Latex tubes and Cross clinchers?

[45K10]

So cross season is on the horizon, and I was wondering if anyone has any experience using latex tubes with cross clinchers:
Do they make a noticeable difference?
Can you run lower pressures than with butyl tubes?
Which sealant if any do you use in the latex inner tubes? How much sealant?

[JStonebarger]

Latex tubes make all the difference in 'cross. Even on the road at higher pressures latex offers much lower rolling resistence. At low pressures, though, the extra stretchiness of latex makes pinch flats much less likely.

At 175lbs I'll run 22-26 psi on most 'cross courses without any great risk of flatting. I've run the front as low as 18 psi, but then had trouble with the tire folding in turns. Still, not many of the tubular fans I race against run lower psi...

[witcombusa]

[QUOTE=JStonebarger;1597992]Latex tubes make all the difference in 'cross. Even on the road at higher pressures latex offers much lower rolling resistence. At low pressures, though, the extra stretchiness of latex makes pinch flats much less likely.

QUOTE]


Can't prove it by me. The ONLY differences I've observed about latex tubes over lightweight butyl tubes is that they need air constantly and they cost more. No difference out on the road.

Spend your money as you like.

[Lewis Moon]

[QUOTE=JStonebarger;1597992]Latex tubes make all the difference in 'cross. Even on the road at higher pressures latex offers much lower rolling resistence. At low pressures, though, the extra stretchiness of latex makes pinch flats much less likely.

QUOTE]


Can't prove it by me. The ONLY differences I've observed about latex tubes over lightweight butyl tubes is that they need air constantly and they cost more. No difference out on the road.

Spend your money as you like.

Yepper. Bubblegum pink placebo.

[redir]

[QUOTE=JStonebarger;1597992]Latex tubes make all the difference in 'cross. Even on the road at higher pressures latex offers much lower rolling resistence. At low pressures, though, the extra stretchiness of latex makes pinch flats much less likely.

QUOTE]


Can't prove it by me. The ONLY differences I've observed about latex tubes over lightweight butyl tubes is that they need air constantly and they cost more. No difference out on the road.

Spend your money as you like.

I've notices that too, no difference. I can't notice a difference in tubular tires between latex and butyl except that the more expensive and nicer tubular tires tend to have latex so it can give the impression that the tube makes a difference when it's really just the over all quality of the tire.

There is a reasonable argument behind the flat prevention hypothesis but I'm not sure I buy that one either. And as far as I remmeber it was not pinch flat prevention but other puncture type flats.

[JStonebarger]

No, pinch flats as well. Jobst Brandt wrote about this ages ago: "Because latex rubber of tubes commonly used in better tubular tires is several times more stretchable than common butyl rubber, such tubulars are less susceptible to snakebites. When sheet rubber is compressed, it stretches laterally like a drum skin, and the farther it can stretch the less likely it is to tear."

Of course, that same elasticity makes latex less likely to puncture as well.

As for the rolling resistance, I won't try to convince anyone. If you think a less supple tube (or tire, for that matter) will somehow roll easier or grip better, you're on your own.

[45K10]

Latex tubes make all the difference in 'cross. Even on the road at higher pressures latex offers much lower rolling resistence. At low pressures, though, the extra stretchiness of latex makes pinch flats much less likely.

At 175lbs I'll run 22-26 psi on most 'cross courses without any great risk of flatting. I've run the front as low as 18 psi, but then had trouble with the tire folding in turns. Still, not many of the tubular fans I race against run lower psi...

Cool, my main objective is to be able to run lower pressures. The minimum I can get away with on butyl tubes is around 32 PSI. I give them a try.

Thanks for the input!

[palincss]

Latex tubes make all the difference in 'cross. Even on the road at higher pressures latex offers much lower rolling resistence. At low pressures, though, the extra stretchiness of latex makes pinch flats much less likely.


Can you cite any research measuring rolling resistance comparing latex with butyl tubes? The only research I'm aware of found latex had a higher rolling resistance than butyl.

[Lovetoclimb]

So cross season is on the horizon, and I was wondering if anyone has any experience using latex tubes with cross clinchers:
Do they make a noticeable difference?
Can you run lower pressures than with butyl tubes?
Which sealant if any do you use in the latex inner tubes? How much sealant?

