FIRST LOOK: Ruster Sports Black Dimond
article & images by Nick Salazar
Sep 20, 2012  hits 66,442

No seat tube here: this is TJ Tollakson's brand new beam bike, the Ruster Sports Black Dimond

If you keep up with the buzz around pro athletes, you may know that TJ Tollakson is known as a bit of a tinkerer. He likes to do a lot of custom projects in the hopes of finding little aerodynamic advantages that his opponents don't have. It's a mindset that we at TriRig always love to see. So when Tollakson announced that he was going to manufacture an entire bike, we took notice. And nestled in a small booth, tucked away at the far corner of the basement at Interbike, we found his first prototype frame, dubbed the Black Dimond. This is a pretty cool piece of kit, and one that a lot of the tri world has been excited to see, yet it was nearly hidden away, and many people aren't going to find it. But we did, and we're delighted to show it to you.

It's a beam bike, and is missing a seat post or seat stays. As expected, the Dimond looks a lot like the Zipp 2001 frame that was its inspiration. It looks so much like the Zipp that some people will be forgiven for thinking Tollakson is just using Zipp's old molds. But these are all his own, and there are definitely changes to the design.

My first impression of the bike is one of mixed feelings. I love the idea of a beam bike, I love it even more because it's being pioneered by TJ, and I like it even more because of its Zipp heritage. And in case you didn't notice, it has TriRig Omega brakes, front AND back, which obviously I love.

The Dimond logo is painted with a reflective pearlescent material that makes it glitter much like its namesake.

On the other hand, the bike's frontal profile is rather wide. It's using a BIG head tube, that covers a lot of frontal area. That's kindof a bummer in my opinion. I understand why it's done - the extra area increases stiffness, which is required due to all the extra forces that are coming down on that head tube area that would otherwise be shared by the seat tube cluster. Moreover, the down tube doesn't drop down to meet the fork, so there's a gap between the rear wheel and the intersection of the fork crown and down tube. There's nothing necessarily wrong with that, but with super clean transitions on bikes like the Felt DA, Cervelo P5, and Blue Triad SL, an expectation has arisen that modern bikes will clean up that area as much as possible. At present, the Dimond doesn't do that.

Of course, everyone is welcome to draw their own conclusions. Despite my nitpicks, I'm very excited to see more of this bike as its development continues, and obviously I'm glad to see TJ equip it with the Omega brakes.


  • The Ruster Sports Black Dimond is a brand new beam bike based on the older Zipp 2001.
  • This is just a prototype seatpost cluster - the production versions will be easier to adjust.
  • Again, this is just a prototype seat post. And it does look a little rough - but the production versions will be easier to adjust, and much cleaner.
  • The beam is secured via these two bolts, and is replaceable if you need a different size - just like how the Zipp 2001 worked. That flat top also looks good for attaching some kind of storage or hydration gear.
  • This is obviously a prototype version, and will be cleaned up for production. No word on whether the frame will be for cabled drivetrains only, or if there will be Di2/EPS compatibility.
  • Here's that frontal profile - it's a bit beefier than I'd like, but that's probably because of the extra stresses that a beam bike's geometry puts on the head tube. I also think TJ could have cleaned up that cable routing. No need for that extra loop of housing up top - that's an Omega after all!
  • The front derailleur hangs on a protrusion that comes out of the down tube. It's stiffened up by the red Kevlar later you see there.
  • The pearlescent paint on the logo is meant to play on the Dimond name.
  • The bike certainly has a striking appearance - the absence of the seat tube and seat stays is a welcome innovation. I'd like to see more manufacturers head in that kind of direction, or at least explain why they aren't doing so.
  • Tucked under the chain stays is a standard brake mount, and Tollakson is stocking the TriRig Omega down there, where it fits beautifully.
  • The massive chain stays make up for the missing frame members to help support the rear wheel.

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