Not looking for any wars on tires or oil.
My 120/90/18 Continental front tire started getting some cracks in it so I shopped for a new tire. I needed a smaller size as it currently is too tight to the Magna fender and rubs at times. I ended up getting a Dunlop 120/70/18 radial for $54. I have the car tire radial on back so I figured, why not? The price was right. I had read that there isn’t a lot of difference on a bike between radials and bias. The 70 profile would give me clearance at the fender.
What kind of blows me away is how much more nimble the front end is now. It’s probably two inches shorter, but wow! What a difference. It cuts on a dime compared to the old tire.
I’m guessing it’s the size more than the radial aspect.
As to the car tire, I think I’ll ditch it next time. There are certain low speed maneuvers where it lurches a little unexpectedly. In a unforeseen emergency situation where you had to move in a direction of uneven road, it could be an issue. That’s just my opinion of it and bear in mind that mine is with the 1200 swing arm which keeps the tires in different planes by about half an inch. I’m sure that doesn’t help either. It does however make nice squealing sounds like car tires do when you smoke it.
Front tire size, performance, radial
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- ericheath
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Front tire size, performance, radial
Whatever I suggest here should be given ample time for a moderator to delicately correct. I apologize in advance.
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi
- Whiskerfish
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Re: Front tire size, performance, radial
Smaller on the front is a huge difference in the front end handling. Turn in seems to be much more controlled and stability through a corner is improved.
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"The book is wrong, this whole Conclusion is Fallacious" River Tam
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2008 GL1800 IIIA "TH3DOG"
1984 GL1200 Standard
1975/6/7/8/9 Arthur Fulmer Dressed Road bike
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Psst. oh and by the way CHANGE YOUR BELTS!!!!
"The book is wrong, this whole Conclusion is Fallacious" River Tam
"Yea I do dance awkwardly, and I am having more fun than you" Taylor Swift
2008 GL1800 IIIA "TH3DOG"
1984 GL1200 Standard
1975/6/7/8/9 Arthur Fulmer Dressed Road bike
1975 Naked Noisy and Nasty in town bike
Psst. oh and by the way CHANGE YOUR BELTS!!!!
- Sidecar Bob
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Re: Front tire size, performance, radial
A 120/70 theoretically has a 24mm (almost an inch) smaller outside diameter than a 120/90 (assuming both are mounted on suitable rims) so the front end should only be about half an inch lower (the same effect as raising the forks in the clamps by half an inch).
From what read about radials several years ago, radial tires are designed to work with wider rims than similar sized bias ply tires would need. If that is true of the tire you have it is possible that you have mounted the tire on a rim that is too narrow to produce the intended cross sectional profile, which usually results in the tire having a significantly smaller contact patch, which usually will feel much more nimble.
From what read about radials several years ago, radial tires are designed to work with wider rims than similar sized bias ply tires would need. If that is true of the tire you have it is possible that you have mounted the tire on a rim that is too narrow to produce the intended cross sectional profile, which usually results in the tire having a significantly smaller contact patch, which usually will feel much more nimble.
Mr. Honda ('83 GL1100/Dnepr) summer How a motorcycle evolves thread
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Click: Colour schematics for all GL1000 & GL1100 and GL1200 standard models plus instructions on how to download the full size version
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Another guy with two sidecars..... Hmmmm... must be something to that....
The Famous Eccles ('84 CX650EI/VeloUral) winter Never Ending Build (CX500forum)
Click: Colour schematics for all GL1000 & GL1100 and GL1200 standard models plus instructions on how to download the full size version
"A guy with two sidecars can't be all bad." - Cookie
Another guy with two sidecars..... Hmmmm... must be something to that....
- ericheath
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- Joined: Wed Jul 29, 2009 11:20 am
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Re: Front tire size, performance, radial
It’s actually about 1.8” smaller. So front end dropped almost an inch and I can tell when side standing the bike. I just raised it about 3/4” in the trees. Haven’t had a chance to ride yet. Rain is close.
Whatever I suggest here should be given ample time for a moderator to delicately correct. I apologize in advance.
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi
- Sidecar Bob
- Honored Life Member
- Posts: 7660
- Joined: Sun Jun 11, 2006 10:14 pm
- Location: Kawartha Lakes, Ontario
Re: Front tire size, performance, radial
I would be very concerned about that.
Mr. Honda ('83 GL1100/Dnepr) summer How a motorcycle evolves thread
The Famous Eccles ('84 CX650EI/VeloUral) winter Never Ending Build (CX500forum)
Click: Colour schematics for all GL1000 & GL1100 and GL1200 standard models plus instructions on how to download the full size version
"A guy with two sidecars can't be all bad." - Cookie
Another guy with two sidecars..... Hmmmm... must be something to that....
The Famous Eccles ('84 CX650EI/VeloUral) winter Never Ending Build (CX500forum)
Click: Colour schematics for all GL1000 & GL1100 and GL1200 standard models plus instructions on how to download the full size version
"A guy with two sidecars can't be all bad." - Cookie
Another guy with two sidecars..... Hmmmm... must be something to that....
- pidjones
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Re: Front tire size, performance, radial
Lowering the front also reduces trail. Keep a hand on the bars at all times to prevent wobble onset.
"Love 'em all.... let God sort 'em out!"
Ex 2006 GL1800 - the Black Pearl SOLD! to make room for:
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Ex 1978 GL1000
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Ex '86 SEi
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Ex '72 Penton 125 set up for flat track
Ex '73 RD250
Ex '68 TR6C - chopped
Ex 2006 GL1800 - the Black Pearl SOLD! to make room for:
2021 Can-Am Spyder RT Limited Dark Chalk Metallic
1975 Red GL1000 project - ex Pistol Pete project
1972 Triumph T150V Trident rescue - finished and FOR SALE!
1976 Yamaha RD400c
1978 GL1000 with '75 engine - the Hunley
Ex 1978 GL1000
Ex 1979 GL1000
Ex '79 CB750F rat bike
Ex '86 SEi
Ex '77 GL1000
Ex '76 RD400
Ex '72 Penton 125 set up for flat track
Ex '73 RD250
Ex '68 TR6C - chopped
- ericheath
- Honored Life Member
- Posts: 9581
- Joined: Wed Jul 29, 2009 11:20 am
- Location: Winnipeg, Manituba
Re: Front tire size, performance, radial
I have my front end raked, so I have ways to go before I reduce trail too much. I need to check my triple tree bearings but cannot find my tools for removing the Honda fasteners. I might have to make some more.
Whatever I suggest here should be given ample time for a moderator to delicately correct. I apologize in advance.
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi
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