Re: Bleeding Disc's

cyclintom <cyclintom@yahoo.com> wrote:

On Fri Mar 21 16:39:35 2025 AMuzi  wrote:

 
Since every system has its own features and foibles, it's
good that we have choice.

 
 
 
 
The word from the rolling resistance gang now is that on the European
roads 40 mm tires have lower rolling resistance than 28's depending on
surface by as much as 70 watts! That is no longer a choice since you
cannot use normal rim brakes on a 40 mm tire. That requires hydraulic
discs with a 148 mm wide rear and 110 front and at least 12 mm through
axles. You cannot do that with CX V-brakes since the diameter or the tire
would interfere with the cross cables. When I ride across cobblestones
with 28's it is like hitting the brakes.

No the rolling resistance across widths with like for like tyres and
pressures is essentially flat for tarmac, some argument for maybe some
rough roads favouring wider tyres but generally any roads that bad tend to
be in relatively small areas, mainland Europe roads are arguably better ie
smoother than UK or US roads by some margin.

Width brings better grip/protection ie pinch flat and comfort and so on,
speed is rather neutral.

 Cobbles does absolutely favours much wider tyres though the cobbled
classic have enough tarmac that a bike optimised for that such as a gravel
bike with 50+ mm tyres would be a hindered somewhat on the tarmac, and
there is cobbles and cobbles some is just a bit jiggly others are more like
riding Gravel etc where line choice and riding light etc are needed.

 
Also, flat mount actuators for 100 mm discs are very specific and very new.
 

Road flat mount have been around for quite a few years now, Tiagra has been
flat mount since at least 2019 others such as Dura Ace etc i suspect before
that, I *think* road hydraulic went flat mount if not from the get go, very
early on.

Either way it’s not a new thing flat mount.

Roger Merriman