New Member, Tire Question
 

OK, so, I dusted off the old mt bike. My gut is getting too big, time to get in better shape. I am a little embarrassed at how badly out of shape I have gotten. No problem, I have a fluid trainer to get me more or less road worthy. I will be riding a mt bike mainly on the roads for a while, with the knobby tires, it is noisy as heck on the trainer. What slicks would be good to get? Been out of biking for years, so have no clue what companies are good these days.

I used to keep up with the latest and greatest, but not now. To put it in perceptive, I have Onza clipless pedals, and that newfangled V-Brake tech on my bike. And my bike is way older than the V-Brakes.

Never had slicks on my bike, anything to look into as far as width, brands... Local bike shop has rarely steered me wrong, just don't know what width of tire to get, what brands are good...

I hate to go shopping without some knowledge of what is optimal.

Thanks.

Nashbar Streetwise Slicks: http://www.nashbar.com/bikes/Product...57_-1___202472 . Anything in 26 x 1.50" with a slick tread will be pretty similar.

You can probably pump them to 80 psi without issue.

I rode my mountain bike with 26 x 1.25" slicks pumped to 100 psi for a while. (I'm 6-foot-4, 230 pounds.) It was a very fast, reliable commuter.

Unless you ride on some pretty seriously rocky trails, slicks will work better for you and won't sound like a motor cycle on the trainer.

I'm sure others will argue, but I'm not a big fan of real skinny tires on mountain bikes. I think that anything less than about 1.5" wide looks goofy. I've got 1.9" tires on my beater bike and never thought I paid a performance penalty over skinnier tires.

What are you looking to spend? Schwalbe Marathon Supremes are pretty much the best slicks out there,but usually go for $50+. Kenda Kwests aren't as nice,but are decent tires and cost less than half as much. Vittoria Randonneurs fall in the middle for quality and price.

I ride with Schwalbe Marathon Supremes, 2 inch wide, and like them a lot. Durable, smooth, good grip.

The wider the tire, the lower you want the pressure. Here is a table I came up with for pressure - weight on a single wheel across the top, tire width in mm down the side, pressure at the corresponding row/column intersection:
http://i140.photobucket.com/albums/r...ps9066802f.jpg

I don't doubt you, Jim, but why wide = lower pressure?

M.

PSI means pounds per square inch. A wide tire has a lot more square inches. If you were to inflate it to the same pressure as a skinny tire, it would have a lot more force trying to push the rim flanges apart.

for the trainer just get
the cheapest slick tire
that the nearest lbs
has in stock

I agree. I don't care how they look, but tires skinnier than 1.5 or so just don't work for me. There's no advantage to really hard, skinny tires, and several disadvantages.
As for brand, I rode an old Bridgestone mountain bike on the road for years, even did a century on it, and I couldn't tell a significant difference among brands of slick(ish) tires. About 1.5, 70-80 psi and just go ride.

Geax Street Runners are good and decent slicks. I ordered them online for my mtn bike and I'm happy with them

That's part of the reason. The other reason is that you can get away with it. One valuable function of tires is that they provide suspension. Getting pounded by rough pavement actually takes energy & slows a ride down. Skinny tires have to be pumped up hard to provide enough force to support the rim and avoid pinch flats, dented rims, etc. Fat tires, because of the same pounds per square inch, can support the same weight with lower pressure. They can avoid pinch flats at the same time they provide suspension.

I just put a pair of 2" Schwalbe Kojaks on my old Trek 930 and am really pleased with them. The ride is so much smoother and quieter now, and the new tires grip the pavement noticeably better than the old knobbies. Plus they're a bit zippier and it's easier to pedal up hills. I've been riding them at 70 psi and the only downside so far is a slight bit of extra harshness over the biggest bumps, but I hardly notice and the benefits are so worth it.

Hi, Unless your an elephant 70 psi is way, way too much, rgds, sreten.

Its about right for 28mm tyres and average weight.

With those tyres I'd use ~ 40 psi rear and ~ 32 psi front,
very different, but loads more grip and no harshness.
Might not feel as fast, but will go faster.
(And the tyres will last quite a bit longer.)
Higher if you are heavy, (I'm average), e.g. 50/40.

I'm not an elephant, I just liked the ride on my old knobbies more when they were inflated to just under their max so I've been starting high with these. I do plan on trying them out with less pressure as well, so I will give your suggestion a shot, thanks.

Hi,

FWIW what I did with my 47mm / 1.75" tyres on my folder :

Pumped them both up to 50 psi. The front was harsh, bouncing off
off road bumps and felt skittish with little grip. So it let it down
to the point it coped well with the typical local crap roads I ride.

I then purposely road over road bumps, ridges, drain covers
etc comparing the back to the front and pumped up the rear
so it felt about as harsh through the saddle as the front.

I've probably settled on generally running it somewhat a bit lower,
but always have the above matching pretty near between the tyres,
the rear being always being pumped up harder than the front.

rgds, sreten.

That's interesting, I really hadn't given much thought to playing with varying the pressure between front and rear. I'll have to pay attention to what I feel and where tomorrow. Maybe I'll let a little air out of the front for the ride home.

