Confused about ideal tire pressure for different tire widths on Ultimate

Recently got a [Canyon Ultimate CF SLX 8](https://www.canyon.com/en-us/road-bikes/race-bikes/ultimate/cf-slx/ultimate-cf-slx-8-di2/3320.html?dwvar_3320_pv_rahmenfarbe=R100_P02) and I’m trying to sort out what tire pressure I should be running. Some info:

* Body weight: 150lb
* Bike weight: 15.75lb (according to Canyon’s site, not sure what size that’s for)
* Extra gear weight (clothes, shoes, water, tools, etc): maybe 7-10lb
* Tire width: 25mm front, 28mm rear
* Wheels: 700c, 20mm inner rim width (I think)
* Tire casing & rim type: unsure

So I’ve punched that info into both [SRAM’s tool](https://axs.sram.com/guides/tire/pressure) and [Silca’s](https://silca.cc/pages/sppc-form) and am getting wildly different advice.

SRAM recommends somewhere around **74psi front and 67psi rear** depending on the casing/rim type/road conditions I select. (Note the front has a higher pressure)

Silca recommends around **85psi front and 87psi rear,** although you can only enter in a single tire width.

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I know normally your rear tire should be at a slightly higher pressure than the front, but is that still the case if your front tire is narrow (25mm vs 28mm in the rear in my case)?

Any tips as I fall into this ridiculous rabbit hole?

by slowpokefastpoke