I have a pair of 40mm Terra Speeds that I bought new for this season, but ended up getting a new gravel bike that came with Goodyear Connector 40mm tires setup tubeless. The Connectors are pretty comparable and I’ve been happy with them so far, so I’m selling the Terra Speeds.
Email me email@example.com if interested.
Decided to keep them. Selling my Goodyear Connector Ultimate 40mm instead.
Good choice. I had the connectors on my Factor too. Slowwwww.
But indestructible. So there’s that.
I didn’t check bicyclerollingresistance.com until it was too late. They ride nice in the loose stuff, but too slow on the smooth stuff for me
I have the Connector Ultimate in their 700x40mm size. I only got a subscription to Bicycle Rolling Resistance yesterday…
I don’t plan on swapping them out anytime soon, however a couple questions…
I’m new to group riding. I typically ride about 22-24kph solo. On the group rides, I have no problems keeping up on the rec road rides (n=3)
I did one intermediate gravel rides, I did ok for the 1st 2hrs, but lagged behind in the 3rd hour.
@40psi@29kph it says that it’s 31.4W / tire. - 35mm width. I assume that the 40mm width is more.
My wife just got a Dolmane+ AL5 and ZIggy’s put 700x37mm WTB Riddler Lights on there
@40psi@29kph it says 22.8W/tire
Is a 20W per pair of tires something I need to worry about as a rec/intermediate rider?
A couple points first…
1/ Anecdotally, I found that the Connectors were about as fast as the Terra Speeds on loose gravel. I also found they handled very nicely. However, they lose on rolling resistance as soon as you hit smooth gravel or tarmac.
2/ bicyclerollingresistance.com measures Crr (hence Watts) on a smooth drum which emulates smooth pavement. To get the total Crr you multiply x2 since they give the number per tire.
To answer your question, rolling resistance does make a difference. How much depends on surface conditions and speed. I put the raw Crr numbers into this calculator An interactive model-based calculator of cycling power vs. speed
Using an intermediate power number of 200W:
Connector: Crr 0.01882 @ 200W = 26.9 kph
Terra Speed: Crr 0.01248 @ 200W = 29.9 kph
Using a rec power number of 140W:
Connector: Crr 0.01882 @ 140W = 21.9 kph
Terra Speed: Crr 0.01248 @ 140W = 25.1 kph
Almost counterintuitively, you can see that rolling resistance actually plays a bigger factor at lower powers due to the lower speed and less aerodynamic drag.
I’ll be doing a 2nd gravel TT on the Terra Speeds soon, and I’ll be able to compare the data to how the Connectors performed the first time around in real life
In real life, I don’t think the difference is as big as this especially as the surface gets rougher, but it is definitely going to cost some speed.
…one more thing. 40mm tires might actually have lower rolling resistance than the 35mm versions. They take an aerodynamic and weight hit however, negating the effect.
I guess one positive is I’m burning more calories than the guy with the better rolling tires…
I was dying on a couple pulls on our rec road ride tonight with these tires… but I can go over defects in the asphalt a lot better.
Be interesting to see what happens after I wear these tires out…
True . I wouldn’t worry too much about it. Any loose gravel and it’s pretty even. I honestly didn’t find them that slow, except when I was considering asphalt or super smooth gravel. Conversely I thought they cornered better than the TS.
Keep in mind the Terra Speeds are pretty much the fastest gravel tires. Other tires on the market are closer to the Connectors.
Here are my results. Keep in mind last night seemed to a fast night and wind was reversed.
Terra Speed 39.2kph
Essentially same power 12.2 km Ride Activity on June 21, 2023 by Erik K. on Strava