Bontrager Race X-lite versus Continental GP3000 tires

[41]

Antti Salonen wrote:
> 41 <[email protected]> wrote:
>
> > I imagine
> > those using the Criterium or Time Trial (1.25mm and 1.0mm thick
> > respectively) would find them a little thin compared to Conti rubber,
> > and this is why they are faster. But the rubber is harder and so wears
> > better.
>
> For what it's worth, I wore two new Avocet Criteriums down to the canvas
> in about 3000 km as a rear tyre. I'm barely 70 kg WITH the bike and all
> equipment so that's kind of dissappointing. As a comparison a
> Continental Grand Prix 4-Season lasted 7000 km. Both tyres are 23 mm
> wide and about 220 grams.

According to Conti and Avocet spec, in Kevlar bead for both, the
GP4-season in 23 is 220g, the Avocet Criterium is 200g. The Criterium
with wire bead is 235g.

Were these the blackwall made in Korea Criteriums, or the tanwall made
in Japan ones? And what year of production? According to Jobst, at
least for some production runs of the made in Korea ones, they reversed
the thicknesses of the two tread layers, i.e. making the hard durable
rubber outer layer thin, and the soft sticky non-durable inner layer
thick. I don't know if current production still has the same defect,
and I presume he doesn't either, since he bought what he has in a big
batch, as I understand it. At your wear rate, the road model at 1.5mm
would give roughly 3600km of wear, while I believe Jobst reports
something like 4-6000km as typical (for the original Japanese
production).


> What comes to puncture resistance I had several flats with Avocets
> especially in wet conditions and when the rubber was already thin.

Of course, these are the worst conditions for any tire. Would you say
the objects that penetrated were at least about 3-4mm thick? If so, I
believe they would have penetrated the Contis as well. I don't know
their thickness, but I imagine the total carcass+tread at the thickest
point, the very centre, to be no greater than 3-4mm. For the
Criteriums, say .6mm+1.25MM = 1.85mm? For the Contis, it should be
about 1.5mm+ I don't know, 2.5mm, to account for the fact that you got
about twice the mileage from them. As you can see, this explains why
the Contis are so relatively slow. But note that the thickness of Conti
tread rubber drops off very fast as you go away from the centre, unlike
Avocets. Is most of your riding in a straight line?

>I've
> had a flat or two with Continentals over about 20 thousand km, but the
> incidence rate is about five times less than with Avocets. It could be
> just terrible luck, but it really smells like something statistically
> significant.
>
> I guess this is when somebody will jump up yelling that flats are all
> about rider skill.

Well, at the centre, by my guesstimate they are about twice as thick as
the Avocet Criteriums. However, the sidewalls are much more exposed. If
you rode gravelly trails and dirt roads with the Contis, you might not
have quite the same luck. The Avocets seem to be designed to mimic the
old Clement tubulars, the ones designed for the old unpaved, twisty
roads of the Giro and the Tour and the Vuelta.

The Criterium is not the ideal Avocet tire. I think the Road, the Duro,
and the Duro Plus are where the series really shines.
±

 

[Antti Salonen]

41 <[email protected]> wrote:

> According to Conti and Avocet spec, in Kevlar bead for both, the
> GP4-season in 23 is 220g, the Avocet Criterium is 200g. The Criterium
> with wire bead is 235g.
>
> Were these the blackwall made in Korea Criteriums, or the tanwall made
> in Japan ones? And what year of production?

They were actually both about 220 g - I'm actually one of those sad
types who weigh bike parts. The Avocet model was Criterium SL (kevlar
bead), black side wall, bought last year from Harris Cyclery.

> But note that the thickness of Conti
> tread rubber drops off very fast as you go away from the centre, unlike
> Avocets. Is most of your riding in a straight line?

I guess it is, but whose really isn't? I've done my riding in the Alpine
passes, and even there you're within a few degrees from vertical 99 % of
the time.

> Well, at the centre, by my guesstimate they are about twice as thick as
> the Avocet Criteriums. However, the sidewalls are much more exposed. If
> you rode gravelly trails and dirt roads with the Contis, you might not
> have quite the same luck. The Avocets seem to be designed to mimic the
> old Clement tubulars, the ones designed for the old unpaved, twisty
> roads of the Giro and the Tour and the Vuelta.

That is why I think the GP 4-Season and also the Ultra GatorSkin are
both very good tyres for dirt roads or otherwise adverse conditions.
They have what Continental calls "Duraskin" sidewalls, and I haven't
heard of anybody having problems with them. If you look at the
lightweight 23 mm tyres on the market, I think they are definitely
among the most dependable.

