NinjaCycler

I am 5'4" and 125 pounds. I am getting a pair of 2015 Zonda's and hear 28mm is much better than 23mm.

I am currently on Shimano 105's with Hutchinson Quartz at 120 psi and it's not fun.

I have a 2007 Easton EC70 carbon road fork on a 2007 Jamis Eclipse. The rear can take it and it looks like the front fork can as well. Should I get 23mm, 25mm or 28mm?

These 23's aren't fun in NYC.

Would you recommend another tire entirely? I can get these for the same price as Schwalbe One's in any width.

redlude97

Why are you running 120psi at your weight on 23mm? Try 90psi first

2lo8

Way overinflated. At your weight the proper inflation is probably below the min printed on the sidewalls. Like 75/85 front/rear. A bit higher if you get pinch flats from potholes.

I still think upgraded tires are worth it, and wider tires won't hurt, but you'd end up running really low tire pressures.

NinjaCycler

They run unbelievably slow otherwise. Everything is crazy effort. I have other issues with sizing and everything is getting addressed accordingly but I am just asking this question not trying to alleviate the current setup.

NinjaCycler

I was running my current setup at 60 - 70 psi and it was slow and I got flats. The ride was unforgiving until a saddle change. If going 28mm won't hurt then I'm good. I can never go higher then the pressure I'm at so lower is better. The tires are suggested at 110 psi.

2lo8

60-70 is too low, and slower cheaper tires suffer even more from being underinflated. I'm not surprised that 60-70 didn't feel right.

Try 80/90 if you're worried about going too low and pinch flats and clock your times. It feels different than 120psi, smoother and less responsive, which might be mistaken for feeling slower. Fatter tires won't really help make low pressures feel less mushy if you dislike that mushy feeling of low pressure tires. You don't have to run them super soft, but try them at a much lower pressure than 120psi, even if it's below the min on the sidewall.

milkbaby

120 psi is way too high for a 125 pound rider. Right now I'm more than ten pounds heavier than you and still can run 70/85 psi (front/rear) on 23 mm Michelin Pro4 or Conti GP4000, no problems. The only time I've ever pinch flatted was smashing into deep potholes that other riders on a group ride failed to point out.

trailflow1

Your frame may be able to accept 28c but your brake calipers may not. Only the latest calipers have really been optimized for 28c. Which calipers do you have ?

NinjaCycler

Well that's unfortunate, very lame of me but it seems that the Centaur 10's have more room then the frame and fork. It might be lower response instead of slower.

I dropped the front to 100 and the rear to 110 and it does ride better. I'll let it drop naturally and measure it to check it out.

I need the response though, I ride though traffic and psychologically it makes a difference when cutting through.

Corbin

No doubt. You know what you like. Try everything in range. I've only ran 25's and 28's but found I run my 28's 10 psi higher than 25's. (120/117 psi total at 130- 140 lbs) Don't listen to all these guys. They'er not riding like we are and are looking for a different feel than us.

The change between 25's and 28's is huge. Much bigger than I thought it would be. I now can easily tell the difference looking at a mounted tire but at first they barely looked larger. However the feel on the road is huge. I'm still shocked 1,400 miles into my switch. My 25's I was running around 110-115. I tried my Panracer Ruffy Tuffys at the manufactures recommended 90 psi and that was like rolling through mud. Extra rubber = more tire to pancake out, This is why my class 2 truck tires run 80psi while a class 1 may be what 55? However even running them 10 psi higher than I had my 25's there improved feel is still great.

As far as agility goes with them I've noticed no problems and I'm the type who likes to see how low and at how high of a speed I can carry through 90° turns.

I would not recommend the tire I mentioned above however as it is built to be tough and I've slid it plenty of times unintentionally. I was planning on trying 25's again next in Schwable Ones however I might just grab that in 28's and call it a day.

If I was you I'd try 25's first. The change will be very big if you go from 23's to 28's.

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Edited in:

I wanted to add that I would specifically recommend against gp 4000 IIs. My brother tried two just this year from 2 different suppliers and both gave way under 400 miles. Side wall blow out. These were in 25c. If you search the web about them you will see threads going back many years talking about this. Some people say they have no problems with them so YMMV. LSS their sidewalls are very thin and easily torn.