# Tyre Size for 700x40c hybrid



## Biggler (15 Jul 2013)

Good afternoon, 

I'm sorry to ask what might seem like a 'newbie' question. 

I've got a Giant Roam 2 2013 with 700X40C tyres, and if it matters Giant CR70 Double Wall aluminium wheels.

I take it '700' refers to the diameter and 40c (4cm?) refers to the tyre width.

How do I know what tyre sizes my bike can take, can it only take 700x40c or can I pick thinner or wider tyres?

Thanks for the help.


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## Nigelnaturist (15 Jul 2013)

You should be able to fit slightly thinner or wider tyres, though I am not sure on sizes.


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## Biggler (15 Jul 2013)

I'll get the manual out or look on the wheels to see if that can shed any light on it. I'm currently in work and fancied window shopping for new tyres, not that I need them... the bike's 2 days old :P


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## MrJamie (15 Jul 2013)

You have to match the 700 (or one of the other terms for the same size! ) and you can vary the width. What kind of width were you thinking of? I have a Roam2 but ive only used 35-42s on it so far, id be confident 30-45 at least though. One major thing IMHO is that tyre width figures don't really mean that much, you can get a much faster rolling wider tyre depending on tread, or a thinner tyre that has better grip offroad. Assuming it came with Kenda Kwicks still, they drag quite a lot on the road and a similar sized slicker tyre is much smoother rolling, but obviously much less able offroad


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## Biggler (15 Jul 2013)

Just about all of my cycling is on road, or cycle path. I've seen (or at least thought i've seen) a rolling difference from a MTB with road tyres and the Giant Roam 2 with stock tyres.

I was wondering if there were slicker/thinner tyres I could get purely for road cycling.


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## mcshroom (15 Jul 2013)

The big thing is how wide the rims are. You should have another number on the rim, something like 700-19c. The last number (19 in this case) is the interior width of the rim. From that you can work out tyre sizes.

I'd guess with 40mm tyres at present, you would probably have 19mm rims (700-19c, though may even be a bit wider), in which case you could go down to about 28mm tyres. Have a look at things like Schwalbe Marathons/Durano, Continental Gatorskins or Bontranger Hardcase to name a few.


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## rovers1875 (15 Jul 2013)

My revolution courier pursuit (hybrid) came with 700 x 42 tyres, They were soon swapped for 700 x 35s and when they recently wore out I have just put on 700 x 32s and can't say there has been any problem at all. Just go for what ever you think.


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## Biggler (16 Jul 2013)

Wheel






Tyre





I cant see anything that looks like 700-19c could it be the 622x19? Nothing about tyre sizes in the manual either.

I was kind of wanting to try the wider road tyres x28's? But I'm kind of weary :P


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## vickster (16 Jul 2013)

How about going to your local bike shop, get their advice and then support their business by buying there  You never know, they may even help you fit the tyres


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## Rickshaw Phil (16 Jul 2013)

Yes, the 622x19 is the wheel size (700c spec wheels are actually 622mm in diameter), which according to this chart means that you are able to fit a 28mm width tyre on to those rims.


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## Rickshaw Phil (16 Jul 2013)

[QUOTE 2550064, member: 259"]It might look a bit strange though? [/quote]No more so than fitting Cityjets on to a mountain bike, which is quite popular.

Oh, I didn't mention - if the OP has a cycle computer fitted, the wheel size will need resetting as it will be overestimating speed and distance with the narrower tyre fitted.


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## Cyclist33 (16 Jul 2013)

Biggler said:


> I'll get the manual out or look on the wheels to see if that can shed any light on it. I'm currently in work and fancied window shopping for new tyres, not that I need them... the bike's 2 days old :P


 
The manual will be useless, Giant like almost all the rest just provide a totally generic "bike manual" with their products, which tells you how to avoid death by putting your feet on the pedals and making a roughly circular motion!


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## Paulus (16 Jul 2013)

vickster said:


> How about going to your local bike shop, get their advice and then support their business by buying there  You never know, they may even help you fit the tyres


That was the reply i was coming in with, I would try a"proper" bike shop for advice, a LBS. as Vickster suggests, not a chain store operation.


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## Biggler (16 Jul 2013)

I would buy my gear from the same guy I bought my bike off (not so local bike shop, but when I popped in he was genuinely nice and helpful), but I don't really want to start asking him about new tyres without the intention of ordering them after his advice. I don't really want to waste his time like that, and I wouldn't blame him if he thought I was going to buy them online if I did do that.

I'd just wanted to know what size tyres my bike could take so I could go window shopping... I tend to do that and I've already started looking for a Garmin, pedals, gloves, n+1......

Thanks for the answers though, it's appreciated..


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## vickster (17 Jul 2013)

Why do you have to buy them online and not from him after getting his advice? You never know he may be willing to adjust his price to be closer to the web


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## Biggler (17 Jul 2013)

I don't have to buy them online, and I definitely *wouldn't* if I took up his time asking for his advice. I may have sounded confusing above, but at the moment I don't have the intention of buying new tyres so I didn't want to take up his time asking his advice and then not buying any... I wouldn't blame him if he thought I was asking his advice then purchasing online.


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## vickster (17 Jul 2013)

Ah I thought you were buying tyres now?!


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## I like Skol (17 Jul 2013)

I went through this dilemma myself just a couple of months ago as after 5000 miles the OEM fit tyres on my hybrid were very tired. After much debate I decided to plump for another set of exactly the same tyre in exactly the same size (700x35c). My reasoning for this was that I was perfectly happy with the ride and performance of these tyres and to be honest even riding my 23c shod road bike or my MTB fitted with 26x2.1 slicks I have never felt compromised by the tyres so why lose the safety margin of the 35c tyre (which is damn useful when you hit that unexpected/unseen pot hole at speed) by swapping to a thinner tyre in search of theoretical/mythical speed advantages?

I ride these tyres - HERE but it looks like they are out of production now


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## tudor_77 (19 Jul 2013)

Hey Biggler, I have the exact same bike as you. As far as I know 700x28 is the thinest you could get away with but 700x32 might be more practical. I've been pondering the same thing but actually quite like the stock tyres on the Roam 2. Despite the chunky(ish) tyres it rides surprisingly fast in my opinion.


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## Biggler (19 Jul 2013)

I've not got any thinner tyres to compare them to, only a mountain bike which are definitely wider, but I'm happy with them too.

However, if I went to 700x32 I could get Slime Inner tubes (I really dont fancy swapping tubes on the road :P ) as I've not found any slimes that go as big as 700x*40.*


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## AndyPeace (19 Jul 2013)

Biggler said:


> I've not got any thinner tyres to compare them to, only a mountain bike which are definitely wider, but I'm happy with them too.
> 
> However, if I went to 700x32 I could get Slime Inner tubes (I really dont fancy swapping tubes on the road :P ) as I've not found any slimes that go as big as 700x*40.*


 
If your going to use slime, don't forget to take a pump or air canistors with you, if the tire puntures and heals it will still loose air . Personally having tried the stuff I wouldn't recomend it, but if your journey's are short and your happy to ride back on a flat tire (yep, even with slime it will still happen!). I'd practice changing the tube to up your roadside confidence and get quality tires with a layer of puncture protection, they rarely fail.


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## Biggler (19 Jul 2013)

I'm not adverse to swapping an innertube, I would just rather not if I could help it  Are inner tubes pretty much the same from brand to brand, other than Slime that is?


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