ADVrider

Go Back   ADVrider > Riding > The perfect line and other riding myths
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-08-2014, 07:12 PM   #1
Soldier311 OP
Beastly Adventurer
 
Joined: Nov 2013
Location: Eastern NC
Oddometer: 1,228
Narrow tires vs. wide tires?

What are some of the things to consider when choosing the width of your tires, particularly the rear? Let's assume a specific brand rear tire, say a Shinko 244, comes in widths that will fit your bike from 4.10 - 5.60......what conditions justify the use of the 4.10 over the 5.60 and vice-versa?
__________________
"It's more fun to ride a slow girl fast than a fast girl slow."
1999 DR350SEX
Soldier311 is offline   Reply With Quote
Old 10-08-2014, 08:00 PM   #2
GlennR
Playin' in the Fire
 
GlennR's Avatar
 
Joined: Nov 2010
Location: Boone,NC
Oddometer: 1,939
I don't know how width affects handling, but I know wider tires weigh more. Wider tires are better in sand. If a tire is too wider it can rub the chain.

The 4.60 is a good looking width in the 244. I had it on an XT225 and it looked beefy on that little bike.

You have a DR350, right? It's not a really bike powerful & heavy bike, so I'd go with the 4.60. The 4.10 would also be a fine size, a little lighter and $5 cheaper.

Dennis Kirk lists the weights for each tire if you want to compare weights of different sizes, models, brands, etc. I've been getting my tires at American Motorcycle Tire, best prices I've found & free shipping on all orders.

my .02 cents
GlennR is offline   Reply With Quote
Old 10-08-2014, 09:36 PM   #3
scootrboi
Beastly Adventurer
 
scootrboi's Avatar
 
Joined: Jan 2011
Location: Vermont
Oddometer: 1,363
A wider tire requires more steering input and a steeper leaning angle for turns.
__________________
42 years on a Heinkel Tourist
scootrboi is offline   Reply With Quote
Old 10-09-2014, 04:19 AM   #4
Soldier311 OP
Beastly Adventurer
 
Joined: Nov 2013
Location: Eastern NC
Oddometer: 1,228
Quote:
Originally Posted by GlennR View Post
I don't know how width affects handling, but I know wider tires weigh more. Wider tires are better in sand. If a tire is too wider it can rub the chain.

The 4.60 is a good looking width in the 244. I had it on an XT225 and it looked beefy on that little bike.

You have a DR350, right? It's not a really bike powerful & heavy bike, so I'd go with the 4.60. The 4.10 would also be a fine size, a little lighter and $5 cheaper.

Dennis Kirk lists the weights for each tire if you want to compare weights of different sizes, models, brands, etc. I've been getting my tires at American Motorcycle Tire, best prices I've found & free shipping on all orders.

my .02 cents
Thanks, Glenn - I just put a 4.10 on the DR350 and kinda wish I'd gone with a 4.60 just for looks - the 4.10 is just narrower than I'm used to. Oh well, I'll just ride the shit out of it and get the larger one next time.
__________________
"It's more fun to ride a slow girl fast than a fast girl slow."
1999 DR350SEX
Soldier311 is offline   Reply With Quote
Old 10-09-2014, 04:43 AM   #5
GlennR
Playin' in the Fire
 
GlennR's Avatar
 
Joined: Nov 2010
Location: Boone,NC
Oddometer: 1,939
Quote:
Originally Posted by Soldier311 View Post
Thanks, Glenn - I just put a 4.10 on the DR350 and kinda wish I'd gone with a 4.60 just for looks - the 4.10 is just narrower than I'm used to. Oh well, I'll just ride the shit out of it and get the larger one next time.

The slow gal might just be a bit faster wearing the lighter shoes.

Keep her rolling. The "looks" only matter when you are stopped.
GlennR is offline   Reply With Quote
Old 10-09-2014, 04:50 AM   #6
C/1/509
Beastly Adventurer
 
Joined: Jul 2006
Oddometer: 3,136
Quote:
Originally Posted by scootrboi View Post
A wider tire requires more steering input and a steeper leaning angle for turns.
A wider tire requires more lean angle for a given turn?
C/1/509 is offline   Reply With Quote
Old 10-09-2014, 05:24 AM   #7
dwizum
Gnarly Adventurer
 
Joined: Jan 2014
Oddometer: 220
Quote:
Originally Posted by C/1/509 View Post
A wider tire requires more lean angle for a given turn?
Yes from a purely geometric sense. Though it depends on how you measure lean angle.

