worse now with the race tech springs no valves
should i take the wheel weights off?, some look like they fell out, i have no clue if they are balanced, or imbalanced
would that cause the wobble?
i check the air pressure on both tires already
If some of the balancing weights fell off, then its almost a surety that the tire is out of balance. On my 85, anything over 65 mph caused a very bad wobble. New tire, and balanced rims, and the wobble was completely gone. I would certainly start by getting the tire rebalanced.
Quote from: ryanschoebel on March 31, 2019, 08:05:24 PM
If some of the balancing weights fell off, then its almost a surety that the tire is out of balance. On my 85, anything over 65 mph caused a very bad wobble. New tire, and balanced rims, and the wobble was completely gone. I would certainly start by getting the tire rebalanced.
ok thanks for your ex[erience, but mostly on deceleration, will check it out
What brand/model tire is on the front
How old/worn is it?
Quote from: FJ_Hooligan on March 31, 2019, 09:56:06 PM
What brand/model tire is on the front
How old/worn is it?
That's the reason in most of the cases. New tire solved it for me.
Quote from: FJ_Hooligan on March 31, 2019, 09:56:06 PM
What brand/model tire is on the front
How old/worn is it?
stock 85 rims
looks newish dunlop, GT501f arrowmax front and rear
Looks like the front tire on that model has a center groove running around the circumference of the tire.
EVERY tire I EVER had with that kind of groove had a coast down wobble. Just the slightest of wear and it would start. I stopped using tires with a center groove and no more wobble.
Quote from: FJ_Hooligan on April 01, 2019, 01:57:20 AM
Looks like the front tire on that model has a center groove running around the circumference of the tire.
EVERY tire I EVER had with that kind of groove had a coast down wobble. Just the slightest of wear and it would start. I stopped using tires with a center groove and no more wobble.
yeah does not inspire confidence, , got me to a crawl with the "new to me fj"
on the fj particularly? or any bike? and kinda makes sense, the contact patch is right on the groove, and take away a large piece of it in the center the two remain sides are gonna squirm... shhhhs, another bug to work out
can i keep the back, i think they are bias plys
what is the recommended budget replacement , while keeping the "arrowmax dunlop rears"
i dialed back the preload( less harsh) and the rear as well ( stock shock)
check tire pressure again not 36 front 38 rear
took all the remain weights off the front wheel and goes to 75 mpg and no problem
but let off at 55mpg and it will shake to 45 on the coast
at least i don't have the death grip on it no more
Try 36 front and 42 rear
Here's a few ideas. Like others have said, the FJ is a bit particular about its hoops and certain tread patterns cause all sorts of oddness, like cupping and wiggling down the road. I recommend Michelin road pilots 2 or 3 or 4.
Certainly wheel weights not being where they should will cause tea trolley skittishness. Once balanced, I like to trace round them with a sharpie so you can instantly see if one flys off.
When I bought my 86 originally, the biggest front end correction came in the form of wheel bearings. The RHS one fell apart when the wheel was removed. Water had got in on this side because of the side stand location tilting it skyward and corroded the internals.
After those three, it's all refinement of the norm with braces (which should have been a factory standard, so treat yourself if you've not got one) stiffer springs and RPM clever valves to smooth out the ups and downs.
Job done.
Oh a plus 1 on the 36/42 pressure split. That'll keep you pointing the right way.
Looking on Dunlop's website, the GT501F Arrowmax appears to no longer be in production. Age of the tire could be part of the issue. Is the tire a 110 or a 120?
After reading your list of issues with the front tire, and the knowledge that the FJ does tend to not like tires with a solid center groove. My recommendation would be to buy a new set of tires and have them professionally balanced. 36/42 air pressure and go from there.
Fred
Quote from: aviationfred on April 01, 2019, 11:58:19 PM
Looking on Dunlop's website, the GT501F Arrowmax appears to no longer be in production. Age of the tire could be part of the issue. Is the tire a 110 or a 120?
After reading your list of issues with the front tire, and the knowledge that the FJ does tend to not like tires with a solid center groove. My recommendation would be to buy a new set of tires and have the professionally balanced. 36/42 air pressure and go from there.
