Gp4000s ii life

[quixoticgeek]

I'm currently running Conti gp4000s ii 622x28 tyres on my bike. They have 4380km in them so far, the twi dots are still visible. I'm trying to work out if I have another 2000km in these tyres, or if I should put new rubber on in advance of a planned 1500km cycle tour or not...

How far do others get from their gp4000s it's??

J

[zigzag]

the front tyre normally lasts twice as long as the rear. i usually swap front and rear when the rear starts to square off (after about 2000km), that way i get around 8000km from the set, the wear holes are still visible but the tyres generally look tired by then. fwiw, from what i observed more than a half of tcr riders were using these tyres.

[quixoticgeek]

the front tyre normally lasts twice as long as the rear. i usually swap front and rear when the rear starts to square off (after about 2000km), that way i get around 8000km from the set, the wear holes are still visible but the tyres generally look tired by then. fwiw, from what i observed more than a half of tcr riders were using these tyres.

Ooh, hadn't thought of swapping the front and rear. Will give that a go tomorrow.

Yeah, I noticed the GP4000s' where by far the most common tyres I saw in Geraadsbergen.

J

[Zed43]

An old rear tyre may be quite square and thus unpleasant for steering. Besides, you want the most grip and reliability on your front wheel. Being a cheap-ass Dutchie I ride the rear until it's done for, then put the front on the rear and a new tyre on the front.

[Pickled Onion]

They would *probably* be ok for 1500 km, but personally I would at least put a fresh tyre on the rear for two reasons. Firstly tyres tend to puncture more often when near end of life, and secondly if it does completely wear out finding a decent replacement can be a pain when on tour. Change one or both now, then swap them back when you return to run the old ones to destruction in familiar surroundings.

[quixoticgeek]

They would *probably* be ok for 1500 km, but personally I would at least put a fresh tyre on the rear for two reasons. Firstly tyres tend to puncture more often when near end of life, and secondly if it does completely wear out finding a decent replacement can be a pain when on tour. Change one or both now, then swap them back when you return to run the old ones to destruction in familiar surroundings.

I'll be carrying a spare tyre with me anyway. Does that change the opinions of the jury?

J

[Torslanda]

1500km in one hit justifies three new tyres and at least two new tubes. If the original tubes are intact not patched then they can go in the barbag as spares.

New kit isn't just shiny, it's preventive maintenance. YMMV

[Gattopardo]

Do contis still fail on the sidewall?

[andrew_s]

I'd put on 2 new tyres, and carry the least worn of the current tyres (i.e. the front one) as a spare.

New tyres significantly reduce the chances of punctures, and you can always put the old tyres back on when you get home.
Another point is that mountains and luggage can result in significantly faster wear, especially on the rear, than at home.

Comment;
Rear tyres tend to wear square, flat across the middle of the tread, and putting a squared off tyre on the front will have a noticeably adverse effect on the handling of the bike.

[T42]

I'd put on 2 new tyres, and carry the least worn of the current tyres (i.e. the front one) as a spare.

+1 only I wouldn't bother with a spare. If you're worried, take a tyre boot.

Keep the worn ones for the turbo or for pottering around.

Do contis still fail on the sidewall?

I binned a Conti at 4500 km earlier this year when it started losing threads from the sidewall. The ends would catch in the hub and the rest of the thread rip out with a loud rasping noise - very soothing during a fast descent.

[zigzag]

for clarity, i do not recommend putting squared off rear tyre to the front. typically, it takes a couple of thousand km before it starts to square off - such tyre is totally fine on the front.

[Brucey]

FWIW contis have, for decades, routinely shed long threads from the 'chafer' ply, and these wrap themselves around the hub as described above.  Seems to be fairly harmless unless you run out chafer ply completely and there are sharp edges on the rim.

cheers