Robert A

I ride a 2015 Specialized Sirrus Comp. The bike is 100% stock except for the SPD pedals I recently installed. The bike feels rather slow and I'm curious what role the tires play in this.

According to the specifications, I've got these tires:

Specialized Espoir Sport Reflect, 60TPI, wire bead, Double BlackBelt protection, 700x30c.

Thank you,

Kindaslow

I had those on my Sirrus, and I think they suck. Two flats in 200 miles and when I went to a much heavier tire (for flat protect) the bike did not feel any slower (and should have). If you want better tires, that are much faster feeling and have some flat protection, go with Armidillos. I went with Schwalbe Marathons with my Sirrus because I commute on it. I use Armidillos on the Venge in the Winter.

Robert A

When you made the switch, was there a noticeable improvement in speed? How about ride quality on roads?

I ask because my bike totally sucks for speed. I don't expect the same performance as with road bikes, but I'd like to try to figure out how much stock tires affect things.

stdlrf11

This may sound like a dumb question, but have you played with tire pressure?

I bought a certain rear tire to replace a gatorskin, and I found it needed to be pumped to 10psi higher than I liked the old tire.

Any less, and it would feel heavy and sluggish.

Robert A

My LBS said the recommended pressure was 85-95. They're sitting at 90 and the ride is pretty firm.

Kindaslow

The Schwalbe Marathon's should have been much slower, something I was ok with given it is my commuter, but I didn't feel any loss of speed. The ride quality was/is much better. I think any good road tire would make a big difference. Check out Schwalbe Marathons, the ones with lots of tread, and this might make more sense after you see them.

stdlrf11

Before I shelled out any money, I'd pump them up to 95 just to see if that helped.

If not, then I'd look at higher quality tires. I'm a big fan of higher volume, higher thread count, rather than heavy flat protection.

Robert A

What qualities do you look for in a tire? Mine will almost entirely be used on the road, almost never in rain. Ride quality and speed matter. I don't mind spending a reasonable amount to get there.

stdlrf11

I look at size first. What volume can I fit? What balance of size and weight do I want on that bike?

Then I look at basic puncture protection. I don't like the heavy thick inserts, but I do like a basic aramid or Kevlar layer.

Then I look at thread count, 60 is the minimum. I like 120tpi. For the longest time, I couldn't tell the difference, but the higher thread count really helps smooth out the ride. I don't get too hung up on it though.

I prefer folding bead. Wire beads are okay, but much heavier. Plus, after a few times using a tire lever, I always end up tearing up the bead area on a wire bead.

I like vittoria, Schwalbe and continental. I found that ~$30 is a good price point. Any less and you get low quality. Any more and you're getting a great tire, but you might not get your money's worth out of them.

That's just me, though.

Robert A

What is meant by Volume? What do you mean by balance of size and weight?

stdlrf11

By volume, I mean tire size, specifically width.

The wider the tire, the more air volume is inside.

The wider the tire, the more material is required to make it, so the heavier it will be.

When I look at tires for my bike, I try to figure out the biggest tire I can fit that won't be too big and heavy.

seat_boy

Testing has shown the puncture protection almost always makes for a slow tire. If you're concerned about punctures, tubeless might be a better way.

Higher pressures can also make for a slower tire, contrary to what many think.

I would suggest tires with decent volume (width), as mentioned above, and look for a supple sidewall.

Panaracer Paselas (non-TG) are a great budget choice, or you can step up to something like the Compass Barlow Pass if you have money to spend.

MRT2

In your earlier posts, you say you haven't ridden much in decades. How old are you, and what is your fitness level? While tires might make a small difference, so will wheels.

More than once, I have thrown a leg over my bike after a hiatus from riding, and found the bike sluggish. Did I inflate the tires correctly? Maybe the brakes are rubbing? Nope.

I dont mean mean to be harsh but, I don't hear a lot of complaints about this bike in stock form being excessively slow. Ride the bike and work on your conditioning. Replace the tires when they wear out, would be my advice.

But it is your money. I like Panaracer Pasela TG. I hear good things about Continental GP4000S.

Robert A

Late 50s, good fitness and working on getting better. Since that earlier post, I've been riding fairly regularly. Still, my OP asks what role tires play in the performance equation. I'd prefer to focus there if possible.

bobwysiwyg

[QUOTE]Higher pressures can also make for a slower tire, contrary to what many think[/QUOTE]

Sorry for the newbie question, but how is this so? It seems to defy physical laws. Would not higher pressure reduce the size of the contact patch as well as rolling resistance? Trade-off being a harsher ride of course.

MRT2

Fine. Your current tires weigh 440 gms a piece. Buy a lighter tire and you can shave 100 to 300 gms of rolling weight.

Now, one full 16 oz bottle of water weighs about 470 gms, not including the weight of the bottle. But that is stationary weight. Increases in Rolling weight is somewhat more noticeable than stationary weight.

Robert A

Does rolling weight have any effect on rolling resistance? I thought it only affected inertia which only mattered on climbs and acceleration not steady state speed.

seat_boy

Because roads are rough. The vibration from the rough road causes energy loss, which is more efficiently absorbed by a softer, fatter tire. If you ride a skinny tire at high pressure, the energy is absorbed through your body, which slows you down.

You can read about it here:

https://janheine.wordpress.com/2015/...re-revolution/

Earlier tire testing was done with a machine on a steel drum, which showed that higher pressure was more efficient... but how often do you ride on a steel drum without a rider on your bike?

[QUOTE=bobwysiwyg;18536676]

badger1

Assuming your bike is the correct size for you and fitted correctly to you, and assuming no major mechanical issues such as binding hubs or dragging brakes, your bike is not "slow"; you are.

The tires you have are not the lowest when it comes to rolling resistance, or the lightest, but assuming correct inflation they might be holding you back by .5 - 1 kmh or so, if that. Reason: low-end casing + double-belted puncture protection. Put on some genuinely good road tires (e.g. Spec. Roubaix Pro, Conti GP4000 or similar) and you'll notice a slight difference.

End of response.

bobwysiwyg

seat_boy, thanks for the link, very informative.

Kindaslow

Nothing like a forum to overthink pretty much everything. And, yes, I am guilty at times, too.

yashinon

I believe tires can slow you down. I had Bontrager Harcase tires on a bike, solid tires but heavy. Switched to Conti Gatorskin and felt a difference!

AlmostTrick

The quickest tires have supple casings and are lightweight with no extra layers for flat protection to slow you down. Like the Compass Stampede Pass 700x32's that I now have on two bikes. Very comfortable riding with only two flats in 3000 miles. Best thing I've done for my bikes.

practical

Thanks for all these tips about tires. It's good to know and I seldom come across this kind of information.

AlmostTrick

The thing about TPI