Riding a road bike on gravel.

Beating the system - the cycling commuting section

Riding a road bike on gravel.

Postby Spork! » Sat Apr 17, 2010 2:32 pm

Hi commuting forum. :D
Hoping to join your ranks again soon. Have commuted by bike before, when I had no license or no car (don't ask - we were all young and silly once...) but this time I want to commute by bike for mostly fitness reasons. Have an old steel framed roadie, Shogun brand bike that I plan to use. I plan to take a shortcut along a gravel path for part of the trip. It is not just a shortcut, it also helps me to use some backroads instead of main roads for a fair chunk of the trip. This section is about 500m long, and cuts approx 2-3k's off the trip, however the gravel is quite coarse, and in parts the rough bedrock is exposed. My bike has 700c rims with 28mm 120psi (max) tires fitted. I have ridden this path a few times, very slowly (10 kph or less) and so far so good...
I have a few questions.
How likely is it that I will get a puncture from it?
Would riding a little faster (maybe 20kph) increase the puncture risk much?
Would tire pressure changes make much difference to the chance of a puncture?
On the rougher sections I stand up, but don't lean forwards, to distribute weight over both tires, instead of remaining seated which I'd presume would put most my weight on the rear tire. Does this make sense, or is my logic flawed?
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by BNA » Sat Apr 17, 2010 3:02 pm

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Re: Riding a road bike on gravel.

Postby SeanB » Sat Apr 17, 2010 3:02 pm

I'm no expert but watching the Paris-Roubaix the other night encouraged me to take a less fearful approach to some rougher patches that I ride along.

In my case it was over a short 'cobblestone' section - the modern kind they use to slow some traffic down (i think that's why they do it).

Anyway, a bit faster seemed to be an improvement to me. Similar thing with a very uneven wooden plank bridge i cross.
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Re: Riding a road bike on gravel.

Postby jules21 » Sat Apr 17, 2010 3:38 pm

my theory is that bikes are made to be ridden. go for it. it's one reason i don't go for top of the range equipment (that is not intended to incite an equipment flame war!).
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Re: Riding a road bike on gravel.

Postby Spork! » Sat Apr 17, 2010 3:52 pm

I agree, esp. 20 YO steel roadies put to use as commuters.
Maybe I should just practice tube replacement, so if the wort happens I won't be (too) late for work.
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Re: Riding a road bike on gravel.

Postby Baldy » Sat Apr 17, 2010 5:41 pm

Yeah I ride gravel roads and paths on the roadie all the time. 23/25mm tires front/rear and have no problems. Obviously the weakest link is cornering closely followed by lack of braking power. Try doing both at the same time and your asking for trouble.

I say go for it 8)
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Re: Riding a road bike on gravel.

Postby Aushiker » Sat Apr 17, 2010 9:42 pm

Hi

You might want to consider dropping your tyre pressure a bit. Say if you are currently running around 110 PSI being it down to around 90 to 95.

On my recent road tour where we did a fair bit of rough dirt roads even with the 38 mm Schwalbe Marathon Cross HS 334 tyres dropping the pressure around 25 psi made quite a difference to the performance on the gravel.

Only one us got a single puncture over the 1000 odd kilometres.

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Andrew
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Re: Riding a road bike on gravel.

Postby trailgumby » Sat Apr 17, 2010 10:31 pm

Why is there a stocking over your head in your new avatar photo?

Are you planning on paying your local bike hating Councillor a visit? :lol:
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Re: Riding a road bike on gravel.

Postby Baalzamon » Sat Apr 17, 2010 11:28 pm

trailgumby wrote:Why is there a stocking over your head in your new avatar photo?

Are you planning on paying your local bike hating Councillor a visit? :lol:


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Re: Riding a road bike on gravel.

Postby silkishuge » Sun Apr 18, 2010 12:30 am

I once had a commute which required me to take 7km on unsealed roads. Road was covered in concrete aggregate and it did increase my risk of puncture. I had to limit my speed not because I was afraid of punctures but because it was slippery. Turning in loose gravel can be tricky. My advice is to take it really easy on the turns. I would turn at about 5 to 10km/h depending on the road condition but could travel 40 to 50km/h on the straights. I would also recommend not riding out of the saddle up a hill. Keep as much weight on the rear wheel for traction.

Welcome back to riding.

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Re: Riding a road bike on gravel.

Postby rustychisel » Mon Apr 26, 2010 2:20 pm

silkishuge wrote:I once had a commute which required me to take 7km on unsealed roads. Road was covered in concrete aggregate and it did increase my risk of puncture. I had to limit my speed not because I was afraid of punctures but because it was slippery. Turning in loose gravel can be tricky. My advice is to take it really easy on the turns. I would turn at about 5 to 10km/h depending on the road condition but could travel 40 to 50km/h on the straights. I would also recommend not riding out of the saddle up a hill. Keep as much weight on the rear wheel for traction.

