Two Things: The Rule of 105 is No Longer Real, and 1 more...

A safe space for discussing performance and marginal gains, without judgement. All disciplines and topics in the pursuit of optimization welcome.

Moderator: robbosmans

Posts: 5500
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

I put in 25mm but my point is that Silca's numbers are just theoretical numbers and going lower per their graph doesn't impose much penalty at all.

by Weenie

Visit Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

Posts: 490
Joined: Tue Nov 02, 2004 7:19 pm
Location: London

by eurostar

With 25mm you can get 81.5 - 100 psi frpm the calculator, depending on the settings you choose.

Posts: 3
Joined: Tue Apr 23, 2024 6:44 pm

by tdbayes

eurostar wrote:
Sat Jun 08, 2024 3:14 am
What assumptions are you making? What tyre width? The Silca calculator says 5.5 bar is at least 1 bar too low for 25mm measured width.
It was in the context of hookless rims which means the max pressure is 5 bar regardless.

But I get your point... I wasn't really very clear, but I wasn't saying he doesn't know what's optimal for RR, which may indeed be > 5 bar depending on setup.

Its more that perhaps he doesn't know much about modern tyre systems in general if he thinks of 5.5 bar as being so low that it shouldn't possibly blow off a hookless rim--it's both over the limit and likely too high for most modern setups. Which I think is quite an important gap in knowledge for somebody whose job it is to work out these trade-offs.

Post Reply