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Shop | Components | Boxcar Stems | Boxcar Stem

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Boxcar Stem

The Boxcar Stem is the perfect combination of stiffness, strength and light weight.  Available in +/- 0^ in 35, 50, 70 and 90mm. Also +/- 15^ in 70 and 90mm, and +/- 7^ in 100 and 110mm. All screws are high strength stainless steel with the popular T25 head. Made in Chico, California with American aerospace alloy.

$156.00 – $172.00Price range: $156.00 through $172.00

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Technical Information

  • Weight
    35mm +/-0: 118g
    50mm +/-0: 137g
    70mm +/-0: 153g
    80mm +/-7: 177g
    90mm +/-0: 155g
    70mm +/-15: 169g
    90mm +/-15: 172g
    100mm +/-7: 181g
    100mm +/-12: 197g
    110mm +/-7: 203g
  • Material
    2024 American Aerospace Aluminum
  • Finish
    Anodized or Polished
  • Anodized Color
    Black, Purple or Silver
  • Bar Clamp Diameter
    31.8 mm or 35.0
  • Lengths
    35mm
    50mm
    70mm
    80mm
    90mm
    100mm
    110mm
  • Stem Angle (deg)
    35, 50, 70, 90mm: +/- 0
    80, 100, 110mm: +/-7
    70, 90mm: +/-15
    100mm: +/-12
  • S.H.I.S. Stem Clamp Diameter
    28.6 mm
  • Stack Height
    36 mm
  • Instructions
    Download
  • Torque Settings
    Steerer Tube: 5nm
    Faceplate: 4nm
  • Rise & Reach
    Download
  • Faceplate Width
    46mm
  • Hardware
    Download

Product Story

This stem was designed from the ground up to be stiff, strong and very light. We went through several design iterations and believe we’ve reached the best combination of these three principles. Extensive real world and machine testing have proven this to be one strong stem.

With respect to torsion, the rounded box shape is some 25% stiffer than the competition. As for strength, we ran it through 1,000,000 cycles of above normal use stress without a single problem. How’d we get it so light, while still being so strong? We started with obsessive computer design time, then took the strongest and highest quality American aerospace aluminum, and precision machined it to .002” tolerance (that’s really tight for a stem). We use over 20 different end mills, drills, saws and taps to make 1 stem.

The stems come in a zero rise and a +/- 15 degree rise, and in 100mm and 110mm length they are available in +/- 7 degree rise. Lengths are 35, 50, 70, 90, 100, and 110mm. All screws are the same pan head T25 Torx type screws in stainless steel. Why Torx? To encourage torque wrench usage and avoid strippage (People tend to overtighten faceplate bolts). Also the Torx head is wider, distributing stress better, and are the same wrench size as the ubiquitous rotor screws all makers use. Also SRAM has made a switch to T25 screw heads in almost all their products, which is a good sign.

As usual, by letting the function and material properties dictate the shape of the product, we have come up with another one of our often complimented and purposeful designs. Yes, it looks a little different, but with us there is always one good reason for this: to make it work as awesome as possible.

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Our monthly email is an ongoing bike conversation for creative people who spend a lot of time in their garage.
Whew! Our friends at @astralcycling up in Eugene O Whew! Our friends at @astralcycling up in Eugene Oregon hand-laced us these beautiful silver Serpentine wheels for the #CascadeCougar. Both rims are offset for more even spoke tension, we’ve got those Cali-made @whiteind hubs, and some jazzy oil-slick decals🌈. Reminder: we’ll be raffling this bike off to raise money for @oakridgetrailsalliance , so all these top shelf components could end up in YOUR stable!😎
What would you call this ano colorway?! Blueberry What would you call this ano colorway?! Blueberry Acid Trip? BTCHN’ Bikes was generous enough to donate these insane titanium handlebars to the #CascadeCougar project. Made right here in Chico! Wait till you see how these tie into the paint… 👀
When it came time to pick a headset for the #Casca When it came time to pick a headset for the #CascadeCougar, you know we had to reach out to our friends at White Industries. Their engraved logos pair so well with our parts aesthetically, they’re machined in California, have a split crown-race for easy installation, and use recycled/able packaging. Man, this bike is gonna be DIPPED! 🤩
@blackcatbicycles making it look so casual as he f @blackcatbicycles making it look so casual as he fires up the #CascadeCougar 🧊. I guess after 24 years of building beautiful custom one-off frames for people, you either get stressed out, or you find the zen workflow. This dude is a straight up WIZARD, stay tuned!🍿 
📹: @mybucketsgottaholeinit and @onko_rinkus
Ok, so here we have the inspiration for the @black Ok, so here we have the inspiration for the @blackcatbicycles #CascadeCougar we’re building up for the @made.bike show! Mr Paul ordered this custom Petaluma-made Salsa A La Cart sometime around 1992 when PAUL Component started to become profitable, and he had a vision for a bike that was in many ways ahead of its time, but now is a piece of history. Drop-Bar mountain bikes seem to kinda come and go as a trend (more recently called Monster Cross bikes, and now called…?). This one is a fun example with the “Jelly Bean” paintjob, Cook Brothers cranks, early PAUL “DDT” hubs and brakes, a WTB/King headset, and… that STEM. The Gnass seatbag was made in Chico, I think he makes fire-fighter gear now. Anyways, we aren’t going to *replicate* this bike, we’re just going to take some cues from it. Stay tuned to see what we come up with, and how you can enter to win!
Oh boy, do we have a SWEET project in the works to Oh boy, do we have a SWEET project in the works to tell y’all about! Without spilling out everything all at once (it’s a LOT), let’s just key you in on what’s in the oven. We decided we wanted to bring a sick custom one-of-a-kind bike to show off at @made.bike this year, and we somehow talked @blackcatbicycles into building a frame inspired by Mr. Paul’s original old-school, California-made drop-bar Salsa mountain bike, which is something cool we will ALSO be bringing to Made, and then we’re gona dip that Black Cat in the sweetest of our favorite bike parts (more on THOSE later), and THEN (catching breath), we’re going to raffle the bike off (this could be YOURS?!), to raise money for @oakridgetrailsalliance ! Go ahead and follow the #CascadeCougar hashtag now if you don’t want to miss the process posts by us and some of our favorite brands. Stay tuned! 📷: @mybucketsgottaholeinit
Paul Component Engineering
  • info@paulcomp.com
  • 530–345–4371
  • 11204 Midway
  • Chico, CA 95928
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