Flyboy718

I have a 1984 double butted Univega Nuovo Sport 63cm it is 29 lbs. I just recently got it up and running. I also have a 1985 triple butted Univega Viva Sport 63cm it is 25.8 lbs. I have noticed a nice difference in speed, I ride the heavier Nuovo Sport faster than the lighter Viva Sport. I feel like I am more efficient for some reason with the Nuovo. I have clincher rims on Nuovo and run Kenda K35 with 80-90 psi. The Viva had straight wall rims and I run the same tires but with 60-70 psi.

USAZorro

20 psi difference in tire pressure might explain a lot of the difference. If it's possible to equalize the air pressure or switch out the wheels between the bikes, it could make for a nice little experiment.

CycleryNorth81

What is your speed on the NS and your speed on the VS?

Lascauxcaveman 

I'm a little surprised by the weight difference; I would expect them to be closer. Maybe the wheels/tires are the story here?

For the record my 1987 Nuovo Sport is around 25.5 lbs, also a 63cm, but with the original suede saddle swapped out with a lighter Unicanitor. (original 27" Araya rims and original Univega branded tires, no less!)

jetboy 

is the gearing identical?

rhm

You say you feel faster; but have you actually measured a difference?

katsrevenge

Geometry? handlebars?

jjames1452 

Wheels and tires are an interesting explanation. I was automatically drawn to this thread - because I had the same model bikes with different components that I rode at vastly different speeds. I had an ice pink Prelude with 600/Ultegra indexed components that I couldn't get up to speed. So much so, that I sold the frame. I have another blue Prelude with 600/friction components that I had no problem getting up to speed. The one difference - there is a beautiful wheelset on the blue Prelude. That ice pink frame was mint - I should have swapped components - darn. The ice pink Prelude went to a BF member - who is probably happy..

I did not understand that at the time.

RobbieTunes

Subtle differences in fit.
Tire pressure differences if they vary much.
Gearing differences if you are inclined to favor a certain cadence.
Psychological differences, because they matter.
Not much else explains it.

Generally, it's the nagging feeling that we're giving up some advantage that pushes us to go "faster" on certain bikes.
Under 20mph, not much else is a factor.

oddjob2

Try swapping the wheelsets between the bikes.

rhm

+1, good idea.

daf1009

I had a similar situation...got two bikes "up and running" at the same time...and expected one to be faster than the other (Miyata Team versus Bridgestone RB-1). I expected, with the racier geometry and gearing, that the Team would be a bit faster (not a lot, but a bit) than the RB-1. I did the same course, on the same day, with same conditions...and...the RB-1 was actually 1.2 mph faster! Again, overall the geometry is a bit slacker and the gearing was definitely a bit lower...but...

I attribute it to fit and feel...I simply feel better on the RB-1 than the Team. I have noticed this on several rides of the two since then...so...subtle differences in fit/feel can make a difference as well...at least IMHO!

bradtx

Flyboy718, This question is asked fairly frequently and nobody has found a reason, perhaps because it's so individual.

Fit and gearing seem the most likely reasons. I've had two very similar bikes, Cannondale 2.8 and a Cannondale CAAD3 whose major difference was the color, but over 50 miles I was always faster on the 2.8. Go figure.

Brad

Flyboy718

I unfortunately don't think I have any more clincher rims. My Viva is index shifting Shimano 600 and a ten speed everything else I have is friction shift cogs 12 speed.

Looking at my Strava records and I use a Garmin Edge 305...I am averaging about a mile per hour faster on the same routes which doesn't seem like much but that is average and I am doing 2-3mph faster in stretches of the route that I normally wouldn't and maintaining a higher speed on these routes than with the Viva. I could actually go even faster on the Nuovo if I could use my highest gear(lowest cog) but I am having an issue with that cog where the chain won't stay seated in that cog it skips the whole time under a load. Also, I have noticed a change in my heart rate on the same rides as well...my heart rate is actually lower, by around 10 BPM on the Nuovo. I am taking hills faster as well...enough that a smile has come across my face when I look down at my speed.

Viva is 10 speed Shimano 600 index. Nuovo is 12 speed friction
I am thinking it must be geometry related...I haven't measured anything yet or really know what to measure...they top tube does seem like it may be a hair shorter.

Jarrett2

Any brakes rubbing? Hubs in good condition on the slower bike? When you spin the rear wheel and hold the frame near the skewer, do you feel any rumbling/grinding/vibrations?

Flyboy718

I haven't re-done the hubs on either one yet...they both need to be serviced. But no rubbing or bearings out of adjustment.

USAZorro

I'd still want to see how equalized air pressure in the tires affects the speed. I think it will have some effect, but no idea how much. Some frames are just faster than others for some people. I once tried to like a Trek Tri Series that I picked up for a good price, but it just never felt right despite several modifications to the set-up. I have, and have had other bikes that I was just much faster riding.

noglider 

On both bikes, measure:

- distance between pedal at bottom of stroke to top of saddle, aka saddle height.
- distance of saddle nose behind BB center. (Use a plumb bob for this.)
- lateral distance between saddle nose and handlebar.
- height difference between saddle and handlebar.

These measurements might explain a lot.

Flyboy718

I am going to see if I can find some clincher's for cheap for it and do a comparison. I am thinking it's probably a combo of the air pressure and geometry. I have also a 64cm Nuovo Sport that is a 1981 and it weighs a little more than 30# and is not butted steel and I ride it really well too, don't have exact numbers yet for it but I ride it better than the Viva.

Flyboy718

Will do!

SJX426 

@noglider thanks, I was just going to do that between two bikes. One has become very comfortable with no pain and fast (<22 lbs). The other is slower (45 lbs.) and hard on my hands. Huge difference between the two but I should be comfortable on both. But instead of nose measurement, I was going to use sit bone depression on the saddles.

noglider 

Good point. Sit bone contact points are arguably more meaningful than nose position.

OldsCOOL

Headwind and aero factors become exponential over 15mph. It is deceiving in how you feel over the course of even the most familiar TT routes. Here, the factor of frame geo can make a slight difference due to the rider profile from one bike to another. By all means, do the entire test aero or upright, the whole way.

OldsCOOL

I have a Fizik Pave' on the Cannondale Criterium and it is a BUTT HATCHET, though I noticed my rides are incredibly fast.....so I can get off it.

RobbieTunes

On properly fit bikes, both tuned and at their potential, you should be fairly consistent with speeds on both.
I ride a modern steel bike with aero carbon wheels, and at 16.34 lbs, I have an average speed on it.
The same bike, with my training set of non-aero wheels that are about 700g heavier, non-aero, only about .1 to .2 mph slower, and not always that.
That's close enough to be the same, because there are tons of non-bike variables.

My PR on one course was on a steel Simoncini; I hit every shift, pretty much, and carried momentum when I needed to, didn't have to wait at intersections.
I've only beaten that PR once, on a full carbon bike, and only by .1 mph, so it's irrelevant. Neither bike is "faster."

Generally, when bikes are fairly equal, times get better because you're in a hurry and happen to be physically ready at that time, that day.