Had bad experiences with latex tubes. For the difference they supposedly make I was rolling challenge clinchers in turns anywhere near 30psi, so the benefits of the tubes never came into play. And flatting an $8-10+ inner tube stings worse than something half the cost. Of course this was cat racing so perhaps my skill set was not up to par for nicer equipment but I found a decent pair of tubulars took me much further with a lot less worry about mechanicals.

[zachateseveryth]

Can you cite any research measuring rolling resistance comparing latex with butyl tubes? The only research I'm aware of found latex had a higher rolling resistance than butyl.

Look on the slowtwitch forums. Latex tubes have been repeatedly measured to provide lower rolling resistance than butyl. They save about 5 watts per pair of tubes.

http://forum.slowtwitch.com/cgi-bin/gforum.cgi?post=4412943

and here's some more info (look towards the end for tube stuff):

http://www.biketechreview.com/tires_old/images/AFM_tire_testing_rev9.pdf

[djg21]

Its anecdotal, but I've used them exclusively on the road, and i have had far fewer flats. They also feel plusher than butyl tubes (at same pressure), and i can run a slightly lower pressure. I prefer the Vittoria tubes because they have removable valve cores, which work with the valve extenders I prefer on my aero wheels.

I pump up tires before evet ride anyway, so that has never been an issue.

[JStonebarger]

Had bad experiences with latex tubes. For the difference they supposedly make I was rolling challenge clinchers in turns anywhere near 30psi, so the benefits of the tubes never came into play. And flatting an $8-10+ inner tube stings worse than something half the cost. Of course this was cat racing so perhaps my skill set was not up to par for nicer equipment but I found a decent pair of tubulars took me much further with a lot less worry about mechanicals.

Wow. I dunno. I use several treads of Challenge clinchers and have only rolled one in a crash. And I'm talking low to mid 20s psi.

Meanwhile, I see more tubulars rolled than flat clinchers...

[JStonebarger]

Can you cite any research measuring rolling resistance comparing latex with butyl tubes? The only research I'm aware of found latex had a higher rolling resistance than butyl.

Zachateseveryth beat me to it.

What have you seen showing lower crr with butyl?

[JStonebarger]

By the way, if it helps anyone justify the (comparatively) high cost of latex tubes...

I used cheap butyl tubes for many years, but rarely patched a flat. With a tube costing $3-5 why bother? (No, I'm not proud of that attitude.) With latex tubes... at $15 or so each... I save and patch them regularly. I've never done the math, but I suspect that in the long run I might actually be saving money.

[oldpotatoe]

Wow. I dunno. I use several treads of Challenge clinchers and have only rolled one in a crash. And I'm talking low to mid 20s psi.

Meanwhile, I see more tubulars rolled than flat clinchers...

Yep, crappy wrenching is crappy wrenching regardless of discipline.

[biker72]

[QUOTE=JStonebarger;1597992]Latex tubes make all the difference in 'cross. Even on the road at higher pressures latex offers much lower rolling resistence. At low pressures, though, the extra stretchiness of latex makes pinch flats much less likely.

QUOTE]


Can't prove it by me. The ONLY differences I've observed about latex tubes over lightweight butyl tubes is that they need air constantly and they cost more. No difference out on the road.

Spend your money as you like.

I put latex tubes in the same class as ceramic bearings. Great marketing but not much else. Throw tubeless road tires in there too.

[Hls2k6]

Not pointing any fingers, but one can disagree about an inane topic like this without feeling the need to insult other people. It's especially annoying when someone is calling others ignorant or accusing them of wasting their money while citing nothing but their personal observation. This ain't a relgious debate, folks.

Now that I've noted their worthlessness, here is my personal observation: I love latex tubes with cotton tires. The performance is as good or better than anything else I've tried and the comfort is absolutely better. The cost is higher and they wear out faster, but I'm willing to pay those prices.

According to Josh Poertner, long-time technical director at Zipp and current owner of Silca:

"Yes, latex is probably the best bang for the buck upgrade you can ever make to any of your bikes. They are definitely more labor intensive to install than butyl, and you have to pump them up every day...but you can save 3-5 watts per wheel(!) compared to butyl. At the moment, tubeless is getting better, but still nobody has a tubeless system as efficient as a high quality standard tire with latex inner tube.

