The reason that tubular tires are preferred for cyclo-cross is their ability to run at lower pressures than clinchers with a lesser chance of pinch flatting. But if the casing is too small, in either width or overall volume, the effect is negated – and this is the case with Schwalbe’s new Racing Ralph HT.
Lower pressures offer greater traction, allowing the tire to conform to terrain, and more comfort, by providing a pneumatic suspension. The larger and suppler the casing, generally, the better the tire performs.
While the Racing Ralph HT has an almost perfect 32mm width, its height is 2-5mm less than that of comparable tires from other manufacturers and this small change seems to make all the difference on the 'cross course.
The lower volume casing forces the rider to run higher pressures – the lowest we were able to get away with was around 30psi, whereas our 150lb tester has successfully used Dugast tires down to 20psi. When anything less than 30psi is used, the casing folds under high-angle and high-pressure cornering, and this generally leads to a crash, or at the very least a tripod style save.
The Racing Ralph HT is hampered by its low volume casing, which requires more pressure than other 'cross tires
Because of this flaw in the casing’s design and the tire's exorbitant price (US$145) we can't recommend it. We hope that Schwalbe continue development though, because it’s 60 percent of the way to an excellent tire. Casing aside, the rest of its features are very – if not exceptionally – good.
The triple compound PaceStar tread is possibly the most advanced to ever grace a cyclo-cross tire. Schwalbe pair a base compound with two different external tread compounds – a harder center tread and softer shoulder knobs for cornering.
When it comes to construction, the Racing Ralph HT represents the pinnacle of quality. It's incredibly straight and true, with no perceptible variance in the casing or tread alignment. It's designed to be impermeable to water, and holds up to Schwalbe's stringent quality tests for road tires.
To achieve this high level finish, Schwalbe have taken on all of the production of the new tubulars, from tread and casing to assembly. The tires are produced in a humidity controlled, Schwalbe owned production facility, which is run at the pinnacle levels for high tolerance and quality standards.
Despite the incredible attention to quality and construction, there is one design feature that we're less keen on: Schwalbe coat the tire's base tape in latex. They do this to make the tire impermeable to water, which serves to improve durability and lengthen its service life, but it causes problems when it comes to rim adhesion.
The coating puts the rider at the mercy of the shear/adhesion strength of the latex, rather than the tubular glue itself. This wasn't a problem during our test as we used a wide rim with a continuous undrilled surface that produced a good bond, which we never rolled the tire off of.
However, based on how easily we were able to peel a section of the coating away in our workshop, and on past experience with other latex coated tires, we'd be more wary of using the tire on a narrower rim. for fear that it might roll off.
The Racing Ralph tread is proven for cross-country racing and does well on the cyclo-cross course
On the ’cross course
Once Schwalbe sort the casing, we think this will be a very good tire that can transition through a wide range of terrains. The tread performs well in every condition – possibly better than any other ‘intermediate’ or all-condition tire we’ve used – save for sticky mud, where the knobs become packed.
The Racing Ralph works very well in loamy and dry terrain, including loose-over-hard, as well as in snow and icy conditions, and it rolls fast on road, without any squirm. It provides good traction in wet conditions where the mud is thin and flowing. The narrow size helps here, as it offers more frame clearance and allows the tire to cut through soupy mud and hook up in a harder under-layer.
In the dry, and especially when the course is bumpy, the Racing Ralph suffers due to its casing, as we’ve already stated. This brings us to favor tires with inferior treads to Schwalbe but superior casings, which ultimately provide superior performance.