Tyre on the wrong way round

[puffin]

I've just realised, after cycling quite a while, that my front wheel is on the wrong way round (the quick release is on the right so the tyre is rotating against the directional arrow). Does anyone know what effect (if any) this would have had on the bike? The tyre is a Marathon Plus.

[Jdsk]

I don't.

With some tyres the suggested direction of rotation is the same at front and rear. That might be appropriate for displacing water. But one is driving and the other is being driven...

Jonathan

[thirdcrank]

As you seem to have inadvertently discovered, the tyre going round the wrong way isn't a big deal on a typical road tyre.

AIUI, where something might go wrong is with the wheel bearings. A lot of bike threads are LH or RH to prevent their being affected by rotation. On bike wheel axles it's normal for the RH cone to be extra tight to prevent this. If your front wheel is the wrong way round, that may defeat the intention. I don't claim to be an expert on this and although the same applies at the rear, different arrangements have assumed the wheel will be turned round. eg double fixed or fixed/free. (Flip-flop in the modern lingo?)

[Tompsk]

IIRC (for car tyres) directional tyres optimise the grip for braking performance, so will be the 'same' front and back. This may make a difference in wet or loose conditions more than on dry tarmac. On dry tarmac the best grip is with no tread, i.e. slick tyres. The directional tread patterns I have seen on bicycle tyres always seem to 'point forwards' when viewed at the top of the wheel, if correctly mounted.

[Jdsk]

IIRC (for car tyres) directional tyres optimise the grip for braking performance, so will be the 'same' front and back. This may make a difference in wet or loose conditions more than on dry tarmac. On dry tarmac the best grip is with no tread, i.e. slick tyres. The directional tread patterns I have seen on bicycle tyres always seem to 'point forwards' when viewed at the top of the wheel, if correctly mounted.

For car tyres for high performance use some manufacturers recommend a single direction of rotation, others varying according to whether they're driving or driven.

Jonathan

PS: And some are L-R asymmetric. This just looks wrong.

[simonhill]

Many (most? some? all?) bike tyres have a tread that haves a variety of V shapes, or the unconnected arms of a V. When the correct way round, they have the sides of the V sloping backwards and out. Maybe this is to help displace water or mud, etc. The other way round and they would tend to trap it or direct it to the centre of the tyre. Olf road mud type tyres will have different requirements and tread patterns.

Even my virtually slick Supremes have grooves cut in them running backwards from centre to edge. Water displacement - decoration?

[thirdcrank]

IIRC, it was only the building of motorways which led to the introduction of tread depth regulations for motor vehicles (1968?) I think the likelihood of somebody aquaplaning on a pedal cycle is slim.

[Marcus Aurelius]

The tyre is constructed with a carcass and a tread ( unless it’s a single layer vulcanised rubber type )The tread is layed down in a given direction at the factory. This gives a slightly ‘elongated pear shaped’ profile in the glue used. In order for the tyre to roll with the ideal resistance, you need it to be rolling from tail to head on each rotation. In reality it’s worth diddly squat, but manufacturers have to endeavour to match their quoted figures. The figures match better if they tell you which way the tread was layed down, hence the directional arrows on some tyres.

[Stevek76]

IIRC, it was only the building of motorways which led to the introduction of tread depth regulations for motor vehicles (1968?) I think the likelihood of somebody aquaplaning on a pedal cycle is slim.

I can't recall the required speed off the top of my head but it's something daft beyond 70mph.

Directionality is far more relevant for MTB tyres where knobs are often ramped on the front end to aid rolling but not on the back to help digging in when braking

[Syd]

A general calculation online says that the speed, in knots, where a bike can aquaplane is given by 9 X the square root of the tyre pressure (in psi).

So a road tyre @ 100 PSI would be 90 knots, or 103.57 mph.

[eileithyia]

I wouldn't worry about it, oh so many ride with their tyres on the 'wrong' way around. When i started cycling there was no such thing. Tyres are designed like that these days to aid water dispersal... but it's no big deal.

[RickH]

The only time you really should worry if your wheel is on the wrong way round is if you are running disc brakes!

[puffin]

As you seem to have inadvertently discovered, the tyre going round the wrong way isn't a big deal on a typical road tyre.

AIUI, where something might go wrong is with the wheel bearings. A lot of bike threads are LH or RH to prevent their being affected by rotation. On bike wheel axles it's normal for the RH cone to be extra tight to prevent this. If your front wheel is the wrong way round, that may defeat the intention. I don't claim to be an expert on this and although the same applies at the rear, different arrangements have assumed the wheel will be turned round. eg double fixed or fixed/free. (Flip-flop in the modern lingo?)

Its the wheel that's the wrong way round....and after 10 days the wheel came loose, first time ever. That explains a lot.

[kylecycler]

I had Continental Double Fighter tyres a few years ago and you were supposed to fit the front tyre one way - the way that offered less rolling resistance - and the rear wheel the other way, for traction. The arrows on the sidewalls told you that - like, 'F' with the arrow pointing one way, and 'R' with the arrow pointing the other. That's as far as I can recall, anyway, it was a while ago. I often thought fairly few riders would have noticed or even bothered.

[eileithyia]

The only time you really should worry if your wheel is on the wrong way round is if you are running disc brakes!