Changing from a 23 to a 25 rear tyre.

[Rob3rt]

I was joking before but.....

Grams.

Yeah, about 25 of them for a Conti GP4000S. 25 grams lost on the outside of each wheel (in total 50g of rotational weight saved) for free isn't to be sniffed at! Fair enough, for most, it won't make any difference, but if you are going to get obsessive about weight in any area, the wheels are where you ought to focus in most circumstances (unless all you care about are riding fast, pancake flat out and back 10 mile TT's)! Considering it is a free weight saving (23's cost the same as 25's), why not take it?

 

[MattHB]

I was joking before but.....



Yeah, about 25 of them for a Conti GP4000S. 25 grams lost on the outside of each wheel (in total 50g of rotational weight saved) for free isn't to be sniffed at! Fair enough, for most, it won't make any difference, but if you are going to get obsessive about weight in any area, the wheels are where you ought to focus in most circumstances (unless all you care about are riding fast, pancake flat out and back 10 mile TT's)! Considering it is a free weight saving (23's cost the same as 25's), why not take it?

The current thinking is that the lower rolling resistance of a wider tyre offsets any marginal weight increase. Hence why sky were running 25s this year. But not being at that level, I doubt any of us will notice the difference from either the grams nor the friction.

 

[Rob3rt]

I am aware of the rolling resistance arguments and Team Sky's choice to run 25's. The thing is, rolling resistance is going to be very much dependant on a lot of other external factors (the surface riding on, the tyre pressure, the tolerances on the rim you put the tyre on will have some small effect on the profile of the contact surface etc), a lighter tyre will be lighter regardless. If I was going for marginal gains, I would be choosing what is, not what maybe/might be depending on if I get everything else right.

There are a lot of claims and research, and anecdata surrounding wheels and tyres, eg. Zipp claim clinchers are faster than tubs. Conti's TT clincher only comes in 23's and their premium racing clinchers Attack and Force come only as a 22mm front specific tyre and a 24mm rear specific tyre.

 

[Rob500]

When I got my bike (2nd hand) it had a 25 up front and a 23 at the rear. After around 6 months I bought new 23's and fitted them. I couldn't tell any difference to be honest.

 

[Boon 51]

I was joking before but.....



Yeah, about 25 of them for a Conti GP4000S. 25 grams lost on the outside of each wheel (in total 50g of rotational weight saved) for free isn't to be sniffed at! Fair enough, for most, it won't make any difference, but if you are going to get obsessive about weight in any area, the wheels are where you ought to focus in most circumstances (unless all you care about are riding fast, pancake flat out and back 10 mile TT's)! Considering it is a free weight saving (23's cost the same as 25's), why not take it?

Funny you should mention wheels as I had thought along them lines but then things start to snowball and I'll be after a carbon bike next when I sell my motorbike..
PS.. I would love a carbon bike though?

 

[Nearly there]

I convinced myself that I needed 25c tyres but went with 23's as replacements and can honestly say I can't tell the difference

 

[Boon 51]

I convinced myself that I needed 25c tyres but went with 23's as replacements and can honestly say I can't tell the difference

Thats what I thinking
, I would like to try the 25's but no reall harm done if they dont work out...

 

[User6179]

Changed to 25s as im 90 kg and find them more comfortable as i run them at 100 psi instead of 110 -120 that I ran the 23s at .

 

[Boon 51]

Changed to 25s as im 90 kg and find them more comfortable as i run them at 100 psi instead of 110 -120 that I ran the 23s at .

I'm a tad lighter but I have noticed on different threads how many people run with lower psi which I will try as well..

 

[SatNavSaysStraightOn]

Changed over from 23's which were worn out to 25's earlier in the week and did the first run on them yesterday. I think the only real thing I have noticed is my confidence has increased and I'm happier cornering faster, but that could be the change from the OEM cheap & cheerful tyre to a named brand I have used extensively in the past, rather than 23 to 25's. Running them at 100psi on a 85-115psi range.

 

[User6179]

I'm a tad lighter but I have noticed on different threads how many people run with lower psi which I will try as well..

When your heavy and run 23s your kind of stuck with the higher pressure, makes a big difference for me running 25s but if your not heavy you wont notice much difference as you could run the 23s at lower pressure anyway.

 

[Boon 51]

Changed over from 23's which were worn out to 25's earlier in the week and did the first run on them yesterday. I think the only real thing I have noticed is my confidence has increased and I'm happier cornering faster, but that could be the change from the OEM cheap & cheerful tyre to a named brand I have used extensively in the past, rather than 23 to 25's. Running them at 100psi on a 85-115psi range.

I've only got the Giant Flat Guards on mine at the moment and I dont suppose they are the greatest of tyres being a OE tyre.. My cornering was a bit suspect until I learned to lean and not steer... so I do still wobble a bit round corners..

 

[SatNavSaysStraightOn]

I've only got the Giant Flat Guards on mine at the moment and I dont suppose they are the greatest of tyres being a OE tyre.. My cornering was a bit suspect until I learned to lean and not steer... so I do still wobble a bit round corners..

I had the cheap decathlon tyres on... worn them out in 400 miles or so.
just come back from a very wet & windy run and with the Schwalbe Durano Pluses on, whilst my average was down (hardly surprising given I have had a bad cold, now have a chest infection and am a moderateraly severe asthmatic, plus was at a physiotherapy appointment and the fact that it was yet again a bad head wind for most of my route) my top speed was up quite a bit and its a route I do frequenly, so guess that reflects on the trust in the tyres.

 

[Boon 51]

I had the cheap decathlon tyres on... worn them out in 400 miles or so.
just come back from a very wet & windy run and with the Schwalbe Durano Pluses on, whilst my average was down (hardly surprising given I have had a bad cold, now have a chest infection and am a moderateraly severe asthmatic, plus was at a physiotherapy appointment and the fact that it was yet again a bad head wind for most of my route) my top speed was up quite a bit and its a route I do frequenly, so guess that reflects on the trust in the tyres.

I've been looking at the Continental 4000's or the Michelin Pro's.. Actually I've got loads to buy in the UK in a couple of weeks time hope I can get it all in my luggage