MRT2

OK, not me, but my wife. She splits her riding between two bikes. A 2013 Jamis Satellite Sport, and a modified 1978 Peugeot Touring bike.

First, the bikes. In one corner we have a 2013 Jamis Satellite Sport. Weighs in at around 24 lbs, which is heavy for a road bike. Modded the gearing slightly by swapping out the road cassette for an 11 - 32 mountain cassette, and switched out rear derailleur to handle the mountain cassette and to simplify shifting for my wife, who hates to use the front derailleur if she doesn't absolutely have to.

In the other corner is a 1978 Peugeot Touring bike. This beast was really heavy, originally weighing over 35 lbs. We lightened the bike by switching out the steel wheels to alloys, stripping off the generator/light system, removing the big chainring and front derailleur and shifter, going with a 9 speed 11 - 32 mountain cassette/freehub. switching to a modern Shimano Tiagra derailleur. And removing the drop bars in favor of a Velo Orange Postino bar with Tektro levers and Sunrace thumb shifter. Still, with Brooks saddle, fenders, rack and kickstand, it still weighs around 30 lbs.

When I modded the Peugeot, it was with the idea of using it as a spare bike, or maybe for shorter rides. Surprising thing is, my wife seems to be faster on that bike. Trying to figure out why as the modern bike is lighter. It is a good problem to have, but it gives me pause to ever recommend to someone they switch to a lighter bike to get faster.

blakcloud

My guess, she is more comfortable on the upright bar instead of the drop bar on the Jamis. Being more comfortable leads to faster times. Put the same bar on the Jamis and you most likely see an increase of speed, if that is her goal.

Now if the Jamis has a flat bar, then my reasoning is wrong.

OnyxTiger

Agreed with blakcloud. Fit could be the variable here. A difference of <10lbs doesn't translate to a huge speed difference, especially if on the flats. Sure, it could add up as the miles get longer (and if at that point she's still markedly faster over longer distances then I'd be looking at fit/comfort as the culprit). If she's faster over shorter distances, then I'm guessing you guys have less stops in between? Heavier bikes tend to keep speed easier, yet spin up slower.
If she's still markedly faster and you're in a hilly area, and you have a decent sample size (perhaps more than 10 rides and she's been faster on 7+ of them) then that would be the paradox I'd be interested in.

MRT2

Nope. The Jamis has drop bars, which she seems to like just fine. I thought the problem was the road gearing, which was both too high and required more shifting. So I removed the big ring on the Jamis and switched out to a mountain cassette, essentially giving the Jamis the same gearing as the Peugeot. But even so, she still seems to do better on the Peugeot.

MRT2

The rides range from 20 to 40 miles, and from fairly flat to rolling hills. None of it seems to matter. The Peugeot is a bigger bike, though she seems equally comfortable on both bikes.

wphamilton

This may sound like stating the obvious, but no disrespect is intended. You did ask.

The reason the heavier bike is fast for your wife is that qualities other than weight are more important. The specific qualities can be, but are not limited to, tires, position, bearings, comfort of the fit, and other factors that may relate to comfort in the ride and production of power.

The weight only relates to going uphill and accelerating. Rate of acceleration is almost irrelevant to what we're considering as speed here. Uphill will only slow her around 5 or 6% estimating with the numbers you've given, and that's only directly uphill on steep (slow) hills. On rolling hills (faster) it will be even less, with some regained on the rolling downside - overall the difference due to weight alone could be insignificant. Counterbalanced by whatever she likes better about the other bike, which is probably operative over the entire ride.

10 Wheels

Comfort and Fit worked for me.

CommuteCommando

Physics. The weight to consider is the total weight. A 160 lb rider on a full suspension Next from WalMart will weigh less than a Clyde like me on a Pinnarello. I see you are in Wisconsin, which I understand is not very hilly, and hills and acceleration is where weight is a big factor. Weight affects rolling resistance on the tires too, but less significantly.

I have two bikes, a conventional steel road bike, and a fixed gear track bike with pista bars. I am faster on the track bike. It is a couple of pounds lighter, but if you look at the 225 that I weigh on it vs. the 227 I weigh on the road bike, it isn't significant. I am sure that it has more to do with the more aero position on the fixie.

2manybikes

Way too many variables to know for sure. It could even be an extra coffee that day.
A lot of good answers already posted here too. Could be all of them.

