Forum menu
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.
<div class="bbp-author-role"></div>
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.
Personally I found a cut down the middle – half noodle – was perfect. You’re not trying to replace the entire bloody tyre / air cushion!
At 15psi if it started off at 100% it'll be 50%, at 25 psi it'll be 37% of the original volume. The foam compresses because it's closed cell.
Hi,
A bit of a resurrection post...
Anybody still got some 50mm backer road leftovers? 2-3 meters please.
Don't need 180m reel :-/
Cheers!
I.
Yes, In Exeter / Sidmouth if interested.
I need 2.2m for a 29er wheel tyre, but have 6m or more available.
PM sent 🙂
Cheers!
I.
So it's been 10 months since I stumbled across this thread, and it's time for a little update.
I finally ordered a two 2 metre lengths of 40mm backer rod from Dortech just before Christmas. It took a couple of months to arrive, but to be fair to Dortech they were really nice to deal with, so I would still use them again.
The rod was to go into a new rear tyre for my 25mm internal DT Swiss rims. It took me until April to finally decide on my tyre, which turned out to be an Onza Ibex 2.4, in the rather soft 45a compound. After a little measuring, and trimming to leave space around the valve, I zip-tied it in a loop and proceeded to fit the tyre and rod. I was very confident that everything had gone swimmingly, the Ibex mounted the rims magnificently. The insert didn't seem to cause any particular problems, so I happily put sealant in and inflated the tyre. Then I put the wheel back on the bike, looked at the tread pattern... Tyre on the wrong bloody way around! What a numpty. Happily tyre removal and replacement went well, so all was good.
Three months later and thanks to the misguided purchase of a tyre that was way too soft for the range of riding that it was to be used for, and I've just bought the 55a version of the Ibex (it's a bloody good tyre). The old tyre had a couple of small items embedded in it, and it was reflected in a couple of areas on the insert, but other than those, the insert was in pretty good nick, and still felt pretty firm. It's been used on my daily commute with pressure around 35-40psi, with no noticeable effect. It's been used as low as 23psi for more challenging rides around Wharncliffe Woods. I tend to ride at around 25psi there now, that seems to suit my clumsy style.
I honestly feel it's been beneficial for the more technical rides. It feels like there's a bit more support at the slightly lower pressures I run. For the few quid I spent on it, I think it's great.
Did you see my recent thread using closed cell foam mats from Aldi. They were back in stock last week if you fancied trying a different approach.
https://singletrackworld.com/forum/topic/my-latest-attempt-at-homemade-rim-protectors/
@welshfarmer I have now. They look really good. I'll definitely bear that approach in mind when i need to buy something again. I've got one spare length of backer rod, so I'd imagine it'll be some time next year. Cheers!
Holy thread resurrection Batman! As per others earlier in the thread, anyone tried this on their gravel bike...? Specifically 700c rims (24mm inner width, 28mm outer width), running 40mm tyres.
I suppose the question is: what width of backer rod should I get...?
40mm to provide best sidewall support. I use mine as round - not cut in half down the middle and works great, but you'll need to fit the backer rod real tight to the rim. Only snag with this setup is can be difficult to inject sealant, when tyre beaded to rim.
After fitting 40mm in a 2.4 Maxxis Aggressor on a Hope DH rim which is similar inner and outer dims, I would be tempted with the 30mm backer rod myself on a 40mm tyre.
Wrap it round the rim and where it overlaps, cut it short by 30-40mm. Push a zip tie through and close the two ends together, then cover the joint and zip tie in a wrap of Duct Tape. Where the valve is going to go, screw a 7mm drill through to allow ease of air and sealant.