Putting it in perspective, that $20 latex tube at minimum would be worth maybe 3 watts in a front wheel compared to $1000 for the best ceramic bearings which might get you 0.8-1 watt for a wheelset upgrade."


http://nyvelocity.com/content/interviews/2014/josh-poertner

[JStonebarger]

...This ain't a religious debate, folks...

I'm not entirely sure about that!

[witcombusa]

Not pointing any fingers, but one can disagree about an inane topic like this without feeling the need to insult other people. It's especially annoying when someone is calling others ignorant or accusing them of wasting their money while citing nothing but their personal observation. This ain't a relgious debate, folks.

Now that I've noted their worthlessness, here is my personal observation: I love latex tubes with cotton tires. The performance is as good or better than anything else I've tried and the comfort is absolutely better. The cost is higher and they wear out faster, but I'm willing to pay those prices.

According to Josh Poertner, long-time technical director at Zipp and current owner of Silca:

"Yes, latex is probably the best bang for the buck upgrade you can ever make to any of your bikes. They are definitely more labor intensive to install than butyl, and you have to pump them up every day...but you can save 3-5 watts per wheel(!) compared to butyl. At the moment, tubeless is getting better, but still nobody has a tubeless system as efficient as a high quality standard tire with latex inner tube.

Putting it in perspective, that $20 latex tube at minimum would be worth maybe 3 watts in a front wheel compared to $1000 for the best ceramic bearings which might get you 0.8-1 watt for a wheelset upgrade."


http://nyvelocity.com/content/interviews/2014/josh-poertner

But your's is just a personal observation too :confused:

I couldn't car less what Josh says (that's also a personal observation), If I can't feel the difference then I won't waste MY money on it.

Who would waste their time on a religious debate?

[Hls2k6]

I couldn't car less what Josh says (that's also a personal observation), If I can't feel the difference then I won't waste MY money on it.

You and Alberto, apparently.

http://forum.slowtwitch.com/cgi-bin/gforum.cgi?post=4670632;search_string=;#4670632

And by the way, I'm not suggesting you should. For lots of people, I'd agree they're unquestionably the wrong way to go.

[pakora]

I'm on the pro latex side. I ran clinchers all last season and had two flats: one straight puncture from a sharp rock, and one that was due to rolling the tire skidding sideways down a dip in a 180 degree turn. In that case, I'd been confidently riding at lower than usual (butyl) pressure for me (30 or so, rather than 35-40, depending on the course) and maybe pushed it a little. The tires I was running were also super thin (Vittoria XG non-tubeless) and fit loosely on the rim (Ksyriums).

To compare in the previous season, I had 4 or 5 flats running higher pressures on burlier tires.

I also have run latex tubes in my road bike for years and definitely get less flats, about half as many, but while that's the reason I started, the road feel was totally noticeable. Same tires (Pro4 25s), same bike, lower pressure (80 f/85 r), fewer punctures.

If you're a heavier rider (I'm 220 in kit) I think it's definitely worth it since at cross pressures pinch flats aren't an if but a when.

[pakora]

PS, I had terrible luck with Challenge latex tubes. Uneven thickness, slow leaks impossible to find pumping them way too full and submerged in water that sealant didn't fix either.

Michelins all the way; never flatted one in a cross race. Size matters way less with latex tubes I'm convinced (I ran the ones for 23 road tires in 32 cross tires).

[Pete Mckeon]

:)PS, I had terrible luck with Challenge latex tubes. Uneven thickness, slow leaks impossible to find pumping them way too full and submerged in water that sealant didn't fix either.

Michelins all the way; never flatted one in a cross race. Size matters way less with latex tubes I'm convinced (I ran the ones for 23 road tires in 32 cross tires).

[CunegoFan]

I place latex tubes with super light weight butyl: Not worth the problems for daily use. I believe the data on lower rolling resistance but I cannot feel it, and because of goathead thorns, I usually roll on cheap training rubber anyway. For the bike leg of an IM I use good tires and latex because the combination can have a larger effect than aero wheels.

[45K10]

PS, I had terrible luck with Challenge latex tubes. Uneven thickness, slow leaks impossible to find pumping them way too full and submerged in water that sealant didn't fix either.

Michelins all the way; never flatted one in a cross race. Size matters way less with latex tubes I'm convinced (I ran the ones for 23 road tires in 32 cross tires).

Good deal, I saw that the Challenge tubes had some fairly poor reviews. I'll order some of the Michelins
Thanks

[merckx]

Any other latex tubes in addition to Michelin worth a look?

