Hi,
First of all sorry my english (I'm portuguese). And then, sorry if it is a repost or in wrong place.
I'm interested in making a home-made "ghetto" Procore system, and I will share with you my idea to discuss a possible home-made version.
I have 26" rims (ERTRO: 21-559) on my DH bike.
1) The idea is to use a clincher road tire, for instance, the Schwalbe Insider (ETRTO: 23-559, price 15€ euros, 210grams, 145 psi max pressure).
Insider | Schwalbe North America
2) Do a small hole in the road Insider tire. Something like this:
3) Them, drill a 2nd hole in the rim (my rim is cheap and has already 37 holes, 36 from spokes +1 from valve, so no big problem). Put a 2nd air valve in the rim. Seal the valve holes and rim with tape to be tubeless-ready and avoid air leaks.
4) Put a road air chamber inside the Insider tire, like this:
5) Install the Insider and the skinny air tube, and then the main tire (in my case a 2-ply BigBetty tire) with liquid sealant. When finished should look like this:
6) The first valve is from the skinny air tube. The 2nd valve fills the air inside the Insider tire (but outside of the air tube). So, when inflating the 2nd valve, the air goes to the Insider tire and passes through the hole in the insider tire inflating the main tire [see point 2)]. A picture from moto tubliss system to help visualizing the ideia:
7) After inflating the main tire (1.5 Bar), inflate the inner air tube (1st valve) to ~ 6 Bar.
8) I think this system is similar to the first Procore prototype with 2 air valves. The main "problem" comparing to final Procore, is that you have to drill a 2nd hole (not a big deal for me, at least). The second minor issue is that you may need to deflate the insider tube temporarily in order to adjust the main tire pressure (because if the insider pressure is too high, the air from the 2nd valve will not pass-by the tube and escape from the hole in the inner tire). A 3rd minor issue is that you have to seal well the valve's holes to avoid air leaks (probably an o-ring between the rim and the Presta valve nut will work, or something like that). After the Insider tire being inflated to 6bar, there is no big problem for air leaks from the main tire through the valve's holes.
This system will cost about 20 euros per wheel (almost 10-times less than the original). It's cheaper, and I don't think that the disadvantages are very relevant.
An alternative method of this, is to use a road tubular 26" tire. The problem of this method is that a tubular tire is not a clincher tire, so it will not fit so wheel in the rims. Also a tubular tire is a bit more expensive.
What do you think ?
Greetings,
Andre
First of all sorry my english (I'm portuguese). And then, sorry if it is a repost or in wrong place.
I'm interested in making a home-made "ghetto" Procore system, and I will share with you my idea to discuss a possible home-made version.
I have 26" rims (ERTRO: 21-559) on my DH bike.
1) The idea is to use a clincher road tire, for instance, the Schwalbe Insider (ETRTO: 23-559, price 15€ euros, 210grams, 145 psi max pressure).
Insider | Schwalbe North America
2) Do a small hole in the road Insider tire. Something like this:
3) Them, drill a 2nd hole in the rim (my rim is cheap and has already 37 holes, 36 from spokes +1 from valve, so no big problem). Put a 2nd air valve in the rim. Seal the valve holes and rim with tape to be tubeless-ready and avoid air leaks.
4) Put a road air chamber inside the Insider tire, like this:
5) Install the Insider and the skinny air tube, and then the main tire (in my case a 2-ply BigBetty tire) with liquid sealant. When finished should look like this:
6) The first valve is from the skinny air tube. The 2nd valve fills the air inside the Insider tire (but outside of the air tube). So, when inflating the 2nd valve, the air goes to the Insider tire and passes through the hole in the insider tire inflating the main tire [see point 2)]. A picture from moto tubliss system to help visualizing the ideia:
7) After inflating the main tire (1.5 Bar), inflate the inner air tube (1st valve) to ~ 6 Bar.
8) I think this system is similar to the first Procore prototype with 2 air valves. The main "problem" comparing to final Procore, is that you have to drill a 2nd hole (not a big deal for me, at least). The second minor issue is that you may need to deflate the insider tube temporarily in order to adjust the main tire pressure (because if the insider pressure is too high, the air from the 2nd valve will not pass-by the tube and escape from the hole in the inner tire). A 3rd minor issue is that you have to seal well the valve's holes to avoid air leaks (probably an o-ring between the rim and the Presta valve nut will work, or something like that). After the Insider tire being inflated to 6bar, there is no big problem for air leaks from the main tire through the valve's holes.
This system will cost about 20 euros per wheel (almost 10-times less than the original). It's cheaper, and I don't think that the disadvantages are very relevant.
An alternative method of this, is to use a road tubular 26" tire. The problem of this method is that a tubular tire is not a clincher tire, so it will not fit so wheel in the rims. Also a tubular tire is a bit more expensive.
What do you think ?
Greetings,
Andre