Bino’s trainer comeback, part 1: Schwalbe Kojak tires

I have not written about Bino, my Dahon Vitesse folding bike, in a long, long time. He’s still with me, although I haven’t ridden him very often.

Minoura’s small-wheel adapter for the LR340.

Recently, my wife thought of following in my pedal strokes in returning to indoor cycling of her own. I still have the Minoura LR340 magnetic turbo trainer, and that still has its small wheel adapter to work with Bino’s much smaller wheels. However, there are a few things that need to be done before this plan can take off in earnest.

Tread pattern on the Marathon Racer tires. Center is non-continuous.

The more immediate one concerns Bino’s tires. The Schwalbe Marathon Racer tires are not a good match for the LR340, with their heavily grooved and pattern-cut treads. Most wheel-on turbo trainers require a tire with smooth tread to work their best and last as long as possible, and a treaded tire will make a huge mess of rubber particles on the trainer as it heats up. In a rookie mistake realization, I’ve already gouged a bit of a groove on the LR340’s resistance roller as is, running it without cleaning the rear tire it contacts first.

Step one, then, is to get suitable tires…and really, only one model in the Schwalbe lineup fits the bill: the Kojak.

Telly Savalas portrays the popular lollipop-sucking detective of this mid-1970s crime show.

People one generation older than me will perhaps know of a TV crime show of the same name. That’s exactly why Schwalbe named this tire like it did – its lack of tread pattern matches Detective Kojak’s smooth, bald pate. Even looking at other 406 mm (20″) tire offerings from other tire makers, the Kojak is one of the few options that looks most like a shrunken-down, slick-tread road bike tire.

The narrower Kojaks don’t fill the fenders as well as the outgoing Marathon Racers.

Another difference is the rated width. Unlike the 40 mm (1.5″) Marathon Racers, the Kojaks are slightly narrower at 35 mm (1.35″). With this change, the recommended pressure range increases accordingly, up to a rated 95 psi (6.5 bar) maximum. While the Kojak isn’t explicitly designed as an indoor training tire, the added air pressure and smooth tread should work well with the demands of that job.

I’d like to report that installing these tires was easy, but that would be a complete lie. Schwalbe’s 406 mm (20″) tire offerings almost universally have tight wire beads, and there’s something with the diameter and 14 mm width of Bino’s Newson Sportec rims that makes tire mounting disproportionately hard.

With the swap to the Kojaks, a third difficulty factor arose with the reuse of inner tubes…which were simply too wide for this application. On a road bike, there is little issue with using an inner tube meant for, say, 32-47 mm tires inside a 28 mm tire. On a small-wheeled folding bike, I found out the hard way that the size discrepancy between inner tube and tire width must be kept to a minimum. There just isn’t the same amount of room to stuff away excess inner tube material into the inside of the tire…without it folding in on itself so badly that it makes its own holes and punctures, or pinching between rim and tire bead (the inner tube will blow out explosively when inflated in this condition). My 47 mm (1.75″) inner tubes worked fine with the 40 mm (1.5″) Marathon Racers, but barely worked with the 35 mm (1.35″) Kojaks.

Not sure how I would have mounted this without my trust tire bead jack and Pedro’s tire levers.
Best tire levers around – it takes a lot to break one. Buy a pair for each bike you own!

It took multiple dismounts and remounts to get this absolutely right, stuffing any exposed or pinched inner tube inside the tire bead. It got to the point where one of my burly Pedro’s tire levers had had enough and snapped at the final attempt. If a tire is tough enough to destroy a Pedro’s tire lever while mounting, your wheel and tire combination is no joke to fit. Such difficulty of turnaround is one reason why working on Bino’s tire punctures on the roadside frankly fills me with a bit of dread. On a particularly bad day with crap weather, I wouldn’t look past just folding the bike, hailing a cab, and going home that way. It is a boon, then, that the Kojak tires supposedly come with a measure of puncture protection built into their carcasses.

With the Kojaks mounted, Bino is a QR skewer swap away from being ready for trainer duty. The other half of the puzzle is modifying the LR340 itself, in a bid to replace its broken components with a field repair. That will be a tale for another time.

A gravel ride that didn’t come to be

I had recently joined a few groups on Facebook that catered toward riders of cyclocross bikes, machines just like Hyro. I had gotten an invite to ride the gravel roads around the Pasong Buaya area that the Daang Reyna road cuts through as it links Cavite and San Pedro in Laguna.

Hyro with his original footwear remounted.

This would require some changes to Hyro’s now-default road-going setup. The day before the ride, I removed the rear rack and both full-length fenders, and dismounted the 28 mm Continental Ultra Sport II slicks off Hyro’s wheels. Back on went the 35 mm Schwalbe Super Swan knobby mud tires, which had been sitting in a storage cabinet since their last outing around Heroes Bike Trail in Taguig last year. (They are essentially a tubeless-ready version of the Rocket Ron tire, specifically made for Giant as an original-equipment item on built bikes.) I inflated them to 60 psi.

Setting out, I rode to the Phoenix gasoline station in Molino along Daang Hari, observing Hyro’s behavior on his original footwear. The larger overall diameter had a noticeable effect on the gearing, and I couldn’t lean into turns quite as hard because of the knobs, which emitted a low thrum as they pattered against the road. However, the bigger air volume and lower pressure meant that the bike just steam-rollered its way through road acne and bigger ruts at speed, which was quite welcome on the rough final few kilometers of Daang Hari.

Waiting at the Phoenix gasoline station along Daang Hari. This is also the home of Gran Trail Cycles’ branch in Molino, Cavite.

I arrived at our designated meeting place, but had nobody to ride with, as my ride buddies had failed to wake up on time. I wasn’t keen on exploring the gravel roads by myself, so I retreated to familiar stomping grounds and roads in Alabang. Here I could further observe the bike’s behavior on 35 mm rubber.

As it turns out, the performance delta between the Super Swans and the Ultra Sport IIs is much smaller than it had been previously. I remember the Super Swans feeling much more sluggish, but apparently, the rollout difference between the two tires amounted to just 10 mm, as the nominal 28mm Ultra Sport II slicks actually measure 30 mm across my wheels when inflated to 80 psi. I was just 0.4 km/h slower on average compared to the pace I set on the slicks. The rough surface of the concrete roads further reinforced the virtues of low pressure and greater air volume, as it was less fatiguing to ride. The larger diameter rollers didn’t hinder climbing ability as much as I had thought, too.

The Daang Hari excursion aside, I treated this as a typical Sunday morning long road ride. Even with slightly ponderous cornering, the Super Swans acquitted themselves well, and made me consider deflating my slicks a little. Once the Ultra Sport IIs go kaput, I wonder if I should start looking at a herringbone-tread 30 or 32 mm tire?