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It reminds me a little of the double-top-tube bikes that are traditionally used for cargo bikes and/or tall frames with long head tubes, and have recently been revived by Rivendell and others. They solve the problem that the main triangle isn’t really a triangle when the head tube is very long, and recover the strength that is lost when it’s not. This has the same effect, but also has a lower standover. The disadvantage is that long seat post–that’s not triangulated at all. I had a frame crack at the seat cluster from use with a very long seatpost.
Actually it’s more like a Pedersen http://pedersenbicycles.com/
Another bike similar to this: The Workcycles Pastoorfiets
The Pastoorfiets solves the problem I mentioned of an overly long seatpost by bringing the lower or rear top-tube (terminolgy here?) diagonally up in the back.
It’s cool to see some well-made road bikes that differ from traditional designs, though it might have a hard time finding a market – with that tube geometry, it wouldn’t be UCI legal for racing. (Down with the UCI!)
A technical problem with a frame design like this is the odd locations of the joints – the frame will either have to be heavier or more expensive than a traditional design because the tubes would need pretty complicated butting for the joints to be strong. A traditional frame has all tubes connecting at their ends, which means only the ends need to be butted (thicker).
Maybe something like this could be more appropriate for a racing/commuter hybrid, like a specialized sirrus, etc.
It also reminded me the SE Quad-angle.
Mixtes look good, this doesn’t. Also, I’m no engineer but this looks like a really stupid way to build a a bike frame. I’m all for both innovation and tradition, but neither for their own sake.
Interestingly, I vastly prefer this to mixtes, where the rear triangle always looks awkward and busy to me. This is busy in other ways, but at least it looks like it would be quite stiff.
Can’t say if particularly better than any traditional layout, but it’s sort of neat, anyway.
Always, designs come with benefits and tradeoffs. For instance, here, the effective lateral clearance between your knees and top tube is reduced by a distance equal to the diameter of that cross-member. Moreover, if you’re off the seat climbing or sprinting, I would think any deflections side to side from the wheels would be better handled by a shorter cross tube tube as they are more stiffer. I don’t know the material used here but an FEM analysis should tell you whether there are larger than usual stresses at the junction of the top tube and seat tube. But hey, now you could place a small water bottle or a GPS unit onto the portion of the cross member above the top tube. So there you go…
I like this. I penned someting similar long ago, but used a horizontal tube at the same diameter as the diagonals. I have to think about the tall rear drops, and I agree it probably is heavier a tad. My design was to allow the 6′ and a bit under crowd to still use 700c wheels. Looks like it works for a bigger frame too. When I see Tyrell I either think of Bladerinner or Formula 1 though, then it should be deep blue…
Oops, a typo or two, should have been 5′ and under…
5′ and under–that makes more sense!
But I’m not fully clear on how that helps–the real problem with 700c and 5′ and under is toe clip overlap. I think of this design as being helpful towards a long head tube, as needed when the wheels are small compared to the frame size, not vice versa.
Front center dimension is a decision point. Either you live with overlap or you are designing a transportation/utility bike where you can adjust things for a front load, have free toe clearance and a short effective top tube. Way back in school I worked on this, one of the limiting connections to top tube length for at the time was a standard level top tube was the head tube connection. I figured out a few alternatives, I forget the minimum number I came up with where small toe clips and 165 mm cranks while not raising the Bottom bracket the bottom bracket )as was often done on small frames to the detriment of handling with no help in the standover) but it was under 59 cm. I was not happy with the solution of relaxing the head angle and keeping lots of rake to make that clearance. I had a bike with serious overlap, and while not good for a fixed on the street, it was not a big deal, yes, one did have to know the limits. 650’s cure much, but at the time were not viable., especially for a performance bike.
Yeah, I love to ride one of these babies. I want to check the bikes and try it out on outdoors. Experience the thrill of riding new bicycle. I really want to have this last one here. Good luck for me. thanks a lot.
And by the way there’s no shock absorber in that one? But i want to try it out though. thanks.
Pls note that they are not bought by any Japanese company…they just bought the license for the folding bikes and 700cc bikes. Tyrell is still a german company and their frames are great!! I especially like the Erebus brown which is actually chrome welded using Columbus steel technology.
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