How much slower are Gravel tires?

It's based on BRR's comparisons, mainly.  I've maintained 20+ mph solo on a 700x48 Soma branded panaracer slick before, but it was with more effort than with a higher quality tire.

Regardless of what Jon Hankey of Reen Hers tells us, his tires aren't the best at everything.  They're comfortable, but that's because there's not much rubber in them.  They're 90 TPI vs Vittoria Corsa 320 TPI tires.  Besides, there's more to rolling resistance than just TPI and comfort.  Schwalbe Almotions ride like bricks, weigh a ton, and roll for miles.  It's all about balance and Compass prioritizes feel over everything else.

Plus Compass tires in 32s aren't tubeless, and you can get 32mm wide aero rims and 32mm tubeless Continentals.  Less drag then.

nellborg wrote:That's sort of what I was wondering, i.e. if rolling resistance increases in a linear manner with increasing speed, is the aerodynamic penalty for the wider tires at higher speeds logarithmic and high enough to be noticeable?  

Now I'm curious as to why you say that the Compass tires aren't that fast... are you saying not that fast relative to skinnier road tires on pavement and hard, smooth gravel, or compared to other gravel tires of similar width? 

nellborg wrote:I've been joining the roadies on their regular group rides lately and I'm riding my Lynskey gravel bike with Astral aluminum rims and 38mm Compass tires (which measure out to 41 mm on my 22 mm ID rims) and set up tubeless.  

At speeds of around 20 mph, it seems as if my tires/wheels are smooth and fast and that the riding is easy.  However, when we're pacelining in the 25-30 mph range, it seems as if my wheels are slowing me down relative to the others who are on road bikes, skinny tires, and 4 cm deep carbon rims.  But, since I don't have a road bike, I don't have a "control" to know if it's me or my wheels.  

The question that's bouncing around in my head is:  would I be noticeably faster in that 25-30 mph range with skinnier Compass tires - like 32 or 35 mm width?  Any thoughts?

sake wrote:I just bought an alloy Cannondale Topstone 105 and took it out for its maiden voyage this morning on the road and was surprised by how much slower it was than my road bike with Conti GP4000s (23c). I ride a neighborhood 10 mile  loop multiple times every week and usually average 20 mph on my road bike and averaged 17.4 this morning on the Topstone with similar perceived effort (no power meter). As I anticipate about 70-80 of my riding will be on pavement, I’m going to want to buy some new tires and swap them around depending on my intended ride. I’ll keep the stock WTB 40c tires for when I ride gravel, but would love to hear suggestions on tires which would work well for paved rides on these stock rims. 

I ran 28m GP4000s on 22ID tires (tires measured out at 31mm), and the wheels were so wide it tore up the sidewalls a little.  I would not recommend it.

Compared to the 28mm GP4000, the 32mm GP5000 is 2mm wider, the 28mm is 2-3mm narrower.    So, if your wheel has an ID of 23mm, the 28mm GP5000 is going to be way too small.

Just got back from my first ride on 28mm GP 5ks.  This ride was 20 miles shorter than a ride 5 days ago on WTB Resolutes.  Both routes were paved.  I averaged 16.2 on GPs and 16.0 on Resolutes on a similar route.

I don't have a power meter but wore a HR monitor.  157 avg on the gravel bike (Giant Revolt) and 154 on the road bike (Bianchi Intenso)

Giant/Resolute - https://www.strava.com/activities/2568351507
Bianchi/GP 5k - https://www.strava.com/activities/2582506092

Road bike was 30 seconds faster up a climb, but at this point I'm kind of starting to wonder why I still have it.

Volsung wrote:Road bike was 30 seconds faster up a climb, but at this point I'm kind of starting to wonder why I still have it.

sake wrote:Sorry, forgot to put that in the post. They’re WTB Nano 40c tires on WTB ST i23 TCS rims.