[Hls2k6]

Vittorias work very well. As someone mentioned, you can remove the valve core, and they make nice extenders of various lengths that let you relocate the valve to accommodate deeper wheels. Also presumably good for adding sealant, although I don't personally do so.

[gospastic]

I use Vredestein in my road tires. They are my favorite.

[FlashUNC]

Probably too much thread drift, but why not use tubulars for cross racing?

[JStonebarger]

Probably too much thread drift, but why not use tubulars for cross racing?

I would if I thought they were worth it. Clinchers are cheaper, and easier to mount, and therefore easier to swap out. Any more I don't see much advantage to tubulars. Personally I'm a big fan of tires specific to the conditions, so my treads get more agressive as the season/weather progresses. With any luck this will be a wet year...

For what it's worth I'm building up my first tubulars in years right now, just because I won some nice file treads tubular tires, and every once in a while I race in icy conditions (think <18 psi...). For the most part, though, I'll stick with clinchers.

By the way, you know what's inside all the best cyclocross tubular tires? Latex tubes!

[biker72]

Bottom line is buy what you want and see if it works for you.
It's your bike, your money and your business.

[zachateseveryth]

I would if I thought they were worth it. Clinchers are cheaper, and easier to mount, and therefore easier to swap out. Any more I don't see much advantage to tubulars. Personally I'm a big fan of tires specific to the conditions, so my treads get more agressive as the season/weather progresses. With any luck this will be a wet year...

For what it's worth I'm building up my first tubulars in years right now, just because I won some nice file treads tubular tires, and every once in a while I race in icy conditions (think <18 psi...). For the most part, though, I'll stick with clinchers.

By the way, you know what's inside all the best cyclocross tubular tires? Latex tubes!

I did everything I could to avoid going to tubulars for CX. I tried a bunch of different tires, I tried a couple ghetto tubeless conversions, I tried some actual tubeless setups. I got picked apart in races.

Last season I made the switch to tubulars. I picked up a ton of grip in the corners. It was night and day, especially in the muddy races. It's worth the hassle, especially since two sets of wheels is also you really need in order to get going with it and it isn't that much of a hassle.

Also, I'm not sure anyone makes a mud clincher that actually works. The Michelin Mud2 is garbage. I get the desire to run file treads in the ice, but you might be better off considering the Dugast Diavolo instead of a filetread if you're going to have one set of tubulars. They're studded so you'll have more grip on ice, and it's an open tread so it'll do the best in mud/snow.

[JStonebarger]

The Diavolo is banned, isn't it? Granted, I don't do UCI races, but I'm not quite ready for monster cross. (To me that's like showing up on a mountain bike: within the rules, maybe, but...) Meanwhile, I don't race on ice too often (think 2012 nats in Madison), but when I do I want as much rubber on the ground as I can get.

This year I plan to run four treads up front (five if you count the file tread) and two or three in the rear. That's more tubular wheels than I care to glue, especially when I factor in my partner's wheels. With clinchers I can swap treads for the coming weekend or even that morning if I need to.

You're right, Michelin Muds are lacking. When I discovered real 'cross clinchers the Muds went on my commuter bike. But there are plenty of good cyclocross clinchers. For mud -- aka real fun -- my favorite is the Limus.

[JStonebarger]

Bottom line is buy what you want and see if it works for you.
It's your bike, your money and your business.

Sorry if the discussion offends, but I learn a lot from threads like this. Besides, all this talk of 'cross has me excited!

[pakora]

This probably applies to very few people, but I gave up on tubulars because of the hassle of gluing, the expense, and I actually had a negative performance gain with them. But I'm very tall on a big bike and weigh a lot (compared to most bike racers), so my interpretation was high center of gravity + deep turns + flexy tires was that I was essentially a huge lever with a lot of leverage that won against course terrain by losing grip :)

Probably I just didn't ride them enough to really get a feel for them, but the low pressure and the super supple and naked casing made it way to easy for me to fold tires and I wiped out more than with clinchers (and finished a race lapped because I partially rolled one).

And why am I going tubeless this year?

(well, that's easy - I'm totally sold from mountain biking, my favorite biking besides cross racing)

Cross racing is silly.

