TT Length VS Seatube Angle

[FierteTi52]

I'm considering building a Bleriot this winter but I'm a bit concerned if the 54.5cm TT length is going to be too long. My current rides have a seat tube angle of 73.5 and 74* with a 53cm TT. Stem length of 10cm. I use a non setback seatpost with a flite saddle set almost all the way back on the rails. The bleriot has a seatube angle of 72* with a 54.5cm TT length. Would my saddle be farther foreward with the slacker seat angle, therefore shortening the effect of the longer TT? Also I would use a Brooks saddle which needs a setback post. Would I be even further back behind the pedals? I would really like to give the Bleriot a try if it will not leave me with too long of a cockpit length. I guess a 9cm stem would help shorten up the overall length too. Any comments from the fit experts would be appreciated.
Jeff

[Smiley]

one degree of slacker seat tube would move your saddle forward about 0.9 0.8 cm forward . With the Brooks saddle MAYBE you'd need a set back post. I think you'll be just fine with a 72 STA , that what I went to on my Uniscasi since I did not like my saddles racked all the way back on the rails. I would use a shorter reach handle bar before shortening the stem.

[CNY rider]

Hi Jeff

I'm curious about your change in rides.....the Ottrott going up for sale, and now a Riv in your future. What changed your tastes? Was it the weekend at dbrk's? Do tell.

[93legendti]

Jeff, here are a few threads that might help you:


http://forums.thepaceline.net/showthread.php?t=13975&highlight=seat+tube+angle

http://forums.thepaceline.net/showthread.php?t=1656&highlight=seat+tube+angle

http://forums.thepaceline.net/showthread.php?t=6433&highlight=seat+tube

[FierteTi52]

Hi Jeff

I'm curious about your change in rides.....the Ottrott going up for sale, and now a Riv in your future. What changed your tastes? Was it the weekend at dbrk's? Do tell.
The main reason for the change in bike style is due to lower back problems I have been dealing with for the last few years. Currently my prioirity is comfort and the ability to fit wider tires. My Kirk does this fine along with great performance, so the Ottrott is up for sale. I figure the Bleriot would be a nice change in ride and style too. Of course, a visit to DBRK's and the ability to get into a 650B for a reasonable price, also has an impact on my interest.
Jeff

[eddief]

slacker seat tube angle usually means the seat will be back further than if it were steeper.

I rode a 59 Bleriot last week. What I noticed compared to my 60 Rambouillet was the headtube slackness on the Bleriot and its slightly shorter top tube, brought the bars back to where I'd actually consider a 61 Bleriot.

There were a couple of variables for me. My Rambouillet has a B67 saddle mounted on a Selcof Bi Position post which allows for a lot of pushback. The 59 Bleriot had a B67 mounted on a Nitto post which did not allow the saddle to go back quite so far.

A delicate balance that can usually be worked around a different post with more or less setback and adjusting stem length.

Too bad Brooks won't change the rails a bit to enable more adjustment.