Fred
so you too have experienced grooved front tires behaving badly on your fj?
size 120, not quite in the budget for a new set of tires right this moment, but i know i am playing with fire
had an xs1100 i restored with the most dry rotted, oldest not even made in the past 40 years tire on it and it went 115 mph, no i don't have a death wish, but to count these tires out right this moment is..... :dash2:
Quote from: andyoutandabout on April 01, 2019, 11:29:55 PM
Oh a plus 1 on the 36/42 pressure split. That'll keep you pointing the right way.
so those are the magic numbers
36/42
not 36/40
35/38
but
36/42
forever and ever? lol
ok
Quote from: mtc on April 02, 2019, 12:20:21 AM
....not quite in the budget for a new set of tires right this moment, but i know i am playing with fire....... but to count these tires out right this moment is..... :dash2:
Why don't you look at the date code on your tires and see exactly how old they are?
Quote from: Pat Conlon on April 02, 2019, 12:49:58 AM
Quote from: mtc on April 02, 2019, 12:20:21 AM
....not quite in the budget for a new set of tires right this moment, but i know i am playing with fire....... but to count these tires out right this moment is..... :dash2:
Why don't you look at the date code on your tires and see exactly how old they are?
remind me how to do that please
Its the 4 digit code inside the oval on the side of the tire. The first two are the week, second two are the year. Ex, 2617 would mean they were made the 26th week of 2017.
Quote from: ryanschoebel on April 02, 2019, 01:19:31 AM
Its the 4 digit code inside the oval on the side of the tire. The first two are the week, second two are the year. Ex, 2617 would mean they were made the 26th week of 2017.
thanks i can't wait to find out, on weds
Quote from: Pat Conlon on April 02, 2019, 12:49:58 AM
Quote from: mtc on April 02, 2019, 12:20:21 AM
....not quite in the budget for a new set of tires right this moment, but i know i am playing with fire....... but to count these tires out right this moment is..... :dash2:
Why don't you look at the date code on your tires and see exactly how old they are?
rear 4512
front 3512
45th and 35th week of 2012. Not quite 7 years old.
Quote from: RPM - Robert on April 02, 2019, 10:06:16 AM
45th and 35th week of 2012. Not quite 7 years old.
so are they finished?
if they are,i am going to be an occasional rider, no iron butt here
but i want confidence inspiring
what is a good budget tire, shinko? kenda?
I personally wouldn't run them. But some would, I am sure. The Shinko tires are ok, my dad ran a set on his bike for a year or so. He said they weren't awe inspiring by any means but they are a decent budget tire. I do recall the rear would get real squirmy on longer rides in twisties with them.
MTC, I sent you a PM
Cliff's Notes: It Sounds Like You Need New Tires.
Sorry if that seems expensive. It's going to be $300 to $400, depending on what you get and where you get them and how much you get charged to install them. I carry in my wheels, I think it's $25 / tire for mounting and balancing that way. That fifty bucks stays the same whether you get the best tires around or the cheapest things that'll fit.
You may not believe you need new tires because you can see that yours still have tread on them. Unfortunately, "having tread on them" is not the only deciding factor on whether or not a tire is still good. Sort of like "holding air," it takes more than "having some tread left" for a tire to still be any good.
1) Tires get worse as they age. You have established that yours are pretty old already (seven years is a long time for rubber.)
B) Tires wear oddly sometimes. Yours are probably scalloped, which both results from and causes more of a tank-slapping tendency. More pressure often helps (if the sidewall max pressure is 42psi, you might have better luck at ~40psi or greater; the FJ is at the heavy end of "bikes that would run a tire like this one.") But once they wear funny and it's noticeable in how the bike handles, their day is done.
iii) Some tires are just not that great even when they're brand new. My experiences with earlier versions of your tires (Dunlop "Sport Elite" K591, on both an FJ1200 and on another bike) were not very good. Dunlop does make some good sportbike tires; I would be willing to guess that yours are not those tires, not when they were new, not when they had zero miles. You can argue that the ones I had are different than the ones you had, "Your experience was with a Chevy Cavalier! My Chevy is a Cobalt - COMPLETELY different thing!" Yeah, not that different... It's not like one of 'em is a Corvette here.)
