Equinox

My bike only has clearance for 23mm tires. I recently crashed when I hit a patch of gravel, and I've been wondering if, say, 25mm. tires would have made any difference.

aclinjury

nope.
knobby mtb tires might have saved you if you were doing slow enough, otherwise, nope!

canklecat

Nothing helps much if we hit a patch of debris on a curve. But, yeah, wider and softer tires can help.

A couple of years ago I nearly lost it on an unmarked but freshly repaved intersection. The road crew left some loose gravel and sprayed black sealant over the whole mess so it was invisible. I was on my hybrid with 700x38 tires, taking the familiar (too familiar, in retrospect) curve at 15 mph or faster. Rear wheel fishtailed side to side but I managed to stay upright. Warped the rim, probably because the spokes were loose -- old bike. But I managed to straighten it enough to limp to the LBS where they fixed it properly.

On my road bikes, that would have been a sure wipe out and a painful one.

Occasionally some local casual group rides venture onto the unpaved part of the MUP. It's what they call "chat" or mostly hard packed pea sized gravel, sometimes a little bigger and rougher. That part of the trail used to be an easement solely for use by the water/flood control folks, and they still use it for that purpose. Sometimes their vehicles chew up the unpaved trails, especially in wet weather, leaving potholes. They usually just throw some loose sand and pea gravel over it. That'll cause some definite whoopsie! moments when you hit some unexpected soft stuff with skinny tires.

I found switching from 700x23 to 700x25 tires, run a bit softer, helped a lot. Some folks don't even bother with a proper gravel bike on those gravel trails and seem perfectly happy with it.

But nothing beats knowing what to expect. Or, in my case, I always anticipate the worst and assume there's invisible loose debris on every curve, and that the entire gravel trail is filled with booby traps disguised as "repairs."

WhyFi

On gravel? No, you're not going to feel much of a difference. Even 30mm tires still get too squirrely for me on gravel that's not hard-packed. Just try to keep it directional and speed changes smooth.

Equinox

This is eerily similar to the road I crashed on. The descent got me up to 30mph. The pile of gravel that I hit was not as visible as the one in this image. I heard the gravel under my front tire. I felt the bike become unstable, and the next thing I knew, I was picking myself up off the ground. I'm having a hard time coming to terms with it. I was fortunate my injuries were only full body road rash. It could have been much worse.

MinnMan

No, at 30 mph, 25 mm tires would not have made a dime of difference. Sagan-esque bike handling skills? Yeah, probably that.

Many times you can stay upright through a patch of gravel, even at high speed, if you are going arrow-straight. If not, good luck.

MinnMan

BTW, I highly doubt that your bike can't manage 25 mm tires. You might have to adjust the brakes, but I don't know of any road bike that can't accommodate 25 mm tires. Not that it would make much difference in this case....

Equinox

I know, It sounds unlikely. My bike was made to order from measurements an a questionnaire. (Not exactly custom-made). There is 2mm clearance between my tire and the seat tube. It's crazy. I tried to put a 25mm. tire on it and my wheel wouldn't turn because the tire is up against my frame

Equinox

That's one of the things that's bothering me. I "thought" I was going straight. But as I reflect, there may have been the slightest bend to the right. I MAY have been leaning ever so SLIGHTLY. I would have definitely avoided the gravel if I had seen it no matter what.

big john

I have a bike that will not fit 25s, 23 is a tight squeeze.

Zaskar

Yes. Not nope. With the wider tire, you'll have a bigger contact patch. A bigger contact patch is better. But, going from 23s to 25s or 28s is such a small jump, the likelihood of that being the deciding factor is staying up or looking like Sagan, is low... really low.

Hopefully, this doesn't turn into a brake debate, but this is where good hydraulic brakes really shine - the ability to modulate and turn an understeer into an oversteer (much easier to recover from) is so much better than rim brakes. But, there's still that Sagan factor - even if you had 40s and hydraulic brakes, would you be able to recover from that unexpected sand, gravel, rut, etc. It's not (always) about the bike.

