Continental GP4000S 700x28cc side slashers
#1
Full Member
Thread Starter
Continental GP4000S 700x28cc side slashers
This is the second time it happens to me this season.
I go for a ride, has to ride on the shoulder of the road on heavy traffic roads for couple of kms with some gravel rocks on the shoulder and the first time my front tire was slashed on the side of the rolling band. Didn’t notice it and the tire blew out when I pumped it to 110 PSI and saw that after I inspected the tire.
now it happened Sunday on the road my rear tire blew out and had to repair it and squeeze a Lezyne boot temporarily to get back home.
never ever had that problem with 25cc and I have been riding those for decades.
is it the 28cc that makes the lateral part of the tire prone to that?
I go for a ride, has to ride on the shoulder of the road on heavy traffic roads for couple of kms with some gravel rocks on the shoulder and the first time my front tire was slashed on the side of the rolling band. Didn’t notice it and the tire blew out when I pumped it to 110 PSI and saw that after I inspected the tire.
now it happened Sunday on the road my rear tire blew out and had to repair it and squeeze a Lezyne boot temporarily to get back home.
never ever had that problem with 25cc and I have been riding those for decades.
is it the 28cc that makes the lateral part of the tire prone to that?
#2
Senior Member
Join Date: Jan 2010
Location: TC, MN
Posts: 39,520
Bikes: R3 Disc, Haanjo
Mentioned: 354 Post(s)
Tagged: 1 Thread(s)
Quoted: 20810 Post(s)
Liked 9,456 Times
in
4,672 Posts
Sounds like you were lucky in the past - GP4Ks have a long history of sidewall slashes.
Likes For WhyFi:
#3
Senior Member
28C 110 lbs? What do you weight? It is the supple sidewalls that make these great riding tires.
Likes For popeye:
#4
Senior Member
Join Date: Feb 2017
Location: Hollister, CA (not the surf town)
Posts: 1,737
Bikes: 2019 Specialized Roubaix Comp Di2, 2009 Roubaix, early 90's Giant Iguana
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 642 Post(s)
Liked 1,524 Times
in
550 Posts
I gave up on the GP4000's for that very reason. Had several sidewall flats and one blowout (lost all pressure in about 2 seconds) from hitting small rocks and general roadside debris. I am trying a GP5000 on my new bike rear and so far so good but only have about 500 miles on it.
Why are you running 110PSI? Unless you are a really big guy, that is way too high.
Why are you running 110PSI? Unless you are a really big guy, that is way too high.
Likes For Elvo:
#6
Asleep at the bars
Join Date: May 2006
Location: San Francisco, CA and Treasure Island, FL
Posts: 1,743
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 234 Post(s)
Liked 203 Times
in
135 Posts
Definitely not a gravel tire. I do occasionally ride dirt shortcuts or short byways for the scenery, but if it gets rocky I step off and walk it. Fortunately in my case rocks are easily spotted well in advance, and typically easily avoided. But if there's no getting around... I'll walk a few paces. But even then I understand doing this will likely shorten their life span. (This is GP5k though, but I rode 4000s before, and 3000s before that, and they're all the same deal.)
#7
Senior Member
Join Date: Feb 2018
Posts: 1,410
Bikes: 2017 Specialized Allez Sprint Comp
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 850 Post(s)
Liked 344 Times
in
247 Posts
It’s worth noting that higher pressure tires will cut more easily than lower pressure tires.
If you weigh 160-180lbs, try going way, way, way down. Like 75psi. See what happens.
If you weigh 160-180lbs, try going way, way, way down. Like 75psi. See what happens.
Likes For Tacoenthusiast:
#9
well hello there
Join Date: May 2005
Location: Point Loma, CA
Posts: 15,430
Bikes: Bill Holland (Road-Ti), Fuji Roubaix Pro (back-up), Bike Friday (folder), Co-Motion (tandem) & Trek 750 (hybrid)
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 503 Post(s)
Liked 336 Times
in
206 Posts
I stopped buying them for this reason too.
__________________
.
.
Two wheels good. Four wheels bad.
.
.
Two wheels good. Four wheels bad.
#10
Dont fix whats not broken
Join Date: Sep 2019
Location: Mooresville, NC
Posts: 302
Bikes: Steelman Stage Race, Dura-Ace 9s
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 95 Post(s)
Liked 166 Times
in
93 Posts
I have these in 25mm, I am far heavier than you and keep pressures in the 90's, I've ridden them as low as 80-85 with no issues. Mine are fairly new, but no sidewall issues yet, and I have been checking them pretty regularly.
#11
Not actually Tmonk
Join Date: Jun 2007
Location: San Diego, CA
Posts: 14,114
Bikes: road, track, mtb
Mentioned: 140 Post(s)
Tagged: 0 Thread(s)
Quoted: 2627 Post(s)
Liked 3,144 Times
in
1,654 Posts
I've had sidewall slashes on a few GP4k's. In all other regards they're a decent tire so I'll buy them and risk it if they're heavily discounted. But otherwise no.
