Road bike tyre clearances - Please help

Van Nick

Hi everyone,

I currently ride a 1980's Peugeot road bike, running 1.25" tyres with probably about 1" clearance beteen tyres and frame and it's the only road bike I've ever owned or ridden.

The time has now come to replace this bike with a new road bike and after researching the various models on offer, I'm finding it a bit of a culture shock to be suddenly looking at bikes that have been designed for 23mm tyres, with just a few mm of clearance between tyres and frame / chainstays / forks etc.

The main bike that I have been considering is the Enigma Eclipse and I understand that this offers approx 6mm of clearance in conjunction with 25mm (25C) tyres.

My main worries are as follows

What happens of the wheel should come out of true by a few millimetres or flex (as I've heard they do) or if the tyre should be slightly over inflated ? Surely under these circumstances, the tyre is likely to rub against the frame.

Secondly, I'm a bit worried about the stability, durability and safety of 25mm tyres and ideally, I'd like the option (even if I don't use it) for the road bike to take a 28mm tyre, especially if I ever need the flexibility to use the bike on a slightly rougher surface.

I'm sure that if I once bought a new road bike, I'd wonder why I ever worried about these things, but I'm really hung up about it at the moment and it's stopping me from making a purchase.

I've decided that I definitely want to go for titanium, as I intend to keep the bike for many years and I'm sure I'd be disappointed if I didn't have a road bike.

I'd be very grateful for any advice that anyone could please give me.

Bronzie

23c tyres suit the majority of road riders. They do not rub the frame unless your wheel is miles out of true, What aspect of riding them worries you?

If you really want to stick with wider section tyres, look for audax specific geometry (ie frames that are designed to accomodate mudguards / wider tyres).

redddraggon

Van Nick wrote:

What happens of the wheel should come out of true by a few millimetres or flex (as I've heard they do) or if the tyre should be slightly over inflated ? Surely under these circumstances, the tyre is likely to rub against the frame.

I broke a spoke on a "low spoke count wheel" yesterday, I was still able to cycle 3 miles with a slightly wobbly wheel to my sisters to await a lift home. This was on a frame with very tight clearances and the wheel kept on turning.

I wouldn't be worried about the tyres or frame causing a problem - it would be crappy wheels causing the problem. It's not a common problem so don't worry.

And anyway if the wheel is going to flex/go out of true your rims will be rubbing on the brakes long before the tyres touch the frame.

Van Nick wrote:

Secondly, I'm a bit worried about the stability, durability and safety of 25mm tyres and ideally, I'd like the option (even if I don't use it) for the road bike to take a 28mm tyre, especially if I ever need the flexibility to use the bike on a slightly rougher surface.

25mm tyres are fat...most road bikes get along fine with far narrower tyres. Personally I think 25mm are about the best size tyre for a road - comfier than 23mm and still with plenty of speed.

simon_e

The height of a 25mm tyre is barely more than 23mm. 23, 25 and 28mm should all feel fine on most road bikes. Sizes vary slightly between brands and method of construction will have a greater effect on feel than a couple of mm width. Check with the manufacturer/importer/dealer, if they are any good they should be able to allay your fears. Perhaps a test ride is in order, a reviewer's opinion is not gospel and you might find you prefer something else or the feel is not how you'd hoped.

If a wheel is out of true it will rub your brakes a long time before it gets anywhere near the frame. You won't want to ride it far like that. Overinflating the tyre? Use one with a gauge. High pressures cause more vibration/bump transmission than skinnier tyres, it's why I usually run about 70-80psi for general riding and only increase it for time trials.

A thought: if you want to fit mudguards (well, you did say you want to keep it for a long time) you might want something with more space betwixt tyre and frame.

Van Nick

Thanks Simon for a very balanced, well-informed and dare I say reassuring contribution.

I'm sure that one day, I will be a fully fledged "roadie" and wonder why I ever worried about these things.