 Ardent Race, which was much harder to fit than the bigger tyre was because almost the whole volume was taken up by the backer rod. It rode lovely when pumped up though.

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How tight are you making the “circle” when fitting? Mine was a snug fit initially but is now a bit rattly inside the tyre- this is 50mm in a 2.35 Maxxis/32 internal rim.

I do have spare 2m lengths of 50mm if anyone wants to give it a shot, £5 for 2m + postage.

I pulled the rod together to make a hoop round the rim and trimmed off an additional 40mm or so, meaning it was short of joining up if wrapped round the rim. So,  off the rim I joined it with 2x zip ties and a short wrap of tape. Fitting it onto the rim I had to stretch it on a little but this ensured that it sat in the rim well and wasn’t floppy inside the tyre.

From my post up there^^

Since being fitted its not become rattly and after checking has absorbed minimal Stans Fluid

Carlos

Cheers, will take it off today and trim a bit off.

I’ve had one go a bit baggy and rattly, chopping off a bit more and reattaching did the job.

I’m now on my 2nd insert in each of my HT and FS, both of which ended up looking just like bruneep’s pictures, and I drew similar conclusions.

I’d like to try a 60 mm diameter insert with a little cut off the top for an air gap, but it seems that 50mm is the max size that’s readily available.

I recently broke another carbon rim despite the insert, but it was an oblique hit from a sharp rocky halfway through a turn and there was no damage to the tyre or the insert, suggesting that it was going to happen regardless.

Irrespective of this, I’m convinced that the insert is providing some protection – ImI’definitely getting less rim strikes, and those I do notice are certainly muted. I also really like the ride quality of the wheel when they’re in.

I am very likely going  to be ordering some 40mm for my wheels this week.  Is it advisable to use fresh sealant, or could i just whack a section in and top up a little more sealant if needed?

Won’t do any harm to leave in what’s already in the tyre and add a bit anyway

Cheers! Ooh, exciting times in the tyre pressure department!

A point on sealant by the way – I found that uncut, I didn’t need any additional sealant, however, now I’m shaving a centimeter off its height, there is an area where the cells are exposed and also cut. This part has way more surface area. It does take more sealant, but only a bit and it’s only adsorbed to the surface. Cutting an old insert through has shown me it’s not getting any further into the structure of the insert.

Cheers Mr Officer. Can’t not do it now. All the info I need, very nicely priced product, lots of fun to be had!

Anyone got some long cuts of this sitting around after ordering that I can buy?

The 1.9m lengths from dortech are too short for a 29er rim, but I don’t want 25m!

50mm ideally.

zip tie two shorter lengths together then cut to size. no different really to the single zip tied joint ….

I’d prefer to have a single join – it’s neater, stronger and will weigh less.

Plus someone must’ve bought the 20m roll already!

Probably but in the grand scheme of things it makes no odds.

OCD on things you can’t even see must cost folk as fortune.

Iv just ordered 20 meters of 50mm I will be fitting it to 29er hardtail and 650b full suss

that should leave me with about 10 meters spare

mega. Sent you a pm.

I also have spare 50mm if anyone needs it

Anyone tried it on a gravel bike yet? I got 40mm wtb’s on mine I’m curious,…….

Right mine arrived today.

Tried 50mm in a 2.35 minion on an i23 rim

No way I was going to get the tyre on without damaging it as I couldn’t keep the tyre bead in the well

So I marked the rod and trimmed a strip 40mm wide 10mm thick strip off with an electric carving knife.

this leaves it 50mm wide 40mm thick, positioned so the new flat surface is to the rim curved side to tyre.

This lets the tyre drop into th rim and I could fit the tyre ok with a couple of plastic leavers.

It beaded up fine with a track pump and feels pretty normal. I’ll try it with my normal pressure and then drop down a couple of psi and see how it goes. This is on a hardtail so Iv usually had to keep the rear at around 30psi to avoid pinch and rim damage.

Lets see how it goes……….

Personally I found a cut down the middle – half noodle – was perfect. You’re not trying to replace the entire bloody tyre / air cushion!

ive bit the bullet and bought a ratbite, im optimistic.