Seattle Forrest

Wider tires would have helped some. Enough? Maybe, depends on a lot of things including how much wider. 25 mm isn't much difference. 32 mm with correspondingly lower pressure would have made it a little easier to stay upright but still no guarantee.

Glad you weren't hurt worse.

Seattle Forrest

I've had bikes that cleared 23s but wouldn't clear 25s.

Equinox

LOL. I don't see how this would possibly turn into a brake debate since braking was not a factor in this incident in any way, shape or form.

Equinox

Thanks!

datlas 

Agree wider tires would not have made a difference. I advise you be extra cautious if you are descending and don't have good sight lines on unfamiliar roads. Better to get there a couple seconds later than be surprised about an off-camber turn or surprise gravel etc.

Equinox

Excellent advise. Thanks!

rumrunn6

sorry 'bout your crash

fwiw - speed over gravel is fun on 2.25" 29er tires ...

Zaskar

Typically, when you encounter sand, gravel, deep(ish) water, etc unexpectedly, there's a lot of weigh transfer to the front end as you quickly slow down - from hitting that sand/gravel. The front tire will push. That's hard to recover from. If you can shift your weight back, apply a lot of rear break - even inducing a skid, you can sometimes get the front tire out of that push. It's just easier with hydraulic brakes - that whole modulation thing.

LesterOfPuppets

Don't turn, don't lean. Get out of the saddle and skootch your butt back a bit. Try to let the bike float over the gravel, don't try to correct your course too much if a rock or some soft sand kicks your front wheel off line a bit.

CliffordK

If one is going straight, one should be able to hold the bike up with some gravel. Corners are a different beast. Regulate speed ahead of time if possible.

I have found some moderate traction differences with different tires. But, primarily on wet surfaces, not gravel surfaces. Nonetheless, tires like the Schwalbe Marathon Plus have a soft rubber that give them better grip than say the Gator Hardshells. I'm not sure about other tire models, brands, and tread patterns. I've got some 28? micro-knobbies on my Bike Friday at the moment and they did OK on about 20 miles of gravel in mid September, although not at breakneck speeds.

Note, some bikes will have different tire clearances in the front and rear, so a 25mm may fit in the front but not the rear. There is no reason for the tires to be exactly the same.

Also, note that not all tires are the same, so one brand of 25mm may be significantly larger or smaller than another brand.

Zaskar

^That^

I should've noted, my comments were really for if ^that^ doesn't do it and the front tire is already pushing.

Equinox

You're correct about what happened. But, personally, I did not have time to react or respond in any way. I couldn't brake, let alone determine which brake to use. I couldn't shift my weight. I think that when my front wheel hit the gravel, three things happened. It decelerated, it lost traction, and it shifted position.These things happened in a very short time frame. When the front tire emerged from the gravel patch (which wasn't very big) it suddenly re-gained traction, but it was no longer lined up with the rear wheel. I think I lost it when the bike tried to re-align itself.

Zaskar

I've been racing BMX, MTB and gravel bikes decades... and I would've likely gone down too. When you feel it before you see it... recovery is highly unlikely. As @LesterOfPuppets said - when you see it, shift, float, don't turn. If the front pushes, use that back brake to correct the push. But again... when it happens unexpectedly, we tend to go down fast and hard.

Hope you didn't get too banged up.

Equinox

Although I hope it never happens to you, your words are re-assuring. This was my first crash in 17 years of road riding. My friends told me that their experience with the typpe of riding you do is a HUGE advantage when they are on their road bikes.
As far as my injuries, they were extensive and painful, but not severe. The ER-doctor kept saying, "So, you were in a motorcycle accident?" She couldn't believe you could get that messed up on a bicycle. Everywhere she looked, there was more road rash. I got stitches in my head and my elbow. Helmet was cracked. No concussion. HUGE Hematoma on my hip. And yet, I feel fortunate it wasn't worse.