JerrySTL

The word "seems" stands out here. Take some measurements like riding the same course a few times on each bike in similar weather. See what the clock says.

I've done that on my Giant Defy Advance and Windsor Tourist. I'm 2-3 mph faster on the lighter Giant than the 10 lb heavier, more upright Windsor on a relatively flat course. Throw in hills and I'm even faster on the Giant.

MRT2

It varies. South of Milwaukee and near the Lake Michigan shoreline is fairly flat. North and West of Milwaukee you get into some rolling hills. Further west in the Kettle Moraine area and it is actually pretty challenging. We tend to do a mix of terrain but mostly stick with the flat to rolling hills for most rides.

I was thinking or switching out her tires to something a bit lighter on the Jamis than the Panaracer Urban Max 28s she currently rides on. The Peugeot is a 27" wheel with 27 x 1 1/4 Vittoria Rubino, so maybe that makes a marginal difference.

MRT2

Anyhow, though this is anecdotal, well worth considering for some folks returning to cycling who already own an older bike that fits them. It cost me a few bucks to update the Peugeot, but still a lot less than it cost me to buy a brand new road bike. Honestly if I knew my wife would do this well on her old bike with some updated components, I might never have bought her a modern road bike.

blakcloud

Liking and comfort and fit are different things. Your gearing theory is red herring. Gear inches are gear inches.

RJC1811

I have ridden a Univega Viva Sport since 1979. I love that bike! It was tough on the climbs around here but overall a great bike. This year I decided to splurge and upgrade to a new bike. I bought a Giant Defy 1.

I have done the bathroom scale comparison but don't remember the weights. The Giant is at least 10 lbs lighter. There is a 13.3 mile loop with 250' of elevation I do regularly after work and it's kind of like my TT. I took the new Giant out expecting to be a lot faster and was quite disappointed. Maybe .1 mph and 1/2 a minute faster. I talked to the LBS and they didn't have an answer.

Forward 6 months to today. 3 mph faster and 6 minutes off my time. My take was there were several things happening. 1. I didn't have the fit completely dialed in on the Giant, close but not perfect. 2. I was so comfortable with my old bike I just rode it differently. I would dive into corners, pedal hard coming out and was just one with the bike. 3. My old bike was a 12 speed, the new, 22 with a lower gear available. I think I pushed harder on the old bike and took the easy way out with the new bike and clicked to an easier gear instead of pushing harder.

Bottom line, I love my new Giant. I'm definitely faster on it not that it is dialed in and I'm comfortable and know the bike. The weight savings is more noticeable climbing. On the flats I'm not sure 10 lbs makes much of a difference. Having almost 2x the gears available allows me to keep my cadence in the sweet spot.

I'm not sure if any of this is applicable to your wife's bike but thought it may help explain.

canklecat

It's a mystery. I'm not quite sure why I'm equally slow on my 35 lb comfort hybrid with spring suspension fork and sub-30 lb rigid frame mountain bike. Each feels completely different, of course.

I thought the rigid frame mountain bike would be significantly faster, especially after tweaking a few moving parts for lighter rotating weight and smoothness. It's so much lighter up front sometimes I accidentally wheely on takeoffs from stops in traffic. And some days I can manage a 14 mph average over 20 miles. But usually it's the same 12 mph average as with the heavier bike, even though the mountain bike feels more nimble.

The comfort hybrid has the heavier fork and heavier springy padded saddle, adding to overall inefficiency. Shallower seat tube angle. Inefficient, heavy pedals (only recently replaced, without significant perceptible effect). Heavier puncture resistant tires and heavier double wall rear wheel. Chain ring guard. Massive and heavy aluminum tubes. Yet some days I'm noticeably quicker, particularly on rough roads where the suspension fork and saddle buffer the roughness. During an early Sunday morning ride I was significantly quicker than usual on a long, gradual uphill grade on chipseal, in a taller gear with the usual 80 or so rpm cadence. Same 12 mph overall average as any day on that same route. No measurable difference. It just felt different. Later that day I could hardly get my legs moving.

I'd have to attribute it to engine problems.

