Hello, about 8 months ago I bought my first road bike, a Giant Contend AR 2024, it is a road bike that has the possibility of placing tires up to 700×38 (I know, it is almost a gravel, but technically it is an All Road).
Question, I started using the tires that the bike came with by default, a 700×32 Giant flat guard sr3, despite using the Silca pressure calculator, and trying different pressures, I was never able to feel comfortable, and making trips of more than 2 hours due to the vibrations was impossible, to make matters worse my average speed did not improve either.
So I bought some 700×38 Chaoyang Gravel GP tires ($30 per pair), and the difference was abysmal. Much more comfort, more grip, more stability and improved average speed, it even went up 3 or 4 km/h.
I weigh around 95kg, I only use the bike on asphalt and have almost no elevation. My question is:
Are my 700×32 tires just bad? Is that why they feel bad and perform so badly? If I put on higher quality 700×32 tires, will I be able to go faster and at the same time more comfortable? Or is it simply a matter of pressure? Maybe the 700×38 ones are simply more comfortable and since I'm more comfortable I can go faster?
I would appreciate your comments and guidance. I love using my 700×38 only on the road even if it is excessive, but my fear is that I will never be able to join a peloton since I see that everyone uses 700×25, 28, 32, etc. tires.
by Sanez95
10 Comments
Flat guard tires are the reason. They are heavy, dense, slow and all around awful to ride on.
Use high quality tires. Avoid flat guard tires. If your rims allow for it, convert to tubeless to get puncture protection and good ride quality.
I don’t understand this statement:
*So I bought some 700×38 Chaoyang Gravel GP tires ($30 per pair), and the difference was abysmal. Much more comfort, more grip, more stability and improved average speed, it even went up 3 or 4 km/h.*
I run 30C Continental GP5000 STR tubeless which I’ve found to be the best balance of rolling resistance, aerodynamics and comfort.
I have a Tarmac SL8 and weigh 190 lbs.
Question is are you running tubeless – if not you’re prob having to pump those tires up to 100 psi and if so that’ll feel stiff and bumpy. I run my tubeless at 60 psi and it’s very comfy.
That could be why you’re slower on the 32 esp
If you’re on rough roads bc that high pressure doesn’t absorb bumps, but rather pushes you up. That slows you down and isn’t comfortable
The next is rolling resistance which you can lookup on online easily. A big fat 38c tire will have higher rolling resistance depending on the casing. Also your 32 that came on the bike may be more of a trailing type tire which isn’t supple, comfortable, but is designed to last and resist puncturing.
If pair my performance Contis with slica sealant and it is puncture resistant and supple, fast, corners well.
Needless to say, tires are massively important to performance. You say “join a peloton” which I take to mean you wanna do group rides that are faster, the Conti GP5000 or Vittoria Corsa Pro/N.EXT and other Pirelli performance tires are the go tos.
I def wouldn’t use those gravel knobby tires on the road if you wanna go fast
Tyres can transform a ride, and make a bike great or terrible. If you want or must use cheap tyres, experiment with what’s available, and don’t assume tread patterns are as important as construction and composition.
There’s video on GCN channel about tire width. Wider tires indeed faster because they absorb more of that tiny bumps on the road. Tho they not feel so fast because smoother, lol.
But pressure also matters, of course. Honestly 32mm is not too narrow for a road bike, like true oldschool road tires 23 or 25mm.
On my gravel bike I switched from 35/38mm to 43, for using on really bad roads and gravely surfaces. It feels smoother. But at the same time I like my Brompton with its tiny 16″x32mm wheels. Riding it almost on the same bad surfaces.
And anyway don’t worry about speed of 32/38 tires. The difference is marginal and matters only if you’re on the racing.
Btw If you running classic butyl tubes you might want to try TPU tubes, they’re 3 times lighter and have slightly smaller rolling resistance. but the downside- they need to be pumped at least once a week. not a big deal but still. I swithced most of my bikes to TPU tubes.
I’m a bit confused. “Abysmal” means “really bad” but the rest of your post seems to say you like the wider tires?
Your best upgrade on a bike will always be tyres. Stock tyres are usually terrible.
I have the same bike. Same color even. Though i added pink on mine. The tyres are very good. Is the wheels that are bad. Also if you ride on tarmac only no point going more or less than 32c tyres. You must get used to the bike first of all, and second you must check your fit. Plus your handlebars are too high, lowering them will give you more speed and better handling. Though lower them till you are comfortable, if you lower them too much you will hurt your back. Go see a bike fitter or try some adjustments yourself to see what works best for you.
Good luck.
By the way when the tyres are done for. Pirelli Cinturato Velo TLR is a very good choice. Tubeless.
There’s some tires tested on bicyclerollingresistance that look good, but perform terribly. 25mm Slick road tires that at 60psi have 31 Watts of rolling resistance (per tire). While the fastest are like 6 Watts per tire.
So if you were to swap these you would have one bike with 62 watt of rolling resistance, while another bike with 12 watt of rolling resistance.
I usually average 100W on my ride, so I’d go like half my speed with those bad tires.