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Who should use 19/20mm tires?(23 posts)

Who should use 19/20mm tires?WrigleyRoadie
Nov 25, 2003 3:01 PM
I saw the deal on Maaxis Hors Categorie and was wondering if there's any inherent advantage to a 20mm tire for racing? (I'm 145 lbs and race an aluminum bike on Rolf Prima Vigors). Are they best for TT use only, with the narrow profile?

They run at a slightly higer psi (130), but what are the drawbacks... traction in corners? Flat tendancy?

Just curious...
Nobody (nm)TJeanloz
Nov 25, 2003 3:52 PM
Narrower tires are a tiny bit lighter. That's about it.
TJ's right.OldEdScott
Nov 25, 2003 4:32 PM
No benefit, many downsides.
Ed's right, too nmgtx
Nov 25, 2003 4:38 PM
grx 's a wise guy as well nmPeterRider
Nov 25, 2003 5:13 PM
Peter speaks the truth. nmfirstrax
Nov 25, 2003 6:38 PM
firstrax has it all wrong nmcollinsc
Nov 25, 2003 9:54 PM
;)
Do not listen to collinsc. nmfirstrax
Nov 26, 2003 11:45 AM
At 145 pounds, you could race on them front and backMR_GRUMPY
Nov 25, 2003 4:26 PM
For training, you could use one on the front, and a 23 on the back.
great for nice roads nmandy02
Nov 25, 2003 5:20 PM
re: Who should use 19/20mm tires?ngl
Nov 25, 2003 7:02 PM
The same topic is being debated on the BICYCLING - BUYING Forum. I find the 23mm tires give more comfort, but for a light rider who can afford to give up a little comfort ( especially using a cf frame), the comfort sacrifice is well worth the small time bonus. In summary only you can answer that question, but, they work for me.
re: Who should use 19/20mm tires?WrigleyRoadie
Nov 26, 2003 8:34 AM
Yeah, I started that thread. I'm slumming both sides of the tracks.

Thanks for the considerations. I figured on the ride being more harsh and the PSI being difficult to maintain. I know 3mm worth of tire with is going to have minimal effect on aerodynamics. From a strictly visual perspective it DOES look slightly innefficient to have the tire 'bulging' out a few mm wider than the rim on my Rolf Vigors. The effect is probably exaggerated by the deepness of the rim.

I have an unused pair of Michelin Pro Race tires, a model that I've used for two generations now and love. I'll probably stick with them for now. The roads in Chicago are less than buttery, and that includes the race courses. Any aero advantage would probably be offset by the teeth I lose after bouncing up and down over the patch seal. Thanks all.
re: Who should use 19/20mm tires?russw19
Nov 25, 2003 7:35 PM
Slight weight advantage. But I have seen a Continental Tires Report that found zero advantage in rolling resistance between a PROPERLY inflated 20mm and 23mm tire. The key there is Properly Inflated. As a 20mm tire will lose pressure faster due to a lower tire volume. As a tire loses pressure, the rolling resistance increases. And it's harder to keep a 20mm tire to proper pressure.

Also there is an aerodynamic effect. The effect is not inherently on the tire, but more on the wheel. However it is well known that if the tire's profile matches the rim's profile, it will help the aerodynamics of an aero wheel. Most rims are about 22mm wide, so you are better off using a 23mm tire over a 20mm tire.

Last factor is flats. According to studies done, you are twice as likely to flat on the narrower 20mm tire than a 23 or 24mm tire.

20mm tires were popular in the 80's and early to mid 90's because people mistakenly thought they were faster. They are not. They aren't slower either, but they are more harsh. All other factors being equal, your ride will be faster on a wider tire over a distance because the tire will absorb more road shock that would otherwise be transmitted to your body, causing fatigue. Get the 23's.

Russ
actually most rims are 19mm nmcyclopathic
Nov 26, 2003 7:55 AM
The (many) drawbacks of skinny tires...tube_ee
Nov 25, 2003 8:53 PM
1. Must run higher pressures to avoid pinch flats and rim damage.
2. Less comfortable, because they hold less air, and buecause of #1
3. Less traction, due to elongated contact patch (due to width), and less contact patch area. (due to #1)
4. Higher rolling resistance, assuming equal pressure.

The only advantage I can see to skinny tires is lower air resistance, but if the small increment in frontal area would really improve your performance, you'ld be a pro, and riding whatever your sponsor put on your bike.

Most riders are better off running 25s, or even 28s, at
90-100 psi.

--Shannon
re: Who should use 19/20mm tires?Saddle_Sore
Nov 26, 2003 2:52 AM
I read this entire thread with interest. I'm a bit of a lard-arse at 80kg / 176lbs and I have 19mm tyres on my winter bike - not through choice, it's just that they have been on my wheels for a few years now and never thought to change them...

...Until I went arse-over-tit on a frosty night ride earlier this week (monday). I am convinced this was caused by a lack of traction when cornering.

I hadn't really thought about the pressure issue, but it seems to make sense, and will be getting myself some 22-23mm tyres pronto. Hopefully the bruising on my shoulder and elbows will have subsided in time for me to lever them onto the rims :-|

Incidentally, I see lots of people using (nm) when they post in the topic header.

Please forgive my newbie ignorance, but what do you all mean when you put nm in your posts / headers?
nm in the header means "no attached text"MB1
Nov 26, 2003 4:21 AM
so there is no reason to open the post.
Probably no one should but Miss M could.MB1
Nov 26, 2003 4:33 AM
Miss M must be 100 lbs soaking wet. For a light rider weight savings is a bigger deal as a percentage of the overall bike and rider weight.

Any weight an already light rider can save is a larger percentage of the whole package than the same weight savings of a heavier rider. So many bike parts weigh the same regardless of rider that it make sense for smaller riders to save weight wherever they can.

That being said Miss M seems to be most comfortable on 22-23mm tires and she loves the way they feel on the road.
So why sell them? Who does use them, succesfully? (nm)hrv
Nov 26, 2003 7:38 AM
possible usesColnagoFE
Nov 26, 2003 8:18 AM
really light track riders
nobody should, but you can..dotkaye
Nov 26, 2003 9:51 AM
I bought some 20mm tires when I started racing triathlons, since I believed the 'more aero' contention. They did flat more, and did give a harsher ride. That said, I'm still using the 20mm on the front, being an economical, parsimonious not to say miserly old f@rt. That's working fine (I'm 164lbs) - no troubles with flats, and I don't notice the ride difference between it and the 23mm on my other bike. The only advantage I can find is that I don't have to open the brakes to get the wheel out, open the quick release and it just drops right out..

I use manufacturer-recommended 22mm tubulars on my aero race wheels these days.
re: Who should use 19/20mm tires?MShaw
Nov 26, 2003 10:03 AM
I read somewhere that an aero wheel with a wide tire in the front is almost as slow as a normal wheel in a TT. Seems that the aero profile of the 19mm tire kept the air flowing better...

That said, last time I rode 20c tires, I had 3-4 flats on one ride. No thanks. Then again they were also Open Corsa CXs...

If you're (competitive while you're) TTing, I'd still say go 19mm in the front and 23mm in the rear.

Mike
I used to use themDropped
Nov 26, 2003 10:35 AM
When I started riding road bikes, I used 20's because I was clueless and because I figured skinny must equal fast.

I switched to 23's a while back and I'm not sure if I even notice much difference. Maybe the 23s are a bit more comfortable. I don't know. It really wasn't that noticeable.