treebound 

+1 to looking into new wheels/hubs/tires. What model of old Schwinn is it? Are the shifters up on the stem or down on the downtube? Does your MTB have grip-shifters or RapidFires? All the small things adding a second or five here and there can potentially make up for several minutes on a 17 mile commute. Plus those old steel wheels might be accelerating slower which would give the MTB the jump on you every time you slow down and speed up, again a second or five here and there add up over the commute distance.

Post up a pic of your Schwinn and your MTB, and your Hybrid if you want to, that way we will get a better picture of what you have and will be able to give better suggestions.

As to what is the least expensive frame to look for to allow brifters? Your current Schwinn might be able to be spread or cold-set in the rear to accept an 8-speed cassette hub, but I'll defer to the frame experts for that option.

rumrunn6

'70s era LeTour. Stem shifters so I have to shift my hands and body weight to shift when I'm in the drops. Plus old fashioned friction shifting is hurting me. You know - inaccurate and time consuming shifts. MB has indexed grip shifters.

cetmefree

I tried that once. The helium just bled out.

Mr. Underbridge

Answer #1: You'd be going 20.4mph on average for 17 miles in 50 minutes. Knock 4mph off that, you're looking at 1 hour, 2 minutes. So you'll lose 12 minutes.

Answer #2: For 45 minutes, you'd be looking at around 22.5 mph.

Are stoplights not a consideration? An average speed of 20+mph makes me think perhaps you either don't have any (or else the elapsed time is from your computer, which shuts off at lights). Remember, any time stopped is the same no matter what you ride. Doesn't matter how shiny the bike is, it's just as slow when it's standing still.

Shimagnolo

So how many grams did it save?
Heck there isn't much chance of a bike catching on fire, so why not use hydrogen?
(Of course it would probably leak out even faster than helium.)

treebound 

17 miles at 2.941 minutes per mile = 50 minutes +/-, which works out to around 20.4mph average.

Bike #2 at 16.4mph average would do the 17 miles in a little over an hour.

17 miles in 45 minutes would have to see around 22.6mph average.

If my math is off just consider it is close enough for commuting estimations.

rumrunn6

Regarding the pictures.
The Schwinn 10-speed is the actual bike
The Schwinn hybrid is the Amazon stock picture
The Giant MB is off the internet too. Mine is much older though with no shock absorbers. I found it in the trash in Harvard Square!

Schwinn 700c Trailway
https://www.amazon.com/Men%2592s-Schw.../dp/B000KZ1G7Q

rumrunn6

Mr. Underbridge & treebound - You guys are AWESOME! AGH STUCK IN UNDERLINE MODE

I don't have a computer. There are some lights. I may be a more prudent rider now, stopping more, etc. I was pretty crazy on that MB when I first started. I was an ignorant rider. I am more patient & courteous now.

Mr. Underbridge

Patient and courteous is good!

If you're averaging 20mph with lights averaged in, that's pretty danged impressive. Keep it up.

rumrunn6

Thanks, that was my best time. Haven't beat it yet.

There have been some brutal rides home lasting 30 - 40 minutes longer including laying on my back in the shade or 10 minutes. You know those hot summer days are killers, not to mention thunder and lighting storms w/ torrential rain ... don't miss those!

treebound 

Mr Underbridge beat me on the math quiz.

Your old LeTour with the stem shifters and heavier frame is part of the speed factor. Finding a bike with downtube shifters or updating your's to brifters might give you some speed gains if you also upgrade the wheelset. But now seeing a pic of your bike you might be able to just get some downtube clamp-on shifter mounts if you want to put that money into it.

Realistically, cranking out 17 miles on a commute in close to an hour is very respectable. I'd just ride it as is, don't worry about setting any speed records, keep an eye open for an alloy wheelset, and enjoy the ride.

And, for the record, some of those hardtail MTB's and even the rigid fork'd ones can be set up to be deceptively fast on the street. I've got an old Timberlin rigid MTB currently set up as a commuter and pseudo-tourer and I'm running a set of Serfas Barrista 26x1-1/4" 100psi tires on it, easily as fast as my late 80's LeTour if I'm doing my part.

rumrunn6

Boy that would be funny if all I had to do was stick with the beater I found in the trash rather than all that other stuff with those other bikes! Ha! The MB is definitely better looking, scratches and all - you know - more testosterone, less Fred ...

huhenio

Better tires and wheels, leave the shifters alone.

And get some decent lights if you are riding at night.

rumrunn6

I'll consider it. BTW: The front & rear strobes were just for daytime visibility. I'm not a night rider. Those guys are hard-core.

GV27

You're losing it somewhere else. Do the math - let's say the hybrid weights 10lbs more and you + the bike weigh 200lbs. That's a 5%. Like I said - it's not like you're lifting it, you're rolling it so it makes it relatively easy - there's formulas to figure that out. Anyhoo, 3mph is 5% of 60mph. So even if you do figure a 1-1 relationship, you're riding pretty darn fast. Whether you're doing 60 or 57 you're gonna get there pretty darn quick!

