Kaweco AC Sport Carbon Review

How does a fountain pen that looks like a long bolt perform?

The Kaweco AC Sport Carbon is a uniquely designed compact, 8-sided fountain pen made of aluminum and carbon. It’s is unlike any other design I’ve seen, from the extremely long cap which makes me want to slide it through a box-end wrench, to the lightweight feel of aluminum, this is one manly man’s pen.

  • Compact Size
  • Light Weight
  • Designed for pocket carry
  • Matte Aluminum Finish is cool

  • Only Comfortable Posted

Fountain Pen Design


Steel Nib
Nib Width: 6mm
Nib Length: 16mm
Cartridge/Converter Fill

Screw Cap
Capped: 104mm
Posted: 127mm
Uncapped: 97mm

Mid-Grip Width: 6mm
Cap Band Width: 11mm
Total Weight: 22g
Cap Weight: 8g

The Kaweco AC Sport Carbon Limited Edition fountain pen is made of all aluminum with carbon insets. What you first notice when you look at the pen is it’s short and it’s masculine.

When capped, it’s only 104mm which is unusually short for a fountain pen. This is a pen intended to be a daily carry, don’t let the limited edition fool you. It’s rugged and sized for pants’ pockets.

It’s 8-sided and looks like a tool for the garage more than a fountain pen. The anodized aluminum is a matte finish and very cool to touch.

The carbon fiber inlay, looks like stickers printed on every other facet of the 8-sided edges of the cap and around the entire body. It looks like dark, diamond-plate finish, but the manufacturer’s website says they’re real carbon inserts so I’ll go with that. The carbon detail has depth, when you look at the inlay, you’re looking into it and the finish is almost like a hologram, the reflective detailing moves as you look into it.

The shape and finish are so unusual you can’t help but want to pick it up and play with it. The nib is made of steel and engraved with Kaweco’s logo and some spiral flourishes. What’s interesting about the nib on the Kaweco AC Sport, is it’s interchangeable. The nib unscrews from the section so you can swap it out with any other Kaweco Sport series pen. SO FUN!

The grip section is aluminum and matches the blind cap at the end of the pen body.

This fountain pen is available in black, silver or the limited edition red aluminum I’m reviewing here. I’m reviewing the double-broad nib, but it’s also available in EF, F, M and B. The feed appears to be plastic.

This is cartridge or converter fill and came with one Kaweco cartridge in the body. You can also buy the Sport series squeeze converter for this pen, which is the same size as a cartridge but has a metal handle that spans the length of the converter so you can squeeze it to create a vacuum to fill it.

Fountain Pen Performance on Papers

The double-broad nib is a medium-wet writer. It lays down a thick, luscious line of ink but isn’t so wet that the paper warps from ink saturation. . The slower you write, the wetter the line. I tend to write very quickly, and many feeds have a hard time keeping up, but the Kaweco AC Sport Carbon just laid down a thinner line when I wrote quickly but didn’t skip using Kaweco red ink cartridges.

The double-broad lays down a thinner line on the horizontal strokes and a thicker line on the vertical strokes but did write thinner when I wrote quickly or very softly touched the paper without pressure. Although it’s a steel nib which means it’s stiff and inherently less enjoyable (for me) than a solid gold nib, it is smooth.

On notebook paper, this fountain pen did a great job even though it was a double-broad nib. I fully expected it to bleed-through to the backside tremendously but it just had intermittent spots of bleed-through even on notebook paper. The red Kaweco ink also kept its color even after dry, it didn’t fade to pink like some other brands do.

Heavy paper like Clairefontaine 90g, soaked up ink as fast as the pen could dish it out. You can see some of the darker parts of the letters where the paper absorbed more ink when it traced back over part of the letter.

What was great about the Kaweco AC Sport Carbon aside from the size and cool design was the fact that it didn’t skip or hard start. I used this pen for a few days and even after sitting, I didn’t have to scribble to get it to write, it just started right up.

There wasn’t any bleeding or feathering on notebook or thick paper. That’s a rare find in a fountain pen! This is a daily-carry pen if I’ve ever used one. It’s designed to take a beating and write on anything and it does both well.

Okay, But How Does It Feel?

I fully realize talking about the way a pen SOUNDS is odd. But I can’t help but warn you when uncapping it, the aluminum section flare will make contact with the aluminum cap on it’s way out. Because the cap is so long and the flare on the section (which keeps you fingers from sliding onto the nib) is almost the same diameter means when pulling them apart, the aluminum will bump against it.

The result of the aluminum-to-aluminum contact is a harsh grinding sound that made me cringe thinking the finish was going to scratch off, but it didn’t. I can see this wearing the anodized finish off over time and lots of use, but so far so good! To me, it was hard to believe all the capping and uncapping I did didn’t wear off the finish already, but it shows no signs of wear.

The only downside I noticed while using the Kaweco AC Sport Carbon was the nib assembly is designed to unscrew (because it’s interchangeable) and it came loose once which made it chatter, but that only happened once. I tightened it down and it didn’t happen again.

Because the pen is so short, it’s easy to get your fingers on the short section threads but they don’t have to stay there.

The Kaweco AC Sport Carbon fountain pen feels balanced in your hand. You’d expect it to be heavy because of the chunky cap design, but because it’s aluminum, it is much lighter than you expect. It is balanced and posts extremely well.

It’s too short for me to use without posting the cap, without the cap on, the end of the pen body hits right at the web between forefinger and thumb which would feel awkward after a long writing session. But posted, this pen is a dream and so fun to write with. I didn’t experience any hand fatigue or discomfort with it at all… what a find!

The Cap

This is a screw-off cap and it takes just 1.5 rotations to remove it. The cap is insanely LONG by design and posts very well because of it. The aluminum makes it a delight to use, it’s so much lighter than it would be if it were made of brass or another metal.

When the cap is on, it’s there for life. It doesn’t screw on to post, but its length means it seats incredibly well on the body without chattering or moving around. I have a passion for posting caps and the Kaweco AC Sport Carbon lets me honor it!

Who is the Fountain Pen Good For? Is It a Good Overall Value?

Are you looking for a fountain pen that can take a beating in your bag or pocket?  Most people don’t want to pay over $100 U.S. for a “beater pen” but the compact design and aluminum and carbon make it hard to beat its durability so it will earn its keep over time.  The aluminum and carbon fiber body are also deceivingly lightweight, but hefty enough to feel like a metal fountain pen.

When you get the pen in your hand, you just feel quality craftsmanship.  It’s such a fun and inspired design with a masculine feel but could be used by anyone. I love the compactness of the pen when it’s capped and its unusual shape is eye-catching and fun.

Get the price of the Kaweco AC Sport Carbonfountain pen now on Amazon.


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