For those of you who want to ride offroad as I ride on rough lanes (right through the potholes) on my Big Apples, here's the Schwalbe ProCore Tube that lets you do exactly that.
http://www.chainreactioncycles.com/ie/en/schwalbe-procore-tube-set/rp-prod128958The
ouch! price is for a pair of tubes.
Also at
http://www.schwalbe.com/gb/pressereader/procore-a-revolution-in-mountain-biking.html Schwalbe says development of the tube was spurred by the availability of very wide rims. The system presupposes a bead to bead width of 23mm.
As you can see, the tube consists of two tubes, with a special valve with a selector. The image tells the rest of the story: high pressure to keep the beed locked in, low pressure for riding.
According to the blurb:
Schwalbe ProCore Tube Set
Off road: Riding at lower pressure means better performance... but at the same time it increases the risk of failures. The limit so far is at about 20 psi, below which it's hardly possible to dare to ride normal MTB tires.
But nothing stays the same: In the future, air pressure can be controlled in the tire's double chambers. In the outer chamber, the air pressure is extremely low - ideal for maximum off road performance. In the inner chamber, directly on the rim, there is high air pressure – even a very strong impact cannot dent the rim edge. At the same time, the inner high-pressure system secures the tire onto the rim. "Burping", the dreaded loss of air at low pressure in conventional tubeless systems, is impossible.
Tire pressure can be reduced to a minimum 14 psi, thus providing a huge amount of grip.
Even on the roughest terrain tires "stick" to the ground.
The tire provides extremely sensitive cushioning.
Due to the extra cushioning and traction there is much better steering, braking and traction control.
No more risk of snake bites. The rims are extremely well protected from denting.
Even in the toughest conditions, significantly lighter tires can be used.
Excellent emergency running characteristics due to the internal high-pressure air chamber.
Procore can be used with any tubeless MTB tire.
Weighing ca. 200g (rider weight) per wheel. Compatible with all wheels regardless of brand. Internal rim width of 23mm. Series production is underway.
Sold as a set of 2 with all necessary components, in order to convert a complete bike. Later on components will also be individually available as replacement parts.
Set-Contents:
2 x PROCORE inner tires
2 x PROCORE special tubes
2 x Tubeless rim tapes
Doc Blue
Tire fitting aids.
Tyre Compatibilities:
Set 26" Art-No. 16610001
Set 27,5" Art-No. 16610002
Set 29" Art-No. 16610003