barefoot's XACD custom Ti road/cross bike - build thread
Posted: Wed Dec 26, 2012 7:41 am
This build has been going on for a while, on the sly, on a different thread.
Now collecting all relevant posts in one place.
Enjoy
Copypasta this pre-amble from another post:
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I cropped down a picture of my current road bike, for another thread, but thought I could also post it here to justify why I've needed to go for crazy custom geometry on this disc roadie.
That's a 53cm generictaiwanesealloy frame (which DBR call size "S / 53"). I'm 5'10", and most simple height-based fitting charts suggest would put me on about a 56cm frame.
I need the small frame for the top tube length. Then I need a ridiculous stem to get the bars high enough (and quite a lot of seatpost to get the saddle high enough). This bike puts me in quite a low aggressive position - especially in the drops - certainly not up in the wind admiring the view. I'd probably add another spacer under the stem if the steerer was long enough to fit it (it was a second hand frameset, I didn't get the option of leaving the steerer long).
My other two drop-bar bikes - an On-One Pompino and a Long Haul Trucker - are both 54cm frames, and are both too long in the top tube. I use a 50-60mm stem on each of them to bring the bars closer, up on a big stack of spacers. The three bikes all end up with relatively similar bar position - the LHT is somewhat closer and taller than the DBR, and the Pompino is in between, but all of them are much closer and taller than I can get on a production frame using "normal" parts.
That saddle position on the DBR is universal on all of my bikes. Slammed as far forward as it will go, on a zero-offset post. I think I'd like to go a little further forward still, but I have no way of trying it.
So, my custom frame will have a steep (75°) seat tube angle to bring the saddle forward, short top tube and long head tube to bring the bars up and back. I intend that I should be able to get the same fit position on the new bike as I have on this DBR (and the others), but with the saddle clamped mid-rail, and with a flat ~100mm stem. Like how normal shaped people fit on production frames.
From there, I expect to continue fiddling with my position... but starting from the middle of the adjustment range, rather than hard up against the limits where I am now on all of my bikes. I can tweak saddle position forward _or_ backward. I can swap in shorter _or_ longer stems (angled up _or_ down), I can add _or_ remove spacers. A range of adjustability that is unprecedented for me.
Now collecting all relevant posts in one place.
Enjoy
Copypasta this pre-amble from another post:
---
I cropped down a picture of my current road bike, for another thread, but thought I could also post it here to justify why I've needed to go for crazy custom geometry on this disc roadie.
That's a 53cm generictaiwanesealloy frame (which DBR call size "S / 53"). I'm 5'10", and most simple height-based fitting charts suggest would put me on about a 56cm frame.
I need the small frame for the top tube length. Then I need a ridiculous stem to get the bars high enough (and quite a lot of seatpost to get the saddle high enough). This bike puts me in quite a low aggressive position - especially in the drops - certainly not up in the wind admiring the view. I'd probably add another spacer under the stem if the steerer was long enough to fit it (it was a second hand frameset, I didn't get the option of leaving the steerer long).
My other two drop-bar bikes - an On-One Pompino and a Long Haul Trucker - are both 54cm frames, and are both too long in the top tube. I use a 50-60mm stem on each of them to bring the bars closer, up on a big stack of spacers. The three bikes all end up with relatively similar bar position - the LHT is somewhat closer and taller than the DBR, and the Pompino is in between, but all of them are much closer and taller than I can get on a production frame using "normal" parts.
That saddle position on the DBR is universal on all of my bikes. Slammed as far forward as it will go, on a zero-offset post. I think I'd like to go a little further forward still, but I have no way of trying it.
So, my custom frame will have a steep (75°) seat tube angle to bring the saddle forward, short top tube and long head tube to bring the bars up and back. I intend that I should be able to get the same fit position on the new bike as I have on this DBR (and the others), but with the saddle clamped mid-rail, and with a flat ~100mm stem. Like how normal shaped people fit on production frames.
From there, I expect to continue fiddling with my position... but starting from the middle of the adjustment range, rather than hard up against the limits where I am now on all of my bikes. I can tweak saddle position forward _or_ backward. I can swap in shorter _or_ longer stems (angled up _or_ down), I can add _or_ remove spacers. A range of adjustability that is unprecedented for me.