Is this tire safe to ride on?

I’ve got a weird thing going with my brand new gp5000 tan sidewall tire. It’s like there’s a manufacturer defect that’s making the tire bulge off center at one point in the tire. It’s pretty subtle, and I’ve ridden one 60 mile ride on them with no issue. But tomorrow I have a road race with several long twisty 50mph + descents and I want to trust my tire! It’s not something with the bead seating because I’ve dismounted and remounted the tire and the anomaly stays in the same place on the tire. Attaching a video: edit apparently the upload failed, off to convert

Here’s a post image link to the gif 4 D4 E2990 B442 4 A79 B38 A 2 A6 AA5 FD760 D — Postimages

If you don’t trust it, don’t run it. You don’t need that negativity in your head when you are trying to go full gas. Use it as a training tyre if you don’t want to bin it, but I wouldn’t race on it.


Like @Schmiken, I wouldn’t trust it in a RR.

Should you choose to go ahead and race on it, given you’ve acknowledged the defect, this could place you in a potentially sticky legal situation (depending on which territory you’re in). All assuming that: 1) it blows out; 2) you take other people out if you go down; and 3) people could find your post…

Warranty job?

1 Like

@fleadram it’s possible a small section of the tire isn’t seated. Deflate and make sure the bead is 100% seated all the way around. Look at it from the side. There is a line on the tire which should be equidistant from the rim. When you spin the wheel if it’s seated you won’t see a hop. If not seated it will be obvious where it’s not seated.


Check the rim tape / rim bed at the area it’s off center at. I had a wobble in the tyre recently caused by rim tape riding up the inside of the rim. Remounting wouldn’t fix it until i realised and fixed the tape. Might not be that but worth checking if you haven’t already.

1 Like

Going to mount a training tire and check. Thanks for the responses all! I agree I don’t need it in my head during a race


That you’re worried about it is reason enough not to ride it. I had a GP4000 develop a bulge in the tread that looked similar to what you have. The LBS where I bought it warranty replaced it on the spot.


1 Like

If you have to ask this question then you know the answer


I’d check this first. Had this exact situation with a mountain bike tire recently. Road it for months with a slight wiggle although not as severe as the OP. Last weekend I had to dismount the tire due to an out of balance condition caused by congealed sealant. After cleaning out the sealant, remounting and seating beads the tire now runs true with no wiggle at all.

1 Like

I assume this is on a tubeless rim, with or without a tube. I would let the tyre down and use a sponge with a bit of washing up liquid on the side walls to help the seating. Then pump up to 8 bar and listen for the pops. You can then drop to your desired pressure.

It is on a tubed rim, and almost certainly just a defect with the tire. I can mount and dismount and at each time the bulge is at the same place on the tire, not the wheel. Just put a training tire on it and it’s fine, not what I wanted to race on but better than a defective tire cornering downhill at speed…


Your bike is upside down on the floor, resting on the bars + saddle. I swear I’m not trying to be some kind of elitist, exclusionary, us-vs-them, snob – but dear sweet baby Jesus, that makes me crazy.

The tire? Change it. Tires are cheaper than being stranded on the side of the road. It’s also more fun to swap tires now than apply Tegaderm strips later.

Come on now, after all the great help and support I got here, that’s just not what this place should be about. I don’t really think I should have to defend my current lack of a proper bike stand, and if you have concerns (which I’m open to hearing btw if it could hurt my bike) I don’t think that’s the way to express them. And apologies in advance if I’m misunderstanding.


It was said mostly in jest. It’s your bike and 100% you can (and should) do absolutely whatever you want with it. I’m a random person on the internet.

I just don’t put my bike upside down because it’s not very stable, and has a high probably of scuffing stuff.

1 Like

i’ve had that happen before as well, for me it was not seated properly

If remounting results in a distortion in the same spot, then yes, time to break up with that tire.

1 Like

Good advice here. You don’t need the worry when you’re racing.
As for putting your bike upside down, I’ve always done it with every bike I’ve owned. It’s its own bike stand like this and is perfect for indexing gears as it allows you to sight along the chain to really get precise. I find it wierd that people object to this practice. What are they worried about? Getting a smudge of dust or dirt on the saddle/hoods?
I mean, on a wet ride that saddle is going to have a wet, gritty arse rubbing away on it hour after hour, and the hoods are going to get the same treatment plus snot, gels, suncream…:grin:


With hydraulic brakes if there is any air in the system it can migrate from the top of the reservoir where it is not compressed to the brake line or caliper where it is compressed cause poor braking or brake failure.

Cheers for replying with science :+1:
Has never caused a problem for me though. Few pumps of the brake lever and all seems good.

Traditionally it’s roadies objecting anyway and until a couple of years ago they were all on cable brakes.