At 58, with asthma (worse in allergy season and cold dry winter days, not bad recently), a bum thyroid and consequent erratic energy levels, a bad back and neck, and riding only every other day at most, sometimes only three days a week, without any effort toward a training regimen -- I just ride for pleasure and how every I feel that day -- I'm not consistent enough to notice any significant advantage to a bicycle. It's possible that on a good day I might average 16 mph over a 20 mile or so distance on a 20 lb or lighter bike. It's equally possible I'd be slower on bad days when my back and neck are aching too much to use the drop bars, or my thyroid condition is acting up and I have little energy.

Maelochs

What your wife is doing is physically impossible. Tell her to stop at once.

sarahbruce

There are way too many variables at play to give you a solid answer.....however I agree with most of the other posters about fit. It may seem like both bikes fit the same, but the Puegeot could be just a better overall fit that allows your wife to use her muscles more efficiently. The tires and how they interact with the specific terrain your wife is covering could also be a huge factor. I would not be surprised if the larger diameter and wider tires on the Puegeot handle surface irregularities better than the lighter bike. This could encourage your wife to maintain more speed both physically and "psychologically"(she feels more in control and comfortable, so she continues at speed, instead of slowing down in "rough" areas). Really this is all just wild guesses though.....
Bruce

kepas

Honestly, I encountered very similiar situation with my new bikes when shifting from heavy'ish hybrid bike to CX and I also noticed the same with other people. So in short, you need time to adapt to different bike, different riding position, weight, handling, generally everything. So I would suggest to use only new bike for a month or two, maybe more and then compare the bike speeds, I reckon the lighter bike will be faster.

MRT2

That isn't it. The Peugeot was "retired" 7 or 8 years ago in favor of a Trek comfort hybrid, which she rode for a couple of years. Then she briefly went back to the Peugeot until the front derailleur broke. Then for a time , she spent a year or so riding my Bianchi hybrid while I was riding a vintage Schwinn. Then I bought her another Bianchi hybrid, but it was aluminum rather than steel. She rode that for a couple of years, but eventually concluded she didn't like the aluminum hybrid as much as she did my steel hybrid. So we bought her the Jamis steel road bike, which she rode for two years, and loves, before I refurbished the Peugeot. And now the last two seasons, she has split her riding time between the Peugeot and the Jamis.

I might switch out her tires during the off season on the Jamis just to see if she can tell a difference.

Spoonrobot 

How many data points did you study? How are you defining "faster"?

MRT2

True, and it may make sense to bring her in to the bike shop for a fitting. Maybe the saddle needs to be a bit higher, the bars a bit lower, or switch out the stem. We will see.

As far as gearing goes, I disagree. She was having trouble with the higher road gearing and was not using the triple correctly, so I did switch out to a mountain cassette because I could see she wasn't using the triple and road cassette optimally. And it has helped.

MRT2

Riding weekly over the same or similar rides for the last 4 or 5 months. Tracking average speed using wired computers on both bikes. Subjective things like whether she is keeping up with me and other people we ride with or is she lagging behind.

unterhausen

I was down at the bike shop when they were transferring the measurements from a customer's old bike to his new bike. That almost never happens. Turns out this customer got a new bike, and wasn't happy with it because it felt slow. He hadn't done a good job of fitting, just raised the seat. They transferred his exact old position, and everything was better. That's my guess in your wife's case as well.

I made myself a new frame and when I built up the bike I got the position mostly right, but the handlebars were significantly higher. Turns out that's important.

OneIsAllYouNeed

There's a lot to be said for rider's confidence as a factor for speed. It is related to the rider fit, the bike geometry, and the tires. I would suggest that the OP's wife is simply more confident on her old trusty, stable Peugeot than her new twitchy racing bike.

I've seen similar results with my wife's bike fleet (after painstakingly matching positions). Would you believe a 35lb fat bike is faster than a 19lb cross country bike with high end XC tires... on rail trails? How about a 21lb cyclocross bike versus a 16lb road bike with the same set of wheels and tires on gravel roads? Sure the road bike is faster on paved roads than the cross bike, and the XC bike is faster on roads than the fat bike, but once confidence becomes a factor, those heavy, stable bikes are a clear winners for her.

Beyond that, saddle height and setback are hugely important for power generation, thus speed. Bad tires can slow a bike down significantly. Tire pressure that's too high will make a bike feel disconnected from the road. Drop bars will be faster than upright bars, but she'll have to be cruising over 16mph for the difference to accumulate.

Wildwood 

Vintage bikes are always faster.