> The Criterium is not the ideal Avocet tire. I think the Road, the Duro,
> and the Duro Plus are where the series really shines.

Could be. I put a pair of Duro K's on my girlfriend's bike, and
they've been fine and reliable. Avocets are nice tyres, if they're
available to you at a reasonable price.

In Europe, if you want a nice smooth tyre with carbon black rubber, for
example Michelin Krylion (previously called Carbon) is a great deal.
According to the rolling resistance tests it's pretty fast, and it has
a reputation of great mileage and reliability. Besides, being less than
25 euros a piece in mail order, what's not to like?

-as

 

[41]

Antti Salonen wrote:
> 41 <[email protected]> wrote:
>
> > According to Conti and Avocet spec, in Kevlar bead for both, the
> > GP4-season in 23 is 220g, the Avocet Criterium is 200g. The Criterium
> > with wire bead is 235g.
> >
> > Were these the blackwall made in Korea Criteriums, or the tanwall made
> > in Japan ones? And what year of production?
>
> They were actually both about 220 g - I'm actually one of those sad
> types who weigh bike parts. The Avocet model was Criterium SL (kevlar
> bead), black side wall, bought last year from Harris Cyclery.

At a guess then, that would mean they rolled off the production line
2-3 years ago. It's interesting that the weight wasn't spec though. I
wonder what the significance is.


> > But note that the thickness of Conti
> > tread rubber drops off very fast as you go away from the centre, unlike
> > Avocets. Is most of your riding in a straight line?
>
> I guess it is, but whose really isn't? I've done my riding in the Alpine
> passes, and even there you're within a few degrees from vertical 99 % of
> the time.

I suppose, unless you are doing much hill climbing while standing. And
hill climbing is where the rear will get the most wear.


> That is why I think the GP 4-Season and also the Ultra GatorSkin are
> both very good tyres for dirt roads or otherwise adverse conditions.
> They have what Continental calls "Duraskin" sidewalls, and I haven't
> heard of anybody having problems with them. If you look at the
> lightweight 23 mm tyres on the market, I think they are definitely
> among the most dependable.

Comparing Conti, Michelin, and Avocet, here you have three different
strategies for sidewall durability:

Conti: 86tpi nylon + an open weave mesh reinforcement, something like
the rip-stops of old rip-stop nylon.
Michelin: 127tpi nylon + an additional bead to bead layer. This doubles
sidewall thickness, and so presumably doubles sidewall toughness and
strength to roughly the equivalent of 63tpi, but increases the
thickness of the under tread layer by only 33%.
Avocet: 127tpi, rayon I believe, with a much more wraparound layer of
thin hard rubber.

Of the three, the Avocet and the Michelin strategies make the most
sense to me, the Conti the least. The old rip-stop nylon was not
particularly effective, and it stopped a rip, instead of preventing its
initiation. The 86tpi + two extra belts under the tread gives great
thickness under the tread, but not as much strength on the sides. So, I
would expect better puncture resistance but less sidewall resistance.

However, Conti is the only one still available in brown sidewalls (at
least some models). A big selling point for me. It seems to me that the
Ultra 2000, with thick carbon rubber and 57tpi sidewalls, is a more
sensible tire than the much more expensive UG or 4-season. However, I
believe they have now discontinued it, of course.


> > The Criterium is not the ideal Avocet tire. I think the R oad, the Duro,
> > and the Duro Plus are where the series really shines.
>
> Could be. I put a pair of Duro K's on my girlfriend's bike, and
> they've been fine and reliable. Avocets are nice tyres, if they're
> available to you at a reasonable price.

The total thickness under tread of the Duro would be roughly 1.15+1.75
=2.9mm, whereas the Criterium would be 1.85mm as previously calculated.
That's close to 60% thicker.


> In Europe, if you want a nice smooth tyre with carbon black rubber, for
> example Michelin Krylion (previously called Carbon) is a great deal.
> According to the rolling resistance tests it's pretty fast, and it has
> a reputation of great mileage an d reliability. Besides, being less than
> 25 euros a piece in mail order, what's not to like?

....how about being $50 apiece mail order in the US? I see sometimes
they are on sale for about $30. They seem good tires but I don't like
the colours (where is my tan or brown?), and then again they only go up
to 25c. I would also rather have the rubber wrap higher up the
sidewalls.

Have you tried Michelin Dynamic? If they had 66tpi casings instead of
33 they'd be close to ideal. But probably even at 33, no one is able to
tell the difference. Too bad they never test them in the mags, they
being too cheap.