How much difference between knobbly CX tire & road tire of same size?
 

I have a CX bike with Schwalbe X-One 700x33 tires, which have knobbly profile designed for mud.

As I've been faster on the bike, I've started to feel that the tires might be adding a bit of drag (they certainly add noise), and wondering whether I would be better off with getting a different tire (or a whole new wheel set) for rides on pavement.

Given the same tire width & pressure, how much difference in handling and actual speed would I be likely to notice?

If I chose to get a complete wheel set, are there any recommendations that would be compatible with the current Giant PX-2 rims on my bike? (The group set is SRAM Rival 1 (11-speed, 11-32 cassette).

Thanks!

John

I've ridden on the same bike with knobby cx tires and road tires. I can't say there is a huge difference, but there is a difference, and unless I need to have the traction of the cx tires I'd prefer to not ride on them if I have no intention of riding on mixed trails. Choosing tires is all about compromises. There is no single tire that is suited to every road condition.

I don't know about CX tires but the difference between studded Schwalbe Marathon Winter tires and Conti GP4000s is about 50 vs 40 Calories/mile.

I wouldn't want to commute regularly on knobby tires. I have some 40mm Schwalbe g-one's at the moment that are decent on gravel and feel smooth on the road. If I was only riding on the road I'd go back to the GP4000s.

If you ride mostly pavement, dry gravel roads and/or groomed chat trails, mowed levees, etc., take a look at Continental Cyclocross Speed tires.

Since last autumn I've ridden the wider version, the 700x42 Speed Rides, on my rigid mountain bike. Love 'em for the conditions I described. Smooth, quick and quiet on pavement, tough enough for bombed out cratered asphalt, plenty good enough for the gravel/chat trails I ride, and even enough grip to climb the grassy levees in our area and ride the levee tops -- as long as it's fairly dry. They aren't for mud or loose dirt or serious single track.

A couple of friends ride similar tires by another manufacturer but I can't recall the make/model at the moment. They aren't the Clement X'Plor. I've seen 'em on the racks at REI and Mellow Johnny's but the name escapes me. Anyway, they're similarly designed for dry cyclocross, pavement-friendly, with just a bit more of the diamond or file tread than the Conti Cyclocross Speed and Speed Rides. Their tires also feel a bit heavier, thicker and possibly tougher, but they cost a bit more. The Contis are a great value, especially the Speed Rides from Jenson USA.

on pavement, the motion of the tread elements of a knobby tire, is an energy loss.

There are tons of nice 32 and 35 slicks, get some

I just googled the X-One, and I would definitely NOT want that tread profile on all-pavement rides.

There are plenty of tires out there that have a very smooth center tread profile for straight-ahead pavement riding, and knobby stuff on the sides for light trail work.

Consider for instance also from Schwalbe, the Hurricane, the new Marathon GT 365, the Marathon Cross, Sammy Slick, etc.

Yes, they'll be less rolling resistance on pavement with a proper road tire. But I'd be more concerned with wearing out the knobbies on a good dirt tire.

^^^ Yeah, those X-Ones are not gonna like pavement. You could wear the center knobs off in a week. I did one mostly-pavement 40-miler on Ritchey Shields, and aside from feeling like I was dragging a car tire behind me with a rope, there was visible wear on the knobs after that first ride. Further, CX tires tend to have absolutely no flat protection of any kind, so riding them on the street is likely going to start producing flats sooner than later-- note: this is operating under the assumption that the bike didn't come with the tubeless version.

Where you'll notice the extra rolling resistance is when you stop pedaling on level ground and start coasting. Higher rolling resistance won't coast as far. I can tell a pretty big difference between something like a Gatorskin and GP4000S.

Wow, that is impressive. Lets see - 13 watts resistance from the GP4000S, and 18 watts from the 4 season at 18mph. I'm impressed you are that sensitive! I can't tell a 5 watt difference when I'm putting out over 200 watts...

Speed:
You are talking maybe a 50% increase in rolling resistance, max. Something like 10-20 watts for two tires with 120 watt input power, so that could be well over 10%. Schwalbe does tend to make very efficient tires (even with knobs).