[merckx]

Back to tubes. Does anyone have experience with Panaracer R Air tubes? They seem to be a hybrid of latex and butyl. Maybe they have the suppleness of latex with the durability of butyl? Thoughts?

[lhuerta]

....life is too short to ride butyl !!!

If you can't feel the difference between latex and butyl, then u r doing it ALL wrong....period!

[witcombusa]

....life is too short to ride butyl !!!

If you can't feel the difference between latex and butyl, then u r doing it ALL wrong....period!


You keep telling yourself that...;)

Oh, and it's "got to be 11" shifted electro-mechanically and Carbon is the only frame material too

[holliscx]

Trust me on this don't go there. Ride clinchers w butyl tubes until you can afford tubulars but latex will make you pull your hair out and only cause frustration. Clinchers by nature require more pressure; therefore negate any advantage that latex can provide in theory. But most importantly latex tubes are too fragile for clincher setups. Stay away; I learned the hard way.

[JStonebarger]

Actually, latex is less fragile than butyl: it doesn't tear or puncture as easily. And those 3-5 watts saved compared to butyl? That's at 105-120 psi.

Of course, there is a learning curve...

[45K10]

I did not think this was going to be such polarizing subject when I brought it up. For me it is a $35 experiment. I will put in some latex tubes and use them in my local CX training series in September and see how it goes.

I know tubulars are the way to go but I am just not ready to go there yet. Maybe when I make the switch to discs I'll get a set of tubular wheels.

Thanks for all input everyone!

[zachateseveryth]

The Diavolo is banned, isn't it? Granted, I don't do UCI races, but I'm not quite ready for monster cross. (To me that's like showing up on a mountain bike: within the rules, maybe, but...) Meanwhile, I don't race on ice too often (think 2012 nats in Madison), but when I do I want as much rubber on the ground as I can get.

This year I plan to run four treads up front (five if you count the file tread) and two or three in the rear. That's more tubular wheels than I care to glue, especially when I factor in my partner's wheels. With clinchers I can swap treads for the coming weekend or even that morning if I need to.

You're right, Michelin Muds are lacking. When I discovered real 'cross clinchers the Muds went on my commuter bike. But there are plenty of good cyclocross clinchers. For mud -- aka real fun -- my favorite is the Limus.

Yeah, the Diavolo is illegal in UCI races. for 99% of us that doesn't matter.

I like the tubular version of the Limus. My concern with the clincher would be pressure. I've run the tubular below 20 psi with no issue. You can't do that with any clincher to the best of my knowledge.

[zachateseveryth]

This probably applies to very few people, but I gave up on tubulars because of the hassle of gluing, the expense, and I actually had a negative performance gain with them. But I'm very tall on a big bike and weigh a lot (compared to most bike racers), so my interpretation was high center of gravity + deep turns + flexy tires was that I was essentially a huge lever with a lot of leverage that won against course terrain by losing grip :)

Probably I just didn't ride them enough to really get a feel for them, but the low pressure and the super supple and naked casing made it way to easy for me to fold tires and I wiped out more than with clinchers (and finished a race lapped because I partially rolled one).

And why am I going tubeless this year?

(well, that's easy - I'm totally sold from mountain biking, my favorite biking besides cross racing)

Cross racing is silly.

Good luck with tubeless CX. The tires and rims aren't as developed as for the MTB world. Getting the tires to seal can be just as frustrating as gluing. I also had all kinds of burping issues, even when running the tubeless tires from Vittoria.

In the end I said screw it and decided to just pay the LBS the $50 to glue up some CX tires for me. Best decision I ever made regarding CX. I went from being a backmarker in the B field to being in contention for the 1-2 podium.

[JStonebarger]

I like the tubular version of the Limus. My concern with the clincher would be pressure. I've run the tubular below 20 psi with no issue. You can't do that with any clincher to the best of my knowledge.

Depending on the course I can run 22-24(f-r) without problems, and I'm not small. It does take some getting used to, though -- with latex tubes bottoming out does not mean flatting.

I did run below 20psi once sort of by accident, after letting more air out of the front than intended just before the start. No flat, but the tire did fold a couple times in turns, that was startling. After the race it measured at 17psi.