__________________
"Your beauty is an aeroplane;
so high, my heart cannot bear the strain." -A.C. Jobim, Triste
"Your beauty is an aeroplane;
so high, my heart cannot bear the strain." -A.C. Jobim, Triste
Likes For TMonk:
#12
Senior Member
And I’m 200 pounds and am riding these tires in 23mm width at 80-85 psi with no issues.
Likes For MSchott:
#13
Senior Member
Join Date: Oct 2014
Location: Portland, OR
Posts: 12,902
Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder
Mentioned: 129 Post(s)
Tagged: 0 Thread(s)
Quoted: 4802 Post(s)
Liked 3,922 Times
in
2,551 Posts
I ride Vittoria Corsa G+, 25s @ 102psi, 28s @ 92psi. I don't ride gravel anymore (too rough on my too-many-times scrambled brain and when I knew I was going to be riding gravel, switched wheels and tires but if the pavement ends, it would never occur ot me to walk. I have cut the G+ tires, but not often enough to address as a worry.
I'm not a good judge of Continental tires. Other than the ice tires I love (for one weekend a year here in Oregon) I have had nothing but poor experiences on Contis.
Ben
I'm not a good judge of Continental tires. Other than the ice tires I love (for one weekend a year here in Oregon) I have had nothing but poor experiences on Contis.
Ben
#14
Senior Member
#15
Full Member
Thread Starter
I had a snakebite pinch flat once at the end of last season hitting a pothole with my 28cc at 90psi in my rear wheel.
thats the only reason I run them at 110 now,
I’m 170 pounds off racing, 145 pound while racing
thats the only reason I run them at 110 now,
I’m 170 pounds off racing, 145 pound while racing
#16
Senior Member
Join Date: Feb 2018
Posts: 1,410
Bikes: 2017 Specialized Allez Sprint Comp
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 850 Post(s)
Liked 344 Times
in
247 Posts
I weigh 145lbs at my heaviest and I ran 45-50psi in my 28mm tires, with tubes. I can probably count on one hand how many times I’ve pinched. And some of those were totally brutal hits.
I’m not gonna command you to run lower pressures because everyone is allowed to have their own opinions and you’re not hurting anyone but yourself.
However, you’re not the only person to ever encounter a pothole and perhaps you should consider why the rest of us don’t just run the max pressure all the time.
Likes For smashndash:
Likes For Leinster:
#18
Full Member
Thread Starter
You may as well switch to solid rubber tires with that logic. The tires exist to deform to the road. You should go TL if you are that afraid of pinch flats.
I weigh 145lbs at my heaviest and I ran 45-50psi in my 28mm tires, with tubes. I can probably count on one hand how many times I’ve pinched. And some of those were totally brutal hits.
I’m not gonna command you to run lower pressures because everyone is allowed to have their own opinions and you’re not hurting anyone but yourself.
However, you’re not the only person to ever encounter a pothole and perhaps you should consider why the rest of us don’t just run the max pressure all the time.
I weigh 145lbs at my heaviest and I ran 45-50psi in my 28mm tires, with tubes. I can probably count on one hand how many times I’ve pinched. And some of those were totally brutal hits.
I’m not gonna command you to run lower pressures because everyone is allowed to have their own opinions and you’re not hurting anyone but yourself.
However, you’re not the only person to ever encounter a pothole and perhaps you should consider why the rest of us don’t just run the max pressure all the time.
I give more weight to that than personal opinions or internet experts.
#19
Senior Member
Join Date: Jan 2010
Location: TC, MN
Posts: 39,520
Bikes: R3 Disc, Haanjo
Mentioned: 354 Post(s)
Tagged: 1 Thread(s)
Quoted: 20810 Post(s)
Liked 9,456 Times
in
4,672 Posts
#20
Senior Member
Join Date: Nov 2019
Posts: 701
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 347 Post(s)
Liked 418 Times
in
250 Posts
Not going to enter the tire psi debate but riding where the road derbies have accumulated only leads to tears and heartache.
Not only is it strewn with trash and debris but gravel can hide sharp road edges or shallow depressions filled with sand and gravel. Drivers treat objects in the gutter of the road, including cyclists and pedestrians, with complete disregard as if they are blind to this part of the road. It’s better to ride out to the left just a bit away from the debris, ideally a few inches to the right of the fog line, even on a very busy road so you have some visibility and don’t risk damaging your tires or sliding out into the road because a gravel patch takes out your front wheel.
If there is no way to avoid riding in the gutter then switch a tire that can take this kind of abuse like Gatorskins, and save the lightweight tires for race day or events.
Not only is it strewn with trash and debris but gravel can hide sharp road edges or shallow depressions filled with sand and gravel. Drivers treat objects in the gutter of the road, including cyclists and pedestrians, with complete disregard as if they are blind to this part of the road. It’s better to ride out to the left just a bit away from the debris, ideally a few inches to the right of the fog line, even on a very busy road so you have some visibility and don’t risk damaging your tires or sliding out into the road because a gravel patch takes out your front wheel.
