Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Mark J cleary <mcleary08@comcast.net>
Newsgroups: rec.bicycles.tech
Subject: Re: Tire pressure
Date: Thu, 10 Apr 2025 10:35:36 -0500
Organization: A noiseless patient Spider
Lines: 50
Message-ID: <vt8og6$391kl$2@dont-email.me>
References: <vt19jb$goof$1@dont-email.me> <m5j1cmF7qr9U1@mid.individual.net>
 <vt6n12$1e8o9$1@dont-email.me> <m5pgu6F8unqU1@mid.individual.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Thu, 10 Apr 2025 17:35:35 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="93caae894a7a1be996934d571bfe3243";
	logging-data="3442325"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18H25SiDvVbXTgeEA2m3ZMk"
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:AWS2JFbFm8aW9+3K/DNxqZ/bNSk=
Content-Language: en-US
In-Reply-To: <m5pgu6F8unqU1@mid.individual.net>

On 4/10/2025 4:22 AM, Roger Merriman wrote:
> Mark J cleary <mcleary08@comcast.net> wrote:
>> On 4/7/2025 5:20 PM, Roger Merriman wrote:
>>> Mark J cleary <mcleary08@comcast.net> wrote:
>>>> I am going to Conti GP 5000 32mm clincher tires. I weight 170 pounds and
>>>> the bike and the stuff lets just say 25  pounds. Standard Shimano disk
>>>> rims  RS171 is the wheels. According to the various on line calculators
>>>> they suggest I use a tire pressure of 62 rear and 60 front. A few put
>>>> them up to 68psi in the rear.
>>>>
>>>> To me this is drastically lower than what I am using on the 28's. I
>>>> might have the 28's drop to around 75 front and 80 rear before I
>>>> reinflate but I am surprised. Maybe I am just way off the mark and
>>>> putting in to high psi. What would you experts say. Naturally the 32's
>>>> are going to be less but maybe now even on the 28's I am running to
>>>> much. I usually get the rear up to around 90 and front 80 and then let
>>>> them ride lower for maybe a week or so depends. But 62 is way down the
>>>> line.
>>>
>>> My “old school roadie” that I use for the commute, I run with a bit of
>>> extra air in them, at 80psi with the 32mm tyres, I’m 200+ lb let alone bike
>>> and pannier and kit!
>>>
>>> 60ish sounds about right really, thought these things are guides.
>>>
>>> Note that brains aren’t very good at speed, squishy = slow and hard = fast
>>> to the monkey brain! I’ve had to retrain the monkey over time, as I
>>> certainly used to be 120ish
>>>
>>> Roger Merriman
>> I put the new Conti's on today and they measure out a 31mm I am
>> surprised maybe the will change as I ride them. Hopefully can ride
>> tomorrow.
>>
> What’s your wheels internal rim width that will have an effect, my MTB new
> wheelset is purposely on the narrow side for modern wheels as otherwise it
> would cause clearance issues for the MTB, with 30mm internal rim vs 25mm
> 
> 22/23mm for road bikes seems to be about normal nowadays.
> 
> Roger Merriman
> 
> 
My wheel according to Shimano rs171 has 19mm height and width internal 
and 24.6 width external. I just got done with a 50 mile ride and they 
are quite nice and yes much smoother going over the pavement. My speed 
was about my usual.

-- 
Deacon Mark