Furbz Posted January 8, 2019 Posted January 8, 2019 i'm now pumping my tires to 5 bar and allowing them to drop to 4 or 4.5 bar before pumping up again.running 25mm GP4000ii tires.my rims have an extremely wide internal width of 20.7mm so loads of air is able to get into the tube.i weigh 69kgs so i feel i can somewhat get away with it. yes i know the pothole risks. the comfort level is unreal. i mean really truly unreal compared to 6 or 7 bar.the only time i'll increase my pressures is for racing. and thats more because in a peloton its not always easy to miss road debris due to the tight riding. anyone else doing the same?i'm not sure i will go any lower in pressure, but would be interested to hear what others are doing.
Carmichael Posted January 8, 2019 Posted January 8, 2019 Not a pro at all.... But never go higher than plus minus 6 bar. Coming from mtbiking I never swerve out for drain cover lights etc.. and never picked up any problems. had a tyre pop in my face a few years ago and almost died of shock. Never doing that again.
lechatnoir Posted January 8, 2019 Posted January 8, 2019 I'm on 28's and run 50psi front and 55 rear. so 3.5-4 bar (ish)
Furbz Posted January 8, 2019 Author Posted January 8, 2019 I'm on 28's and run 50psi front and 55 rear. so 3.5-4 bar (ish) i have not checked if my bike will take 28s yet.but with the rims being as wide as they are, the 25's sure do look like 28s!
fanievb Posted January 8, 2019 Posted January 8, 2019 on my roadbike 9 bar (25c, vittoria zaffiro), the harder the better, especially when it comes to glass and potholescommuter 6 bar (28c, WTB thickslick) only reason it's softer is I commute via a gravel section and the tire's I fitted is a bit more puncture resistant
porqui Posted January 8, 2019 Posted January 8, 2019 I used to run my 23's at 7 to 8 bar but recently dropped to 5 and enjoying my ride more.Would like to go to 25's but the 23's are still to good to turf.Would 28's be a better option? Not a race snake.
100Tours Posted January 8, 2019 Posted January 8, 2019 i'm now pumping my tires to 5 bar and allowing them to drop to 4 or 4.5 bar before pumping up again.running 25mm GP4000ii tires.my rims have an extremely wide internal width of 20.7mm so loads of air is able to get into the tube.i weigh 69kgs so i feel i can somewhat get away with it. yes i know the pothole risks. the comfort level is unreal. i mean really truly unreal compared to 6 or 7 bar.the only time i'll increase my pressures is for racing. and thats more because in a peloton its not always easy to miss road debris due to the tight riding. anyone else doing the same?i'm not sure i will go any lower in pressure, but would be interested to hear what others are doing. What rims are you riding? I've been looking for something wider
bikebloke Posted January 8, 2019 Posted January 8, 2019 just putting this out there and i agree the ride on soft tires is nice and plush but i assume we all buy GP 4000ii because of the rolling resistance properties they have at high pressure as a race tire . When you run them at 50-60 psi you are paying a high premium for an expensive tire that doesnt perform well at low pressure( and the risks of flats and rim damage) so why wouldnt you just buy a less expensive tire like a gator(with better puncture protection) etc as you arent looking for performance from a premium race tire at a premium price ? i suppose im asking why pull a cart with a race horse ?
Furbz Posted January 8, 2019 Author Posted January 8, 2019 What rims are you riding? I've been looking for something wider Roval CXL50'si actually have a set of them up for sale (i bought a set each for my 2 road bikes)
Furbz Posted January 8, 2019 Author Posted January 8, 2019 just putting this out there and i agree the ride on soft tires is nice and plush but i assume we all buy GP 4000ii because of the rolling resistance properties they have at high pressure as a race tire . When you run them at 50-60 psi you are paying a high premium for an expensive tire that doesnt perform well at low pressure( and the risks of flats and rim damage) so why wouldnt you just buy a less expensive tire like a gator(with better puncture protection) etc as you arent looking for performance from a premium race tire at a premium price ? i suppose im asking why pull a cart with a race horse ? do you have supporting info regarding the GP4000 performing poorly at low pressures? long and short of my story. i'm lazy. i'm not going to change my tires each and every time i do a race. then change them back again to cheaper tires for training.that and the GP4000 have excellent puncture resistance. so they make an ideal tire for me. i also do not conform to "race day wheels".i paid a lot for my wheels, i'm going to use them each and every day and enjoy them. imagine paying a fortune for wheels and 3 years later they are out of date and you've used them only a handful of times. seems silly
bikebloke Posted January 8, 2019 Posted January 8, 2019 https://www.bicyclerollingresistance.com/road-bike-reviews/continental-grand-prix-4000s-ii-2014
Furbz Posted January 8, 2019 Author Posted January 8, 2019 https://www.bicyclerollingresistance.com/road-bike-reviews/continental-grand-prix-4000s-ii-2014 from the article: Noteworthy is the very flat rolling resistance graph of this tire, dropping air pressure to 80 psi increases rolling resistance by only 1.5 watts per tire. This is a great feature because rider comfort will increase greatly at 80 / 90 psi at a very low cost.
BuffsVintageBikes Posted January 8, 2019 Posted January 8, 2019 I'll never run a road tire that low, it isn't worth the risk of a stone, pophole or cateye blowout (for me).
bikebloke Posted January 8, 2019 Posted January 8, 2019 im not trying to win an argument here im just asking why run an expensive race tire below recommended pressure and risk pinch flats etc when you could run a cheaper tougher tire and get the same effect .its just intended as a money saving informational observation
s14phoenix Posted January 8, 2019 Posted January 8, 2019 I am on Schwalbe One and run a 25 rear and 23 front - 6.5ish bar rear and 6.5 front due to the size difference making up the comfort difference. When I know the roads are smooth I increase to 7 bar. I weigh +-69kg. I could run less but just don't like it.
'Dale Posted January 8, 2019 Posted January 8, 2019 67 kgs25c6.0 front6.5 rear Lekka like my couch ????
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