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Shop | Components | Cockpit | Boxcar Stem

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  • Tall and Handsome

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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.

$147.50 – $166.50

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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 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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📣The 2023 @lostandfoundbikeride registration is 📣The 2023 @lostandfoundbikeride registration is OPEN!📣
 🚵This is EPIC riding in some of the most beautiful areas of the #LostSierra. 🏕️Camping, live music, swimming, and partying with your friends, this is one of our favorite events of the year. 
⛏️Every penny raised by registration goes right back into building local trails and supporting the local mountain communities via @sierratrails .
🥓We’ll be there with our 🔥 Aid Station as usual. Paul himself will feed you pickles and bacon out on course. No, really!
📝LETS GOOOOOOO! 🎉
 📷: @johnprolly
We’ve been offering a front Flat Mount Adapter f We’ve been offering a front Flat Mount Adapter for a few years, so we figured it was about time to make a matching rear. 
  This adapter is +20mm, so good for putting a 160mm rotor on a 140 frame, and also helpful if you need a little more cable housing clearance at the chainstay. We aren’t usually weight-weenies, but after machining a pocket into these they end up at only 9 grams. 
  As usual, these are CNC’d by us to ultra-high tolerance right here in Chico, California. 
  Have a great weekend!
Canti Lever blades fresh out of the tumbler and re Canti Lever blades fresh out of the tumbler and ready for anodizing. As with all of our bearing press-fit features, we hold +/-0.0002” tolerance on these parts. That’s about 5 microns, and for comparison, the average human hair is about 70 microns thick. So yeah, these tolerances are TIGHT is what we’re saying!
Is this weird? Be honest. Is this weird? Be honest.
🚨NEW PAUL HOODIE ALERT🚨 We recently disco 🚨NEW PAUL HOODIE ALERT🚨 
  We recently discovered these absurdly cozy hoodies that are made here in the USA by Royal Apparel and tried a couple samples out and WOW. This is the closest thing to being gently hugged by the world’s softest teddy bear all day. 🧸 
  We just had a batch screenprinted with a giant red MotoLite brake and threw them on the website…LET’S CUDDLE! 
 (Oh yeah, Lucas is a BIRD NERD and no, we don’t know how that chair got broken.)
Going through a folder of photos by @johnprolly fr Going through a folder of photos by @johnprolly from 2018 and we are having some FEELINGS of EXCITEMENT that @downievilleclassic is BACK!🎉 This event is SO much more than a bike race, it’s a big family party with all your bike friends in some of the most beautiful rugged mountains in the #LostSierra. We’ll be bringing back our on-course aid station and breakfast tent downtown to support, and y’all wouldn’t believe how many pounds of bacon and coffee we go through on a weekend like this, it’s wild. Anyways, registration opened Sunday night and rumor has it the fields are filling up pretty quick, so don’t wait to pull the trigger on this, it is hands down the BEST mountain bike party in the USA!
Paul Component Engineering
  • info@paulcomp.com
  • 530–345–4371
  • 11204 Midway
  • Chico, CA 95928
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