All else being constant, to make a given turn you've basically got to hit a certain angle measured on a line that connects the center of pressure on the contact patch to the center of gravity for the bike. That angle has to be constant.

On a wider tire, the contact patch is further from the centerline of the bike, which means the "lean angle" as most of us would measure it - the centerline of the bike - has to be steeper in order to keep the above-mentioned angle the same.
dwizum is offline   Reply With Quote
Old 10-09-2014, 05:35 AM   #8
Rucksta
Chronic Noob
 
Rucksta's Avatar
 
Joined: Oct 2008
Location: Gold Coast
Oddometer: 2,603
Quote:
Originally Posted by C/1/509 View Post
A wider tire requires more lean angle for a given turn?
A popular theory is that the reduction in effective diameter of the wheel caused by leaning the bike contributes significantly to that rate of turn possible.

Keith Code and others have written extensively and provided multiple diagrams to quantify the effect.
There would seem to be some basis for the argument when considering on road turn of a bike maintaining traction
.
The effect is evident with ease of tip in when initiating a turn.

The wider tyre has a flatter slope to the edge so requires more lean angle to achieve the turn rate says the doctrine.

If you're a lean the bike until the tyres break traction then apply more throttle sort of rider then the effect is perhaps less important.
__________________
My bike is slow but the earth is patient.
Rucksta is offline   Reply With Quote
Old 10-09-2014, 05:57 AM   #9
Soldier311 OP
Beastly Adventurer
 
Joined: Nov 2013
Location: Eastern NC
Oddometer: 1,228
Quote:
Originally Posted by GlennR View Post
The slow gal might just be a bit faster wearing the lighter shoes.

Keep her rolling. The "looks" only matter when you are stopped.
You've got a point there!
I can say that I could definitely feel a difference it the weight of the two tires just holding them in my hand. The one I removed was a Shinko 705.
__________________
"It's more fun to ride a slow girl fast than a fast girl slow."
1999 DR350SEX
Soldier311 is offline   Reply With Quote
Old 10-09-2014, 12:23 PM   #10
markk53
jack of all trades...
 
markk53's Avatar
 
Joined: Dec 2007
Location: Delaware Ohio
Oddometer: 7,835
Quote:
Originally Posted by Soldier311 View Post
Thanks, Glenn - I just put a 4.10 on the DR350 and kinda wish I'd gone with a 4.60 just for looks - the 4.10 is just narrower than I'm used to. Oh well, I'll just ride the shit out of it and get the larger one next time.
Doesn't work that way with the inch system. The 4.60 is a low profile 4" wide tire, the 4.10 is a slightly lower profile 4" wide tire and a 4.00 is a full height (100%) profile 4" tire. There is only the oddball (which actually makes sense) 4.50, which is oddly enough a full 4.5" full profile tire. Go figure.

That's why metrics make sense.

4" about 100
4.5" is half way between a 110 and a 120 This would have been your "looks" tire.
5" is about 130

The profiles speak for themselves. A 120/90 is 90% of the 120 profile. The 120/80 is 80% profile of the 120. Kinda makes more sense than the inch system.
__________________
Ever get lost? You know, that good kind of lost - come to a dirt road intersection and you have no idea where you are or which way to turn? I like when that happens!

Mark - klx678
95 KLX650C w/Vulcan piston bigbore, Now an 09 KLX250S, selling my 90 Zephyr 550
markk53 is offline   Reply With Quote
Old 10-09-2014, 12:37 PM   #11
markk53
jack of all trades...
 
markk53's Avatar
 
Joined: Dec 2007
Location: Delaware Ohio
Oddometer: 7,835
ONe more consideration when buying for a dual sport or off roader. You can have too much rubber on the ground. Seems a 450 MX runs about the equivalent of a 120 knobby and the 250s run about a 110. The smaller engines need a smaller tire to be able to break loose when needed, otherwise too much traction will bog the engine.

