Mixing tyres

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ROBRIENMIKE
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Joined: 29 Sep 2009, 3:44pm

Mixing tyres

Postby ROBRIENMIKE » 7 Feb 2016, 8:10pm

I need to replace a front Gatorskin ( many battle scars + wear etc) immediately on my winter bike. Yet another puncture yesterday convinced me, ( I do check our tyres after every ride). The only new tyre I have immediately to hand Is a 700 x23 Marathon. The rear tyre is a fairly recent 700x23 Gatorskin in good shape.
Now, I know that it is dangerous to mix up car tyres ( radials & cross ply = deadly, and, the mixing of some radials is not recommended). So, what about on a bicycle??? Any thoughts?
My wife's Audax bike has X32 Marathons fore & aft ( mainly because I maintain it)....I have never educated her about rolling resistance, but, I have often thought of putting on a x27 Gatorskin to ease her journey.
Years ago we put on what we could get, but, then we knew no better being guided by economics rather that H&S.
Mike.

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Vantage
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Re: Mixing tyres

Postby Vantage » 7 Feb 2016, 8:16pm

It won't make the slightest bit of difference in safety terms.
Different front and rear tyres are often fitted due to the different forces they are expected to deal with. The rear mostly needs traction for pushing the bike along and the front needs it for steering which require different tread patterns. Having said that, tread in itself is pointless on most road bikes as we pretty much never reach speeds were aquaplaning is likely to occur.
Mix and match to your hearts content :)
Bill


“Ride as much or as little, or as long or as short as you feel. But ride.” ~ Eddy Merckx
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Heltor Chasca
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Re: Mixing tyres

Postby Heltor Chasca » 7 Feb 2016, 8:37pm

This is interesting. My daughter's BMX was factory fitted with a 2.0" front tyre and a 1.95" rear tyre. Any BMX bandits out there know why? I'm sorry if this is a thread hijack...b

Stevek76
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Re: Mixing tyres

Postby Stevek76 » 7 Feb 2016, 11:49pm

Can you even get cross plys for modern cars? :?

Regardless, the main issue with cars is mixing across the axle, this is because if you're using tyres with different levels of grip one side is going to go before the other and the resultant additional rotational force can make handling more... interesting. With higher spec cars now with per wheel traction control etc it likely only means you'll be limited to the worst tyre of the pair.

Front/back differences will have an impact on car handling but not really a dangerous one (no more so than getting in another car anyway) and possibly an intentional/desirable one.

And the same applies to bikes really. It's only a front/rear thing so all you'll be doing is shifting the balance of the grip and whether the front or the rear gives out first when pushed to the limit. On a road bike you're generally in trouble if you've reached that point anyway.

Different front and rear tyres are quite common in mtb due to the reasons Vantage notes as well as many people preferring the back to give up before the front in terms of lateral grip (easier to control). Some models actually have specific front and rear versions.

Brucey
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Re: Mixing tyres

Postby Brucey » 8 Feb 2016, 11:42am

there is only one condition which would commonly render an unmatched pair of tyres dangerous on a bicycle and that is if the front grip becomes a lot less than the rear grip. Provided you avoid this situation you should be OK. The problem is that this is dependant on the road conditions as well as the tyres.

If you do have poor grip all round you may well feel it before it causes any trouble. But if the front has poor grip and the rear doesn't, you may suddenly lose the front of the bike worse than you might otherwise.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Vorpal
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Re: Mixing tyres

Postby Vorpal » 8 Feb 2016, 12:26pm

ROBRIENMIKE wrote:I need to replace a front Gatorskin ( many battle scars + wear etc) immediately on my winter bike. Yet another puncture yesterday convinced me, ( I do check our tyres after every ride). The only new tyre I have immediately to hand Is a 700 x23 Marathon. The rear tyre is a fairly recent 700x23 Gatorskin in good shape.
Now, I know that it is dangerous to mix up car tyres ( radials & cross ply = deadly, and, the mixing of some radials is not recommended). So, what about on a bicycle??? Any thoughts?
My wife's Audax bike has X32 Marathons fore & aft ( mainly because I maintain it)....I have never educated her about rolling resistance, but, I have often thought of putting on a x27 Gatorskin to ease her journey.
Years ago we put on what we could get, but, then we knew no better being guided by economics rather that H&S.
Mike.

I've mixed tyres, no problems. Like Brucey implied, I would put the tyre with the best grip (probably the Gatorskin) on the front.
I'm not familiar with Gatorskins, but I use Marathons on our tandem, and I don't think that the traction is as good on them as on many other tyres.
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom

Smiles
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Re: Mixing tyres

Postby Smiles » 8 Feb 2016, 2:31pm

Brucey wrote:there is only one condition which would commonly render an unmatched pair of tyres dangerous on a bicycle and that is if the front grip becomes a lot less than the rear grip. Provided you avoid this situation you should be OK. The problem is that this is dependant on the road conditions as well as the tyres.

If you do have poor grip all round you may well feel it before it causes any trouble. But if the front has poor grip and the rear doesn't, you may suddenly lose the front of the bike worse than you might otherwise.

cheers


On my journey to try an prevent punctures I went though a stage where I fitted Marathon Plus tyres front and rear to my bicycle. My personal experience (I have the scars to prove it) is that the hard compound, together with a stiff sidewall gave very poor grip particularly in wet conditions, particularly poorly surfaced tarmac. To the OP I would follow Brucey and other posters advice and swop the Marathon to the back.

One question; I am not expert but I did not think Schwalbe made a 700 X 23 Marathon?

Smiles

ROBRIENMIKE
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Joined: 29 Sep 2009, 3:44pm

Re: Mixing tyres

Postby ROBRIENMIKE » 14 Feb 2016, 9:48am

Well folks, if you are still out there, I had to do it or take out a summer machine without mudguards for a start. The 700x23 Marathon is on the front ( yes they have existed since marathons first appeared).
To date, I have completed approx. 170 miles mainly over wet mucky country lanes and last Thursday, with slush and even remnants of ice about. No problems so far. There was the pschycological one of " this bike ain't moving so well, it must be tyre drag," but I soon forgot that. The other problem is, that with mudguards with small clearance, a tyre with a tread like a Marathon picks up mud etc and deposits a certain amount under the guard causing annoying rubbing sounds.
I know plenty of people Audaxing on 700 X 25 Marathons with no grip problems.

Thanks for all the advice,

Mike