Sunday, October 17, 2010

Lazy Sunday!

Well, not _that_ lazy. I did get most of a frame built for myself. It might be of interest to the geeky folks out there (before anyone points it out, yes, the crossbrace between the toptube and seat tube isn't there yet).

The bike is intended to be a long-travel trail/freeride setup. Here's the rundown, with annoying commentary:

-145mm rear travel. Yes, that's a lot. No, the rear end is not custom, it's just a "customized" selection of rocker/shock to get the travel I want. Yes, I can do this for anyone. The unsagged BB height is a little over 14", which is on the low side for this much travel, but I like low BBs and non-excessive amounts of sag.

-43cm chainstays/109cm wheelbase (42.9" for you SAE freaks). It's quite possible that I'll hate the super-shortness of this bike (it's a solid 2" shorter wheelbase than most 29ers in this sort of travel range), but I doubt it. Yes, there's a catch. I'll get to that in a minute.

-69.5/73 head and seat (effective) angles. That's assuming a 120mm travel fork. If you throw on a 140mm (which I eventually will) everything slacks back about a degree.

-44mm head tube for tapered steerer fork. Natch. I'm gonna run a Fox, I think. Probably order it this week.

-23.2" toptube. Yes, that's very short. But with the slack front and and 44mm rake fork, I wanted to keep the front center under 66cm (there's no magic to that number, it's just close to what I tend to like).

-Big long head tube (140mm) and seat tube (21"). I have very long legs - the bike has 31" standover, so I will have tons. I will still need some spacers and a high-rise bar to get the grips to the height I want. Should be reasonable to loan this out to friends of similar height without too much adjustment, though, which was also a (minor) design criteria.

-No ability to run a front derailleur. I just simply do not need more than 1 chainring, ever (I'm not bragging, that's just the way it is) - especially with the advent of wide-range 10 speed cassettes. This bike won't accept a front derailleur due to the pivot/chainstay positioning, so 1 ring is all I get. For a customer, I'd probably use an 83mm BB shell (this is 73mm) and an ISCG for a Hammerschmidt or something if more gears were needed.

-Tubing is 4130 for the seat tube, heat treated 4130 head tube, and Supertherm everywhere else. The frame is about 7.5# with the shock, which I think isn't too bad. Honestly, I don't care at all what it weighs. Heavier is fine, I want to be able to get a workout riding with my friends and wife, then bomb the downhills. Maybe this thing will let me keep up with Steinwand...on his hardtail...when he's drunk. Yeah, right.


chris said...

looks like fun. we might have to test it on the lifts next year eh?

grannygear said...

Nice. Some interesting tweaks to the norm, there. Interested to see how it turns out. That would be sweet with a WB 150 on it.

I have a Reba 140 Ti that will be going on a bike soon, but that frame is only 130mm rear sus.

Walt said...

Chris -

Yup, she'll hit the lifts, for sure!

GG -

I try to only buy US-made products, so no Rockshox for me. It will be Fox or WB - waiting to hear more about the new WB forks - they look cool, but I have not had great luck with them in the past.

MMcG said...

Gonna use a Dropper seatpost?

Walt said...

M - Probably just a standard seatpost and QR. Most of our riding here is VERY long climbs followed by long downhills, and I am not generally a huge fan of dropping the saddle a bunch anyway. If I go to the resorts, I'll just lower it 2 or 3 inches and call it good, otherwise it will probably stay at the same height.

Oh, and I have super bad knees, so I really hate changing things around once I get the saddle where I want it... but I guess that could be a reason to use the dropper post, just to be able to replicate the position.

We'll see. For now, an old Thomson. It's gonna be winter soon, I can't imagine I'll be riding anything that gnarly until next year.

Nowork said...

Come on Walt! Git'er built so we can go play before the snow comes!

Walt said...

Fox says 3-4 weeks for the fork, so probably no love until the snow flies - unless I find a 120mm taper steerer 29er fork at Veloswap... fat chance.

Nv29er said...

I like it! I'd have gone a degree slacker on the HT though. Who makes the rear end for you?

Walt said...

NV -

Keep in mind that the frame is really intended for a 140/150mm fork, which will put the HTA in the 68 degree range. I just don't like the options for forks that length right now.

The rear end is made by Ventana. I may build a new chainstay assembly to run a maxle in the rear at some point.