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.

Reprise: Schwalbe Marathon Racer tires, 20″ x 1.5″

After four years, Bino was due for a change of footwear. Part of the reason why I stuck him on the turbo trainer at home was simply in anticipation of this fact.

The smaller 406 mm wheel size means greater rolling resistance and a faster overall wear rate, since the tires’ tread circumference makes more revolutions to cover a given distance compared to, say, Hyro‘s 622 mm. This was demonstrated in dramatic fashion by the sheer amount of rubber dust generated by my rear wheel whenever I used Bino on the turbo trainer.

Soon enough, it was also made crystal clear to me by how badly worn the rear tire got. At first the tread’s profile got flatter, with more of a pronounced step between the center and the shoulders. Later, the biased threads of the tire carcass were beginning to peek through, some of its carbon black oozing out and slipping on the turbo trainer. At this point, Bino sorely needed new rubber on his wheels and was definitely unsafe to ride on the road.

The outgoing Impac Streetpac 20″ x 1.75″ rear tire. You can see how much it’s flattened on its center tread.

The threads on the casing are starting to show due to the impregnated rubber having worn away. These aren’t roadworthy any more.

I paid a visit to Tryon in Makati and bought a pair of Schwalbe Marathon Racer tires. Bino’s outgoing front tire was also a Marathon Racer, but of a previous generation. The appearance of the sidewall logos, tread pattern, and other features were quite different between them, but they do share the Marathon series’ signature puncture protection.

FEATURES

• 20″ x 1.5″ (ISO 40-406 mm); also available in 16″, 18″, 26″, and 700C wheel fitments
• “Level 4 Raceguard” double-layer nylon puncture protection belt
• “SpeedGrip” rubber compound for good handling
• “LiteSkin” full-length reflective sidewall
• Wire bead
• 67 TPI casing
• Maximum load rating: 75 kg per tire
• Claimed weight: 340 g per tire
• Pressure range: 55-85 psi

IMPRESSIONS

According to the marketing spiel, Schwalbe’s Marathon tires were specifically built for toughness and long service life, for applications ranging from touring to commuting. The “Racer” is so-called because it is the lightest model of the Marathon range – not really for its competition chops. Reinforcing the commuting bent, this was the first tire I heard of that had reflective sidewalls, although my original outgoing pair didn’t as they were of an older vintage.

The new Marathon Racers I got had beads that were ridiculously tight. This particular set was perhaps the toughest pair of tires I’d ever fitted onto my custom LitePro x Newson Sportec wheelset with 14 mm internal width, especially the one I mounted on the front wheel. Every time I used my bead jack to wrestle the tire up and over the rim, the wire bead would just walk itself right out of the bead hooks somewhere else. It was a frustrating ordeal that resulted in at least one tire lever getting sacrificed to the tire mounting gods. Eventually I ditched the bead jack and used every other trick in the book to finally seat this tire on Bino’s front wheel, after much cursing, the process leaving me a sweaty mess.

The “arrowhead” tread pattern on the current generation of Marathon Racer tires. Some people have already tried these tires on a turbo trainer and were put off by the noise due to the broken center tread.

Despite the deeply cut directional blocks on the tread, the Marathon Racer is strictly an on-road tire. Not that you’d want to take a folding bike like Bino to the trails anyway; it’s just not made to withstand that sort of riding. At 60 psi front and 70 psi rear, grip is fairly good, even in the wet. They lend themselves well to the deep lean angles that small-wheeled folding bikes excel in when cornering at speed, even on shiny concrete parking floors where traction isn’t so great compared to paved asphalt or concrete roads. They will relinquish grip quite quickly when cornering or braking on wet steel surfaces or wet leaves, though.

Normally I’d go into more of the minutiae of tires, but any discussion about the rolling resistance these tires offer is moot, at best. Neither is any discussion on ride comfort much of one. The 20″ wheel and tire combo is never really going to roll or cushion road acne as well as a 700C combo, and I don’t think this will change much with the kind of tire you mount. That said, since starting my indoor training in January, it’s no hardship for me to maintain an average pace of 17-20 km/h around my usual commute loop, so the Marathon Racers do seem pretty efficient.

These tires sure look good in profile. Most of it is down to the reflective stripe aping a gum sidewall.