I have Resist Nomad 2.25" on my dedicated street mtb. Upon telling my mechanic I wanted the widest slicks that fit, he suggested them. At about 50 psi they measure 2.15"... so easily 2.20 at higher pressures. Awesomely wide, fill forks and chainstays nicely. Their rated to 80 psi, but that was of course way too harsh. Reduced to about 60-70, better, but about 40-50 is where they're at now and will stay...I inflate 10 psi more on my rear tires. This mtb is a heavy, cro-moly, rigid...the tires are the suspension. The tires are 30 tpi (threads per inch) so a lower pressure helps them to flex better, and since the frame doesn't seem to flex at all, it's definitely needed. Despite the width, as a slick, these tires roll fast and are are quiet, especially in comparison to knobbies and semi-slicks. http://resistparts.com/

I'm curious about the Bontrager Hank http://bontrager.com/model/02856 I discovered them earlier this week by accident. At 60 tpi they should give a smoother ride.

I used to be a max inflation rider, but even though it doesn't feel like it, lower pressures are faster due to bad terrain not displacing the tires energy/inertia...and, it's considerably more comfortable. The Schwalbe Kojaks look great but I wanted wider. Anyone ever measure the Kojaks actual width?

Your wish is my command. I just went down and measured one of mine at 1.33". That's on a 20" Aero-Heat rim. The actual tire width will vary somewhat depending on rim width.

We've been through this before.

I run 70psi in the 26x2" Marathon Supremes on my Safari. If you disagree with this,then you are wrong. You can pull out your chart and give me examples from personal experience,and you'll still be wrong. That's because it's my bike,not yours. 70psi is within the manufacturer's specs,as well as the rim's,and I like it. So that is the correct tire pressure.

Sorry, I need to setup email notification of posts.... I got a $25 Kenda and a smaller tube at the LBS. Will have to look into some wider slicks for the road, as that is most of my riding. This one is pretty thin, says 100 psi on the tire. Don't think I would want to do too much bunny hopping with this tire on. Of course, can't do that on the trainer.

It sure is much more quiet on the trainer.

Nice work on the chart, but it doesn't take handling, rim width, max tire pressure, or max rim pressure for a particular tire width into consideration. For example, I weigh 152-162 depending on season and ride 23c at 110-140 lbs. on my road bikes depending on road and bike. 90 lbs. doesn't corner very well on 19mm rims, though it might be fine on 22mm rims, and is slower on smooth roads. On our tandem for sport use we ride 25c at 120 lbs. and 170# per wheel weight, and for touring use 28c at 120 lbs. and a 210# wheel weight in the rear. Works great, never a pinch flat, corners well, no rim problems, and is at max tire pressure for the tires we use. So charts really aren't that much good. Sorry. Go by sidewall pressure and feel. In general, max sidewall pressure for a particular tire width will coincide with max rim pressure for that width, which actually is not a coincidence.

My wife rides an MTB frame and wheelset on the road with Ritchie Tom Slick 26 X 1" tires at 100 lbs. They work great on the road and trainer both. Obviously she doesn't run up on curbs with these, though bunny hopping is fine. You want big fat tires for curbs to absorb the shock, though they are contraindicated for normal road riding.

Ah, my chart also neglects wheel diameter! I think pressure is inversely proportional to the square root of the wheel diameter. The chart is a fit to Berto's graphs for 700C tires. For 26 inch tires, about 10% more should be good.

It is certainly true that charts like this are way too simple. But I would say that the pressure range on the sidewall is also rather simple. Certainly going much over the top is risky. But just what makes a manufacture put a particular pressure range on a sidewall can be rather strange, it seems. There are engineers, marketeers, lawyers, etc. and who wins the debate will vary.

The business of pressure vs rim width is quite fascinating. Just the subject of rim width vs tire width. It seems like wide tires on narrow rims is quite common these days. It's not clear it is anything like optimal. Look at the range of rim widths "approved" for 50 mm tires:

http://www.schwalbetires.com/tech_in...dimensions#rim

Is the best pressure for a 50 mm tire the same on a 17 mm rim as on a 27 mm rim? Yeah my chart totally omits this little detail but I suspect it really isn't so small. It does seem that at least on the narrowest rims you won't want to be putting too high a pressure in the tire because that puts a very large stress on the rims. On the wider rims the angle of the sidewall leaving the rim is not so abrupt so a higher pressure should be less risky.

Definitely on rough roads a bit lower pressure is good, to provide suspension, but not so low as to risk pinch flats. On smooth roads the suspension isn't so valuable and so higher pressure is nice to reduce the rolling resistance. There are a zillion factors. Yeah if you have lots of luggage then suspension is nice but if it's just you on the bike then maybe high pressure is good if you can just hop the bike over any rough spots. Much harder to hop a bike with 60 pounds of groceries in the panniers, especially with platform pedals!

The real purpose of the chart is just to try to open up thinking on the subject. Once you start thinking about optimum pressure as a function of width and load.... it can be a fun space to explore!

Oh, how I would like to hear that more often. :lol:
Thanks for checking, good sign that all sizes might be as accurate. The Kojaks are great looking tires, they remind of goodyear slicks on rail dragsters. I hadn't thought about them in 20" before, but know I'm tempted to put a set on my childhood bike that I'm slowly rebuilding. Oh, man!!!

I am by no means a weight weenie, but those tires are 750+ grams/tire, in a 26" size. I will not run over three pounds of tire on anything that I have to pedal uphill.

The best selection of 26" street tires that I have found is here.

Well they're on my urban assault bike so I want them to be bombproof, and at 35 lbs, it's a steamroller...once it's rolling, it keeps on going. I'm more worried about pinch-flats and punctures than weight, I even run them with downhill tubes for added durability. Now if I lived in area with hills and dales, I'd surely feel differently.

Looking at the tires you linked, I'd only be interested in the Maxxis Hookworm 2.5"; unfortunately they're too wide for my brakes. And, wow, 1250 grams each!