on saleNoodler's Ahab Flex Fountain Pen - Mesa Tortoise

Product Code N15045

In Stock

out of stock

on saleNoodler's Ahab Flex Fountain Pen - Mesa Tortoise

Product Code N15045

In Stock

out of stock

Noodler's 308 Refillable Cartridges (5-Pack)
Add Refillable Cartridges + $6.50 Noodler's 308 Refillable Cartridges (5-Pack)

Noodler's 308 Refillable Cartridges (5-Pack)

Product Code N18070

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Noodler's Ahab/Konrad #6 Steel Nib - Flex
Add a Spare Nib + $7.00 Noodler's Ahab/Konrad #6 Steel Nib - Flex
Nib Type:

Noodler's Ahab/Konrad #6 Steel Nib - Flex

Product Code N18094

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The Noodler's Ahab flex pen features a steel flexible #6 nib and a slide piston mechanism. If you'd like, you can even remove the piston mechanism and use the pen as an eyedropper for a massive 6ml ink capacity. This yellow-orange Ahab is made of a celluloid derivative and is technically biodegradable and formed from a "renewable resource". The vegetal resin body of this pen may show particles or striations within the material. This is most noticeable in demonstrators and bright colors.

The Noodler's flex pens were designed for the hands-on tinkerer - they are made to be taken apart and adjusted. The nib and feed pull right out and can be adjusted and heat set for optimal performance. Don't be afraid to get a little ink on your fingers while you learn how to use this pen.

As a simple rule of thumb for writing with a flex pen, just apply slight pressure on your downstrokes, which will spread the tines and increase the line width, achieving that optimal line variation. Make sure to go slowly so that the ink can keep up with your writing. As with any flex pen, it just takes practice!

Due to the residual machining oils used when cutting the feeds for these pens, we highly encourage you to give the pen a good flush before use. We recommend any of the following options: distilled water, water with a touch of dish soap, a pre-packaged pen flush, or a solution of 10% clear ammonia to water. This should resolve most ink flow issues!

We do our best to photograph the pens to show how they will appear in person, but due to the nature of the material, there will be some variation in the pattern seen here. This adds an element of uniqueness to the pen, with no two patterns being exactly the same. We cannot honor special requests.

Click here to download the printable PDF instruction sheet for the Noodler's Ahab.

Formerly known as Apache Tortoise, renamed in June 2022.

Fountain Pens

Whether or not the barrel of the pen is translucent, allowing you to see the ink and filling mechanism inside.

Body Material
Cap Rotations

For pens with a screw-cap closure, how many rotations it takes to uncap/recap the pen.

Cap Type

How the cap is opened/closed from the barrel of the pen. Some common options include Snap-Cap, Screw-Cap, Magnetic Cap, or Capless (no cap).

Compatible inks & refills

Which ink this pen will accept. Choices include bottled ink and various styles of pre-filled ink cartridges.

Bottled inks
Filling Mechanism

How the pen fills with ink. Click here to watch our video tutorial on common filling mechanisms.

Eyedropper, Piston
Grip Material
Nib Size
Nib Color
Nib Material

Whether or not the cap fits securely onto the back of the barrel when open.


Whether or not the nib/tip can retract into the body of the pen (usually for click or twist-open style pens).

Diameter - Body
14mm (0.6in)
Diameter - Cap (without clip)
15mm (0.6in)
Diameter - Cap (with clip)
20mm (0.8in)
Diameter - Grip (mm)

Measured from the place most people choose to rest their fingers, which varies with each pen.

Length - Body

The measurement from the back end of the barrel to the tip of the nib.

128mm (5in)
Length - Cap
60mm (2.4in)
Length - Nib

The measured length of the visible portion of the nib when it is installed in the pen, from grip to tip.

20mm (0.8in)
Length - Overall (Closed)
139mm (5.5in)
Length - Overall (Posted)

When the cap of the pen is posted onto the back of the pen body, this is the measurement of the entire pen including the nib.

170mm (6.7in)
Weight - Body

If a converter is included with the pen, this weight is reflected in the total.

12g (0.4oz)
Weight - Cap
6g (0.2oz)
Weight - Overall (g)
Max Ink Capacity - Eyedropper

The maximum volume of ink that can fit in the pen when filling the entire barrel of the pen via eyedropper.

Max Ink Capacity - Piston Vac

The maximum volume of ink that can fit in the pen when using the built-in piston or vacuum filling mechanism.


Customer Reviews

Based on 43 reviews
Defect Maybe?

This pen must have been on sale for a reason? I am unable to get through a journal entry with out skips and taking action to get flow. This pen has frustrated me to no end. It has changed my attitude toward fountain pens in three days!It is nice looking is the only positive of this pen.

It gets better

I was about to return this pen, it was inked with Robert Oster 'Caffe Crema' and it was a poor writing experience. Hard starts, skips, railroading and the scratchiest feedback. But as soon as I switched to Noodler's American Eel Black ink things got better. It feels more lubricated now. I don't enjoy how this pen makes my handwriting look, but I can see its my own unfamiliarity with a flex nib that is to blame. I will get better with practice but the pen is very exhausting to use. It DOES STINK! like rotten cheese and vomit. My partner says she can smell it a few feet away but I'd say it's not the end of the world. It's kind of funny. The color is nice, I enjoy looking at and the feel of the material in my hand. But overall the pen looks pretty cheap, with a silly looking clip too. In the end I can't return it as the novelty of the flex nib keeps me interested. I have dip pens that flex better but they don't use fountain pen inks well, I have so many sample inks so this is going to be a lot of calligraphic fun

