# Wheel and Tyre Sizes...a question



## Paulq (15 Aug 2011)

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


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## gaz (15 Aug 2011)

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


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## Andy_R (15 Aug 2011)

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


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## Paulq (16 Aug 2011)

gaz said:


> 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?


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## gaz (16 Aug 2011)

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.


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## cyco2 (16 Aug 2011)

Paulq said:


> 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 !!!!!!


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## Paulq (16 Aug 2011)

cyco2 said:


> 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.


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## Angelfishsolo (16 Aug 2011)

cyco2 said:


> 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?


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## LosingFocus (16 Aug 2011)

cyco2 said:


> 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?


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## gaz (16 Aug 2011)

Paulq said:


> 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.


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## Angelfishsolo (16 Aug 2011)

gaz said:


> 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.


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## John the Monkey (16 Aug 2011)

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.


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## John the Monkey (16 Aug 2011)

Angelfishsolo said:


> 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.


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## Angelfishsolo (16 Aug 2011)

John the Monkey said:


> 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


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## MacB (16 Aug 2011)

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.


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## John the Monkey (16 Aug 2011)

Angelfishsolo said:


> Gotcha. So silly of me not to realise that



That's how we rolled, pre-internet, baby.


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## Angelfishsolo (16 Aug 2011)

John the Monkey said:


> That's how we rolled, pre-internet, baby.


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## Paulq (16 Aug 2011)

Guys

Thanks for all the help so far I do appreciate it. A little more digging has given me the following descriptor of the rims:

*Araya GP-710, 700C, 32H, black

*That any help for those more clued up than me as to whether I can get 28c tyres on? For info the bike is a Scott Sportster 55 (2011).

Thanks again.

Paul.


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## Paulq (16 Aug 2011)

Thoughts anyone? Would like to order some new tyres tomorrow if poss.

Thanks again.

Paul


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## gaz (16 Aug 2011)

It's an 18mm internal width, no less than 25mm tyres.


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## Angelfishsolo (16 Aug 2011)

I'm going to say 28's should be fine.
EDIT - Cross post with Gaz


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## Paulq (16 Aug 2011)

To both of you that's great I really appreciate it.

Now. Conti Gator Skins or Marathon Supreme?

OK I am pushing my luck now I know...... 

Cheers

Paul


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## Angelfishsolo (16 Aug 2011)

Paulq said:


> To both of you that's great I really appreciate it.
> 
> Now. Conti Gator Skins or Marathon Supreme?
> 
> ...


The Marathon range seem to get the best overall reviews. Gatorskins seem to be Marmite tyres


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## slowmotion (16 Aug 2011)

If you want information about tyre sizes and maximum pressures for those Araya rims, try sending them an email. Here is their website.

http://www.araya-kk.co.jp/rim/

Click the "Contact" thingy.


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## gaz (16 Aug 2011)

slowmotion said:


> If you want information about tyre sizes and maximum pressures for those Araya rims, try sending them an email. Here is their website.
> 
> http://www.araya-kk.co.jp/rim/
> 
> Click the "Contact" thingy.



Or you could just look at the product information on the website, and see what it says. No point waiting.


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## slowmotion (17 Aug 2011)

Gaz, either I missed something, or your Japanese is better than mine


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## John the Monkey (17 Aug 2011)

slowmotion said:


> Gaz, either I missed something, or your Japanese is better than mine



Click "Products" (label is in English), click GP710 (label is in English), read bead seat diameter measurement (which is in european characters, and is 18mm). 

Job done.

28s will be fine. Never ridden Marathons (£32 for one tyre? Chuff me.) Have ridden gators (25mm, wire on) - roll very nicely, but appalling in the wet (too slippy).

Conti City Contact are on my commuter/tourer - 2,500 miles with no unplanned defaltions before a nail went through the back tyre's tread. Cost me £15 for a pair of tyres off eBay.


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## paulmac (17 Aug 2011)

If it helps, my Felt hybrid came with 700 x 37c tyres on as standard. I have just replaced those this weekend just gone with Continental gatorskins 700 x 28c and i love them, bike rolls a lot better and i can go quicker  and there is the bonus of them looking better too  im glad i changed them i had no problems swapping them down to that size and my original tyres was wider than yours.


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## Paulq (19 Aug 2011)

Well I took the plunge and replaced the tyres on the Scott (which were Specialized Infinity and 700 x 38c not 35) with a set of Marathon Plus in 700 x 28c and, whilst I was at it, stuck some Gator Skins on the Sirrus Elite I have as they were pretty shot too. Cost me a bloody fortune but at least I have tyres on that, fingers crossed, I have some confidence in.

I'm commuting in on the Scott 4 days next week and am expecting a much livelier ride from the narrower Marathons so we'll see. They were an absolute bitch to get on though - no problems with the Contis.

If I get a visit from the fairy at any point on the next year I know where you all live


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