Handling:
With knobbies, I notice that my cornering on the street (at say 20+ mph) is a lot more cautious because the knobbies don't grip the road like a slick.

Stick with the schwalbe's if you like. The G-one isn't going to hold you back much on the road and can be a good complement to the X-one , and of course you could go with their slick version...

My winter ride uses 35mm marathon extremes, which I don't think they make anymore but are pictured here next to a marathon supreme. I don't feel like they are the limiting factor in my slower winter rides. More the heavier panniers and erring toward over rather than under dressing. If I were aiming to commute closer to 20mph I might not want them but I can't commute closer to 20mph and avoid road hazards etc...

Hard to quantify, but you'll notice it. Hard cornering on the road with those knobbies is especially bad when you're riding on that outside row of knobs.

huge, like being young again. N+1? :D

Like I said, it's noticeable when you stop pedaling on flat ground. Not when you are pedaling. But thanks for the snark.

25mm@80psi the difference is more like 17 watts worse for a pair of Gatorskins vs the GP4000S II.

I've just ordered a pair of Schwalbe Marathon Supremes (700x35). I was weighing up these vs Vittoria Hypers and there was a general trend towards people thinking to Supremes had better grip in the wet, but that both had very good (low) rolling resistance.

I'm hoping that these tyres will also be OK on dry gravel or dirt trails.

If I ever actually get into cyclocross, or find myself on a ride that is predominantly grass or mud, then I will change to the original Schwalbe X-One knobblies. My guess is that this would be < 5-10% of my current riding, so I'll just change tyres instead of buying a whole new set of wheels ($$$ with hubs, disc rotors, new cassette...).

Thanks for the suggestions!

John

Good to know! (and a bit alarming too :eek:)

My X-Ones have tubes fitted.

Even compared to my Bontrager HD5 700x32 , which are pretty sturdy commuting tyres, the X-Ones felt really sluggish, and have a lot of "road buzz" like an MTB tyre. They're clearly not designed for lots of use of pavement....

I've ordered some Schwalbe Marathon Supremes, which look like a better bet for my current (80-90% pavement) use.

Thanks,

John.

I just made my spring change from Schwalbe Marathon Winters to Marathon Plus and saw my 40 minute commute drop to 36 minutes.

My commuter came with Kenda Kwik cyclocross tires and I took them off after a couple hundred and have used protek from michelin for a long time. I finally decided to go lighter and now am running Gatorskins. I like the gatorskins. Rolled over a saw blade yesterday (on it before i could go around it) They have been tough for commuting some light gravel riding too. Just cant push them in the corners like the knobby tires. They speed up faster and throw less water in my face on rainy rides.


I would say if you are not ridign gravel/ trail you might consider some smoother tires.

I dunno. I used to think a few watts makes zero difference...but I've sort of changed my tune - a bit. I started looking around for new tires at the end of last year. It became a bit of an obsession...I researched every single pavement tire on bikerollingresistance.com...and ended up switching from basically the slowest touring tire (Vittoria Randonneur) to the 2nd or 3rd fastest touring tire (Vittoria Voyager Hyper). It was a difference of 10 watts or so.

It's definitely noticeable. Not mind blowingly faster of course...I had on a no tread tire previously, it wasn't like I went from a 3 inch off road knobby to a racing tire. But I definitely felt it. Or...placebo effect from spending so much time picking out a tire? Who knows lol.

Consider:
continental bicycle Travel CONTACT

You write this very fairly. It's really hard to do blind tests on a bike.

In as much as tires can make a difference, yes, that Voyager Hyper is an amazing tire. When I felt it in my hands, I was very doubtful, but it rides great.

Yeah. I got those tires mostly on your recommendation BTW, so thanks. It was between that and the GP4000sii. If I get a more racy style bike, which I probably will, I'll get a set of those to compare :thumb:

Wow, glad to hear it. I had heard about them from [MENTION=45088]nlerner[/MENTION], I think. He called them "fast clouds." :lol:

I got the 35mm size which ended up being 37mm, and I can't fit them in my Raleigh. :( I should get another pair.