faster tyres for my sherpa

[freddered]

You need to be aware that tyre pressure is dependent on tyre size/volume - a fat tyre will be pretty rock hard with 65 PSI. Skinny tyres have a smaller volume so the pressure will naturally need to be higher for the tyre to be hard ! Stick to manufacturers recommended works best - They do test 'em you know !

Yes, but a lower-pressure tyre puts a bigger 'footprint' on the road. 50psi gives twice the footprint of 100psi.

ie. for a given pressure any tyre puts exactly the same footprint on the road (if you weigh 100 pounds and inflate your tyres to 100psi you should have a 1sq.inch footprint), the only way to reduce that footprint is to use higher pressures (which normally means skinnier tyres)

The problem is worse if you don't use a track pump with pressure guage because a 65psi tyre can feel properly inflated at 40psi.

My Vredestein 23mm slicks are rated to 170psi, I don't go beyond 130psi but they fly along.  There's hardly any rubber on the road.

[PH]

Stick to manufacturers recommended works best - They do test 'em you know !

Newbies often take these arbitrary ratings as if they had some scientific basis. While you'll rarely get in trouble with this approach, you will usually not be getting the best possible performance with this rote approach.
Not my words, Sheldon Browns.

The full article is worth a read;
http://www.sheldonbrown.com/tyres.html

[stutho]

blazingsaddles

The max for the Pacaracers I have is 65psi

Just for your info - The  Pacaracers Pasela 1.25" TG are also have 100psi printed on the side.

[freddered]

blazingsaddles
Just for your info - The  Pacaracers Pasela 1.25" TG are also have 100psi printed on the side.

I'd say that a pair of those actually pumped to 100psi would fairly zip along.

I've used my track pump on friends' bikes and found that they normally have 30-40 psi in the tyres.  Using something like a plastic 'Halfords' frame pump makes it difficult to get anything like effective tyre pressures.

[stutho]

I'd say that a pair of those actually pumped to 100psi would fairly zip along.

They do!  But like I said earlier  I don't think they are very robust. - Also not a comfortable as a wider tire.

[blazingsaddles]

BS, Fast Tourer:

1986 British Eagle Touristique
28mm Schwalbe Marathons.  Not exactly a fast tyre but rugged and dependable.



Going from a 65psi tyre to a 100psi tyre will make a noticeable difference.  Unless you use a track pump and/or a pressure guage you may be shocked to see how little pressure there is in your tyres.

Thanks Freddered,

Will look at getting a track pump with guage. Thats a nice looking bike your British Eagle.

Thanks to all else for advice.

BS

[jags]

say fred, what have you got in the s/bag ,great looking bike btw.

[freddered]

say fred, what have you got in the s/bag ,great looking bike btw.

Thanks, I'm really pleased with the rennovation.  I've had it from new.

In the bag (Carradice Barley):

Sidepocket1: 2 Innertubes
Sidepocket2: Mini-tool, punc repair outfit & some rubber gloves
Inside: It depends on how long I'll be out but always a waterproof.  Maybe a windproof Gilet, Mobile phone, overshoes, skull-cap, some snacks and a spare jersey. (In summer hardly anything)
On the flap: 2 leather toe straps holding a rolled-up hi-viz waistcoat.


I would say it's the perfect size bag for day rides.
Many people agree by the number of them I see on Audax rides.  You can strap a lot to the outside using the metal d-rings.

Here it is at the end of an eventful 400km ride on the Thorn (Everything is strapped to the Bag, the Rack is redundant)

[jags]

thank's fred,great info. would that be 400km on the same day or ,over how many day's.