Welcome back to riding.

J


[above] this is the word.

I've done a bit of this, recently a randonnee on canal paths and goat tracks in southern France, riding a race bike with GP4000s. Not a problem...
The front wheel will have tendency to dig in to loose surfaces, especially with narrower tyres, so unweight the front of the bike by trying to sit a bit further back and a bit more upright. Steering is a particular issue; it's best to have a loose grip on the bars and allow the bike to find it's natural path through looses stuff, and there is no way to steer accurately through tight corners and the like other than slow down - a lot. Keep the bike as upright as possible, using your body mass as a balance point and to effect turns rather than leaning the bike into turns.
A loose grip on the bars also means when the bike kicks or rears (on the edge of a concealed pothole, for example) you can allow it to absorb the shock rather than act as a rigid member transmitting the shock up through your arms. To the same end, let your legs do the most work they can, they're the best shock absorbers in the entire (bike + rider) system. Sit in the saddle but be poised and able to move yourself up and down off the saddle as required, sometimes only a few millimetres. It doesn't matter if the bike jumps around a bit, that's much much better than having it try to plough through all obstacles with those relatively light tyres. Incidentally, they won't puncture unless you ram a hard edge (pinch flat) or get unlucky with a sharp edge (like a bunch of crushed flints).
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Re: Riding a road bike on gravel.

Postby hartleymartin » Thu Apr 29, 2010 12:19 am

You could just use wider tyres at lower pressure. I ran 32mm tyres at 60psi quite a bit. So many other cyclists with their 23mm 110psi tyres were slowing down to try to avoid dirt and gravel, whilst I just rolled straight over everything else. Come to think of it, they also slowed/stopped when they came to water/mud, whilst I just ploughed straight through it (mudguards are wonderful - all bikes should come with them).

That looks more like it:

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:lol:
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Re: Riding a road bike on gravel.

Postby cp123 » Thu Apr 29, 2010 10:46 am

My driveway is blue metal and about 60 m long.

I rode for many years to horse agistment morning and night, and riding in and out each time was over gravel. I don't think i ever got a flat in that spot at all. But i have good tyres on my bike for that reason.
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Re: Riding a road bike on gravel.

Postby rustychisel » Thu Apr 29, 2010 11:14 am

hartleymartin wrote:You could just use wider tyres at lower pressure. I ran 32mm tyres at 60psi quite a bit... blah blah


Your point is correct and valid but having read the original post I found the questions were of risk assessment and technique. Did you read the original post?
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Re: Riding a road bike on gravel.

Postby mikedufty » Thu Apr 29, 2010 1:53 pm

I used to ride on gravel quite a bit on 27x1 and 1/8 tyres before I had a mountain bike, including a 500metre section of my daily commute. Never had any issues, didn't slow down or use any special technique. Standing up and going as fast as possible seemed to give the most pleasant ride on the rough bits. Soft surfaces like sand or deep pea gravel are not a lot of fun, but gravel roads shouldn't be a problem. I'd think punctures would only be a problem from pinch flats on sharp edges if you let the tyre pressures get really low (eg 40psi ).
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Re: Riding a road bike on gravel.

Postby Spork! » Thu Apr 29, 2010 5:24 pm

Thanks everyone. The path is dead straight, the only steering is to dodge the odd puddle, and bigger rocks, including 2 boulders at the end to prevent motorbikes or cars from using it. I have 28mm tires. Guess I should just ride it and enjoy, and leave the worrying for when I get to work.
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Re: Riding a road bike on gravel.

Postby mianos » Thu Apr 29, 2010 6:21 pm

Do a web search 'cyclocross' or 'cyclocross technique' . That's the sport of riding a roady on dirt and mud at speed.
If I had the room I'd have a dedicated cyclocross bike as I'd be scared to smash my 7K roady.
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Re: Riding a road bike on gravel.

Postby trailgumby » Thu Apr 29, 2010 8:10 pm

Cyclocross is hilarious to watch, especially when it's wet. Just think Road Bike Steeplechase. :lol:
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Re: Riding a road bike on gravel.

Postby Mustang » Thu Apr 29, 2010 8:41 pm

Same as motor bike riding, KEEP YOUR HEAD UP & dont look dowwn!!! :roll:
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Re: Riding a road bike on gravel.

Postby Nobody » Thu Apr 29, 2010 11:10 pm

rustychisel wrote:
hartleymartin wrote:You could just use wider tyres at lower pressure. I ran 32mm tyres at 60psi quite a bit... blah blah


Your point is correct and valid but having read the original post I found the questions were of risk assessment and technique. Did you read the original post?
If you reread the original post, you should find the following question:
Spork! wrote:Would tire pressure changes make much difference to the chance of a puncture?
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