If you were asked if you wanted carbon spoke wheels, of course you'd say yes.

However, if asked to elaborate on their appeal, the answer would be surprisingly vague.

I surveyed a few of my road-biking friends, and many were interested in the following points, so I'd like to share some information about them.

Questions about carbon spoke wheels

The most common questions and concerns were:

Do any of these match your questions?

・Ride comfort

・Aerodynamics

・Durability

・Maintainability

・Quality

Ride Comfort and Durability of Carbon Spoke Wheels

Comparing ride comfort is extremely difficult, and it will include my personal impressions, so please keep that in mind as you read on.

To get straight to the point, ride comfort will improve.

In the case of bicycles, the tires bear most of the shock absorption.

Lowering tire pressure increases shock absorption, but also increases rolling resistance.

Increasing tire pressure makes shocks more easily transmitted, but reduces rolling resistance.

We will proceed assuming the "appropriate pressure" is used here.

After the tires, the rims and spokes absorb the shock.

Two factors related to material strength are "stiffness (resistance to deformation)" and "strength (resistance to breaking when pulled)."

Stiffness is indicated by "Young's modulus," and strength is indicated by "tensile strength."

• Young's Modulus (GPa): Tensile Strength (MPa)

Iron (S45C): 210:570

Stainless steel (SUS304): 200:590

Aluminum (A5052): 71:260

Carbon: 60:650

Carbon: 200:2200

Carbon: 300:1000

It seems that carbon's Young's modulus and strength can be controlled quite freely depending on the material used, so I have described three patterns.

Incidentally, the materials often used by ICAN are Toray T700 and T800. According to Toray's website, their respective Young's modulus:tensile strength are T700: 500:4900 and T800: 560:5490.

This means it is stronger and less likely to break than iron.

Although I'm not in the business of bicycle parts, as a mechanical designer, if such materials were available, I would naturally make the structure more delicate than iron.

This would allow for more flex, resulting in a product with a softer ride.

If there were products of exactly the same shape made of iron and carbon, the carbon product would likely feel stiffer.

However, in reality, carbon allows for a reduction in volume, leading to a softer ride and further progress in "weight reduction," which is a crucial factor for bicycles.

Aerodynamics of Carbon Spoke Wheels

Looking at carbon spokes, you'll notice something interesting.

This is part of the product image for ICAN's "AERO55." Can you tell what it is?

Considering the cross-section of the central part of the spoke, it's not round but closer to an ellipse, meaning each individual spoke is aero.

The rim is, of course, also aero.

I've never seen iron or aluminum wheels that go to such lengths to reduce wind resistance.

Carbon wheels are products with enough value that they wouldn't be out of place being used by professionals.

Maintainability of Carbon Spoke Wheels

Since carbon is a composite material of carbon and resin, its biggest enemy is ultraviolet light.

If the resin part of the composite deteriorates, the wheel itself will also deteriorate.

Generally, a UV-cut coating is applied, so it's not a ridiculous idea that you shouldn't ride it outdoors.

If you ride it normally, you can use it without any problems.

Just in case, I think it would last longer if you store it in a place not exposed to direct sunlight when not riding it.

Also, not limited to carbon wheels, center misalignment can occur, so you'll want to rotate the wheel to check for lateral runout and deviations in the radius of rotation, and then adjust it.

It's also a good idea to occasionally retighten the "lockring" that secures the sprocket, check the wear on the rotating axle, check the wear on the bearing balls, and re-grease.

These tasks are relatively difficult, so finding a reliable shop that can handle them will give you peace of mind.

Probably, truing alone would cost around 1000 yen per wheel, but if you request greasing, truing, and bearing checks, it would likely be around 8000 yen for a complete overhaul.

It's not necessary to do it every year, but for long-distance riding, sometimes a lack of maintenance can damage the wheel itself.

Quality of Carbon Spoke Wheels

As for quality, since we can't observe the manufacturing process directly, we can only judge it based on whether the company is trustworthy.

By the way, in the case of carbon wheels, the process generally consists of the following steps:

Step 1: Design

Most designs are done using 3D CAD.

Step 2: Cutting carbon fiber material

Carbon is cut into usable sizes with a cutting machine.

In ICAN's case, most of the material seems to be Toray T700 and T800.

Japanese-made materials are highly trusted worldwide, so you can rest assured.

Step 3: Laying carbon material in the mold

Carbon material is applied to a specialized mold without any gaps.

Since the shape is complex, if this process were done uniformly by a machine instead of by hand, weak spots would be created.

Making it by visually checking takes time and effort, but manual work is more reliable.

Step 4: Setting the material and wheel in the mold

Once the carbon is set in the mold, it is placed in a press and compressed.

Step 5: Deburring and spoke hole drilling

After deburring, holes are precisely drilled using a machining center.

Since a spindle drills the holes, they are opened more accurately and cleanly than if done by a human.

Step 6: Surface finishing and inspection

Deburring is not the final step.

The surface is finished by hand, and then inspected.

Step 7: Rim surface and hole check

Each hole is checked individually because misaligned holes or burrs in the holes can be dangerous.

Step 8: Check for roundness and lateral runout

As it's a wheel, it's checked to ensure it maintains perfect roundness.

Naturally, the absence of lateral runout is also subject to inspection.

And, regarding inspection standards, since they adhere to global ISO standards, the products meet the required standards anywhere in the world.

In Japan, JIS (Japanese Industrial Standards) is more common, but in recent years, JIS has been aligning with ISO (international standards) in some areas, so there's generally no problem considering them to be nearly the same within Japan.

ICAN has disclosed all manufacturing processes, so please check them out.

It's rare to see the manufacturing process of carbon wheels, so as a road cyclist, I think it's worth watching.

How ICAN factory makes carbon bike rims

You can also see how each carbon spoke is assembled by hand.

100% Handmade ICAN AERO40 Wheel

Companies that publicly share this information are trustworthy, aren't they?

As a customer, you can also imagine what kind of product you'll receive.

There will probably be things you won't know until you actually ride them, so I think it's a good idea to try out a bicycle with carbon spoke wheels at a local shop.

However, shops often have high prices and limited options, so buying online is recommended.

External Writer: Koichi Okuno