I’ve just spent the last 3 hours in the garage faffing about trying to get this to work, but it still needs some modifications.

Anyone else tried it? Did it work?

This chap used a road bike tubular tyre.

[video]http://vimeo.com/74188832[/video]

Actually did a good job with it. I was considering having a go at this myself, I even got round to buying some tubular tyres. That’s about as far I got with it.

How do you pump up the tubeless part? is there a tubular tyre way of doing so without drilling a second hole in the rim?

I drilled my rim, don’t think you can do it without a fancy valve

Do you know what, that looks a bloody good bodge. Suppose if you have the bits it is a bargain, otherwise you are actually buying 2 tyres so probably not much cheaper than just stumping up for the real thing.

Was the guy using a tub on a 26 rim? I’m tempted.

@sausage need some photos / details of what you used and if it worked on your first ride

I’m wondering if there will be any serviceable parts available in the near future. I don’t fancy drilling holes in my nice rims.

@DT78, yes the guy is using a tub on a 26″ rim. I managed to get a pair off ebay for £12. In the anticipation that the valves will become available at some time.

@sausage, any feedback please..

@sausage how are you getting the air around the tub into the tyre.

Pro core strikes me as a faff too far. I can’t see me bothering with it.

There’s a Swedish guy used a 23mm tubular and then filled the outer tyre with a needle (sealant inside, obviously). This was only the other day but he said it’d held air over a couple of days and felt like an ordinary tubelesson the one ride he’d got in. I think I’ll just wait until Procore, or something similar, just drops in price before maybe giving it a try.

700 / 28″ tub?

The fact that Schwalbe are now saying Feb for launch, means they must be having difficulties getting it together.
I really like the idea, but will take a ‘wait and see’ approach.

That said, if on my new bike I don’t suffer from burping at my preferred <18psi because of the wider hookless rims, then perhaps I’ll not feel the need.

asbrooks – Member
I don’t fancy drilling holes in my nice rims.

Have you considered that someone has already drilled 33 holes in your rim? a 34th is unlikely to hurt

It’d be nice to stop dinging rims with any less than 35psi in the tyres… 180 quid seems step initially, but considering that even the cheap end of worthwhile rims costs £40 I reckon I’d make back that cost within a couple of years. Less if it were nice rims

So what the advantage over regular tubeless?

legend – Member
Have you considered that someone has already drilled 33 holes in your rim? a 34th is unlikely to hurt

Yeah, but that someone has a nice jig to make sure the holes are where there supposed to be.. 🙂

You don’t dent your rims if you hit them on sommat, so you can run really low pressures for more aggressive riding.

More for the gravity boys then.

This is really interesting, thanks sausage and asbrooks. I’ve had a very frustrating year of dinging rims, and am currently upgrading to some tougher ones but they have schrader valve holes. 26″ tubulars look pretty expensive, but I reckon I could machine a collar and base to work with a slightly modified presta valve on a narrow inner tube+trainer tyre.

I went for a very much cheap and cheerful approach,

I started with a 24 inch inner tube, covered it in duct tape to stop it expanding when it is fully inflated.
Then drilled another hole in my rim opposite side of the rim to the existing valve hole, I don’t thing it really matters where this hole is, so long as it isn’t too close to any spokes.

Then I Inserted a tubeless valve to the original valve hole and fitted the tube and tyre to the rim and put some sealant into the space between the tyre and tube.
Inflated the inner tube to approx 30-40psi, then inflated the outer tyre.

This sounds pretty straight forward…however!

The duct tape covering the inner tube kept splitting meaning I had to add more and more tape to withstand the pressure, (good idea to pressure test the inner tube before you fit it as this may take several attempts)

Getting the tyre so seal and seat was a real ballache though I was using a floor pump and a homemade lemonade bottle ‘compressor’ type set up.

Once I got the tyre sealed and seated, I struggled to get the secondary valve hole to seal despite it being a really tight fit. Then once I got it to seal the ductape split again on in inner tube and I gave up for the evening.

Doing all this in a cold garage probably didn’t help much though it was for the best as I did make a lot of mess.

Next time I give it a go I need to use better quality ductape (not aldi own brand), wrap the tape on with more overlaps and use more sealant.

So I never got to ride ghetto Pro-Core but first impressions of having a solid inner innertube inside a 15psi tyre where pretty positive, it seams like its a go-er, it just needs a bit more fine tuning

Instead of using a tape wrapped inner tube or a tubular tyre, I did wonder whether a slick tyre + tube would work.

I don’t fancy drilling holes in my nice rims.

I don’t blame you I’ve died five times since drilling these holes in my rims.

[url=https://flic.kr/p/8WfTrr]2010_1126cheeserim0015[/url] by multispeedstu, on Flickr

A slick tyre would add a hell off a lot of weight. An inner tube covered in ductape is heavy enough, plus you want the inner inner tube to have as much flex as possible otherwise your bike will handle like one of those kids bikes with foam tyres on

surely a road tubular tyre is going to be too big and wont sit properly on a 26 wheel .

