Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Winter Cycling Don't let snow and ice discourage you this winter. The key element to year-round cycling is proper attire! Check out this winter cycling forum to chat with other ice bike fanatics.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 11-13-10, 08:44 PM   #1
gecho
Senior Member
Thread Starter
 
Join Date: Sep 2010
Location: Regina, SK
Bikes: 2009 Trek 520
Posts: 1,100
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Studded Tire Front vs Rear Pressure Suggestions

I have a set of 700x35 Marathon Winters on my Touring bike. I'm generally riding with panniers so there is plenty of weight in the rear and not much weight in the front. I was riding home on icy roads with both tires inflated to about 55psi, the rear tire was ballooning on the sides a bit and the front looked fully inflated.

What tire pressures do those of you with drop bar bikes and rear panniers use? Much lower pressure in the front than rear?

I'm thinking my rear pressure could go up to at least 60 and lower the front to the high 40s. It was getting warmer on the ride home, does anyone find that warmer temperatures make the tires more flexible, hence justifying higher pressure than when its colder?
gecho is offline   Reply With Quote
Old 11-13-10, 09:02 PM   #2
Hezz
Senior Member
 
Join Date: Dec 2005
Bikes:
Posts: 1,649
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by gecho View Post
I have a set of 700x35 Marathon Winters on my Touring bike. I'm generally riding with panniers so there is plenty of weight in the rear and not much weight in the front. I was riding home on icy roads with both tires inflated to about 55psi, the rear tire was ballooning on the sides a bit and the front looked fully inflated.

What tire pressures do those of you with drop bar bikes and rear panniers use? Much lower pressure in the front than rear?

I'm thinking my rear pressure could go up to at least 60 and lower the front to the high 40s. It was getting warmer on the ride home, does anyone find that warmer temperatures make the tires more flexible, hence justifying higher pressure than when its colder?
This depends on what the tire is rated and your weight. But for a 35mm tire you should be running about 70-80 PSI unless it is a low PSI tire. If so you need a different tire for a touring bike that is meant to carry heavier loads. Most 700c road tires 35mm and under are designed to run at 80-110 PSI. 35mm tires are kind of in between wide tires and narrow road tires. You should run them at least 70 PSI in my opinion.

Last edited by Hezz; 11-13-10 at 09:08 PM.
Hezz is offline   Reply With Quote
Old 11-13-10, 09:09 PM   #3
gecho
Senior Member
Thread Starter
 
Join Date: Sep 2010
Location: Regina, SK
Bikes: 2009 Trek 520
Posts: 1,100
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
The sidewall pressure range is 35-85.
gecho is offline   Reply With Quote
Old 11-13-10, 09:11 PM   #4
hockey
Senior Member
 
hockey's Avatar
 
Join Date: Jan 2003
Location: Tichborne, Ontario, Canada
Bikes: Trek 5200, Giant Rainier, Devinci Destination,Motobecane CF, Cannondale road tandem, Bike Friday NWT
Posts: 272
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Schwalbe suggests lower air pressure when you want the studs to dig in. When you run regular psi, the centre groove of the tire contacts the ice,snow resulting in less grip.
Hockey
hockey is offline   Reply With Quote
Old 11-13-10, 09:27 PM   #5
Hezz
Senior Member
 
Join Date: Dec 2005
Bikes:
Posts: 1,649
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by gecho View Post
The sidewall pressure range is 35-85.
With those tires you have quite a range of pressures. My suggestion is to run them 70-80 PSI when the road conditions are good. This will make it easier to pedal but will make the ride a little less soft. When it's slick or snowy drop the pressures down to the 45-55 psi range like you have been doing. As long as you don't get a pinch flat on the rear it will not matter if the tire is ballooning a little bit. Experiment. In slick conditions lower pressure grabs a little better as long as it is not too low for the weight being carried.
Hezz is offline   Reply With Quote
Old 11-13-10, 09:28 PM   #6
AEO
Senior Member
 
AEO's Avatar
 
Join Date: Jun 2007
Location: A Coffin Called Earth. or Toronto, ON
Bikes: Bianchi, Miyata, Dahon, Rossin
Posts: 12,258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Hezz View Post
This depends on what the tire is rated and your weight. But for a 35mm tire you should be running about 70-80 PSI unless it is a low PSI tire. If so you need a different tire for a touring bike that is meant to carry heavier loads. Most 700c road tires 35mm and under are designed to run at 80-110 PSI. 35mm tires are kind of in between wide tires and narrow road tires. You should run them at least 70 PSI in my opinion.
depends on your weight.
http://www.bikeforums.net/showthread...=1#post6571222

Tire Width=35: Pressure(psi) = (0.17 * Rider Weight in lbs) + 33.67 for normal conditions.
a bit less, like 10% less for sloppy conditions.
__________________
Food for thought: if you aren't dead by 2050, you and your entire family will be within a few years from starvation. Now that is a cruel gift to leave for your offspring. ;)
http://sanfrancisco.ibtimes.com/arti...ger-photos.htm
AEO is offline   Reply With Quote
Old 11-13-10, 09:31 PM   #7
tsl
Plays in traffic
 
tsl's Avatar
 
Join Date: May 2006
Location: Rochester, NY
Bikes: 1996 Litespeed Classic, 2006 Trek Portland, 2013 Ribble Winter/Audax
Posts: 6,955
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Quote:
Originally Posted by Hezz View Post
Most 700c road tires 35mm and under are designed to run at 80-110 PSI.
We're not talking road tires, but studded snow tires. There's a world of difference.