Given how much swearing it took to fit these tires onto Bino’s wheels, the Marathon Racers should make up for all that gruntwork with their puncture resistance. For the most part, they do. Even on my old set, I had only ever one puncture.  Best to carry a beefy set of tire levers with you if you run these on your folding bike, not the ones that come with your multi-tool…and make sure your rim strips or rim tape is up to snuff to avoid punctures from inside.

With the air volume of an inner tube under it, like most other tires, it should stretch out and loosen up a bit over time, allowing for easier dismounting and remounting…I hope. Fingers crossed.

With my camera’s flash fired, the reflective sidewalls really pop as a couple of rings.

Finally we come to the reflective sidewalls. I think they’re nice, and any feature that boosts visibility to other road users, especially at night, is worth considering. They’re not perfect, however. The reflective stripe on mine doesn’t follow the circumference of the tire so well – it has a few wiggles along its length. I’d also prefer that Schwalbe broke these down into four long segments instead of making the tire one reflective hoop, because when the tires are in motion, the reflective segments are more eye-catching and convey a sense of the bike moving much better.

The outgoing Schwalbe Marathon Racer bought back in 2013 that served as Bino’s front tire. It’s worn, but the difference in tread pattern is still notable compared to the newer pair.

VERDICT

Schwalbe’s Marathon Racer tires, in a sense, are ideal for small-wheeled folding bikes such as Bromptons or Dahons, where wheel removal, tire dismounting, puncture repair, and tire remounting can be such bothersome procedures that any measures taken to avoid all that faff are worth your money. Virtually unknown in mid-2013, my old pair went for PhP1,300 apiece; with their popularity rising in the past few years and manufacture moving to Indonesia, they can now be found for PhP1,000 each.

Despite the “Racer” name, I don’t really consider these ideal for competitive use. They’re jack-of-all-trades tires; durable, grippy enough, resistant to punctures, and mid-pack in width. For really fast folding bike riders, Schwalbe’s diamond-patterned Durano or full-slick Kojak might be better options, while comfort seekers might be better served by their balloon-like two-inch-wide Big Apples. For ultimate puncture protection, everything else be damned, Schwalbe can sell you a Marathon Plus.

Tool review: Bike Hand tire bead jack

An unfortunate fact of life for those of us with small-wheeled bikes is that their tires can be very stubborn to remove from, and remount to, their wheels. Some cyclists can remove and reinstall tires using their bare hands on a typical 700C road bike wheel; they’d struggle to do the same on a 20″ BMX or folding bike tire.

Moving the tire off the rim of a 20″ folding bike tire is a fairly straightforward job involving at least two tire levers, one preferably hooked over a spoke. Remounting is a different story, though. Sure, you could use tire levers and reverse their action, effectively hiking the bead from outside into the rim bed…but that also introduces the risk of pinching the inner tube. That’s why many people recommend not using levers at all for tire remounting. It doesn’t help that almost all folding bicycle tires have wire beads, too.

There has to be a better way…

…And here it is.

This scissors-like tool is called a tire bead jack, or a bead jack for short. This one in particular is made by Bike Hand, the same tool company that makes torque wrenches re-sold under different brands. I bought mine while on vacation in Shinjuku back in 2014.

The bead jack is a specialized tool, meant only for yanking stubborn tire beads up and over wheel rims. Because I’m sure most people have zero idea of what this is, I decided to write an entire post about it.

You remount one of the tire’s beads onto the rim as normal, with the partially inflated inner tube inside. Then you try to push the other bead into the rim.

You’ll naturally come to a point where that last part of tire bead starts to fight off your attempts and basically become uncooperative.

This is when you press the bead jack into service.

You’ll notice that the two arms of the bead jack have different ends. One is shaped like a “U” or half a cylinder; the other is hooked. Rest the U-shaped end on the side of the rim which has the bead inside it. This will act as your fulcrum point.

While continuing to rest the U-shaped end on the rim, make the hook-shaped end grab the remaining tire bead that you want to hoist over and into the rim. Once it catches, close your hand around the handles – much like how you would a pair of scissors.

Now for the bead jack’s party trick: Maintain downward pressure on the U-shaped end while pulling the hooked bead into the rim bed. In effect, the bead jack acts the same way a tire lever does, but in reverse. Because the bead jack’s lever action never intrudes into the inner tube, it will never puncture it.

Work the bead over into the rim in small sections until you have all of it inside the rim bed – and you’re done!

This is a supremely useful tool for stubborn tires. It’s just a minor shame I haven’t seen it sold anywhere in Metro Manila, so I guess it has the rarity card going for it too.