Paul 100% Pure Cranks Review: Past and Present Collide

The latest release from Paul Component Engineering in Chico, California, is likely to delight and perplex in equal measure, and we’d expect nothing less from the unconventional company. They’ve gone back to basics with a reboot of their square taper Paul 100% Pure Cranks. The originals were eye-catching but imperfect, with a few quirks that made them a little less than foolproof. And where the earlier 100% Pure Cranks were offered in distinct versions for road/track and mountain, the latest version cleverly takes shape with a single, more adaptable design.

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After 35 years of lovingly manufacturing high-quality bike bits that go against the grain of the bike industry’s often senseless pursuit of novelty for novelty’s sake, Paul Price and his team of around a dozen people know a thing or two about designing and machining components that take advantage of tried-and-true technology. Alongside several varieties of rim brakes, quick-release skewers, mechanical disc brakes, rigid seatposts, and other trusty bits, the Paul 100% Pure Cranks are the US-made company’s latest reminder that if it ain’t broke, it probably doesn’t need fixing. I’ll examine them in detail below.

WHAT’S NEW?

First produced between 2007 and 2016, it’s been almost a Decade since the 100% Pure Cranks were available in Paul’s lineup. Back then, they were only compatible with their matching Circles or Royal Flush chainrings, which were costly and available in a fairly limited range of sizes and colors. It wasn’t until last summer that BTCHN’ Bikes finally released a 3D-printed aluminum adapter that made it possible to use any 104 BCD chainring on the original 100% Pures, helping revive old cranksets with long-worn-out chainrings. The earlier square taper cranks attached using a pair of good old-fashioned crank bolts and used the less common ISO spindle standard.

Like their predecessors, the updated Paul 100% Pure Cranks are machined from ultra-strong 2024 American alloy, but they smartly address the earlier compatibility, attachment, and spindle puzzles, opting instead for more widely available and user-friendly specs. The most significant change is the adoption of the popular SRAM 3-bolt direct mount chainring standard instead of a proprietary interface. This makes finding and installing chainrings a breeze and opens up a broad range of styles, colors, and sizes to suit different bikes. That would be an update worthy of a rerelease on its own, but they didn’t stop there.

Another notable improvement is the addition of self-extracting chainring bolts, which dramatically simplifies the removal of the cranks without having to dig around your toolbox for a crank puller—one of the biggest hassle factors with many other square taper cranksets. Another small but welcome change is the switch from an ISO to a JIS bottom bracket spindle. The differences between the two are subtle, and surely, countless ISO cranks have been installed on JIS spindles as long as both standards have been around, and vice versa, but mismatching the two will have an effect on your chainline. 

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I was undoubtedly mixing ISO and JIS for years in my early bike days before even knowing there were multiple standards, but according to his holiness Sheldon Brown, using an ISO crank on a JIS bottom bracket will push your chainline about 4.5mm outward, and using a JIS crank on an ISO bottom bracket moves it 4.5mm inboard. In short, it’s wise to match crank and bottom bracket standards for best results. JIS is the more readily available bottom bracket of the two, and you can still find them in just about any decent bike shop. 

FIRST IMPRESSIONS

I’ve always appreciated Paul stuff because it looks equally at home on a uniquely wide range of bikes, from a worn-out Surly Cross-Check built mainly from the parts bin to a bespoke titanium rig from a custom builder. Being fully CNC machined, it’s not the most elegant, which is part of its appeal. It’s utilitarian, well-engineered, easy to take apart into its straightforward constituent pieces, and can last a lifetime if even remotely cared for. The Paul 100% Pure Cranks are no exception.

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In the hand, the new cranks have a solid heft, are precisely machined, and look rugged but considered in unpolished silver. Installing a chainring on the drive-side crank took seconds with the provided hardware, and they went onto my JIS bottom bracket without trouble. Popping them off was easy, too, thanks to the self-extracting bolts.

THOUGHTS ON SQUARE TAPER

Underneath all the complexity and new standards the bike industry continues to churn out, cranks have always been a relatively straightforward component. There’s only so much to them. Square-taper-compatible cranks aren’t so much maligned as forgotten by most brands in 2025, and few still spec them on their complete bikes beyond the budget realm. 

