stirring in the UO-8

i realized late last night that the UO-8 i rode and loved but had been unable to measure is sitting in the basement of my parents' house, where i'm staying nowadays. so i pulled it out and took a tape to it to quantify some of my impressions of it.

turns out it's very close to what i've been getting at. as i've been reading on the archives, it appears to be a low-trail design.

it seems my various influences (see sidebar description) are at odds with one another in a way i'm just starting to really grasp.

but i think i've gotta go with the Peugeot. it really felt great all the time. i hopped on it for a second last night and it just felt right immediately. it's too bad the drivetrain was in such bad shape, so it seems right to build an homage to it.


Jim G said...

My first road bike was an old UO-8 that I heavily modified. I sold it years ago when I was able to get "better" bikes. Mine was a 60cm and I used to think it was too big for me, now I think otherwise. I've always wondered if it was a "low trail" design. Can you share what size yours is, and what the trail/front-end geo figures are?

thefastfifty said...

mine's a 58cm c-c, 59.5 c-t
as close as i can measure with a stainless protractor thingy from Enco, the HT is 74°, and my best guess of the rake is about 70 mm. i know, that seems like a whole assload of rake, but i'm pretty sure that's what it is.
with a 694 mm tire diameter (630 BSD + 2.5" for 1.25" tires) the Kogswell calculator says that's 27 mm trail and 8 mm flop. super low trail. even if i'm off by 10 mm and it's 60 mm rake, that yields 38 mm trail. i plan to build around 46 mm trail, which i still consider quite low.

i had also thought mine was too big, then i stopped riding it and meanwhile learned the Rivendell gospel. having just hopped back on it briefly, i think the reason i thought it was big was the high standover (i measured 32.25"), which would be alleviated by a sloping TT. my PBH is about 85 cm or 33.5"

Jim G said...

Your bike sounds like it's the same size as mine was (roughly 60cm c-t, 56cm top tube). I wouldn't doubt if it's 74°/70mm rake. Damn that is a lot but I do remember the fork curving quite a bit. 27mm trail/8mm flop? WOW. I kept the 27-inch tires on mine, and still had TONS of tire/fender clerance. I wonder how 700Cs would've fit? Now I really wish I still had mine (damn those French threads), or even a good photo of it!

Anonymous said...

Peugeot UO-8 was my first ten-speed bike. The head angle was NOWHERE near
74 degrees - they came with a 72 degree head angle and 2 and 1/4" fork rake. This was a very common combination among low priced bikes that were aimed at the beginner market. Low-end $150 Raleighs, Gitanes, ETC. ETC. - they all came like that, it was sort of a standard cookie-cutter touring geometry of its day, mid sixties to mid seventies.
It absolutely was NOT a low-trail machine by any means.
Later - around 1977, Peugeot responded to common criticism about slow handling on its higher-end PX10 and redesigned it to a 74 degree parallel design with a much shorter wheelbase.

The ONLY UO-8 with a 74 degree head angle was one that was ridden into the back of a car or into a tree. Ha Ha, saw a lot of that over the years but it didn't come from the factory that way.