Indoor training, part 6: The flywheel effect

I’ve had the Minoura LiveRide LR340 turbo trainer for a while now and I’ve used it with both Hyro, my cyclocross bike with 700C wheels, and Bino, my 20″-wheeled folding bike. A few buckets of sweat later, shared between these two bikes, I started noticing a few differences.

At this point, I’ve documented numerous times the more rapid rate of tire wear from the smaller wheels – and the larger resulting mess that comes with it. It turns out that’s not the most telling difference between the two bikes.

With Bino, I find I can crank up the resistance and use much heavier gears. I regularly dip into the higher end of the gear ratio spectrum. I’ve gotten to the point where I can sprint in the 50×12 top gear combo at the final flat-out interval of a workout…and push as hard as an indicated 60.8 km/h on my cyclocomputer.

I have no idea how I’d sprint to this speed on a folding bike. My limit on the road is around 44 km/h, at which point I’d be pretty spun out.

Even in my 50×12 top gear, it’d take my legs a pedaling cadence of 154 RPM to get to this indicated road speed. Yes, that’s not sustainable for long periods, and most likely very hard to do out on the open road due to aerodynamic drag, but I’m mentioning it to illustrate my case.

On Hyro, though, it’s a different story. I use nowhere near half the LR340’s total resistance range, and despite using the same cassette and chainrings as Bino, I usually never breach the halfway point of the cassette. Beyond 50×19 or 50×17 are gear combos that are too big for me to push my pedals to on a turbo trainer. My indicated road speed also peaks at a significantly lower 52.5 km/h.

V-max on Hyro while on a turbo trainer.

It’s entirely possible that the two bikes are giving me slightly different workouts, and I pin this down to their rear wheels acting as flywheels of different sizes.

With Bino, the smaller 406 mm rear wheel acts as a flywheel that is much lighter and quicker to spin up with pedaling the cranks. The consequence is it takes much more resistance from the turbo trainer to give the training load called for by sprint intervals. Hyro’s 622 mm rear wheel, on the other hand, has more mass and needs more energy to get going…but requires less out of the turbo trainer to give roughly the same training load.

In practical training terms, I think that indoor training with Bino is more of a test of souplesse, or pedaling smoothness. With the smaller wheel size, I find it is much easier to accelerate and decelerate simply by changing my pedaling cadence. Peculiarly, with a change of bike, I find I could get the same kind of training coaches used to recommend getting a roller trainer for. Bino also has a slight edge for really high cadence work. Mounting Hyro’s bigger rolling stock on the LR340 will allow me the low-cadence training that replicates endurance climbing efforts, as well as getting used to holding low positions for faster riding.

Without hard data, and sharing just my palpable differences training between the two bikes, I feel like I may just be blowing a load of hot air. For that reason, I would love to quantify all this difference with a power meter. Unlike heart rate or speed, where external factors such as aero drag or physical condition can affect readings, power meters are more “insulated” and are better at actually quantifying your training load and output – a watt is a watt is a watt. Unfortunately, while they have been coming down in price almost constantly since 2012, they’re still too rich for my blood.

How do I get faster on the bike? Part 1: Beginner tips

One Sunday morning, I had arranged to meet my colleague Jayson at the SM Mall of Asia area, that urban mecca of cycling along Manila Bay. It had been a while since he last pedaled his hardtail mountain bike, and was keen on putting in some kilometers in his quads and hip flexors.

Cruising along Seaside Boulevard

He wasn’t that familiar with riding on the road; he preferred to ride trails and trail parks. The initial plan was to visit the makeshift trail park in the area; unfortunately it had already closed down. Instead we spent the morning doing laps of Seaside Boulevard.

Eventually we began to talk about his aim of steadily increasing his performance on the bike. I offered a few pointers, primarily from a road cycling point of view, and I decided I should share them here.


Most beginner cyclists make the mistake of pushing too hard of a gear and grunting away slowly, thinking that this will build up their leg muscles faster, or that this will maximize effort. In reality, that will do nothing but tire you out early, and discourage you from cycling for long periods at a time.

Mashing pedals out of the saddle? This is more the exception than the norm, reserved for short bursts. Better to sit down and spin.

