"Street" tires vs. All terrain...

[Manic]

I have another newbie question. I have heard that street tires are faster than knobbies. That makes sense to me but I am wondering how much of a difference I would feel if I changed out my all terrain tires for a smoother street tire. The tires I have now are mildly knobbied on the bottom and knobbied on the sides. I'm not after breaking any speed records or maximum speed, just want to increase my average speed a little and reduce my effort a smidgen. I think the tires I have now are 26-1.95. I am riding a Giant Sedona ST comfort bike.

 

[Scotty_Dog]

For road endurance training on my mountain bike, I recently went from lightweight 2.1" front and 1.9" rear knobby tires to 1.4" road slicks. Over my typical 23 mile route, my average speed increased by 2 MPH.

 

[Eastway82]

I have another newbie question. I have heard that street tires are faster than knobbies. That makes sense to me but I am wondering how much of a difference I would feel if I changed out my all terrain tires for a smoother street tire. The tires I have now are mildly knobbied on the bottom and knobbied on the sides. I'm not after breaking any speed records or maximum speed, just want to increase my average speed a little and reduce my effort a smidgen. I think the tires I have now are 26-1.95. I am riding a Giant Sedona ST comfort bike.

Go for it. When I converted my old Giant Coldrock mtb into a tourer, the last thing I changed was the tyres – should have been the first! The old tyres (Tioga Farmer Johns) weren't very aggressively treaded, but still, in retrospect, squirmed a lot, deadened the feel from the road surface, and made a lot of noise on tarmac. When the front one went bang (probably because I was using higher pressures than usual to get rid of some of the squishyness), I put on some cheap hybrid tyres (own brand from Decathlon, a European sports shop chain), which are pretty much smooth tread but they're still a big heavy tyre – the difference is amazing. It rides like a road bike now, not like a converted mtb.

 

[meb]

For road endurance training on my mountain bike, I recently went from lightweight 2.1" front and 1.9" rear knobby tires to 1.4" road slicks. Over my typical 23 mile route, my average speed increased by 2 MPH.

I have some of the all terrain tires like you have on my mountain bike but have occaisionally put street tires on for short intervals before flatting. My experience is in terms of speed, the all terrain tires are closer to the knobbies than the slicks, but in terms of smoothness, they are much closer to the slicks than the knobbies.

So in view of the Scotty_Dog's quantitative info, I'd suggest you might receive about 2/3 of the speed benefit he mentions.

 

[Manic]

Thanks for the info. One more question: since I use fairly wide tires would I need new wheels if I go to a road tire? Not sure what my rim size is...

 

[Scotty_Dog]

One more question: since I use fairly wide tires would I need new wheels if I go to a road tire?

I seriously doubt you will need new wheels, though you will need appropriately sized tubes. Most mountain bike rims can handle a tire from 1" to 2.3" wide. Your rim might or might not handle those extremes.

Follow this link for more tire sizing info:
http://sheldonbrown.com/tire-sizing.html

Go here for a past topic on mountain bike slicks:
http://www.cyclingforums.com/t291662.html

FYI, I'm using the Ritchey Tom Slick Kevlar 1.4" with good results.

 

[montreal5]

Another thing to consider is PSI (or bars). A lot of times I see guys on mountain bikes with their tires smooshed out on the street. If youre gonna be riding on the street, you wanna fill them up to the max pressure. I have a sirrus sport and I can feel the difference between 80psi and 120 psi (max) in terms of rolling resistance.

 

[gclark8]

MY GF has the 2007 Giant Sedona and fitted Conti city Contact Slicks, 26x1.5, it goes much faster now! And the bike looks cleaner with the v section rims.

I would suggest from 28mm-1.5" as the most beneficial size range. Gearing is another consideration, a cassette with an 11 tooth cog and a crankset with a 48 tooth big ring helps the top speed.

See also the MTB slicks topic in the Aus Forum.