I know that wheelbase will be a function of top tube length and steer tube angle... my question is, does wheelbase effect steering radius (how tightly can turn) solely, or are there other considerations.

i look specifically at similarly sized specialized secteur and allez... in a 61cm bike, the difference in steerer angle is 0.5*, and WB is 2-3cm... i know that the allez is the 'road race' geometry... when looking for a new bike if it is not listed as a 'comfort' or 'road race' bike, can this be determined somewhat by wheelbase in it's responsiveness? i would like to find a bike that i could ride in a cat 5 crit as well as cruize on a century

my SS has a shorter wheelbase and it feels substantially more nimble than my other bikes. Seems like if you're looking for distance and speed, the Secteur would be a better choice between the 2 since it is based on the Roubaix which is designed for LD & Endurance riding.

yes, i am torn, because i can get the riding positions nearly the exact (did this at the LBS) by changing stem angle up.down and changing around spacers...

secteur with one spacer removed below and flipped stem can be set up like allez and allez with stem flipped up can get more 'relaxed'.

my century this year was rode with appx 1" drop seat to bars, and i am riding now with about 2" drop. my problem is, on a 61-63cm bike, a non-cut steerer tube doesn't gain much in stack height... basically an allez with an extra spacer or 2 rides similar seat to bar drop to the secteur....

aagghh, bike shopping sucks, especially when i want to try so many different types of riding

buy them both

I'm kinda thinking of getting a new road bike next year and I dont have a clue where to start... I thought Orbea looked pretty good until I flipped the tag over...

Yes, turning, leaning and balancing:

More

Trail matters, its the difference between the straight line thru the head angle\ and the vertical line | thru the axis of the wheel.

on the ground.. , + pneumatic trail which is the size/shape

of the contact patch of the tire.

Wheelbase is only one part of the equation. In addition to the top tube length and the steering tube angle, you have fork rake and trail, chain stay length and seat tube angle to consider.

And yes a short wheel base bicycle will usually turn in a shorter distance than a long wheel base.

For extremes take a look at a Raleigh Tourist rod braked roaster or a Surly Big Dummy for the long wheel base and slack angles. Look at track frames for the shortest wheel bases around. One bad thing about moving stems around is that it can affect the center of gravity and change the handling drastically.

Aaron

My 42" wheelbase recumbent certainly makes a snappier u-turn than my 65" wheelbase 'bent.

Often forgotten is that a longer wheelbase maintains better control when speed increases, all other factors being equal. Think of it this way. One section of road is 1" higher than the next and the transition is effectively a very small cliff. When the front tire rolls over the transition at slow speeds it just drops down onto the lower section. At higher speeds, it will be airborne for a fraction of a second before touching down on the lower section. Now imagine going fast enough that the front tire is still airborne when the rear tire goes off the transition. For a very small fraction of a second, no wheels have contact and there is zero control. A longer wheelbase gives more time for the front wheel to touch down before the rear wheel gets airborne. It isn't very much time... milliseconds, but that is enough for riders to feel that one of two bikes is more skittish at speed when they handled the same at lower velocities.

:)ensen.