Instead, I suggest starting from the easiest gear you can use, then pedaling to a sustainable effort. The easiest gear will usually end up with you spinning the cranks too fast, so shift one cog harder. Then repeat until you find a comfortable balance between the tension in your muscles and pedaling speed. This will naturally help you find your natural pedaling cadence. It’s self-selected, but it’s also usually within the range of 70 to 90 revolutions per minute (RPM).

At your natural pedaling cadence, you are as efficient as you’re going to get. You will be able to keep turning the cranks in comfort over extended periods of time – indeed, this is a large part of how I survived my first randonnee. Armed with this knowledge, you can progress to the next step.


So, you’ve found your natural pedaling cadence by following the instructions above. On the flats, one good way of gaining speed is basically a matter of maintaining that same pedaling cadence, while gradually increasing the load your muscles have to pedal.

You do this by making use of your gears again.

The teeth on a cassette’s cogs, and the gaps between them, are an indicator of how hard or how easy it will be to pedal. For this Shimano Tiagra CS-4600 unit, the cog teeth are 12-13-14-15-17-19-21-24-30.

On the next harder cog, there will be a tendency for your cadence to drop slightly, because your leg muscles now have to push a little more weight on the pedals. One way of putting this is there will be a “jump” in effort as you shift between cogs. Aim to reattain your pedaling cadence with each shift to a harder gear.

Going the other way, as you shift towards easier gears, the logic remains the same. This is mainly applicable when the road becomes inclined and more vertical. When shifting to easier gears, aim to keep your cadence.

That’s the whole point of why modern bike drivetrains have so many gears. Human legs don’t create a lot of torque and are most efficient at a certain range of cadence, so it’s up to the gearing to either multiply torque for climbing, or to multiply cadence into higher road speeds.


Many people are either mystified by front shifting, or just don’t bother with it at all. Take the time to learn it, because it widens your speed range.

The main thing to remember is to maintain the straightness of a chain as it goes between the front chainrings and rear cogs. As much as possible, you want to avoid cross-chaining, which is when you force the chain into extreme diagonal angles, such as pairing smallest cog with smallest chainring, and biggest cog with biggest chainring. Pedaling your bike in a cross-chained state puts huge stress on your drivetrain and accelerates its wear.

Cross-chain situation: Biggest cog, big chainring
Cross-chain situation: Smallest cog, small chainring

On a typical road bike with two chainrings, I use the small chainring for spinning the cranks in an easy gear – usually one of the larger cogs. The small chainring is also used for climbing hills. When you’re going fast enough to make use of the smaller cogs on the cassette, that’s when you should shift to the large chainring.

A shift between chainrings usually results in a far larger change in cadence compared to shifting between individual cogs at the back. One tip to maintain comfortable cadence is to perform front shifts with corresponding rear shifts. If I were to shift to the big ring, I usually also shift two cogs easier at the same time. Conversely, shifting to the small ring, I shift two cogs harder. This minimizes the shock of the shift to your legs.


The reason why folding bikes and other small-wheeled bikes are so effective as training tools, in my opinion, is their small wheels and their higher rolling resistance. What that means is, with a small-wheeled bike, more of the total amount of rubber material in a tire gets deformed on the contact patch than on a larger-wheeled bike, and more energy is lost there as rolling resistance. This is why a folding bike with small 406 mm wheels loses speed much faster when coasting after a 42-km/h sprint, compared to a road bike with 622 mm wheels.

Seeking small-wheeled speed? Spin those cranks.

In order to keep a high average speed (around 21 km/h+) on a small-wheeled bike, and avoid rolling resistance eating away at your momentum, you will need to keep spinning the cranks. Due to rolling resistance and the greater amount of drag from an upright riding position, any time spent coasting or freewheeling is effectively deceleration without braking, so unless you’re going downhill or entering a turn, don’t stop pedaling!

The active avoidance of coasting will also force you to adopt a smooth, high-cadence pedaling style naturally. Road cyclists call it souplesse.

Once you transition over to a bike with larger wheels, this souplesse training will improve your endurance, acceleration, and speed control.


Of course, none of this is going to make much sense unless you apply it as often as you can. With more saddle time, you will become more familiar with your body, your cycling biomechanics, and your equipment. The more in-tune you are with all three, the better equipped you will become to unleash more speed as a cyclist.


I intend to follow this up with tips for more advanced riders. Let me know what you think. Did these tips help? Leave a comment and let me know what else I should be writing about.