Spied On Trail: 3D Racing 29+ Bike: by Grannygear
Visiting from the frozen wilds of Durango, Co, So Cal expatriate Chris Herting, the man behind 3D racing, was caught enjoying some prime spring weather and dry dirt on our backyard trails. Chris knows aluminum construction and has been turning out sweet bikes for years now, one of those quiet innovators making cool stuff we want to ride.
Today he was on the yet to be named 29+ 3D bike. I snapped some fairly awful iPhone pics in less than ideal lighting and with poor framing, but hey, it was what I had to work with at the time without my glasses on. Notice the twin top tube design and the yoke at the BB/CS area. Chris built this with a Niner EBB setup (V2.0 version with the twin bolt set-up) so he could SS it and it was, of course, running the 29×3.0″ Knard tires. Also, yes that is an XFusion fork on there. I though I had seen something really new and special, but this was a stock XFusion 29er fork with the arch shaved down. Don’t do this at home, etc.
Chris says that the twin top tubes enhance vertical compliance and yet retain torsional stiffness. I like the look and it reminded me of the Siren Bikes Twinzer.
No info on price, etc, but this is a production bike so call 3D racing for details. Chris is on the road, so he may not get back to you till he is home, but the wait could be well worth it.
3D Racing website.
Custom builders working around the Knard tires! Future looks interesting
interesting to see another 29+ bike. but: a rigid fork would work better with the idea behind it, wouldn’t it?
@oli_muenchen: Perhaps some see the suspension fork as superfluous, but it is notable that during the trip out to Interbike last year, Surly employees were all riding Krampus bikes outfitted with suspension forks as they stopped at various places to ride. Apparently, from hearsay we heard, the bike works fabulously with a suspension fork, although none are cleared for use with the 29+ format by fork makers that we are aware of. Use a sus fork on a Krampus at your own risk then.
So good to see 3D racing in the news. Love that green. Wonder if Curtis makes his jerseys in that color?
Shaving down a fork casting is a really, really, really bad idea. Castings develop a lot of their strength in their outer skin, where they cool quickly against the wall of the mold. This causes small crystals to form, which are less susceptible to crack formation. Exposing the larger crystals of the interior….well, it’s right up there with sawing partway through your stem.
@BigHank53…while we would never suggest such a thing and I would not do it to a fork of mine, there is talk of how critical that brace even is, especially with thru-axles. For the sake of perspective, if that shaved arch cracked in half, it would not have the same result as your stem breaking in half.
gg
“Surly employees were all riding Krampus bikes outfitted with suspension forks”
What fork did they use?
Images are out there- I am pretty sure they were Fox.
I have not played with every 15mm thru-axle out there, I’ll admit. But the ones that I have worked with…well, let’s just say I wouldn’t count on one to keep the left fork leg from rotating a couple degrees if the brace cracked. I don’t know what it’s like to have a rotor jam in a brake caliper and I have no intention of finding out the hard way.
Maybe the forks are so overdesigned it’ll never be a problem. I hope so.
What about a Lefty?
Love it.
If it was anyone else shaving down a fork arch to make a tire fit, I’d be very very scared.
But Chris Herting’s been working with metals for years. I bet he’s done the math before that arch hit a grinder. Hell he probably figured out some clever way of doing it or barely shaved much off
Mike Curiak and some folks he knows have been riding Fox forks with shaved braces for quite some time with no issues.
It’s certainly a do at your own risk mod, but it’s working for some folks.
http://lacemine29.blogspot.ca/2012/07/there-are-many-like-it-but-this-one-is.html
“Head shot. Fox 36 x 180mm fork sitting at full height. I milled the arch (or rather, I had he-who-would-prefer-to-remain-nameless do it) to accommodate a big wheel, then limited the travel to ~167mm internally. I’ve been waiting and waiting and waiting for someone, anyone to release a ~160mm travel 29″ fork, even experimenting with an older dual-crown Dorado that didn’t really scratch my itch. What pushed me over the edge to mod this Fox was the fact that *several* of my wheel customers had it done, some of them 3+ years ago. Some of these guys are 260# or more, riding LunchBoxes and similar, and have yet to have a problem with theirs.
safe riding,”
Vik
At least a couple of people have successfully stuffed a Lefty on a Krampus, so that that looks to be an option, too.
Reminds me of the 1986 or 87 Haro Masters with the neon green and dual top tubes. Should have never gotten rid of that!
Stock Lefty fits a Rabbit Hole / Knard pretty well, a little rub on the stanchion when climbing out of the saddle or in hard cornering. Could always switch out to P321 clamps for more clearance if your Lefty has removable clamps…