[BSUdude]

Nothing to add to the OP's question regarding latex tubes for CROSS use. But I have been training and racing on the road exclusively on latex tubes for over 4 years now. I probably have flatted 5 times or less in that period. And I ride between 150-200 mpw, 8 months per year depending on the time of year

If you can't tell a difference between butyl and latex you might be running crap tires or the wrong pressure. If your latex tubes are giving you problems you are probably buying crappy challenge ones. I've been using green bontrager ones and they do the job, have removable valve cores, and behave well even when subjected to multiple tire changes.

The amount of disinformation here is staggering. There are MANY tests that show that latex tubes are faster than butyl, as others have wisely pointed out earlier.

Also I would recommend to the OP to try to get a friend or teammate to let you borrow a set of tubular cross wheels. Put them on your bike. Take a few laps to get your pressure dialed then compare them to your tubed or tubeless wheels. At that point the original question might become moot... :)

[witcombusa]

If you can't tell a difference between butyl and latex you might be running crap tires or the wrong pressure. If your latex tubes are giving you problems you are probably buying crappy challenge ones. I've been using green bontrager ones and they do the job, have removable valve cores, and behave well even when subjected to multiple tire changes.

The amount of disinformation here is staggering. There are MANY tests that show that latex tubes are faster than butyl, as others have wisely pointed out earlier.


Well if you call Open Corsa CX tires crap then yeah I'm sure that's the problem.
btw, is "faster" the criteria here? Cause I don't care if that's the case, one way or the other. I'm talking feel. Tires matter, pressures do too. From what I've tried tubes not so much (well, maybe not thorn-proof!)

And for the last time, tests, I don't care either, we're talking FEEL. Completely subjective and the reason for the different responses.

[Grant McLean]

A nod is as good as a wink to a blind horse.

-g

[potatochip]

Well if you call Open Corsa CX tires crap then yeah I'm sure that's the problem.

btw, is "faster" the criteria here? Cause I don't care if that's the case, one way or the other. I'm talking feel. Tires matter, pressures do too. From what I've tried tubes not so much (well, maybe not thorn-proof!)



And for the last time, tests, I don't care either, we're talking FEEL. Completely subjective and the reason for the different responses.


Who cares about how the tires feel!?

[Pete Mckeon]

Who cares about how the tires feel!?



Seat, wheel, tire pressure and on and on are really not worth it:mad:


Yeah I amold snd slow but recall when a 21mm were the help , ss well as drilled bard:mad:cool::eek:


Life is experience

[lhuerta]

Can't prove it by me. The ONLY differences I've observed about latex tubes over lightweight butyl tubes is that they need air constantly and they cost more. No difference out on the road.

Spend your money as you like.


....life is too short to ride butyl !!!

If you can't feel the difference between latex and butyl, then u r doing it ALL wrong....period!


You keep telling yourself that...;)

Oh, and it's "got to be 11" shifted electro-mechanically and Carbon is the only frame material too

I think your initial comments above reinforce my point that you are doing it ALL wrong….all tires (with butyl or latex tubes) should be pumped up to correct pressure before EVERY ride.

It was at this point where you should have tapped out of this thread.

Well if you call Open Corsa CX tires crap then yeah I'm sure that's the problem.
btw, is "faster" the criteria here? Cause I don't care if that's the case, one way or the other. I'm talking feel. Tires matter, pressures do too. From what I've tried tubes not so much (well, maybe not thorn-proof!)

And for the last time, tests, I don't care either, we're talking FEEL. Completely subjective and the reason for the different responses.

If you are using Corsa CX and latex tubes and still can’t feel the difference, then see my point above….you are still doing it ALL wrong, yet you insist on doubling down….?

There is a reason all the best tubulars use latex tubes and have done so for many decades….latex is more flat resistant and has lower rolling resistance because of its deflection properties, and allows for a more supple feel that translates in to enhanced cornering/traction, and most importantly (to me at least) it allows for greater road feel.

It is not about weight as there are some butyl tubes that are lighter then latex, its about road feel and all the other factors listed above.

Lou

[Grant McLean]

There is a reason all the best tubulars use latex tubes and have done so for many decades…

Lou

To pull a hoax on the internet invented years later? :banana:

-g

[45K10]

Ok Im resurecting this because I have an update.
So 1st training race of the season tonight and the Michilen latex tubes worked great.

I ran 28psi in the front and 30 in the rear over a very bumpy and rough course. People had flats all over the place but I came through okay. Im 180 and have never been able to run below 35 without pinch flatting. Thanks for the tip JStonebarger