I can't recall what year / size tires you have. If you're riding something pre-1988 with stock wheels, you have a 16" front wheel, and none of the specific recommendations I can make will be of any use to you. All my experience is on a 17"x3" FJ wheel from 1989 (US) or later.
For years, I was fitting my 17x3 front wheel with Metzler tires, and some of them would wear funny and tend toward tank-slappers like you are experiencing. This would become noticeable after 3,000 or 4,000 miles on a tire, long before they were "worn out." Recent tires (ME-Z6 and ME-Z8 radials) have been much better, and they go to 6,500 without wobbling, but earlier ME-Z1 or ME-Z2 tires would wobble when there was still tread showing. I used to hate throwing out a tire that still had some tread on it, until I rode on the new tire and realized "yeah, this is how it's supposed to be."
Higher pressure helped, and I was running ~40 psi up front (which didn't seem unreasonable, since the FJ is among the heaviest of bikes that will use most sporting front tires.) But after a while, the tire would be worn in a scalloped pattern and it would be a nightmare to ride.
If you can find radial tires in appropriate size, that's what you want. Radial tires are like synthetic oil - they are better at everything you want out of a tire (or oil) and there's no reason to hamstring yourself with 1980's technology just because our bikes are from the 1980s.
Randy Thompson had Shinko tires. I tried his bike (never could get him to try my 998, but I think I got him to try my FJ with the RaceTech / Penske.) I do not like riding on Shinko tires. I know they're cheaper, I don't care. (Also, I don't think they last as long as the 6,500 to 8,000 miles I get from Roadtecs, so they may not even be cheaper to run; the lower price might have to be paid more often.)
Good luck.
- Bill
Quote from: Bill_Rockoff on April 03, 2019, 03:20:21 PM
Cliff's Notes: It Sounds Like You Need New Tires.
Sorry if that seems expensive. It's going to be $300 to $400, depending on what you get and where you get them and how much you get charged to install them. I carry in my wheels, I think it's $25 / tire for mounting and balancing that way. That fifty bucks stays the same whether you get the best tires around or the cheapest things that'll fit.
You may not believe you need new tires because you can see that yours still have tread on them. Unfortunately, "having tread on them" is not the only deciding factor on whether or not a tire is still good. Sort of like "holding air," it takes more than "having some tread left" for a tire to still be any good.
1) Tires get worse as they age. You have established that yours are pretty old already (seven years is a long time for rubber.)
B) Tires wear oddly sometimes. Yours are probably scalloped, which both results from and causes more of a tank-slapping tendency. More pressure often helps (if the sidewall max pressure is 42psi, you might have better luck at ~40psi or greater; the FJ is at the heavy end of "bikes that would run a tire like this one.") But once they wear funny and it's noticeable in how the bike handles, their day is done.
iii) Some tires are just not that great even when they're brand new. My experiences with earlier versions of your tires (Dunlop "Sport Elite" K591, on both an FJ1200 and on another bike) were not very good. Dunlop does make some good sportbike tires; I would be willing to guess that yours are not those tires, not when they were new, not when they had zero miles. You can argue that the ones I had are different than the ones you had, "Your experience was with a Chevy Cavalier! My Chevy is a Cobalt - COMPLETELY different thing!" Yeah, not that different... It's not like one of 'em is a Corvette here.)
I can't recall what year / size tires you have. If you're riding something pre-1988 with stock wheels, you have a 16" front wheel, and none of the specific recommendations I can make will be of any use to you. All my experience is on a 17"x3" FJ wheel from 1989 (US) or later.
For years, I was fitting my 17x3 front wheel with Metzler tires, and some of them would wear funny and tend toward tank-slappers like you are experiencing. This would become noticeable after 3,000 or 4,000 miles on a tire, long before they were "worn out." Recent tires (ME-Z6 and ME-Z8 radials) have been much better, and they go to 6,500 without wobbling, but earlier ME-Z1 or ME-Z2 tires would wobble when there was still tread showing. I used to hate throwing out a tire that still had some tread on it, until I rode on the new tire and realized "yeah, this is how it's supposed to be."
Higher pressure helped, and I was running ~40 psi up front (which didn't seem unreasonable, since the FJ is among the heaviest of bikes that will use most sporting front tires.) But after a while, the tire would be worn in a scalloped pattern and it would be a nightmare to ride.
