I am mid 180s. I was trading emails with a HED guy about weight and tire pressure. He suggested 80 - 85 PSI for me. I have ridden at 90 on my rides so far with my 9/Disc Black combo. It felt great, and I was fast. But, I am not quite ready to jump down to 85. I have the 23mm Attack and 25mm Force combo in mine.

The 25mm GP4000SIIs on Jet+ rims will measure ~28mm. Assuming your bike weighs ~25lbs I'd start at 85psi and then gradually go down from there. Tire pressures do not equate 1:1 as you change size. As you go up in size you have to go down in pressure. 40psi in a 23mm tire will feel like a sponge but 40psi in a 2.3" mtb tire will feel like a rock! Why? Here's a good read from Flo Cycling: http://flocycling.blogspot.com/...u-use-less-tire.html

Definitely less pressure than what you were previously using. I use between 75-88 depending on the tire I am using.

---

---

Save: $50 on Speed Hound Recovery Boots | $20 on Air Relax| $100 on Normatec| 15% on Most Absorbable Magnesium

Blogs: Best CHEAP Zwift / Bike Trainer Desk | Theragun G3 vs $140 Bivi Percussive Massager | Normatec Pulse 2.0 vs Normatec Pulse | Speed Hound vs Normatec | Air Relax vs Normatec | Q1 2018 Blood Test Results | | Why HED JET+ Is The BEST value wheelset

23mm Conti GP4KS2's on my HED Jet+ Blacks, and I roll them between 80 and 85 psi. I range from 174 to 180 lbs. The lower pressure is one of the things I love about these wheels.

You can use a higher pressure, but it will be slower.

I run 116psi on narrow rims and 87psi on the Jet 6+ (23mm GP4000s II on both).

---

ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

You could run 150psi if you want.

https://www.hedcycling.com/...us-and-black-wheels/

Thanks everyone. I'll try 85 maybe 87 psi and see how that feels. Going from 115 down to say 100-105 I probably wouldn't have thought much about it but going down 30-35 psi in tire pressure seemed like quite a big jump.

I also have the Jet Blacks, about 180 pounds, using 23mm conti gp4000sII's with latex tubes.

I can't help but think that all these various floor pumps we use probably have a margin of error of a few psi anyway? That combined with the fact that you'll probably lose a few psi during the course of a ride..........I just aim for close to 90 on the dial and don't put any more thought into it. No flats or rim blowouts yet... :)

Based on this, you'd want to go 75-80 psi:
https://www.hedcycling.com/tire-pressure/


I'm about 185lbs currently and running Ardennes Plus wheels and 25mm Conti 4000's (inflated to 28.5mm)... I normally run about 70 lbs front, and 72-73 rear on my road bike. Note that those charts are for labeled tire width, not inflated width.


115psi is SUPER high for a tire that big, even at 200 lbs. That pressure might be okay if you had 23mm (labeled) tires, and a glass-smooth perfect road surface.

I have 2 sets of Heds, I think the 90 PSI recommendation only came out a couple of years ago (or at least that is when I first heard of it.)

I had initially run them at 100, I now run 80-85 and so far so good, no issues. I weigh 175# and ride lots of bad roads on them, with cracks and potholes. I did a race on Monday where I did two high speed rail road track crossings and I was totally convinced I would pinch, and they were fine.

Tires are a mix of GP4000s, Attack, Force, with latex tubes. I do 85 rear, 80 front. I have not played with going lower.

Interesting chart. It has me at 65psi as a 140 pound guy on a HED Jet+ Black disc.

Since I run a FLO 60 front wheel with a 23mm Conti GP4000s II I’m a bit torn how to inflate. Maybe 75psi front and back?

---

-------------------
Madison photographer Timothy Hughes | Instagram

I bought an Accu-Gage 160 psi gauge from amazon which is super accurate. I figured my inexpensive Serfas pump would be off but I was pleasantly surprised at how accurate the dial is. After checking it several times I just trust the dial now as it’s always been on.

---

-------------------
Madison photographer Timothy Hughes | Instagram

I have the Jet 6+ with 25mm GP4000SIIs, weigh 145 pounds, and I run them at 65-70 psi. It still feels strange to inflate them to such as a low psi, but I have no complaints about the ride/ speed. On smooth roads it feels great, like sitting on my sofa. I live in Chicago and most of my roads are trash, but I've had no issues running at 70 psi.

Pretty amazing to run that low after we've been so accustomed to 100+ for years. I dropped down to 95 on narrower rims a few years ago and it's been good. I've been running 90 in my 23mm Corsa Speed tires w/latex tubes on the Hed + wheels, but will try dropping down to 80 this weekend in a 40KTT and see how it goes. The road is very rough, so at least it'll feel better. Hope it's fast, too. :)

Wow - @135 I should be running 65psi from that chart. I've been at 100 since I got the wheels. Time to ride and see.

Any diff in pressure if in trainer?

I have been riding at about 87-88 psi for the last few months. Not sure if that's optimal but I'm not riding slower that's for sure. I PR'd my 10K TT time on pretty low training miles at this point in the year so I can't say there's been any negatives out of the lower pressure. I might even try and run lower based on the chart on HED's website.

FYI, I think HED has a YouTube video stating the fastest tire on this wheel is a 22 or 23mm. I just bought a Jet 4+ / Jet Disc Plus set and use with 23mm Conti TTs for race only. Got the set just one day before Eagleman last weekend and in the rush to get the bike ready neither my LBS or I noticed the 90lb max pressure recommendation. I ran at 108 lbs (I weigh 155-160) for the race. Bike (P5) felt great and bested my former time by over 2 minutes. I'll experiment with lower pressures before next event (Philadelphia OLY)....too much info out there stating lower is faster.

I looked through the Flo article but didn't see the 15% drop mentioned. Any idea where that general rule comes from? If that is a nearly optimal value, it would seem you could measure that with the bike on a trainer

15% came from Bicycle Quarterly but I believe others have tested it as well.