If there is no way to avoid riding in the gutter then switch a tire that can take this kind of abuse like Gatorskins, and save the lightweight tires for race day or events.
Likes For billridesbikes:
#21
Full Member
Thread Starter
“
Tyre pressure and rolling resistance
“It is true that the higher the inflation pressure, the lower the rolling resistance of the tyre,” Schwalbe UK’s Dave Taylor says. “It’s also worth pointing out that a tyre’s susceptibility to punctures is lower with high pressures, too. And if the inflation pressure is continuously too low, premature tyre wear is the result, which usually means cracking of the sidewall and unnecessarily high abrasion.””
#22
Full Member
Thread Starter
Not going to enter the tire psi debate but riding where the road derbies have accumulated only leads to tears and heartache.
Not only is it strewn with trash and debris but gravel can hide sharp road edges or shallow depressions filled with sand and gravel. Drivers treat objects in the gutter of the road, including cyclists and pedestrians, with complete disregard as if they are blind to this part of the road. It’s better to ride out to the left just a bit away from the debris, ideally a few inches to the right of the fog line, even on a very busy road so you have some visibility and don’t risk damaging your tires or sliding out into the road because a gravel patch takes out your front wheel.
If there is no way to avoid riding in the gutter then switch a tire that can take this kind of abuse like Gatorskins, and save the lightweight tires for race day or events.
Not only is it strewn with trash and debris but gravel can hide sharp road edges or shallow depressions filled with sand and gravel. Drivers treat objects in the gutter of the road, including cyclists and pedestrians, with complete disregard as if they are blind to this part of the road. It’s better to ride out to the left just a bit away from the debris, ideally a few inches to the right of the fog line, even on a very busy road so you have some visibility and don’t risk damaging your tires or sliding out into the road because a gravel patch takes out your front wheel.
If there is no way to avoid riding in the gutter then switch a tire that can take this kind of abuse like Gatorskins, and save the lightweight tires for race day or events.
it’s not even a debate
#23
Senior Member
Join Date: Feb 2018
Posts: 1,410
Bikes: 2017 Specialized Allez Sprint Comp
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 850 Post(s)
Liked 344 Times
in
247 Posts
“
Tyre pressure and rolling resistance
“It is true that the higher the inflation pressure, the lower the rolling resistance of the tyre,” Schwalbe UK’s Dave Taylor says. “It’s also worth pointing out that a tyre’s susceptibility to punctures is lower with high pressures, too. And if the inflation pressure is continuously too low, premature tyre wear is the result, which usually means cracking of the sidewall and unnecessarily high abrasion.””Your excessive sidewall cuts are a) to be expected from the gp 4k but also b) to be expected from a tire run at excessive pressure.
https://www.cxmagazine.com/gravel-ti...all-protection
#24
Full Member
Thread Starter
Again, you should ask yourself why we don’t ride on solid rubber or rubber coated steel tires. A steel tire would easily record fewer losses than even a TT tire pumped up to 150 psi. But we don’t use them.
Your excessive sidewall cuts are a) to be expected from the gp 4k but also b) to be expected from a tire run at excessive pressure.
https://www.cxmagazine.com/gravel-ti...all-protection
Your excessive sidewall cuts are a) to be expected from the gp 4k but also b) to be expected from a tire run at excessive pressure.
https://www.cxmagazine.com/gravel-ti...all-protection
as stated in your article
““lower pressures expose more sidewall to cuts. Trends towards wider rims are exposing more tire sidewalls to rocks too, sometimes before the sideknobs would hit. This is a big reason why our gravel tires either have sidewall protection via EXO inserts or bead-to-bead protection via our Silkshield breaker.”
Brown did add that “[l]ower pressures may [also] bottom out on the rim, pinch flatting the tube or tire casing, but higher pressures do not add protection against cuts. Lower pressures will, however, expose more of the sidewall to gravel by flattening out the tread,” before making sure to note that Maxxis’ “Mud Wrestler CX tire also has EXO sidewalls since you never know what you’ll run into in a deep enough mud-hole.” Interesting, and a good note of caution.”
#25
Full Member
Thread Starter
Again, you should ask yourself why we don’t ride on solid rubber or rubber coated steel tires. A steel tire would easily record fewer losses than even a TT tire pumped up to 150 psi. But we don’t use them.
Your excessive sidewall cuts are a) to be expected from the gp 4k but also b) to be expected from a tire run at excessive pressure.
https://www.cxmagazine.com/gravel-ti...all-protection
Your excessive sidewall cuts are a) to be expected from the gp 4k but also b) to be expected from a tire run at excessive pressure.
https://www.cxmagazine.com/gravel-ti...all-protection
same reason they use carbon frames, the stiffest for the weight, even if they are not the most durable or stiff.
some people would prefer riding stainless steel frames with steel wheels at 15kph and never change parts.
come people would prefer riding carbon frames with rubber inflated tires and change tires during the season.