When I was racing a TM125 back in the day, guys would stick 5.10 knobbies on them and they'd run like crap. Too much tire - except on sand as previously noted. The smaller peakier powered engine needed the capability to break loose and spin a bit when in mud or loose stuff, to keep the engine in the good power, letting traction catch up. Too much tire makes it that much harder to accelerate out of soft gooey stuff.

The 350 would do fine with a 120, maybe a 130 would be a bit much.

I went down to a 4.00 (no 100 was available) dual sport tire for my KLX250. OEM is 120/80. My reasoning was the slightly narrower tire would allow me a bit of spin when dealing with mud, without bogging the bike. I did get in sand and found it worked well. I could start out spinning the tire in the power while the bike was picking up speed - far easier on the clutch. Actually looks right on the bike to me. Now my 650 has a 130/80 on the back - looks fat - but the 650 can use it. No bogging there.

The other advantage in mud/slop is the narrower tire can cut down through the soft stuff to find solid ground. Part of the reason for a 3.00-21 (or 90/90-21) on off roaders, cut through to solid ground. The narrower rear tire would allow that on the 250 too, without bogging it down.

Not everyone agrees with this concept, but mostly because of looks and the "bigger is better" thought process, not solid reasons. You still don't see overly fat tires on true enduro or MX bikes - for a reason.

One last reason for a narrower tire - they're usually significantly lower priced. My 4.00-18 Duro Median 904 was about $20 less than the 120/80-18 Median 904.
__________________
Ever get lost? You know, that good kind of lost - come to a dirt road intersection and you have no idea where you are or which way to turn? I like when that happens!

Mark - klx678
95 KLX650C w/Vulcan piston bigbore, Now an 09 KLX250S, selling my 90 Zephyr 550
markk53 is offline   Reply With Quote
Old 10-09-2014, 12:58 PM   #12
GlennR
Playin' in the Fire
 
GlennR's Avatar
 
Joined: Nov 2010
Location: Boone,NC
Oddometer: 1,939
Mark,

Your explanation makes a lot of sense. I recently mounted the lightest knobby I could find on my little XT225 to see how it handled the woods. Even though it's the smallest & lightest tire I could find it still has too much traction for the bike. The bike will flip itself over before it breaks traction. I was better off with the Shinko 244, a new one is quite impressive and feels perfect on the 225.

I'll most likely pull the knobby off even though it's almost new. The bike isn't really good on the street anymore & that's half the reason of having a dual sport. I'd read a number of guys running knobbies on them and had hoped I could get by using it as my trail riding bike, but the trails are too rough & steep here and my ego doesn't like the bike being the weakest link preventing me from climbing big hills.

I found a deal on a 05' KTM 300 2 stroke and now I'm the weak link!
GlennR is offline   Reply With Quote
Old 10-09-2014, 04:41 PM   #13
markk53
jack of all trades...
 
markk53's Avatar
 
Joined: Dec 2007
Location: Delaware Ohio
Oddometer: 7,835
Another reason to ride a muddling Japanese dual sport - blame it on the bike!

I never ran knobbies on the street (well on a road legal machine for any distance). My brother did DOT legal ones and burned them up in 1000 miles, so I took that to heart. Not many people run them, but I've had fantastic experience with the Duro Median 903/904 on my 650. They just plain work everywhere I've ridden. They stick well enough to chase sport bikes and supermotos through turns, then clean out pretty well when actually off road.

Decent spread of sizes, tread design makes sense. I've done over 30,000 on them over the past 14 years. I bought them when I couldn't afford Avons or Metzlers, then after using them I didn't switch back when I could afford the more expensive ones. Why quit what works.

I will say my experience with their road tires wasn't near as good. They looked cool, but weren't confidence inspiring.
__________________
Ever get lost? You know, that good kind of lost - come to a dirt road intersection and you have no idea where you are or which way to turn? I like when that happens!

Mark - klx678
95 KLX650C w/Vulcan piston bigbore, Now an 09 KLX250S, selling my 90 Zephyr 550
markk53 is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

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 On

Forum Jump


Times are GMT -7.   It's 03:27 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014