Luke DeMoe
Jeremy Powers runs between 24-27 and he is god. We all should bow down, and
hit up Slate for some Rapha kits. They are 7% faster then all other
clothing...
On Thu, Sep 20, 2012 at 6:12 PM, Drew Coleman wrote:
> This is a pretty good call. I weigh 165-170 and run pretty darned close
> to what he guessed. 35 in rear, 32.5 in front with adjustments based on
> conditions. Tubies are a revelation, by the way. I switched this year and
> will never go back (that is until I inevitably flat and get glue all over
> myself as I learn that phase of cycling).
>
> Drew
>
> ------------------------------
> Date: Thu, 20 Sep 2012 16:08:13 -0700
> From: cyclematt@gmail.com
> To: birdman@teamfoodbaby.com
> CC: obra@list.obra.org
> Subject: Re: [OBRA Chat] Tubular Tires - air pressure
>
>
> Tom,
>
> Be prepared! You are going to get lots of replies on this! Here is my two
> cents...
>
> Quick answer: assuming you are running 700 x 32's. At 175 I would guess 35
> in the rear and 30 front.
>
> Longer answer: It depends on your tire, weight, riding style
> and conditions. Run a bit more pressure on a dry course and a bit less on a
> wet course relative to what you typically run.
>
> The main way tires stick to the ground is by allowing the casing of the
> tire to conform to the ground. The goal is to get as large a contact patch
> as possible while not pinch flatting or having
> the casing roll in corners. The lower the pressure the larger the contact
> patch and the more traction you get. On a cross bike the only suspension is
> the tire. Too much air and you have a very bumpy ride that is hard to
> control.
>
> Too low pressure and you will dent the rim, pinch flat, or roll the tire
> off the rim.
>
> I like this "rule of thumb" method for checking tire pressure. Take your
> left hand and make a fist. Now stick your thumb out. Place your right palm
> over your thumb. Now place your thumb on the tire so your outstretched
> thumb is perpendicular to the wheel. Using your body weight you should not
> quite be able to touch the
> rim. Thats a good starting place for tire pressure and a good technique
> in general for learning to check pressure.
>
> I weigh 145 and in this dry weather, running 700 x 32 Tufo Cubus tubulars,
> I start with 30 in the rear and about 26 up front. I ride very
> aggressively...cornering hard where I can so I don't have to slow down.
> When cornering hard with low pressure there are lots of lateral forces
> being applied. I have seen tires roll off rims mostly with riders who run
> very low pressures. It makes sense.
>
> You have to find that balance of suspension, traction, and reliability (no
> flats or tires coming off!). Hope this helps.
>
> Matt Martel
>
> On Thu, Sep 20, 2012 at 3:31 PM, Tom Bird wrote:
>
> So getting ready for first races on my new tires and wheels. Never been on
> tubulars before and looking for a starting air pressure for the cross
> races. I weigh 170-175 depending on how much beer I drank the night before.
>
> I figure once I have a good idea I will adjust from there once I get some
> ride time under me.
>
> Oh and with things hot, dusty, and dry now how much do you vary the
> pressure when it gets wet and sloppy?
>
> Thanks
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