droptop

I have been riding now for about 2 years, and I am looking to have one bike to replace the rest, just to take up less space. having 4-5 bikes that ride primarily on the road is just silly.

If anyone knows where I can find the geometry of an 84 schwinn super le tour or an 87 schwinn world, i would be greatly appreciative- as these are my primary two rides, and i would like to come close to them with the new bike (all i have now is measurements of the TT, ST, HT, and chainstays, but no angles).
the bikes i am considering, along with geometries, are listed below.

_____________size-----eff TT-- TT-- HA----STA-- CSL-- SOH-- HTheight--BB drop--- WB
doublecross ___56cm ---576--- 570-- 72 ---72.5- 425-- 31.9" ---135* -----66 ------1032
smoothie es___ 56cm---568--- 560-- 73 ---73.5- 425-- 32.0" ---155 -------70------ 1016
smoothie__ 58(55)cm---570--- 560-- 73.5-- 73 --410-- 31.6" ---172 -------70 ------993



CSL = chain stay length, WB= wheelbase
*as i understand, the cross fork im looking at is 24mm longer than a typical road fork, making the HT height 159, right where i would really like it. (the 58cm smoothie would have to be run with no spacers).

I am mainly concerned with how the head angles and seat angles will affect the handling. overall fit on these bikes can be adjusted later- i will be needing a stem and seatpost, and i can work out the fit as i ride and make adjustments as needed. I understand that the doublecross will be more relaxed, but are we talking by a lot, or a little? I am coming from the super le tour, but again i do not know its geometry.

NoReg

As far as handling is concerned HT angle is pretty critical, but ST angle is largely just a mater of making it all work. Stuff that might affect ST angle would be the degree to which the wheel needs to be tucked in; Lug angle availability, where relevant; seat position relative to the BB; Seat position relative to streamlining. Not really handling stuff. Within a wider range you will find bikes with near recumbent positions that certainly have extremes of ST angle, but within the road bike range the ST angle is not terribly handling relatted.

You need to take the angles off the bike yourself. Tables of measurements may well be wrong. Angle measures are not terribly expensive, but you could probably improvise something pretty simple with a level and a protractor.

droptop

for taking head tube angles, would a level or plumbob and a few strings suffice, along with a protractor (and a friend's help)? im assuming that the rake/trail of the fork will come into play as well on the handling. thanks for the quick response peterpan1, i just want to know how all of this comes into play. I will add the measurements of my old bikes to this thread as soon as i get a chance to take them, along with my next theory.

should be taking a test ride on a crosscheck soon- almost the exact same geometry as the doublecross, and hopefully a road bike with almost the same geometry to the others i am looking at, that should really clear this up more than just poking in the dark with numbers. i just like to know the theory behind things... its my one of my vices.

Road Fan

Seat tube angle and chainstay length control the fore-aft position of your butt, and hence how far ahead of the rear axle your center of gravity falls. Considering this with the front-center distance one can control the bike/rider/load weight distribution. Recommended weight distribution is 55/45 rear/front to 60/40 rear/front.

I'm not sure how critical this will be for you, but in a Shimmy thread, someone reduced shimmy by moving the saddle forward. I find low speed maneuvering is easier when my bike is within that balance range.

Beyond that, I'm not sure how critical it is.

Road Fan

You may be able to work with enough precision with that toolset, you really need to know it to the degree if you're going to relate it to trail. I think the friend has to be a very good one, you'll really need to hold everything still to stabilize the plumb line and to get a reading you are sure of.

I like digital levels with an angle readout. There are some small ones that can be pressed up against short head tubes. I also use angle finders, with the big dials. Harbor Freight has one of those for around $5.00, but I don't know its accuracy. I have one from Ace Hardware that is pretty good, but not as good as digital.

If you go with a protractor, the bigger the one you can find, the better.

droptop

well, finally got a chance to get some measurements. they were taken with a standard metric tape measure and a small protractor. I will have a chance later this summer to take the seat tube angle and head tube angle with an angle finder. however, since i had such problems finding this info, I will post it. i would say the measurements are within + or - 2mm.
this is for an 84 schwinn super le tour.

size--eff TT- TT-----HA----STA-- CSL-- SOH-- HTheight--BB drop--- WB--axle to crown
23" --570---570--~72---~74----440---830-----150-------70-----1045---390

I did not get the fork rake, nor the trail. I hope this helps someone else.

after looking at the geometry, I am fairly certain that a cyclocross bike will give me the closest geometry to my old bike. now, to pick a new frame... my search has expanded much wider than from the somas since last time. now considering some higher end bikes, or a custom (seems somewhat overkill for a fairly standard geometry, but if it is the only way to get the geometry i want with the rack braze-ons on a higher end tubeset, i might just do it).