If you can find radial tires in appropriate size, that's what you want. Radial tires are like synthetic oil - they are better at everything you want out of a tire (or oil) and there's no reason to hamstring yourself with 1980's technology just because our bikes are from the 1980s.
Randy Thompson had Shinko tires. I tried his bike (never could get him to try my 998, but I think I got him to try my FJ with the RaceTech / Penske.) I do not like riding on Shinko tires. I know they're cheaper, I don't care. (Also, I don't think they last as long as the 6,500 to 8,000 miles I get from Roadtecs, so they may not even be cheaper to run; the lower price might have to be paid more often.)
Good luck.
- Bill
ok thanks good explanation... better than skin grafts like pat says
but.........
can i hang on to the old rear tire and just deal with the front for the time being?
Is your life worth the cost of new tires? Why risk it? If the tires are questionable at all; they are worth replacing. Things that happen on a bike can turn ugly very quickly.
Quote from: copper on April 03, 2019, 04:36:20 PM
Is your life worth the cost of new tires? Why risk it? If the tires are questionable at all; they are worth replacing. Things that happen on a bike can turn ugly very quickly.
first it's skin grafts and now it's my life, this is turning into a pricey hobby, but you are right, a new pair for sure
Have you had a look at the steering head bearings and bearing races?
Quote from: RPM - Robert on April 03, 2019, 05:44:44 PM
Have you had a look at the steering head bearings and bearing races?
your'e killing me here ... the mere fact of tearing it down to the triple clamps makes me nauseous
41k miles, used but not abuse, kept ootof the sun, that is apparent
(https://i679.photobucket.com/albums/vv159/Salsadancer383/20190317_122415_zpsqppwrya0.jpg) (https://s679.photobucket.com/user/Salsadancer383/media/20190317_122415_zpsqppwrya0.jpg.html)
If trouble shooting a problem just do one thing at a time. Check and test tyre pressures, and, if problem persists, upgrade the tyres then see how things are. If problem still persists, take the next step, head bearing adjustment, whatever.
mtc - checking is pretty straightforward - put the bike on the centre stand, weight the rear end to get the front off the ground and grab the bottom of the forks. Pull the fork bottoms back and forth to see if there is any "play" that you can feel, or "knocking". If you're not sure, put the steering onto full lock each side and try the same pull each side.
If there's no undue/excess play, then your bearings aren't overly loose. With the front wheel off the ground, the handlebars should swing easily to both lock-stops, with no resistance or tight spots (if there are tight spots, you'll need to investigate further (just to see if adjustment/lubrication isneeded).
Assuming those check out OK (other than the triple clamps maybe needing to be disassembled and the bearings re-greased), then your wobble is nothing to do with the steering head bearings.
It costs nothing to find out, adjusting then is easy and you only need to spend money if your bearings are goosed.
Quote from: Millietant on April 03, 2019, 07:20:55 PM
mtc - checking is pretty straightforward - put the bike on the centre stand, weight the rear end to get the front off the ground and grab the bottom of the forks. Pull the fork bottoms back and forth to see if there is any "play" that you can feel, or "knocking". If you're not sure, put the steering onto full lock each side and try the same pull each side.
If there's no undue/excess play, then your bearings aren't overly loose. With the front wheel off the ground, the handlebars should swing easily to both lock-stops, with no resistance or tight spots (if there are tight spots, you'll need to investigate further (just to see if adjustment/lubrication isneeded).
Assuming those check out OK (other than the triple clamps maybe needing to be disassembled and the bearings re-greased), then your wobble is nothing to do with the steering head bearings.
It costs nothing to find out, adjusting then is easy and you only need to spend money if your bearings are goosed.
ok i ck it when i got the front rim off for the tire
Quote from: mtc on April 03, 2019, 03:56:25 PM
Quote from: Bill_Rockoff on April 03, 2019, 03:20:21 PM
Higher pressure helped, and I was running ~40 psi up front (which didn't seem unreasonable, since the FJ is among the heaviest of bikes that will use most sporting front tires.) But after a while, the tire would be worn in a scalloped pattern and it would be a nightmare to ride.
got them up to 40 psi and it's much better, i can ride...