Challenge Tires Strada Bianca 36 Tires: Getting Rolling
Challenge Tires, probably best known for cyclo cross tires, has recommended a few of its models for gravel riding. The Almanzo 30 and the Gravel Grinder 38 are tires Challenge has actually designed for gravel riding. The Strada Bianca has always been in the line, and in its original 30mm width, a tire recommended for rougher riding with road bikes. However; Challenge also recognized that many riders don’t do gravel or dirt exclusively with their gravel bikes, but have a large amount of miles ridden on paved surfaces as well. These bikes can typically fit a larger volume tire. This is where the Strada Bianca 33mm and 36mm tires come in.
Challenge has sent over three sets of Strada Bianca tires, one in each size available, for test and review. We have two sets in the hand made, “Open Tubular” style, and the 33mm set is in the vulcanized, 60TPI version which Challenge has available also in a 120TPI “Race” version. All tires feature the “PPS” puncture protection system, but the Open Tubulars have the “Double PPS” which is supposed to be even more resistant to punctures. This protection runs under the tread area only, by the way.
So, What Is The Difference? – Challenge Tire uses an “Open Tubular” versus traditional vulcanized tires as a way to gain a ride and traction advantage over their competition. Traditionally, tubular tires, which must be tediously glued on a special rim in a process which used to take days, was the way to go for racing bicycles. Those tires were made on handmade silk or cotton casings with a glued on rubber tread and an encased rubber “tube” to hold the air. The resulting supple nature of tires made in this manner allowed cornering traction and comfort to be maximized and all that with a light weight.
So, what’s not to like? Well, as said before, the tubular tire type requires lots of special, manual labor to set up. That along with the difficulty in repairing tubulars led to the vulcanized clincher type tire most of us know well. Vulcanized tire casings start out as textile casings, but the beads are added so the tires will “hook” or clinch into a special hook beaded rim. Tread is essentially “cooked” on to the casing, which results in a durable tire, which is easily repaired, and is tougher. However, this comes at the sacrifice of the tubular’s superior flexibility which gives those tires a great ride quality and better traction.
Challenge Tire champions a technique which uses traditional manufacturing techniques used in hand made tubular tires, but with a bead to hook into a clincher rim, and have dubbed this “Open Tubular”. You get the benefits of a tubular in an easy to use and repair clincher format. The best of both worlds? Well……about that.
The original Almanzo 30 gravel tires, amongst some other Challenge tires made in the Open Tubular method, showed signs of delamination for some riders. This has been addressed by Challenge Tires and they feel confident that they have overcome the issues. The following is taken from Challenge Tire’s FAQ information page on their site:
Making handmade tires is a difficult process and we pay constant attention to each step and detail along the way. Nevertheless, rare situations may occur that are imperceptible during production and that may also pass the QC (quality control) inspection.
The tread is applied manually and as with any manual operation slight, involuntary human error may at times occur. These are rare cases that occur less than 1% of the time and we are constantly striving to bring that number to zero.
The most common case is when the side of the tread isn’t properly adhered to the casing. This is a rare case of human error during the production process. If a worker touches the side of the tread improperly when applying it to the casing, his fingers may have taken off a spot of glue, causing adherence problems. In this event, the glue may appear well adhered in the QC check , but the problem becomes more perceptible later during use, because of that ‘weak’ spot.
With three sets of tires here we are using three different test riders. The 30mm tires will be mostly tested on various paved surfaces, the 33 vulcanized versions are going to be tested on multiple surfaces, and I will be tilting the balance of the new 36mm versions toward gravel more than pavement. The 36mm versions are so new that they are not even listed on the Challenge website. We have weighed the 33mm and 36mm tires, and oddly enough, they weigh roughly the same, with all four tires coming in between 350 and 360 grams. (Note: We did not weigh the 30mm tires, but obviously, they are a lot lighter.) The Open Tubular tires we have are 260TPI for a super supple ride and you can expect to pay $70.00-$80.00 a tire depending on where you get them from
Mounted up, both the 33mm and 36mm tires are at claimed width, or a tic wider. We will get in to the ride characteristics in our follow up post dubbed “Checkpoint”. Mounting of the vulcanized 33mm tires is fairly straightforward, however, the hand made, Open Tubular type tires require some special work to get mounted. Challenge Tires hand made Open Tubulars are actually flat hoops of rubber when you remove them from their packaging. Challenge recommends that you mount them by first slipping the flat tire over the rim with the beads hanging off either side of the rim. This will require some stretching, but fear not. The natural rubber the tires are made from stretches far easier than a vulcanized tire will. From there you set one bead, then insert a tube, and then set the remaining bead. It is a process that takes longer, but it isn’t hard to do if you follow Challenge’s recommendations. By the way, talc powder on the tube is highly recommended for ease of mounting and results in a safer, easier airing up of the tire.
So Far……. Challenge Tires Hand Made Open Tubular Strada Bianca tires are a unique product in the marketplace and promise a smooth, supple ride. They are a bit fussy to mount up, but the natural rubber stretches to finally allow a good result. Stay tuned for ride characteristics and more in our next post in a few weeks.
Note: Challenge Tires sent over these Strada Bianca tires at no charge to RidingGravel.com for test and review. We are not being bribed nor paid for this review and we will strive to give our honest thoughts and opinions throughout.