Boxcar Stem – Paul Component Engineering Skip to content
  • Shop
  • Story
  • Videos
  • Contact
  • Newsletter
Account Cart: 0
Menu
  • Shop
  • Story
  • Videos
  • Contact
  • Newsletter
Account Cart (0)
Shop | Components | Cockpit | Boxcar Stem

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.

Clear

Technical Information

  • Weight
    35mm +/-0: 118 g
    50mm +/-0: 137 g
    70mm +/-0: 153 g
    90mm +/-0: 155 g
    70mm +/-15: 169 g
    90mm +/-15: 172 g
    100mm +/-7: 181g
    110mm +/-7: 203 g
  • Material
    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
    90mm
    100mm
    110mm
  • Stem Angle (deg)
    35, 50, 70, 90mm: +/- 0
    100, 110mm: +/-7
    70, 90mm: +/- 15
  • 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

Product Videos

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.

 

 

Related Products

Related products

  • 4NM Torque Wrench

    $22.95
    Add to cart
  • Tall and Handsome

    $205.00 – $225.00
    Select options
  • Boxcar Stem Faceplate

    $36.00 – $42.00
    Select options

Stay in Touch

Our monthly email is an ongoing bike conversation for creative people who spend a lot of time in their garage.
Should we bring back #FixtureFriday ? Before you c Should we bring back #FixtureFriday ? Before you can make all the parts, you have to make all the fixtures, and these aren’t something you can buy off a shelf! All of our production and assembly fixtures are one-offs made by Paul or Patrick or Jacob in the manual machine shop (although Jacob just made our first ever 3D printed fixtures, but that’s a story for a different Friday 😉). 
  This fixture is for pressing the little sealed cartridge-bearings into our Canti and Love levers. Once mounted in an arbor press, a little magnet holds the bearing until you press-fit it into the lever blade with a pull on the arbor press. In theory these bearings could be replaced down the line, but we haven’t had to do it yet. Thank you for attending our Ted Talk, happy Friday! ✌️
Shop ride! Shop ride!
Freshly polished Boxcar stems, ready for packaging Freshly polished Boxcar stems, ready for packaging. ✨🤩✨
This is what our bottle openers looked like back w This is what our bottle openers looked like back when @sierranevada bottle caps were twist-off. 😂
Boxcar Stems are available in 35 through 110mm len Boxcar Stems are available in 35 through 110mm length, and are machined right here in sunny Chico California to the tightest tolerances, using the highest grade 2024 American-milled aerospace aluminum available. Sure, you might see us goofing off and getting weird at bike events, but when we get back to work in the machine shop, we take our work VERY serious!
Daydreaming while looking through some more of @jo Daydreaming while looking through some more of @johnprolly’s photos of @lostandfoundbikeride of the past and thinking about how great it’s gonna be to get out there again and see all our friends. Who else is going this year?!
Paul Component Engineering
  • info@paulcomp.com
  • 530–345–4371
  • 11204 Midway
  • Chico, CA 95928
Support
  • Policies
  • Dealer Application
  • Support
  • Story
  • Say Hello
  • Gift Certificates
Follow Along
© 2023 — Have a nice ride.