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.

 

[Globalti]

Well thousands of riders ride bikes with that setup and they don't seem to have any problems!

 

[Tim Bennet.]

Don't worry about minimalist tyre clearances as long as it will take the size you want (with any mudguards if that's also what you want). Just make sure the rear is not too much of a fight to get in and out.

I would think that a titanium bike that could take 28c plus guards and a light rack would be an incredibly versatile bike. I'm sure there's a Van Nic Audax bike that does that. Failing that, 25c plus guards would be nearly as versatile.

Certainly don't worry about stability with 25c tyres. I've used Michelin ProRace 2s in that size for everything from winter training, to PBP to Paris Roubaix over the cobbles and they have been perfect. Would I have used 28s if I could have fitted them in the frame? I would certainly have given them a try.

 

[Chris James]

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.

Whilst many titanium bikes are lovely, they are also rather expensive. I have a 1980s steel frame that is still in good nick, and presumably your Peugot is still going. Titanium is not the only material that will last a long time.

 

[Van Nick]

Hi Tim,

Thanks very much for your well informed reply.

I understand that Audax bikes are designed for long distance rides, but I would assume that if it were possible to find an audax bike and a road (race) bike that both weighed the same, but the audax bike could accommodate wider tyres, the road bike with its "tighter geometry" must be quicker or more responsive, otherwise everyone would go for an audax bike.

Maybe I'm missing something.

 

[andrew_s]

I'm like you and prefer to have the wider tyres available, both for use off (surfaced) road, and for comfort and pothole resistance. I can run 28mm at 80psi, but with 23mm I need more like 110psi, as gauged by snakebite resistance. The lower pressure makes a lot of difference to comfort, and on typical British crap roads, the rolling resistance is just as low. Having wider tyres can make a lot of difference to your off-road speed, so on an abandoned and rough road a bike with 44m tyres was about twice as fast as one with 28mm


How big a tyre you can fit is determined by the frame design, and changing the brakes will make no difference whatsoever.

A typical racing frame designed around Campag or standard Shimano brakes will generally take a 23mm tyre, possibly with room for 'guards, or 25mm tyres with no room for 'guards.
An audax frame will often be designed around Shimano deep drop (57mm) brakes, and will normally take 28mm tyres with 'guards, or 32mm without. You do have to watch out though, as some frames described as audax frames use Campage brakes and are limited to 25mm tyres. The best way of checking what the clearances are is to see whether is says 57mm brakes are necessary.

If you want more clearance, there are a number of cyclocross-cum-light touring frames available, like the Airborne Carpe Diem or whatever the Van Nicholas equivalent is (Amazon?). You will need to use cantilever brakes with these. The best are frogleggs, tektro 520/720, or the bling Paul Components version. The brakes work fine, but need more care setting up than dual pivots, and you may have to fiddle with the setup part way through the pad wear rather than just twiddle the adjuster.

 

[Van Nick]

Hi Andrew,

Nice to hear from someone else that shares my view regarding clearance and tyre width.

Thank you very much for your contribution and I will look into the bikes that you mentioned.

Thanks again

 

[Over The Hill]

I bought an all alloy road bike that was on very thin tyres but have put on some thicker rubber (was for the winter but stayed on). I did have problems with the tighness between the front forks. I have about 1mm each side of the tyre and it did rub at the top even without mudguards.
To get over it I fitted a little spacer of about 2mm into the U groove where the front wheel sits to drop it down slightly. It was a bit of aluminium nail glued in with epoxy resin.

So yes it is a problem! I would say go for something with a bit of space in it for your tyre size. After all it is not going to make it more difficult in any way to have the space there. I think the tight space is popular to make the bike look more sporty and professional but in the real world problems arise from this.

 

[Van Nick]

Hi Over The Hill

Thank you for a very sensible and valuable contribution.