Instead of using a tape wrapped inner tube or a tubular tyre, I did wonder whether a slick tyre + tube would work.

surely a road tubular tyre is going to be too big and wont sit properly on a 26 wheel

Triple 😀

I did wonder whether a slick tyre + tube would work.

A slick tyre would add a hell off a lot of weight.

Trainer tyres are pretty light and might do the job. I’ve spent the evening googling and found a bunch of people suggesting them+tubes. On looking at it more, I’m not that tempted, as a tubular tyre and second valve hole seem a lot more straightforward for a similar result.

On that note: PSA, 650 sized tubular tyre for less than £16:
http://www.ribblecycles.co.uk/sp/road-track-bike/Juniores-Tubular-600x21mm-Black-Tread/VITTTUBA450

I’ve ordered a couple to experiment with. Going by other deaneasy videos, 650 tubulars sit tight enough on a 26″ rim but when deflated have more than enough slack to put sealant in through a tubeless valve.

What would be best for sealing the tubular valve to the rim? PTFE tape?

Stupid question but.. how are you planning on getting the air out of the part with the trainer tyre so that it inflates the tubeless part?

The only way i can see it working is if you puncture the tyre but then if you blow up the tube in the trainer tyre, it will seal the hole so the air cant get through….

.

I can’t see a clincher/innertube working acceptably without a special valve like the Schwalbe kit. Tubular tyres however…

The proper procore kit uses a fluted plastic spacer (inside the ‘inner tyre’) which allows an air path past the innertube and into the main tyre through a hole in the top of the inner tyre. It would be quite easy to do the same thing with a ghetto version. With a tubular set-up you will have to deflate the tubular to adjust the main tyre pressure, although im sure something similar could be made, it would probably be a faff.

i understand how the proper version works… cant see the ghetto version working that way..

If you deflate the inner to inflate the outer.. when you reinflate the inner it will knock out the pressure readings in the outer….

it seems like a lot more than a faff.. 🙂

Given you are going to run a lower pressure with this type of system, you will undoubtedly be trying a range of pressures. Knowing the actual pressure is not a concern, just what you inflated it to (given it will always have the procore bit inflated). Trial and error, note down what pressures you inflated to, problem solved.

Unless of course knowing the actual tyre pressure is more important than how it feels riding, in which case far be it for me to suggest a proven tried scientific approach.

How much will you lot pay for my old 650 tubs?

Postage?
How long do they tend to hold air for? I’ve heard they can leak a bit if they have latex tubes.

aracer: less that £15 each 😀

What would be best for sealing the tubular valve to the rim? PTFE tape?

Dunno, but when I try this I’ll take photos. I’ve a feeling it’ll need proper tubeless tape.

Stupid question but.. how are you planning on getting the air out of the part with the trainer tyre so that it inflates the tubeless part?

People who have tried it or are planning on trying it have been making a holes in the tyre and putting a tape collar on the innertube to leave a gap for air, which mimics Schwalbe’s setup. It looks really faffy to me though, so it’s one of the reasons I’m put off that approach.

I’m leaning toward just putting extra valve holes in my rims right now: Mount half of MTB tyre, mount tub, insert other MTB bead, inflate tub to seat tyre, deflate tub, push tub valve down to create space, pour sealant through tubeless valve, inflate both chambers. I might make a spacer for the tubeless valve so it can be used to adjust the outer chamber pressure even with the tub inflated.

If that works, it seems about equal in faff compared to actual procore installation, but less than a third the price.

so what sized tubs do you need for 650b…?

650a

Good luck finding them!

Fairly sure they’re all latex tubes, so need topping up fairly often, though I presume the pressure in the tub doesn’t need to be that high and isn’t critical? I’ll check what I’ve got if anybody is really interested – I think some Veloflex, some Wolber, all have good condition carcasses, but worn out tread.

though I presume the pressure in the tub doesn’t need to be that high and isn’t critical?

The Procore ‘inner’ tyre is designed to run at 55-85psi, so not hard in the context of tubs, but not exactly soft. The whole point is that it has to be able to deflect hits that would pinch against the rim after all.

Right, I’ve given mounting a quick go with a 650b tubular tyre, an unbuilt, untaped Spank Subrosa 26″ rim, and a Minion DHF. There’s so little slack in the tubular tyre that I think the deaneasy videos are most likely 700c tubs on 26″ rims. A couple of people elsewhere have mentioned that tubs that size expand downwards to meet the rim.

With that rim profile (hard to seat tyres, but solid once they’re in) and so little slack I give it a 10% chance of actually being able to mount at all, seat the bead and inflate. The tub and tyre sidewalls just lock together, probably not such an issue with 700c. Someone suggested talc to make make them slip; I’ll give it a go in the next few weeks and take plenty of photos.

Even with the beads of the outer tyre unseated though, the tub does lock the tyre to the sidewalls of the rim. The valve on the tubular makes it stick up from the rim and create an air gap, so it’ll definitely need tubeless tape on the rim.