Project 4X: SupercrossBMX Propel – Full Review

Ready for fast 4X courses or your local Dual Slalom course… the SuperCross Propel.

Along side out Project Dh, we have also been testing our the bigger brother to the SuperCrossBMX Shine we reviewed earlier.  Its been a fun ride so far and a very capable bike.  They don’t come as completes so we set out to transfer alot of the parts that have been solid and kept us happy so far to see how they fit with the Propel.  We kept in with the BMX theme and added some Profile race cranks featuring their new outboard bottom bracket and spline drive spider.  Also from the BMX lines were the pivitol seat and post both from SuperCrossBMX.

Lots of colors, but they work well together.

Complete Build Specs –

  • Frame – 2012 Supercross Propel, size Long, 3.75” of travel
  • Rear Shock – RockShox Sid, Custom Tuned by HippieTech Suspension
  • Fork – 2011 Marzocchi 44 Micro TI, lowered to 100mm
  • Bars – Joystick Analog Carbon, 725mm
  • Stem – Marrow Components 50mm
  • Headset – Cane Creek Carbon IS-8i
  • Grips – ODI X-treme Lock Ons
  • Seat – SuperCrossBMX Pivotal Race
  • Seatpost – SuperCrossBMX Pivotal
  • Seat Clamp – Speedline QR
  • Wheels – Novatec Diablos
  • Tires – Kenda Small Block 8, Happy Medium, H-Factor, BBG
  • Cranks – Profile with Spline Drive spider and Composite chain ring
  • Bottom Bracket – Profile Outboard
  • Pedals – HT AE-01
  • Brakes – Sram Avid R (rear only set up BMX style)
  • Shifter – Sram x7
  • Derailleur – Sram x7

Short travel and similar design to some others out there…but it works!

The Propel is intended as a full on race bike for 4x and Dual Slalom. With just under 4″ of travel you should be able to tackle any course out there.  The frame comes in at $1399 from SupercrossBMX and weighs in at 6 lbs 6oz before the shock is mounted.

Here are the Propels specs –

Top Tube Actual – 21.75″
Top Tube Effective – 22.75″
Headtube Angle – 69.3 degrees
Seatmast Angle – 71 Degrees
Bottom Bracket Height 12.3″ ( With 26×2.5″ Tires Front and Rear )
Chain Stay Length – 16.5″
Headset – Campy Integrated  1 1/8″
Seatmast – 27.2 Post with a 31.9 Clamp


The Propels linkage is simple and can be found in similar fashion on several other brands. For a good reason, it works. Now that doesn’t mean because it “looks like” this bike or that bike that it is going to ride the same. It can all boil down to several factors that include choice of shock, bearing sizes, geometry and fork selection just to name a few. Our frame came without a shock, as they were still waiting for them to come in from their supplier. But expect them to come with a Marzocchi Roco Air. Since I was unable to wait to ride this bike I summoned my friend Jerry Vanderpool over at HippieTechSuspension for something to get me by, and on the cheap. What arrived was a new older stock RockShox SID dual air and lock out…and to be honest I am loving it for this bike. Jerry put a “Hippie” tune on it for my riding style and weight…in fact it’s so good that when I borrowed a new RockShox Monarch, I promptly switched back.  Cable management was well thought out.  Everything on this bike is nice and tidy.

Solid welds and Integrated headset.

For a short travel bike the Propel is a fast and smooth. I put this bike next to a Yeti 4x which has a similar frame design and linkage, as well as geometry being pretty close. The Yeti has been a top 4x/DS racer for the last handful of years, so I felt this was probably the best match up. The Propel flat out accelerates faster than the Yeti. It also out cornered the Yeti. Both bikes share a 69 degree head angle. But what I think made the difference was the stiff rear end of the Supercross. I attempted to set up sag, fork pressure and tires all the same to help eliminate too many differences between the two bikes. Now this is not to say the Yeti is a slouch. On the contrary its one of the best most capable racers out there. But the Propels lower bottom bracket lets you really rail it out. The Propels suspension linkage also used large diameter sealed bearings to help the bike feel solid throughout its travel.

The Propels steep head angle makes this a fast steering bike that can be a bit twitchy at times but none more than the Yeti 4X.  It’s neutral throughout the ride from gate starts to jumping and hauling ass.  The lower swingarms are also quite well braced with a beefy x-member.  All combined with a low standover height and weight…you should be able to do anything on this bike that you want.  It is easy to flip the bike back and forth through fast tight slalom courses.

Our complete build topped the scale at 25.5 lbs, which is fairly light for a dual suspension bike. Its weight feels very neutral in the air, which makes the bike easy to jump. Setting up the suspension firm lets you ride this bike like a hardtail but just a bit more forgiving on miscued jumps or the occasional case. All in all the Propel is a very capable bike.

For a full squish 4X bike, 25 lbs isn’t too bad.

What would we change…. well just like Supercross’s Shine, we would favor a tapered headtube over the convenience of the integrated head tube. This allows you to have the option of running an angle set type headset or the stiffer tapered steertubes on many of your choices of forks. Along with that a slightly slacker head angle (say 68 Degrees) would make the bike a bit less twitchy. We have found that racers are far more picky to their bikes setup and optional settings than many DJ riders who prefer the simple / strong approach. The other thing we would change is the dropouts in favored for fixed versions. The adjustable dropouts on this bike are not neccesary and could be executed a bit better. We never moved them and can find no reason to do so, but they are there if you decide you want to. The bike just sits right. Plus if you ran it single speed you would still be required to run some sort of tensioning device due to the suspension design.

The Supercross Propel is a fast, nimble bike. It screams through the turns and is super stable in the air.  With our shock semi locked out, it snaps almost as good as the hardtail Supercross Shine.  Unlike the Shine, we came around quickly to the way the Propel handles.  This is a bike for all the BMXers out there wanting to make the jump to 4X and Dual Slalom.

We would like to thank a few that really made this bike possible-

SupercrossBMX –

Profile Racing –

Novatec Wheels –

HT Components –

HippieTechSuspension –

Joystick Components –

Marrow Components –

Kenda Tires-

About WingNutt

Rider, Racer, Owner of A long history in racing and riding, from BMX and freestyle to Downhill, Dual Slalom, 4X and even some Road races spans nearly 25 years. Spent some time working in bike shops. I love to ride my bike.

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