My four-seasons commuter is also a drop bar bike. I run the 700x35 Nokian Hakkapeliitta W106. I adjust pressure according to conditions, starting from a dry pavement baseline of 50F/60R. I've run as low as 25F/35R with no problems, and improved grip in dicey conditions.

PSI Rx is the resource I use to establish a starting point for experimentation. None of my tires on any of my bikes fall exactly on the graphs, but they're near enough that I find it a useful tool.

The formulas AEO references are also good starting points.

The key thing, as Hockey points out, is adjusting pressure for conditions. There seems to be no hard-and-fast rule, but it's something you just develop a feel for.

Last edited by tsl; 11-13-10 at 09:35 PM.
tsl is offline   Reply With Quote
Old 11-13-10, 09:35 PM   #8
2_i 
Senior Member
 
Join Date: Sep 2005
Location: Michigan
Bikes: Trek 730, Bike Friday NWT, Brompton M6R*2, Trek 830, Trek 720, Dahon HAT060, Dahon HT060,...
Posts: 1,558
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Opinions vary about the pressure when there is ice only and/or thin layer of snow. In any case, I do not think there is a reason to push to or above the maximal pressure of the tire. When some level of snow appears you definitely want to go down with the pressure and when there is a lot of snow, you want to go a lot down. With 37mm Hakkapeliittas W106 I have been going down to 20-30 psi in the front and just a bit above 30 in the rear on a bike highly loaded in the rear. For low pressures, dirt start getting inside the tires, so I would be wiping the tubes and potentially washing tire interior when changing the tires.
2_i is offline   Reply With Quote
Old 11-13-10, 09:45 PM   #9
AEO
Senior Member
 
AEO's Avatar
 
Join Date: Jun 2007
Location: A Coffin Called Earth. or Toronto, ON
Bikes: Bianchi, Miyata, Dahon, Rossin
Posts: 12,258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by 2_i View Post
Opinions vary about the pressure when there is ice only and/or thin layer of snow. In any case, I do not think there is a reason to push to or above the maximal pressure of the tire. When some level of snow appears you definitely want to go down with the pressure and when there is a lot of snow, you want to go a lot down. With 37mm Hakkapeliittas W106 I have been going down to 20-30 psi in the front and just a bit above 30 in the rear on a bike highly loaded in the rear. For low pressures, dirt start getting inside the tires, so I would be wiping the tubes and potentially washing tire interior when changing the tires.
at those pressures, I'm surprised you haven't rolled the tire off the rim or gtten punctures from potholes.
20~30psi range is what you'd want for +48mm tires.
__________________
Food for thought: if you aren't dead by 2050, you and your entire family will be within a few years from starvation. Now that is a cruel gift to leave for your offspring. ;)
http://sanfrancisco.ibtimes.com/arti...ger-photos.htm
AEO is offline   Reply With Quote
Old 11-13-10, 10:06 PM   #10
2_i 
Senior Member
 
Join Date: Sep 2005
Location: Michigan
Bikes: Trek 730, Bike Friday NWT, Brompton M6R*2, Trek 830, Trek 720, Dahon HAT060, Dahon HT060,...
Posts: 1,558
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Quote:
Originally Posted by AEO View Post
at those pressures, I'm surprised you haven't rolled the tire off the rim or gtten punctures from potholes.
20~30psi range is what you'd want for +48mm tires.
I haven't got a flat ever yet with a studded tire. Otherwise Hakkapeliittas tend to sit tightly on a rim compared to other tires. I go to 47mm when conditions get rougher but I generally try to limit my time with them.
2_i is offline   Reply With Quote
Old 11-14-10, 09:45 AM   #11
gecho
Senior Member
Thread Starter
 
Join Date: Sep 2010
Location: Regina, SK
Bikes: 2009 Trek 520
Posts: 1,100
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
10 psi lower in the front seems like a good starting point. I'll have to make myself some notes when I figure out what works best in various conditions.
gecho is offline   Reply With Quote
Old 11-15-10, 06:22 AM   #12
vantassell
Banned.
 
vantassell's Avatar
 
Join Date: Feb 2006
Location: SLC, UT
Bikes:
Posts: 832
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I'm subscribing to this. I just mounted on my Nokian Hakkapeliitta W106 (700 x 35) and realized I have no idea what I should pump them up to.... I just went with what was on the tire wall since it hasn't snowed yet. Just rain and freezing overnight temps.
vantassell is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 07:00 PM.