25 tyres on my hybrid?

[Jezston]

25mm tyres on my hybrid?

Currently have a Kona Dew Plus with 37c tyres on it - would like to put some coloured stripe tyres on (for purely asthetic reasons) but the largest size I seem to be able to find such things in is 25c.

Now the rims on the Dew are pretty thin compared to many hybrids - they are Rigida ZAC-19SL if that means anything to anyone - but I doubt they'll take 23's.

My local Evans reckon they may work, and I can bring them back if they don't, but to save the hassle (especially as I've never changed a tyre before and the Dew has disc brakes which'll make it an interesting experience!) can anyone confirm / deny if this will be the case?

 

[Downward]

I had some 28's on my Kona but they didn't have much of a sidewall and winter took it's toll. I may put them back on for summer but beware of a greater increase in P**etc

 

[Sam Kennedy]

Oh I thought your hybrid had 25 wheels!

Does your rim not have a sticker with the tyre sizes on? Normally it says something like 35-42 or something.

 

[Jezston]

I had some 28's on my Kona but they didn't have much of a sidewall and winter took it's toll. I may put them back on for summer but beware of a greater increase in P**etc

Kona what? Similar rims to mine? If so then I guess 25 will really be pushing it!

 

[Jezston]

Does your rim not have a sticker with the tyre sizes on? Normally it says something like 35-42 or something.

Not that I can see ... unless it was there and is long gone.

 

[Downward]

Dew Deluxe 2008 I think ? Erm yeah LBS said 28 would be fine but with the potholes, and general crap in the road over winter I changed back to some 32s with puncture protection and sidewall. They were great though for the few months of summer we did have so maybe come april you might give them a go.

 

[bottombracket]

From CTC website
"any tyre from 1.4 to 2.2 times rim section should fit – always provided that the bead diameters correspond..."

http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3802

Scroll down the page and you'll see a handy table with the info you need - and a whole lot more you probably don't...

 

[HLaB]

If you currently have 37mm tyres, I doubt you could go any lower than 28mm but there is a chance if you have a 17mm rim (interior width), Sheldon does quite a good article on it summed up quite nicely in a coloured chart at the end.

 

[Jezston]

From CTC website
"any tyre from 1.4 to 2.2 times rim section should fit – always provided that the bead diameters correspond..."

http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3802

Scroll down the page and you'll see a handy table with the info you need - and a whole lot more you probably don't...

Cheers for that - sadly I have no idea what size my rims are to start with!

So I got the 25c tyres + innertube with the promise of a refund if they are wrong, and have put one on the front wheel. It went on easy and have to say looks really nice ... however (after a few WTF moments with the presta valve) I can't seem to fully pump it up - it refuses to pump after about 25 PSI - and it should go up to 100, which leaves it rather squishy.

Is this a sign of the tire being too small, or me putting it on wrong, or my pumps being rubbish?

I'll take the wheel into Evans tomorrow for them to yay or nay it.

If it is the case that 25 is just too small for my wheel, does anyone know where I can buy a 28 to 37 size tyres that are coloured?

 

[Jezston]

If you currently have 37mm tyres, I doubt you could go any lower than 28mm but there is a chance if you have a 17mm rim (interior width), Sheldon does quite a good article on it summed up quite nicely in a coloured chart at the end.

Hmm, having looked at that chart, it's made me think that perhaps the 19 in ZAC-19SL means 19mm interior rim width ... which would mean that 28c is the minimum suggested tyre.

Again, I'll get them to have a look at it tomorrow, but it is increasingly looking like it's too small.

So - again - anyone know where you can get tyres with coloured stripes in 28?

 

[rusky]

I have Alexrims TD20's on my hibrid, I thought the 20 was the rim width. The sticker on the rims says 18mm!

The easy way would have been to measure the rim when you had the tyre off

 

[Jezston]

The easy way would have been to measure the rim when you had the tyre off

Now that would have been far too sensible

I've looked them up on Rigida's website:

http://www.rigida.com/en/products/hybride-city/rims-5/zac-19-4

And they say 19mm, and take a 28-66mm tyre.

However, they look nothing like mine. Hmm.

 

[Jezston]

Well I took a wheel+tyre into Evans yesterday, and they managed to pump it up fine and ok'd it (hence my new thread in beginners about pumps). Put the chunky ones back on as it's still a little frosty round here.

Will have a proper measure tonight (especially as I need to put one of my tyres back on the correct way round!) but I do suspect my rims are actually a couple mm shy of 19 - they do look nothing like regular hybrid rims.

I should add they also look totally badass. One of my neighbours commented that my bike now looks like one of the light cycles from Tron

 

[buddha]

I have a set of Mavic A719 wheels - that have a 19mm (internal) rim. Been running 25mm tyres on them for over three years with no problems.
When first dropping to 25mm tyres I did ask here and at the LBS (after looking at Sheldon's chart). Everyone said it would be fine and it has been.

 

[Crankarm]

I have a set of Mavic A719 wheels - that have a 19mm (internal) rim. Been running 25mm tyres on them for over three years with no problems.
When first dropping to 25mm tyres I did ask here and at the LBS (after looking at Sheldon's chart). Everyone said it would be fine and it has been.

Mavic recommend 28-47C tyres for the A719s on their website.

http://www.mavic.com/road/products/a-719.324119.2.aspx


For tyres 25C and below you really need the Open Pro rims 15mm width and ideally the more durable CD finish.

http://www.mavic.com/road/products/open-pro.323926.2.aspx