700 X 23 or 25 tire value

[ledslinger]

Unfortunately I destroyed one of the new 4000s tires with 50 miles on it tonight. My rims aren't hook bead and this along with a too wide rim strip that impeded on the raised area that retains the bead. I don't think it would have failed with the correct rim strip, but the guy who assisted me at the bike shop assured me they use them on everything. My gut told me it wasn't right, but I deferred to his experience. It failed at the stem where the butyl rim strip was double thickness, further blocking bead seating. A not too cheap lesson.

The tire blew on a flat straight and I hit both brakes to slow quickly to limit the revolutions on the flat tire. I think I may have skidded the rim on the sidewall, perforating it. When a bike tire blows out from a bead unseating, the deflation is immediate and the flat tire offers no support. The sidewall of the tire with the bead still seated takes the entire weight and gets damaged very quickly.

20/20 hindsight, correct width rim strip would have probably prevented the bead unseating. If you have a blowout on the back, don't use rear brake.

 

[ledslinger]

I'm not sure if I have hook bead rims or not. They have a projection that is radiused, where other rims have more of a square cut groove for the bead to sit in. My bike was bought in 1984, so I don't know if hook beads were standard then.

There is a prominent shape to the inside of the rim to interface and accept the tire bead, but the ridge that contacts the outer circumference of the tire bead is rounded, not square.

 

[ledslinger]

I decided to lace in a new rim to be sure the bead didn't blow out again. I installed a Mavic Open Pro with straight gage spokes on the drive side and double butted on the non drive side. Put some latex tubes in the 4000S tires and I think the ride and feel is improved a bit.

 

[ledslinger]

I I'm pretty sold on the Conti GP 4000S tires. They really hum along at speed. I did about a mile at 35MPH with a tail wind last night. They look like they will last based on how long it is taking to get the parting line mould flashing to wear off. Couple of hundred miles on the front tire and its still there.

I think the 25 mm width was the right move, especially after learning wider tires have less rolling resistance.

 

[ledslinger]

I I'm pretty sold on the Conti GP 4000S tires. They really hum along at speed. I did about a mile at 35MPH with a tail wind last night. They look like they will last based on how long it is taking to get the parting line mould flashing to wear off. Couple of hundred miles on the front tire and its still there.

I think the 25 mm width was the right move, especially after learning wider tires have less rolling resistance.

One problem with the tires is they make you want to ride all the time. My legs need a day off but I just can't do it.

 

[dailydriver]

Originally Posted By: ledslinger
I I'm pretty sold on the Conti GP 4000S tires. They really hum along at speed. I did about a mile at 35MPH with a tail wind last night. They look like they will last based on how long it is taking to get the parting line mould flashing to wear off. Couple of hundred miles on the front tire and its still there.

I think the 25 mm width was the right move, especially after learning wider tires have less rolling resistance.

One problem with the tires is they make you want to ride all the time. My legs need a day off but I just can't do it.


I am going to try some 25s as well (with latex tubes of course).

I just hope I can find some VERY responsive, FAST, 'open tubular' types in that width (like Vittoria Open CX slicks, Challenge Criteriums, and such).

 

[ledslinger]

I answered my original question by accident. I did a 200 mile rails to trails ride yesterday and decided to put on some Vittoria Zaffiro Pro tires on to save the Conti 4000s for gentler road use.

They are 700 x 25 but look more like 23 mm, I haven't measured them for their true width. They are about half the price of the Contis, have a decent ride and roll well. They held up to running over everything on the trails since much of it was run at night we didn't have the ability to avoid everything. No flats and had good feel on 40 mph descents when on the road.

My son ran Vredestein Duocomp tires and they are good performers too. One flat when he got a goathead thorn running through five feet of grass cutting a corner.

 

[zzyzzx]

Originally Posted By: ledslinger
They are 700 x 25 but look more like 23 mm, I haven't measured them for their true width.


I hate when that happens! As far as I can tell it either is or used to be that one company's 700 x 25 might be equal to another company's 700 x 23