Myth 11: Rear tires should run at higher pressure

Off The Beaten Path

To celebrate Bicycle Quarterly‘s 15th anniversary, we are looking at myths in cycling: things we used to believe, but which we’ve since found out not to be true. Today, we explain why your bike’s weight distribution should not affect your tire pressure.

Bicycle Quarterly is partly responsible for the myth that front tires should run at lower pressures. When we first started researching tires, we published Frank Berto’s tire pressure chart, which lists inflation pressures to achieve a ‘tire drop’ of 15% with average tires. That pressure depends on the width of the tire and on the load on the wheel.

Most bikes carry roughly twice as much weight on the rear wheel as on the front (above). So we reasoned that it makes sense to inflate the rear tire twice as hard as the front one. Except it doesn’t work that way.

During hard braking, the entire weight…

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Compass Antelope Hill 700C x 55 mm Tires

Off The Beaten Path

We are proud to introduce our biggest tire yet, the much-anticipated 700C x 55 mm Antelope Hill. The new tires have arrived with the latest shipment and are now in stock.

Antelope Hill is the unofficial name of the last great climb of the iconic Oregon Outback, the 360-mile gravel race that traversed Oregon from the south to the north. Like many gravel rides, almost a third of the Outback route is on pavement, including Switchback Hill itself (above). The ideal tire for this and similar rides combines excellent speed on pavement with enough width to float on top of the gravel, rather than sink into the loose aggregate.

The new 700C Antelope Hill completes the trilogy of ultra-wide Compass allroad tires, which also includes the 650B Switchback Hill – named after the first big climb of the Oregon Outback – and the 26″ Rat Trap Pass.

Like most Compass…

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Myth 10: Stiffer Forks Steer Better

Off The Beaten Path

To celebrate Bicycle Quarterly‘s 15th anniversary, we are looking at myths in cycling: things we used to believe, but which we’ve since found out not to be true. This week, we have a ‘double feature’ that looks at fork blades. In the first post, we looked at whether they flex enough to improve comfort. Here we examine the belief that stiffer fork blades make the bike steer better.

Looking at Hahn cornering hard on the comparatively flexible Kaisei ‘TOEI Special’ fork blades (above), you can see that the wheels are perfectly aligned as he scythes around this fast downhill corner. His bike steers no differently from a bike with ultra-stiff fork blades. This goes against the widely held belief that a stiff fork offers more ‘precise’ steering.

Stiffer setups improve the steering response in cars and tricycles, where the forces of cornering flex the suspension components. On a…

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Myth 9: Fork Blades Don’t Flex

Off The Beaten Path

When we first started talking about shock absorption and fork blades, it was commonly believed that fork blades didn’t flex significantly. Experts told us: “All the flex in a fork is in the steerer tube, where the lever arm is longest.” And yet, when we rode bikes with flexible fork blades, they clearly took the edge of bumps. Was this another myth in need of debunking?

We designed a simple test to measure the flex of fork blades. By combining a small bag-support rack with the hoop of a low-rider, we could easily visualize (and measure) the flex of the lower fork blades: The two racks will move against each other only if the fork flexes between their attachments – in the lower 2/3 of the legs. (If the flex occurs higher on the fork, both racks will move in unison.)

The video above shows the same test on my…

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Handlebars: Wide vs. Narrow

Off The Beaten Path

One of the hardest parts of bike fit is the width of the handlebars. There are many recommendations, but not all make sense. For decades, racers have been told that handlebars should match the width of their shoulders – but nobody seems to agree how to measure shoulder width! Let’s look at what we know about handlebar width.

Historically, handlebar width has matched the handling of racing bikes. When bikes had slack head angles and much wheel flop (1920s), bars were very wide: 46–48 cm was common to provide the leverage required to keep the bike going straight. When low-trail geometries were popular (1940s), bars shrank to 38 cm, because that was enough to guide the bikes with a light touch. Narrow tires made the bikes less stable again (1970s), and bars grew to 42 cm. I wrote about that in detail here, but even that is not the…

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How are Compass Tires Different from Panaracers?

Off The Beaten Path

From time to time, a customer will ask us: “How are Compass tires different from Panaracers?” It’s no secret that Panaracer makes our tires – we benefit from the research and technology of one of the best tire makers in the world. Panaracer’s engineers know more about casings and tread rubber than almost anybody, and they translate our ideas into tires that outperform all others in their intended environments.

That also means that it may not be immediately obvious how our tires are different from Panaracer’s own tires, like the Gravel King – or even Panaracer’s budget model, the Pasela. At first sight, with tan sidewalls and black tread rubber, they can look very similar. They are even made in the same factory!

Recently, we had the opportunity to spend some time with Mark Okada from Panaracer Japan (right) and Jeff Zell from Panaracer USA (left). When I mentioned the Pasela…

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SKF Bottom Brackets Back in Stock

Off The Beaten Path

Bottom brackets are almost invisible, and you only notice them when something goes wrong. When the bottom bracket in my Firefly started to bind after just a few hundred miles, I put in an SKF, and that was the last I thought about it. When the bike was overhauled, the BB was spinning as smoothly as ever. That is how it should be!

How does the SKF last so much longer than other bottom brackets? SKF is a world leader in bearings, and they’ve applied all their technology to these bottom brackets. The two biggest advantages are larger bearings and better seals.

Let’s look at the bearing size first. SKF runs the bearings directly on the spindle and on the shell of the cartridge (above). That way, there is enough room for large ball bearings that can handle the high torque and low rpm of a rider’s pedaling, which is…

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