Hi all – i’ve got a 100 mile sportive coming up (dragon sportive in brecons). I figured I might increase the size of my tyres (currently schelbe 25mm ‘Ones’ or something) on my cube road bike to 28mm (they should fit apparently). I recall lots of people mentioning that you can’t go wrong with continental grand prix something or other.

Looking at the bike discount.de I can see I can get “Grand Prix 4000 S II 28-622 black” – are these the ones I want – cost is 30 quid a tyre which seems reasonable.

Feel free to tell me 28mm tyres are ridiculous and I should stick to 25mm, but apparently it doesn’t increase your rolling resistance, so why not?!

28c isn’t as aero, 25c seems to be the compromises for teh speedz!

HAve a look at Decathlon, they seem to price these well and locally.

28c isn’t as aero, 25c seems to be the compromises for teh speedz!

I’m not sure i’m very aero either (!), but i’d read that this wasn’t the case – something to do with creating an aerofoil shape. That said I can see that only applying if your wheel width is the same width as the tyre.

Yup, but luckily if you want 28c then Enve make a rim to match! Otherwise the lightbulb shape comes into play

Decathalon have ‘GP4000 S II ROAD TYRE’ or ‘GP 4 SEASON ROAD TYRE’.

I assume it’s the 4000 ones that I want?

Yup, but luckily if you want 28c then Enve make a rim to match! Otherwise the lightbulb shape comes into play

Has anyone done any research to see how big a deal that actual is? I can’t see the loss of a couple of watts making much difference to me. I’m hardly optimised!

Velo flex Master 25. You can thank me later.
Lunge, hater of Cont tyres.

I’m a bit out of the loop on slim tyres, but it’s something I need to get clued up on, since receiving my bargain yesterday. My Cube came with 25c Continental Grand Sport SLs and they felt pretty good on last night’s first ride, no worse than the ~8/9 year old 25c Schwalbe Stelvio (Plus?) on my Felt that had similar rides this last week.

But do check out the likes of CRC; Wiggle; Merlin; Ribble; Athleteshop etc. for deals. And don’t forget that you can use your British Cycling 10% code for baskets over £99 at CRC, plus all the above are on Topcashback.

28c+ will lower rolling resistance, giving a more cushioned ride over carp roads, but at the expense of extra rubber weight and more aerodynamic drag. All about compromises.

http://www.bicyclerollingresistance.com/

https://mywindsock.com/ (tells you about how wind affected your Strava recording)

I assume it’s the 4000 ones that I want?

Depends, its a choice between:
GP4000s – Very fast, supple, grippy with moderate puncture protection
GP4Seasons – fast, bit less supple, insanely grippy, with high puncture protection.

Can’t go wrong with either really – they are both extremely popular for a reason.

Is it really worth worrying about the aerodynamics of 25mm vs 28mm tyres for Sportives??

Ignore the comments about aero…

The fact you can run a 28mm at slightly lower pressures than a 25 will mean you have better comfort which is worth its weight in gold over 100 miles.

Conti 4000S II is what folk rave about for summer…

and the 4 Season for winter which has insane grip on wet slimy cold roads.

Good prices on Merlin with included tubes:-

https://www.merlincycles.com/continental-gp4000s-ii-folding-tyres-with-2-free-inner-tubes-pair-71989.html

Has anyone done any research to see how big a deal that actual is? I can’t see the loss of a couple of watts making much difference to me. I’m hardly optimised!

Nah its all marginal of course. This is conti’s own report on it:

http://www.conti-tyres.co.uk/download_files/Wide_Tyre_Test_TourMagazine_2014_UK.pdf

Fit the biggest tyre you can fit into the frame. If you can go bigger than a 28 try the schwalbe speed 30.
No point talking aero as the differences are so small and I’m sure you won’t be in a skin suit n pointy helmet 🙂

The fact you can run a 28mm at slightly lower pressures than a 25 will mean you have better comfort which is worth its weight in gold over 100 miles.

That’s what I figured. I’ll take being 2 minutes slower but having a comfier bum!

GP4Seasons – fast, bit less supple, insanely grippy, with high puncture protection.

Can’t go wrong with either really – they are both extremely popular for a reason.

GP4 seasons: come up narrow, average ride quality, average puncture protection, good wet grip. Mine got binned after the tread delaminated.

I have nothing but praise for 4 Seasons – better puncture protection than the 4000’s in my experience so I’ve ended up using them all your round……you don’t want to be stood at the side of the road cursing during your sportive – far better to keep moving!

I personally wouldn’t switch from Schwalbe One to GP4000S, Ones are preferable and much more durable – particularly towards end of life – in my experience.

Edit – by durable, by the way, I actually mean susceptibility to punctures. I have got around thousands of miles out of the Ones currently on my bike, and don’t recall a single puncture on them. The (several pairs of) GP4000s that preceded them were a very different story, particularly once they were a bit worn.

I much prefer my Schwalbe G One Speeds in 30c to my GP 4 seasons in a 25c. But my favourite tyre is a Corsa G+ in 25c. On a wide rim these come up more like a 28. Fantastic tyres that roll beautifully, and you can go skinwall if you must! I also run their Corsa G+ tubeless in 23c on my TT bike, and these have the lowest rolling resistance of any tested tyre. I’d also recommend latex inner tubes. This will save you at least five watts, which doesn’t sound much, but will add up over 100 miles.

I like 28c Challenge Paris Roubaix. They roll so much nicer than Contis.

Ones are also quite large volume compared to the continental I have on a different wheel, although rim width maybe a factor in this. Personally, for 60quid I wouldn’t be changing.