Cycling UK Forum

Posted: **21 Sep 2024, 8:29am**

Hi, I'm looking for some advice please. I've have bought new tyres the same size as my old ones (47-622) and they have been delivered yesterday but they look so much wider/chunkier than my old ones. Before I go to the faff of removing the old ones and trying to put the new ones on, are these going to fit? I do have mud guards on my bike so are worried they are going to catch on them. P.s I'm new here so please be nice

Posted: **21 Sep 2024, 8:50am**

Welcome

They might fit, but they might not.

First read the opening two paragraphs of this so that you understand what those measurements mean, and what they don't tell you:
https://sheldonbrown.com/tire-sizing.html

But it's the exterior size that determines whether they'll clear your mudguards/frame/brakes. What make and type are the old and the new? Please add a photo of the old tyre in place on the bike where the clearance is tightest. And a photo of the old and new side by side showing the exterior width and depth.

Jonathan

Posted: **21 Sep 2024, 9:50am**

Hi, thank you for the quick reply. My current tyres are Schwalbe Road cruiser, and the new are Michelin Pro Tek max. I've added photos, hopefully they are of use. Apologies for the filthy bike, my plan was to clean and then replace the tyres.

Posted: **21 Sep 2024, 9:57am**

You can sometimes find exterior width on the manufacturer's website, but I can't for either of those:
https://www.schwalbe.com/en/Road-Cruiser-11101255.01
https://www.michelin.co.uk/bicycle/tyre ... reSize=700

Jonathan

Posted: **21 Sep 2024, 10:11am**

...at this point and looking at the minimumal mudguard clearance on your last photo, I'm not sure the 47 mm (1.75") were supposed to fit anyway.....
All it needs is a firmish piece of mud to be picked up by the tyre, get stuck between the tyre and mudguard and ....if you're lucky you'll just end up with an interesting anecdote...

Posted: **21 Sep 2024, 10:14am**

Personally, I'd consider slackening of the mudguard stays and seeing if you can move the mudguard back away from the tyre, before securing all the bolts again..

...and editing this post, it's possible that the front mudguard has been knocked at some point and might need straightening...

Posted: **21 Sep 2024, 10:17am**

The only other option is a narrower tyre..
Something in the 42 or 38 range (1.5" to 1.25") if you do alot if riding on sealed road surfaces you might find your speed slightly increasing - along any unsealed surfaces might be slightly more bumpy....
Certainly I'd think quite hard about riding that bike with seemingly so little mudguard clearance with the front mudguard....

P.s.. I'd like to generally appulade your choice of bike and its equipment... i' m especially envious of the springy thing between the front forks and the bike frame, which keeps tgd front wheel straight when you park it..

Posted: **21 Sep 2024, 10:46am**

Thank you to both Jdsk and cycle tramp. So the tyres are a definite no go!?

I think I've been lucky if the guards are too close as I've been riding it for a few years with that size on there. Luckily I only ride on roads, for a small commute and a bit of shopping. I do prefer wider tyres as I had 37-622 for a very short period of time but didn't feel quite as sturdy. I think a trip to a bike shop is in order, as this is definitely getting a bit more technical. Thank you for the info about the spring, I didn't even know that's what that was for!

Posted: **21 Sep 2024, 11:56am**

I notice from the photo that your front mudguard appears to be fixed with simple screws near the wheel axle. When you go to the bike shop ask them to check the fixing for safety. The modern standard is to have a small part, usually plastic, that allows the mudguard stay to pull away from the fixing near the axle. That prevents an accident that can happen if something gets stuck between the front tyre and mudguard. A very small gap between the tyre and mudguard makes this more likely to happen.

Posted: **21 Sep 2024, 12:26pm**

cycle tramp wrote: ↑21 Sep 2024, 10:17am The only other option is a narrower tyre..
Something in the 42 or 38 range (1.5" to 1.25") if you do alot if riding on sealed road surfaces you might find your speed slightly increasing - along any unsealed surfaces might be slightly more bumpy....
Certainly I'd think quite hard about riding that bike with seemingly so little mudguard clearance with the front mudguard....

P.s.. I'd like to generally appulade your choice of bike and its equipment... i' m especially envious of the springy thing between the front forks and the bike frame, which keeps tgd front wheel straight when you park it..

I agree with 'cycle tramp', the current tyres look like they're the maximum you can get away with and are probably bigger than the originals the bike came with when new. The front-on photo of the front tyre shows that the width of the mudguard is for a smaller tyre than fitted. Fitting a 35+ to 42 mm wide tyre will improve frame clearance and likely mudguard coverage.
If the mudguards are metal (they look to be painted steel) then there is much less need for a jam release mechanism in the stays. Steel guards don't fold up and jam under the fork crown the same way as plastic ones.

Posted: **21 Sep 2024, 1:19pm**

When assessing clearance, bear in mind that the tolerance on tyre width is ±3mm, and inflation pressure can vary the width by another millimetre or two on top of that.

Posted: **21 Sep 2024, 1:54pm**

Out of curiousity, what's the problem with the existing tyres?

On the photos, they look good for another 5 years or more of the sort of usage you described.

Posted: **21 Sep 2024, 3:25pm**

Thanks for all your help and info everyone. Luckily I can return the tyres.

Posted: **21 Sep 2024, 3:31pm**

andrew_s wrote: ↑21 Sep 2024, 1:54pm Out of curiousity, what's the problem with the existing tyres?

On the photos, they look good for another 5 years or more of the sort of usage you described.

I've had them on the bike, for nearly 4 years, and thought that's was a long time! When the bike was 14 months old I took it for a service and the guy there said that's as the original tyres had "cracked" that they needed replacing, and had these current had started to slightly crack and also had a few holes where stones and glass had stuck in I thought I'd get new for the winter. I'm now putting 2 and 2 together and thinking maybe he was having me on. He was the one who also replaced them with the thinner tyres which I didn't like, as he did have the original tyres size in stock.

Posted: **21 Sep 2024, 3:46pm**

Iykyj wrote: ↑21 Sep 2024, 3:31pm
andrew_s wrote: ↑21 Sep 2024, 1:54pm Out of curiousity, what's the problem with the existing tyres?

On the photos, they look good for another 5 years or more of the sort of usage you described.
I've had them on the bike, for nearly 4 years, and thought that's was a long time! When the bike was 14 months old I took it for a service and the guy there said that's as the original tyres had "cracked" that they needed replacing, and had these current had started to slightly crack and also had a few holes where stones and glass had stuck in I thought I'd get new for the winter. I'm now putting 2 and 2 together and thinking maybe he was having me on. He was the one who also replaced them with the thinner tyres which I didn't like, as he did have the original tyres size in stock.

Well..its kinda difficult for anyone in a bike shop, if they see a fault, but don't mention it, and something bad happen then happens, there's always a(n implied) risk they could be sued. Certainly I've run tyres with cracks in them, for some time, but I've kept an eye on the cracks...
..bike tyres are subject to the same wear or stresses ad car tyres, and I've had one set last longer than 10 years

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