monfils

Hey guys,


got my first road bike 2 months ago, and I am now chasing those KOMs, so naturally I am looking on possible improvements.

The TCR Advanced 2 comes with Giant Gavia Course AC 1 tubeless tyres.


So far they hold up great over probably 800 km, without any visible punctures. I ride in dry conditions and have had no grip issues.

I have read that upgrading the tyres might be the cheapest speed upgrade.

Would it make a real speed difference to switch to for instance Continental GP5000 TL, or does it not really matter too much?

Would those be as tough as the Gavias, or might they puncture easier?


When buying Conti GPs, would I have to put sealant on them? I am a bikenewbie, and the Gavias have not required sealant, but that might be applied in the factory?


Thanks a lot :-)

MattTheHat 

The Continental GP5000TL is a nice tire. Unless the Gavia is a horrible tire I don't think you'll see much of a speed upgrade. They are a nice tire, though. I've run them in 28mm and 32mm.

Yes, you need sealant. I recommend Orange Seal. And from experience, I'd say avoid Stan's.

monfils

Hi Matt!

How do you put the sealant on? Just all over the rubber? I am sure I can find an educational video on that.

With the Gavias, pumping the tyres seems rather weird. It is my first road bike, so that might play a role.
I always pump to 120 PSI before each ride. Often, I will start at 40 or 50 PSI, meaning the tyre seems to have lost a lot of pressure, which is not the case at all with my MTB Schwalbes with tubes.
However, i am not sure if it the road bike valves that naturally lose air when putting on and off the adapter?

Hopefully somebody with experience with the Gavias and better tyres like the Continental could comment on the speed.
If there is no substantial difference, I would not see a good reason to switch.

WhyFi

Have you checked inside your Gavia? Though they're tubeless ready, they were likely set up with tubes. If you do have tubes in there, and you've had no flat problems thus far, I'd probably pop on some tube-type GP5Ks and see how they fare. If you continue to have no problems, stick with the tubes. If you really want to chase a couple watts, you can move over to the GP5K TL, but with no flat protection benefit, I don't think that it's enough to warrant the move to tubeless.

WhyFi

Unless you weigh 250lbs and you're riding on 23mm tires, this is way too high.

Some loss in pressure is expected, but going down to 40-50psi is extreme. Maybe you've got a slow leak? That or the tires are set up tubeless but are leaking because of a lack of sealant?

monfils

The shop claimed that they were tubeless, but now I am not sure and will have to check.
Should there in general not be a protection benefit? Sooner or later, the tube is going to let me down out there, and as a new road cyclist I am enjoying not having to carry tubes and levers, while the confidence to being able to fix the problem out there is not the highest.

monfils

I suspect this might be the case.
Not sure what should be expected of the Gavias out of the factory. Will call the shop about that tomorrow.

WhyFi

Flat protection isn't a benefit if you're not getting flats in the first place - tubeless is great if you regularly get flats from small (<5mm) punctures. However, the sealant doesn't last forever and there's maintenance involved - you need to periodically check and replace/refill the sealant. Some people running tubeless do leave the tubes, levers and pumps at home, but I wouldn't recommend it if you like to ride a fair distance away from home/your vehicle.

Getting comfortable with basic maintenance, like maintaining your drivetrain or addressing a flat in the field, is a good idea regardless.

WhyFi

Do you have your bike in front of you? Let the air out of the tire, pop the beads, lever out one side and have a look.

monfils

You are right of course, but it seems like a bit of a chore, while road cycling for me is nature, stressfree training and attacking KOMs. I think the maintenance things come naturally, but there are some setbacks. For instance, I saw videos on optimizing the derailleurs, so I went for it on my mountainbike, but overtightened and destroyed the front gear cable. When you are sure you can do it, and it goes wrong, that is not the best feeling.

In regard to pumping the tyre, does the pump make a difference, and what is the best technique? I use this pump (edit: can't put links or images as a newbie <10 posts), open the Valve, put the adapter on, pull up the lever to tighten it, then at the right pressure simultanously pull up the lever and pull off the adapter. Is there any further art to it?

WhyFi

If you're comfortable with calling someone to pick you up and take you home when you get a flat, as opposed to taking a few minutes to fix it and continuing on with your ride, then by all means, you can go that route if you want to. Similarly, if you're okay with dropping your bike off at the shop for a couple days, likely missing riding time, for something that could be easily addressed, go for it. I'm envious that you've got a singular vision of what road cycling is and isn't after two months and 800km - kudos.

Ogsarg

Anyone riding a bike should be prepared to fix a flat on the road. You first need to figure out what you have in regards to tube or tubeless and then look into how to deal with a flat. Find out the basic tools and parts you need and put together a kit to carry in a jersey pocket, small saddlebag, or wherever. Talk to the shop that sold you the bike. They should be able to give you this info and if they are decent people, they can demonstrate how to fix a flat. You'll feel a lot better having the knowledge.

DrIsotope

The Gavia series sits among the leaders on my list of tubeless road tires. You would gain virtually nothing in RR/speed/longevity going from Gavias to GP5000s. Difference in rolling resistance might amount to a single watt.

I routinely get 4500-5000km out of a rear Gavia, around double that from a front. My wife has been on the same set of Gavia Race for two years, they're going to crack from age before the tread wears down to the dots.

WhyFi

There's a pretty big range, no? I've only had some top shelf Gavia SLRs, and I would say that they were on par with the best at the time, but what he's riding sounds like an all-weather kind of tire.

edit: yeah, looks like the AC1 is a 60TPI tire. I wouldn't be surprised to see a ~10w/tire difference between these and something towards the top of the class in RR.

DrIsotope

Giant has renamed the line so many times I don't know what's what-- they have like 15 TL models, and it seems like they're all cousins-- triple the thread count of an AC1 and you've got a Race0, take the nylon protection belt out and put in Kevlar and you've got a Course0. To the best of my understanding, the AC0 replaced* the Race, which replaced the SLR. The AC1 is so far as I can tell, the same exact tire as the SL, just with a different label. I rode the SL, then SLR, then Race, then AC1 and honestly couldn't tell the difference between any of them in terms of rolling/handling. The Race/SLR are a little lighter and therefore a little less hardy, but I had similar longevity across the line unless glass got involved. At least for me, thread count doesn't seem to be super critical when I can get away with running a 700x25 @ 85psi, despite weighing 215lbs.

*Giant still sells both the AC0 and the Race0, and so far as I can see they're the same tire. They weigh the same, they have the same protection belt, they have the same thread count.