A quick warning: if you don't know what terms like "steering trail" and "front center" mean, this isn't going to make tons of sense, necessarily. So go google up some bike geometry terminology and come back.
Here's the basic rundown:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiL47_1zcOsqxRATV6McFmEi_DRnfyXQwPmeTdKLHCBRSeghq5mG8MH_ogdwJPqMRPcGdVUx9ETZV5-mysSrM4asrvbpOMNrhXaXyYc5maPya4Q304mJBaUGr2WbBTIWZDcBUx_SQ/s200/Blackcat1.jpg)
-68mm BB drop/11.9 or 12" BB height, depending on tires. I like my BBs low, and I'm not a big pedal-strike complainer. This is quite a bit lower than I would normally build for a customer planning to run 175 cranks.
-20.5" seat tube, 6" head tube, 23.4" effective toptube. Why such a weird combo of attributes? Well, I'm 5'11" tall with a ~36.5" inseam (with my shoes on). That means my BB to saddle measurement is 81cm - and to get the bars anywhere near saddle height, I either need a huge stack of spacers (ugly), a giant riser stem (fugly) or a long head tube. I chose the long head tube here. Standover is pretty high at about 32", but that's not an issue for me. And I need the short-ish toptube to keep the front-center reasonably short with the slack head angle. Also, that way I can run a 90 or 100mm stem comfortably.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiL3S4ts_IrpplOUGmspRQZTu-m5_q93QP1CnUKsFIw1qWI2lun49Im9UDkFGE_RJSafVkPEPCyO9gI46PbbJ5xYhs2Cw4dPRbUEhzTiH8qIbt26pq_AJ6FB3yJ-qZsPpz8o9W1Xw/s200/Blackcat2.jpg)
-I'll probably add a direct mount front derailleur mount (it's pretty low profile) and I'm using dropouts with a hanger, so if my knees give out, I can put some derailleurs on. Of course, that's what I did on my last SS frame, and I never actually used the hanger, so we'll see.
This frame was inspired by conversations with my CB friend Matt (who is far and away the best technical rider I know) about how he wants a 29er version of his favorite frame - the trusty Chameleon. It's a VERY close replica of that geometry, tweaked to fit me better and for our local trails (ie, the steering geometry and wheelbase are very similar, but the BB is lower and I've made the frame really tall to accomodate my long legs).
I *should* have it assembled enough to ride later today, if all goes well. Perhaps more pictures then.
13 comments:
So the shoemaker's kids are finally getting new shoes...
How about a post describing the evolution of your bike ideas.
I remember when you thought discs were un-necessary, seatpost sleeves were decoration,short chainstays were unstable, and tomatos were poisonous.........
23.4" TT sounds super short. I feel like your last singlespeed had a TT closer to 25"? I recall your shorter stem giving about the same reach as with my slightly shorter TT and longer stem.
But really, the thing that offends me most is that I thought *I* was the best technical rider you knew. Guess I'm losing my mojo. I think I'll need to challenge this so-called CB Mike to a duel. (Or, at least, I need some additional impetus to pile the wife and kid into the car and head to CB)
Yeah Walt! Thats what I'm talking about! And since the BB drop is so much greater than the chameleon, it will be more stable, won't loop out on technical climbs etc, yet with a "shorter" wheelbase. Shred ready I say! Curious to see if it will ride "harsher" for the short chainstays. I love the niner sir9 for the plush ride, the chameleon is a jackhamer up my ass in comparison, of course the niner has the 29" wheels goin' or it, and steel... But I hear the short chainstays are harsher , which makes sense...
And as concerns this Feldy guy, bring it I say!
Screw the finer aspects of bike geometry, I want to know more about these poisonous tomatoes!
Yes, my life is now complete, since I've been compared to 16th-century European royalty. Anyone for a tomato, er, I mean poison apple? I have some totally sweet lead-glazed plates to serve it on...
Oh, I forgot, the world was flat then too............
What stem length do you normally use?
I love the dropouts. I too hope that you will comment on the ride "quality" of short chainstays including comfort, traction, climbing, etc.
It sounds very close to what I would like built. (Okay, minus the person with stilt leg geo.)
While the TT seems short, it makes perfect sense for your body.
I want a 72* STA though...
Looking forward to complete pictures and ride impressions!!!
Are those the Deda S-bend stays? Are they stock or did you massage them a little? 68 or 73 bottom bracket?
Very keen to see how you like it all. I am most curious about the very short CS potential. Having ridden from 17" all the way to 18.25", I have found that just under 17.5" on a HT feels nearly perfect. Curious to see how you like it under 17".
And you sold me on 17.9" CS!!! Does that qualify me for a discount on the next one?
And you sold me on 17.9" CS!!! Does this qualify me for a discount on my next frame?
Good luck with that low BB.
Hey Nevada -
Well, I doubt I'll actually run 'em that short. For most people, super short is dumb, because they can't really manual anyway, and it makes the bike kinda crazy on rough/steep/loose stuff. Long can be good for that.
All my bikes have super low BBs. I just don't care much about pedal strikes, I guess. Plus our local terrain leans towards fast and open, not slow technical.
Walt, just given you a hard time on the CS, so far no major lawn darts, and the bikes rides great in the rough. How much adjustment do the sliders give you?
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