Bicycle Mechanics - How much taller are 700x32 tires?

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View Full Version : How much taller are 700x32 tires?


croscoe
02-12-08, 03:11 PM
Hi. My road bike has 700x25 tires at the moment. I'm thinking of putting something a little wider on it. It looks like I have a handful of MMs vertically for a bigger tire. So basically, how much taller would the 32mm tire be than the 25mm tire? Thanks.


Retro Grouch
02-12-08, 03:17 PM
What kind of brakes do you have? As a general rule road calipers max out on 28mm tires and won't open far enough to allow wider tires to squeeze between the brake pads.

croscoe
02-12-08, 03:21 PM
Tektro R530.


Ex Pres
02-12-08, 03:26 PM
basically the tire is (32-25) =7mm taller and wider. You'll need that 7mm clearance to the brake bridge and 3.5mm on on each side at the chain and seat stays.

Plus check your brakes.

late
02-12-08, 03:30 PM
Prob not.. you could look into a Conti 28c (they run small) or if there is plenty of room the Rivendell Ruffy Tuffy 27c.

croscoe
02-12-08, 04:03 PM
So, when a tire is 700x??, the ?? is both sidewall height and width? Nice to know. On the other hand, Gah! I knew I should have gotten a cross bike instead. Back to the drawing broad! Thanks for the replies.

Retro Grouch
02-12-08, 04:20 PM
So, when a tire is 700x??, the ?? is both sidewall height and width?

In theory but not always in life. Rim width matters and they're not all the same. If you put a tire on a narrower rim the sectional arc distance from bead to bead hasn't changed but the beads are closer together. That means that the sectional arc is going to be tall and narrow rather than short and wide. The front of the tire will be closer to the seat tube but the sides will be farther from the chainstays.

HillRider
02-12-08, 05:13 PM
Assuming a bike tire is cylindrical and the height = width is a pretty good approximation when installed on most common rims. It isn't exact, as RG pointed out, but it's close enough for government work.

hhabca
02-12-08, 05:34 PM
Hi. My road bike has 700x25 tires at the moment. I'm thinking of putting something a little wider on it. It looks like I have a handful of MMs vertically for a bigger tire. So basically, how much taller would the 32mm tire be than the 25mm tire? Thanks.

OK.. I'm trying to do the same thing - I asked in another thread about what tires actually measure out to 28mm, about the max I have. I'm hoping a Panaracer Pasela 32 will actually be 29mm once mounted on my rims. Otherwise, I see the reason for GP at Rivendell to come up with those RolyPoly tires. I don't want to even think of shipping tires from CA, unless they can fold into a tiny box.

For a real change take look at the 650B conversions out there! Might be cheaper than a cross-bike...

HillRider
02-12-08, 05:37 PM
For a real change take look at the 650B conversions out there! Might be cheaper than a cross-bike...
Unless you have disc brakes, this can be a real no-go.

hhabca
02-12-08, 06:43 PM
Unless you have disc brakes, this can be a real no-go.

There's the Tektro R556 brakes that have the reach to do it - next step up from 47-57 'long reach' (what used to be called 'standard' reach). They are 53 to 63 reach or something. Rims, spokes, brakes and tires are needed.

http://www.bikeman.com/content/view/1161/33/

Personally, I'd rather convert a 27" bike to 700C and have a better choice of tires.

Retro Grouch
02-12-08, 06:52 PM
I don't want to even think of shipping tires from CA, unless they can fold into a tiny box.

What's the big deal about shipping bike tires?

relyt
02-12-08, 07:02 PM
If you have a roadbike, you can probably do 28c, but 32c is a bit large for some forks. Your fork, especially if is is carbon, is probably the culprit, rear clearance is probably better.

As far as shipping bike tires is concerned, UPS and FedEx charge extra for "oversize" packages, and a package with unfolded tires in it would qualify. Wouldn't weigh much, though.

I corresponded with Sheldon Brown about a month ago regarding tire sizing on the Pasela Tourguard, and he said that Panaracer sizing used to be a bit off, but is now mostly accurate.

If you want to buy a 28c tire and be sure it is actually 28c, Continental is the way to go.

hhabca
02-12-08, 08:39 PM
What's the big deal about shipping bike tires?

I'm in Canada. It's a $$$ thing. If it goes USPS ground, then it's uninsured, untracked, and takes 3 weeks. USPS air might cost $30. UPS or FedEx will cost $25 or so, but also add a $25 to $40 'broker fee' to go through customs, and then there's the 15% tax added on to all of it. $70 tires end up at around $130. I once bought $30 in parts and had to pay $40 at the door in 'fees' to get the package. I've pretty much stopped buying anything mail order from the US (sorry). Well, except clothes from LL Bean - the products are actually shipped form Canada, so no customs 'fees' and shipping is reasonable. If Nashbar or Performance did the same, I be back on board...

hhabca
02-12-08, 08:45 PM
I remeasured my tires. Pasela 35s on 19mm rims are 30mm high by 30mm wide - these are about 5 years old though. Continental Touring 28 are 25mm wide and 23 mm high, also about 5 years old. The Pasela have a central ridge that is finally just about worn down on mine, and this must have been an extra 0.5mm when new.

operator
02-12-08, 08:55 PM
I'm in Canada. It's a $$$ thing. If it goes USPS ground, then it's uninsured, untracked, and takes 3 weeks.

Pfft. Either it's uninsured, untracked and takes 3 weeks or it's insured, tracked takes 3 weeks and then you get raped by Fedex/UPS on bogus brokerage charges.

Learn how to order from PBK. If you want instant gratification, you have to pay for it.

hhabca
02-13-08, 07:17 AM
Pfft. Either it's uninsured, untracked and takes 3 weeks or it's insured, tracked takes 3 weeks and then you get raped by Fedex/UPS on bogus brokerage charges.

Learn how to order from PBK. If you want instant gratification, you have to pay for it.

Pfft? PBK? Instant gratification?