Have I just bought the right tyres?

tmcd35

Active Member
Location
Norfolk
Okay, I know I should have asked here before hitting the buy button, but still it'd be nice to know I've got this right.

My hybrid has 622-19 rims with 700x35C Kenda tyres. I've just ordered, from eBay, 700x28C Schwarbe Marathon Plus tyres.

According to a nice chart Sherradons website they should fit fine, can anyone confirm I haven't just bought totally the wrong thing?

Am I right in thinking that thinner tires will be lighter and faster due to less road resistance as there is less rubber making contact with the tarmac?

Cheers.
 

Soltydog

Legendary Member
Location
near Hornsea
The tyres should be fine. I dont think you'll notice much difference in performance TBH. I've changed 2 bikes to M+ tyres & they are a bit heavier than normal tyres, so changed to a narrower tyre may compensate for the weight, but the difference is likely to be minimal, but with M+ you'll spend less time at the side of the road replacing or fixing tubes :girl:
 
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tmcd35

Active Member
Location
Norfolk
Thanks Soltydog - thats pretty much what I thought, just wanted my mind set at ease. Four flats now on the front alone in under a week was enough for me to put my hand in my pocket and get some M+'s.
 

Moodyman

Guru
Four flats now on the front alone in under a week

Front flats are unusual as it normally the rear and four in a week is very odd.

When you removed your tube, were you checking for and removing the offending item from the outside tyre?
 

shippers

Senior Member
Location
Sunny Wakefield
That sounds like crud in the tyre to me too. Got to be worth checking the rim and the rim tape too, just in case.

When you put your new tyres on (assuming the Kednas aren't going back on in the mean time) line the logo up with the valve, that way you can tell where in the tyre the punctures are coming through.
 

Soltydog

Legendary Member
Location
near Hornsea
I had 3 flats in 2 days prior to changing to M+ (no crud in tyre, just glass & flint off cycle tracks, TPT near Hull)
Had only 2 in over 3 years since changing :girl:
 
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tmcd35

Active Member
Location
Norfolk
Thanks guys,

Yes it is very strange! 600+ miles and no flats and then this! I did check the tyre and I couldn't find nought. And the two tubes I've repaired had the hole in pretty much the same place so I'm obviously missing something.

I wanted to change to better tyres at some point anyway - this has just accelerated it. I've bought some new tubes and some new rim tape so hopefully it'll all come together and punctures will be a thing of the past.
 

kettle

Senior Member
Location
Ladybank, Fife
I changed tyres and had all sizes the same as you. All is fine.
 

Globalti

Legendary Member
Sometimes a thorn or shard of glass will retract into the rubber and you won't feel it as you run your fingers round. As suggested you really need to become the forensic detective when repeated punctures keep happening - how about pumping the tyre, immersing the whole wheel rim in water and marking the puncture on the tyre itself for investigation later?

Also did you check for tiny pieces of aluminium swarf around the spoke holes on the rim?
 

ASC1951

Guru
Location
Yorkshire
Globalti said:
As suggested you really need to become the forensic detective when repeated punctures keep happening - how about pumping the tyre, immersing the whole wheel rim in water and marking the puncture on the tyre itself for investigation later?
This is why old cyclists always put their tyres on in precisely the same position relative to the valve hole. TBH it's always struck me as a bit OCD, but then I only get one puncture every 5000 miles or so.

What do you have at home, Globalti, that you can submerge a whole wheel in?
 

Banjo

Fuelled with Jelly Babies
Location
South Wales
The hole wasnt next to the valve was it?

I had a spate of those where the dodgy rimtape was jamming the valve stem in its hole.

The valve stem must be free to move or the tube may be held away from the rim leaving it unsupported next to the valve stem.Worth checking and also that theres nothing sticking through the rim tape anywhere.
 
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tmcd35

Active Member
Location
Norfolk
Well my new tyres haven't yet arrived. I've got a big ride on Sunday so I may just have to get forensic on the pesky front.

On the tubes I've repaired the whole has been in the exact same place. The tyre wasn't taken completely off or moved around the rim so it's likely something nasty may have retracted back into the tyre.

Yes it was near the valve, but it is on the other side of the tube - nearer the main tyre tread rather than near the rim.
 

RedBike

New Member
Location
Beside the road
tmcd35 said:
Okay, I know I should have asked here before hitting the buy button, but still it'd be nice to know I've got this right.

My hybrid has 622-19 rims with 700x35C Kenda tyres. I've just ordered, from eBay, 700x28C Schwarbe Marathon Plus tyres.

According to a nice chart Sherradons website they should fit fine, can anyone confirm I haven't just bought totally the wrong thing?

Am I right in thinking that thinner tires will be lighter and faster due to less road resistance as there is less rubber making contact with the tarmac?

Cheers.
Thinner tyres should be lighter but i'm afraid M+'s weigh a ton.

Rolling resistance is the energy thats lost as the tyre deforms. The more the tyre deforms (the lower the pressure) and the slower the material is to spring back releasing this energy the more energy is lost (and therefore the higher the rolling resistance.)

I'm afraid M+ tyres have quite a hefty puncture protection system. This means the tyres casing isn't as flexible as it could be and therefore the tyres are likely to have a higher rolling resistance than you'd find on a race specific tyre.

Up to a point wider tyres generally deform less (for any given pressure) and therefore irronically can have a lower rolling resistance.

However, as you tend to run narrower tyres at higher pressures than wider tyres you probably wont notice any increase in rolling resistance with a narrower tyre. Factor in the decreased weight and areodynamic drag of a narrower tyre and you should find that generally the narrower the tyre the quicker it is.
 
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