The reality of the physics is that at 60mph - or 30 or 20 aero drag is way more of a factor than weight. If you do the math, you find out that when cruising the weight cancels itself out. It's a total non-factor. If you could accelerate it up to 20mph a 5000lb bike would be just as easy to keep there on flat ground as a 10lb bike. Rolling resistance would be a factor in that case but let's ignore that for now.

If weight was such a factor a bike with a loaded trailer would barely move. But really, you only lose a little riding a bike like that.

Your numbers actually prove my point - you're attributing 3mph on flat ground to the weight but only 4mph on hills? 1mph for lifting the weight up the hill, but 3mph just to keep it rolling on flat ground? Think about that awhile.....

GV27

LOL - OH COME ON NOW! Wheelset maybe, but do you really think you're going to gain time measurable by any watch by shaving a couple ounces with brazed-on shifters?!? And heck - brifters are going to be heavier - how the heck will that make him faster?

Pig_Chaser

It's hard to compare totally different rides on totally different days. It depends on wind direction, light timing and how you were feeling on those particular rides.

treebound 

My point about going to downtube shifters was in efficiency in using downtube shifters over stem mounted shifters, and brifters have both formats beat as far as being quick to shift at least as far as my personal experiences go. Weight wasn't a factor in my figuring on the the shifters. A couple of ounces can be made up with how much water is carried in the water bottles.

Cranking out 17 miles in under an hour anywhere around Boston for a commute time is doing good in any book.

tjspiel

1. Your weight (and anything on your person) is sprung weight. Weight on the bike itself is unsprung. It makes a difference. Lowering unsprung weight helps more than lowering sprung weight.

You pay the price with heavier wheels every time you accelerate, whether you're going up hill or not.

3. The extra weight hurts you more going up hill than it helps you going down.

frankenmike 

My commuter mtb feels much lower than my commuter road bike, probably a combination of geometry differences and smaller wheels. Lower=less wind resistance, which is considered by some (Jobst) to be the single biggest factor affecting speed.

T-Hussy

I havent taken the time to read all the comments posted so far but.... My opinion, as my buddy dave and I have discussed, is that most hybrid bikes are kinda worthless. They are not great for any specific application. The design of the bike puts you in a terribly inefficient stance with no leverage. Bigger wheels, who cares when you are sitting straight up like the wicked witch of the west. My wife used to have a hybrid and I would rather ride my mtb any day over that slow machine. Also, Jdtyk, you are running 100 psi on your mtb but only 60 on your 700cm bike? Thats just bass-ackwards You need to get some new tires for the 700. The difference of 60 to 120psi would make you feel like grease-lightning.

tjspiel

Last year I picked up a used 2005 Specialized Allez for $350 offseason. It was ridden maybe 100 miles. Keep that in mind before spending too much $$$ on your Schwinn.

If you want indexed shifting you'll need a wheelset that's dished for at least a 6 or 7 speed freewheel. You may not find many used 27" wheelsets like that. 700c wheelsets will cost you'll more + you'll need new tires (which you'll probably want anyway).

An indexed shifter will require another derailleur. More $$$.

Think of what you could sell the Schwinn for and subtract that off the cost of another bike. You may be way better off in the long run than if you upgrade your Schwinn. If you stick with the Schwinn, no matter what you do you'll be stuck with a pretty heavy frame.

Keep in mind though that your goal is going to be a tough one to reach. I did a short "sprint" triathlon last summer and I had the 7th best time in my age class (though I am an old guy, so you need to factor that in). My average speed over 15 miles was around 20 mph and that's without having to stop at intersections. Of course that was right after having to swim 1/3 mile in some nasty wind and chop but I doubt I would have been that much faster without having swam first.

Mr. Underbridge

You're forgetting some reality in the math (and trust me, I'm fine with the math and Newton's laws) - if the bike weighs 35 pounds, just *getting* it to speed, and handling the hills, takes quite a bit of energy out of you such that you might be pretty drained. I should point out that on my ride, I'm looking at a lot of rolling hills and very little distance to coast, so the end result is that my top speed is effectively reduced. So when I say the bike costs me 3mph when cruising, I should be more accurate - I generally don't get to within about 3mph of real cruising speed since it takes longer to accelerate (did I mention the wheels are steel too?), and the total ride is far more draining.

If I lived in Kansas, you'd be right - I'd expect to lose less than 1 mph, assuming no aero differences. But Dorothy, this ain't Kansas, and after a steep 200 foot climb on a 35lb bike, I'm cooked. Your loaded trailer is actually a good example - try a 10% grade with it, see how much slower than usual you end up going!

The most realistic assessment would be to consider how much start/stop and hill climbing goes on - if there's a lot of that, then the weight difference will be felt. If not, it's completely negligible.

darkmanx2g

Ride a Trek Madone and tell us which is faster??

GV27

It's tougher but not THAT much tougher. I can put both my kids in the trailer and it weights ~100lbs. The bike I tow it with weighs 19lbs. Basically 5 times the weight. It doesn't take 5 times the effort to get it up a hill. Not even close People like to think that 10lbs from their gut is a little, ten pounds from a bike is a lot. 10lbs from a bike COSTS a heck of a lot more, but they're actually even as far as overall weight goes. You don't weigh a car without the engine.