Tyre sizes

jozi

Wondering could someone clear this up for me.

Ordered new tyres for a friends bike, giant cypress ladies hybrid, and got them delivered and they dont' fit

The size on the tyres on the bike is 28x1.1/8 and 700x40c as well as 42-622 and the rim has 622x20 on a label

The tyres ordered were 28x1.1/5 and 700x38b Schwalbe Marathon Plus Tyres and they don't fit.

So what size should we be ordering in future or getting these replaced by?

Thanks,
Jozi

papac

Hi.
Seems to me you ordered a 700B when you needed a 700C.

700b is quite rare in this neck of the woods.

Its best to always go with the ISO Standardised designation.(42-622 in your case.) Over the century and a bit that bikes have been around there have been umpteen sizing standards. The iso system clears it all up.

622 is your diameter and 42 is your width. You have leeway on the width-you can go bigger or smaller depending on what you want -but the 622 must be right.

700b is 635 diameter afaik.(I am open to correction).
The vast majority of modern 700 tyres are correct for you.-Bit of bad luck to choose one that isn't.:)

kumate_champ07

the new tires you ordered are compatible as far as I know, you might just be struggling with fitting them. push the tire deep into the rim and work your way around till you get to the last bit that youre having problems fitting, you should have more tire to work with

blorg

kumate_champ07 wrote: »

the new tires you ordered are compatible as far as I know, you might just be struggling with fitting them. push the tire deep into the rim and work your way around till you get to the last bit that youre having problems fitting, you should have more tire to work with

635 tyres are not going safely onto 622 rims.

victorcarrera

papac is correct. The tyres you bought are too big according to this table.
http://www.schwalbetires.com/tech_info/size_markings

You should replace with tyres marked with 700C and or 622

More general info here.
http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3802

kumate_champ07

blorg wrote: »

635 tyres are not going safely onto 622 rims.

no, but I think his new tyres are 622 even tho they contain '28' in the markings

kumate_champ07

jozi wrote: »

they don't fit.

just to clear things up, they are too tight or too loose?

jozi

Thanks for the replies.

I should have mentioned, the tires are way to big for the rims.

Could someone point me in the right direction for a tyre that fits? All I can see is 26 and 29" tyres on the chainreaction site, not sure how I found that 28" tyre. Them only showing imperial sizes doesnt help either.

papac

http://www.chainreactioncycles.com/Models.aspx?ModelID=18837
http://www.chainreactioncycles.com/Models.aspx?ModelID=24544

Two optionns.

700c is what you want.ie marked 700 x XXC

jozi

I never seen the road tyres section! I'll order them right away.

Thanks very much papac :thumb: