Wheel and Tyre Sizes...a question

[Paulq]

I have a hybrid with 700 x 35c Schwalbe Marathon Plus tyres on. I want to swap these for some Conti Ultra Gator Skins sized 700 x 28c to make it roll a little quicker.

Will my wheels take these smaller width tyres (28c)?

Thanks

 

[gaz]

Depends on the interior width of the rim wall.
Which rims have you got?

A safe rule is
19mm = no less than 28

17mm = no less than 25

15mm = no less than 23

13mm = no less than 18

 

[Andy_R]

Sheldon of the Beard also has a handy little chart here Beardy Link about 3/4 down the page.

 

[Paulq]

Depends on the interior width of the rim wall.
Which rims have you got?

Hmmm. How can I find out what they are on my bike?

 

[gaz]

Has your rims got stickers on? Should say what it is.
Did you buy your bike new? If so, what bike did you get and what year.

 

[cyco2]

Hmmm. How can I find out what they are on my bike?

Sometimes in life you really need to have a little think about how things are done and provided you cannot harm yourself or others you should have a go.

So. have a look at your wheel and have a go at thinking the problem through and see what solution you can come up with. Discuss this with your peers to develop the technique and then go ahead and do it.

Amaze yourself !!!!!!

 

[Paulq]

Sometimes in life you really need to have a little think about how things are done and provided you cannot harm yourself or others you should have a go.

So. have a look at your wheel and have a go at thinking the problem through and see what solution you can come up with. Discuss this with your peers to develop the technique and then go ahead and do it.

Amaze yourself !!!!!!

Thanks for the mini lecture but the my thinking is that this is a 'help' forum. By definition this is where people ask questions about stuff they don't know and they get 'help' from people who do. That's how knowledge gets shared is it not?

The bike I am referring to doesn't give me any indication as to the rim width/depth or I wouldn't have posted the question. The reason I did is that I need to know how to figure it out.

Once I do then I will.

 

[Angelfishsolo]

Sometimes in life you really need to have a little think about how things are done and provided you cannot harm yourself or others you should have a go.

So. have a look at your wheel and have a go at thinking the problem through and see what solution you can come up with. Discuss this with your peers to develop the technique and then go ahead and do it.

Amaze yourself !!!!!!

How is the OP to know if what he wanted to do won't cause harm without asking?

 

[LosingFocus]

Sometimes in life you really need to have a little think about how things are done and provided you cannot harm yourself or others you should have a go.

So. have a look at your wheel and have a go at thinking the problem through and see what solution you can come up with. Discuss this with your peers to develop the technique and then go ahead and do it.

Amaze yourself !!!!!!

Time of the month, dear?

 

[gaz]

The bike I am referring to doesn't give me any indication as to the rim width/depth or I wouldn't have posted the question. The reason I did is that I need to know how to figure it out.

Most won't show the rim width, just ignore that other guy.
The easiest thing to do is find out what brand rim you have and look online. Sometimes you can't find out online, in which case you need to take the tyre and inner tube of the wheel and measure the internal gap between the rim edges. Use the measurements i posted above to work out what safe minimum width tyre you can put on.

 

[Angelfishsolo]

Most won't show the rim width, just ignore that other guy.
The easiest thing to do is find out what brand rim you have and look online. Sometimes you can't find out online, in which case you need to take the tyre and inner tube of the wheel and measure the internal gap between the rim edges. Use the measurements i posted above to work out what safe minimum width tyre you can put on.

 

[John the Monkey]

FWIW, I went from 32c Vredestein Perfect Max to 42c Continental City Contacts.

The difference in average speeds between the two was non-existent. (There was a substantial increase in comfort, mind).

I'd be surprised if 28s weren't ok, if the bike was supplied with 35s. Key is to check the rim width though, to know for sure.

 

[John the Monkey]

How is the OP to know if what he wanted to do won't cause harm without asking?

He has to fit the tyres, and if he doesn't die horribly horribly, or wreck his wheels, it was ok.

 

[Angelfishsolo]

He has to fit the tyres, and if he doesn't die horribly horribly, or wreck his wheels, it was ok.

Gotcha. So silly of me not to realise that

 

[MacB]

It is confusing because there are still so many descriptors for tyres and rims around and they jump between metric and imperial. There is a standard called ERTO and that is always in the format xx-xxx or xxx-xx, where the xx is the width of tyre or internal rim width and xxx is the diameter, both numbers are always in mm.

So a road rim 700c would typically be 622-13 up to 622-15, an in betweenie would be 622-17, touring/general 622-19 and heavy touring/serious off road are wider.

There are claims around the ideal size of tyre being at a ratio of about 1.8, so take the rim width internal and multiply that by 1.8 to get the ideal tyre width. There are further recommendations that indicate the ratio can fall in the range 1.4 to 2.2 so for a 622-19 rim that would be:-

1.4 x 19 = 27mm
2.2 x 19 = 42mm

You can go above and below these limits, going lower is generally thought of as worse than going bigger. In actual fact you'll see many manufacturers indulging in ratios up to x3 or greater.

That said if you're running M+ at 700x35 you would see a marked improvement in speed, comfort and weight by running a Marathon Supreme, or similar, in sizes from 700x32 up to 700x42. The differences between your desired 700x28 and a lighter, faster rolling, larger tyre like the M Supreme would be minimal and the bigger tyre would probably be comfier.