Why does my old bike feel so slow?

[Ugo51]

Hi guys,
Lots of time on my hands, so I ask myself this kind of seemingly futile questions.
I have a Peugeot Premiere (Carbolite frame) which I've been using for over a year to commute to and from work.
Over time I've done some upgrades, but it feels slower than before, like constantly battling with headwind.
I changed the steel wheels with alloy one (I built them myself, using the original Maillard hubs), I replaced the freewheel and the chain (I kept the old chainrings) and swapped the BB with a sealed Shimano UN55 unit.
I still feel a lot of drag, even on flat roads at constant speed.
What could it be? The hubs spin very smoothly. Could it be the chainset?
I noticed today the rear derailleur arm is not perfectly straight. I will try to fix it/replace it, but can I really expect it to add a lot of drag?
I don't expect it to ever be a fast bike, but I'm baffled by how much effort it requires even to keep constant speed. Somehow I feel it's slower than it's ever been, but I can't get why...

Any ideas?

 

[pigman]

Re:

Daft question, but have you recently started using panniers. They don't half create a drag. I once put panniers on a commute bike and couldn't believe how much difference it made. Felt like a parachute brake

 

[mk one]

My first thought would be wheels/tyres. Does the bike slow down quickly when coasting or is the drag all the time, even when pedaling?

 

[mattr]

Shit tyres and tubes?
IIRC the difference between the very best and very worst combinations of tyres and tubes is something like 40 watts, even when at correct/good pressures. Which seeing as an average club cyclist can only sustain in the 175-200 watts region, is a lot. (obviously subject to speed changes etc etc blahblah.)

 

[Ugo51]

Thanks for the replies.

- No, I don't use panniers. Never have, although at one point I will, because I m tired of carrying a backpack

- The bike seems OK when coasting. I tried to measure myself also against other cyclists (not very reliable, I know) and I've never had the impression of the bike to grind to a halt.

- I use Panaracer Pasela 28c. I have no idea whether they are good or not, but I've never had any other tires and I have recently replaced them with new ones (same size) so it should not make a difference.

Update: I tried my other oldER peugeout. It's a touring model, same frame, different rear triangle. It's at least 2kg heavier (steel wheels, steel mudguards) and has a busted BB.
It FLIES.
The difference in effort is so evident that the only comparison I can come up with is to pedaling on tarmac vs sand.
I'm baffled.
I will now try to swap the wheels.
Don't know what else it could be! :O

 

[Y282]

Re:

Got pics of both bikes?

 

[Ugo51]

Re:

I'll post them soon.
Just out of curiosity, or is there something in specific you'd like to see?

 

[Ugo51]

Re:

Here is my everyday Peugeot:



Here my other Peugeot, which it used to be my wife's:

 

[Ugo51]

Re:

I tried doing the easiest/most obvious thing: swap the wheels.
It makes a difference, but not enough to be the sole element....

 

[greencat]

I presume the chainset/cranks spin freely? Ditto pedals? Jockey wheels on mech? Rear wheel not dragging on frame/mudguards/brakes?