Serguei M.
Definitely worthwhile, can require tuning with some inks

I got the Ahab pen in two colours, and have been using one in its stock configuration with Noodlers Heart of Darkness and another one in eyedropper mode with Bay State Blue (yes, I was feeling dangerous). The Heart of Darkness pen has worked with 100% reliability, proving this is a solid workhorse pen with the right ink.On the other hand, the pen I used in eyedropper mode has been spilling ink into the cap on an unpredictable basis. Let's say I familiarized myself with the proper techniques to clean Bay State ink out of various surfaces while I learned about how to adjust the nib, clean the cap, and try to get it not to spill again. As far as I can tell, the HUGE reservoir of the eyedropper mode makes the pen very heat-sensitive while capped, although I haven't had any burps while writing. The flex handwriting on both pens looks very good, much better than my old Nib Creaper or the Noodlers Charlies that I've found to be a bit wet, and competitive with my more expensive Pilots. Great value, but be prepared to buy more than one and either experiment to find an ink that works reliably, or be prepared to learn about the advanced aspects of adjusting & heat-setting a nib.

John S.
Good flex, but hold your nose!

This is my first flex pen. I wanted an inexpensive way to try writing a bit fancier, and the Ahab was a great way to do that. It's comfortable to hold and easy to flex when you want. There is a ton of railroading, but I'm allowing for the strong possibility that I just don't know yet how to use it properly. The included instructions suggest taping the nib, and I'm sure there are plenty of other tips I can get by doing some research. The really weird thing about the pen is how badly it smells. At first I thought it was just the paper that it came packaged in, but nope, it's the pen itself. I read that this is due to the resin that is used, and there are a few suggestions that I'm going to try to diminish the smell. Even if I can't, I can ignore it for a little while, and it doesn't make the pen unusable. Overall I'm happy with the purchase, and I'll be even happier if the coffee grounds work!

Lila S.
We're all stinky sometimes?

Other than a stinking, stinkiness that can fill a small room if it gets warm enough, this pen is fantastic. It has a great feel, writes well, versatile fill, high capacity, fun nib. And it's super pretty. The patterning is nice, but there's a surprise... There are 4 consecutive, small, clear, air bubbles just in line of my view above my thumb that catch the light and make all the stink worth it? I think the stink will subside. It could almost be my favorite daily pen, but why decide such things?

FAQs about Fountain Pens

How do I fill a fountain pen with ink? 8EDA1617-F73A-4DAF-8245-6D2BF4ABEB7B

It depends on the pen's filling mechanism, which you can find in the Technical Specs section above. 

Here's a quick definition of the most common filling mechanisms:

  • Cartridge - A small, disposable, sealed plastic reservoir that holds fountain pen ink. These come pre-filled with ink, and typically you just push to insert them into place and you'll be ready to write! Check out our quick guide here.
  • Converter - A detachable and refillable ink reservoir that allows you to use bottled ink in a cartridge-accepting pen. Typically you will install the converter into the grip section, dip the nib/feed into the ink, and twist or pull the converter knob to draw ink into the converter. Here's a video for how to fill a cartridge/converter pen using a LAMY pen as an example.
  • Eyedropper - A pen that utilizes the entire barrel as a reservoir for ink. Ink is directly filled into the barrel, allowing for a high ink capacity. Here's a video on how to do it!
  • Piston - A type of filling system that uses a retracting plunger inside a sealed tube to draw ink into a pen. They are typically either twist or push-operated. These pens cannot accept cartridges or a converter, and only fill from bottled ink.
  • Vacuum - A push-style piston that uses pressure to fill the large pen body with ink. They seal the ink chamber when closed, making it ideal for flying without risk of leaking. Check out our video on how to use a vac filler here.

Check out more info on these filling mechanisms including a video on how to fill each one on our blog.

How do I clean a fountain pen? 8EDA1617-F73A-4DAF-8245-6D2BF4ABEB7B

It depends on the filling mechanism, but it mostly comes down to flushing it out with water, and sometimes a little bit of Pen Flush if the ink is really stuck. 

It's a bit easier to show than to tell, so we've put together a few quick videos showing you the process:

How often do I need to clean my fountain pen? 8EDA1617-F73A-4DAF-8245-6D2BF4ABEB7B

We recommend a good cleaning every 2 weeks, and any time you change ink colors. 

Water will usually do the trick, but we recommend you use our Goulet Pen Flush if the ink has been left in the pen for a while and could have dried up, or when you’re switching ink colors.

My pen won’t write! What do I do? 8EDA1617-F73A-4DAF-8245-6D2BF4ABEB7B

First things first... make sure you have ink in the pen! Be sure that the ink cartridge or converter is seated properly in the pen, and that you aren't out of ink.

We always recommend you give your pen a good cleaning first, using our Goulet Pen Flush, or a drop of dish soap in some water. New pens often have some machining oil residue left in the feed, so a good cleaning often does the trick first.

If that still doesn't work, try priming the feed. This consists of either dipping your pen nib and feed in ink, or forcing ink from the converter down into the feed. 

If it’s still not working after that, please reach out to us so we can help! 

What's your return policy? 8EDA1617-F73A-4DAF-8245-6D2BF4ABEB7B

You can submit a return request within 30 days of your order date. You can read all our Return Policies here.

To initiate a return, please submit a request at the Return Portal. Our Customer Care team might reach out to you for more information.

Please note we are unable to accept a return of any Namiki or Sailor Bespoke fountain pen for any reason once it has been used with ink. Please thoroughly inspect and dry test the pen before use.