Still, even if they’ve long fallen out of fashion in the mainstream, square taper bottom brackets are phenomenally reliable, uncomplicated, and tough. They just work, and they’re available for as little as a few bucks from your local bike co-op. Companies like Phil Wood, SKF, and White Industries make them for buyers who need the best, and Soma/Merry Sales offers several mid-range options from Tange and IRD. I’ve always had good luck with Velo Orange BBs, and Shimano makes affordable ones that work great. In my experience, price doesn’t matter much for what non-performance-minded riders need. Square taper bottom brackets are beautiful in their simplicity and will last many thousands of miles with limited fuss. 

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For all they have going for them, square taper bottom brackets are also generally heavier than more modern bottom brackets, inherently less stiff due to their smaller axle, and not compatible with the vast majority of cranksets on today’s market. Figuring out chainline can be a pain, too, which I’ll get to below. Compatible cranks are relatively limited, but there are good options to suit a variety of tastes and budgets. These new Paul 100% Pure Cranks are a particularly exciting offering for riders who want to mix classic styling, square taper unpretentiousness, and smaller 1x chainrings. 

ON CHAINLINE and Q-FACTOR

“What spindle length do I need?” is an age-old question for anyone trying to install a square taper bottom bracket, and it can be confusing to navigate. According to Phil Wood, they’re available in lengths from 102mm up to 185mm. It’s always been my experience that a certain amount of trial and error is involved, and if you’re interested in running a pair of 100% Pure Cranks but don’t have the slightest idea where to start, consulting your local shop is a good course of action. A bad chainline can lead to noise when pedaling, poor shifting performance, premature wear to your drivetrain, and even dropped chains. 

In a nutshell, an ideal chainline puts your chain right around the center of your cassette. Your bike’s rear spacing is a good starting point for determining the proper chainline. I installed my Paul 100% Pure Cranks on an older frame with a 68mm bottom bracket and 135mm rear spacing, and the chainring I used has a -6mm offset. Aiming for a 47mm chainline, putting it just a tad outboard of center, the handy installation guide on Paul’s site told me I need a 108mm JIS BB spindle, which I happened to have installed already. The resulting combination shifts smoothly and quietly. Not bad for a first attempt, thanks to a little guessing and the provided chart. I’m lucky to have a drawer full of square taper bottom brackets in various lengths, but at-home experimenting with chainline can be expensive for folks without such access.

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Being able to tweak the bottom bracket spindle length and chainring offset (0, -3, -6mm) in tandem makes the Paul 100% Pure Cranks highly configurable for folks sensitive to Q-factor, too. This means you have some flexibility in how far apart your cranks sit while maintaining optimal chainline. 

1X OR 2X?

I can only speak to setting the 100% Pure Cranks up and dialing them in using a 1x configuration, as that’s all I’ve had a chance to do. However, I don’t see any reason why you couldn’t run a 2x spider if you were so inclined, other than some potentially funky aesthetics.

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I asked Travis from Paul Components if he could foresee any compatibility issues, who told me he thinks many 2x spiders would fit without problems but that he hasn’t tried it, either. Regardless, at least visually, I see the 100% Pures being better suited to a single chainring. I’ll try mine with double rings and report back with any bugs when I get the opportunity, so stay tuned. 

PRICE AND AVAILABILITY

Paul’s 100% Pure Cranks are offered in 155, 160, 165, 170, 175, and 180mm (but not 172.5mm!) lengths and available in Black, Purple, Silver (pictured here), and Pewter. There’s no polished option, at least for now. The claimed weight for a pair of 180mm cranks is 516 grams with chainring bolts, crank bolts, and extractor caps. My pair of 170mm cranks weighed in at 503 grams with all hardware. Regardless of color or length, the cost for a set is $308, putting them roughly on par with the other high-end square taper cranks on the market (which is to say, way more than your run-of-the-mill cranks).

• Model/Size Tested: Paul 100% Pure Cranks, 170mm (Silver)
• Actual Weight: 503 grams
• Place of Manufacture: Chico, California, USA
• Price: $308
• Manufacturer’s Details: PaulComp.com

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