educate me on fork oil viscosity please


Information and questions on GL1200 Goldwings (1984-1987)
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sportsfreaked
Posts: 370
Joined: Fri Mar 13, 2015 7:23 am
Location: Independence, MO
Motorcycle: 1981 Honda Goldwing Interstate GL1100I
1985 Honda Goldwing Limited Edition gl1200

educate me on fork oil viscosity please

Post by sportsfreaked »



I finally have my 1985 gl1200 LTD sorted out. I have new swing arm bearings new tires and wheel bearings, steering head repacked with grease and adjusted. Have new progressive springs in front and progressive shocks (air) in the back. The ride up front is a bit bouncy I guess is the best way to describe it. I am using 15wt fork oil. The forks were rebuilt as well. Now keep in mind I was use to 33 year old springs and shocks. It rode good before but was a more softer ride it also bottomed out in the rear especially with 2 up. I have the TRAC setting on 1 abd run no air in the front.
Will changing the 15wt oil out and replacing it with 5wt or even ATF make for a "softer" ride up front?

This is not related but thought I would share this. I put balance beads in the front tire when I put it on and I couldn't get past 65 mph without major vibration. I thought it had to be the beads. I took the tire back off and vacuumed out the beads and static balanced the tire and put it back on and what do you know smooth as can be. I'm stumped at the fact that the beads didn't work. This nay help someone down the road.

I really would like the front end to be a bit softer then what it is now. So any and all suggestions would be appreciated. Thanks to one and all.


Thanks to all who answer and help. It is greatly appreciated!
Ed

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virgilmobile
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Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: educate me on fork oil viscosity please

Post by virgilmobile »

Thinner viscosity oil will allow the front wheel to extend quicker than thick oil.It is dampening fluid.Valves open to allow a quick compression and close to slow the extension as the oil squeezes through.The trax is a control valve used to restrict compression dampening.I theory its suppose to reduce the nose dive under hard braking.
If your ride is stiff,try a thinner oil.Some even mix oils to fine tune the fork action.
I've used balancing beads exclusively on all my bikes.Never had a issue with balance through.....well...I'll say the posted speed limit.
There may be another underlying problem.Swing arm?Wheel bearings?Brake drag?Alignment?Watch for tire wear and proper air pressure.

sportsfreaked
Posts: 370
Joined: Fri Mar 13, 2015 7:23 am
Location: Independence, MO
Motorcycle: 1981 Honda Goldwing Interstate GL1100I
1985 Honda Goldwing Limited Edition gl1200

Re: educate me on fork oil viscosity please

Post by sportsfreaked »

Virgin thanks for the reply. In regards to the balance beads I used them on my 81 with no problem. The bike rides fine now that there are no beads. Go figure. The ride is just a bit to firm. I'm going to try the lighter oil and see how it works. Thanks again for taking the time!
Thanks to all who answer and help. It is greatly appreciated!
Ed

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virgilmobile
Posts: 9080
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: educate me on fork oil viscosity please

Post by virgilmobile »

Keep us posted on the results.

harvey01
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Location: Henrico, Virginia
Motorcycle: 2004 GL1800

Re: educate me on fork oil viscosity please

Post by harvey01 »

sportsfreaked wrote:
Sun Aug 13, 2017 8:01 pm
I finally have my 1985 gl1200 LTD sorted out. I have new swing arm bearings new tires and wheel bearings, steering head repacked with grease and adjusted. Have new progressive springs in front and progressive shocks (air) in the back. The ride up front is a bit bouncy I guess is the best way to describe it. I am using 15wt fork oil. The forks were rebuilt as well. Now keep in mind I was use to 33 year old springs and shocks. It rode good before but was a more softer ride it also bottomed out in the rear especially with 2 up. I have the TRAC setting on 1 abd run no air in the front.
Will changing the 15wt oil out and replacing it with 5wt or even ATF make for a "softer" ride up front?

This is not related but thought I would share this. I put balance beads in the front tire when I put it on and I couldn't get past 65 mph without major vibration. I thought it had to be the beads. I took the tire back off and vacuumed out the beads and static balanced the tire and put it back on and what do you know smooth as can be. I'm stumped at the fact that the beads didn't work. This nay help someone down the road.

I really would like the front end to be a bit softer then what it is now. So any and all suggestions would be appreciated. Thanks to one and all.
I am just guessing but do you have springs up front from Progressive Suspension or are they from some other manufacturer. If from Progressive are they the correct springs for your bike and weight including you?

If you do change out the oil in the forks, I would go with a good oil designed for the forks, Bel Ray, or even Honda's brand and try a 10wt before going to a 5 wt. One of the big advantages to using a fork specific oil is they come in different weights so you know exactly what you are using. Also did you need spacers?
harvey
Ride Safe and Ride Often

sportsfreaked
Posts: 370
Joined: Fri Mar 13, 2015 7:23 am
Location: Independence, MO
Motorcycle: 1981 Honda Goldwing Interstate GL1100I
1985 Honda Goldwing Limited Edition gl1200

Re: educate me on fork oil viscosity please

Post by sportsfreaked »

Harvey they are progressive springs up front and they are the correct springs and they dont require spacers of any kind. It would appear that the fork oil may be the problem. I have read a lot of folks who went with progressive and used 15 wt oil that it was to rigid/rough of a ride. I'm going to change it tomorrow to atf or a 5 wt oil. A lot of folks went back to atf and said the ride was smoother. I will report back what I do and find out. Thanks. Ed
Thanks to all who answer and help. It is greatly appreciated!
Ed

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oldishwinger
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Motorcycle: 1986 GL1200 Aspencade

Re: educate me on fork oil viscosity please

Post by oldishwinger »

sportsfreaked wrote:
Mon Aug 14, 2017 2:31 pm
Harvey they are progressive springs up front and they are the correct springs and they dont require spacers of any kind. It would appear that the fork oil may be the problem. I have read a lot of folks who went with progressive and used 15 wt oil that it was to rigid/rough of a ride. I'm going to change it tomorrow to atf or a 5 wt oil. A lot of folks went back to atf and said the ride was smoother. I will report back what I do and find out. Thanks. Ed
I found the 15w was too heavy when I installed progressives in the front, I went back to ATF fluid which is the OEM recommendation and with no air, and the trac set on 1 it rides really nice. its a slightly stiffer ride, than OEM but in my humble opinion, it handles better, particularly when carrying a bit of weight in the bags.

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thrasherg
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Re: educate me on fork oil viscosity please

Post by thrasherg »

For the balance bead question, I can only think that maybe you didn't put enough beads in your tyre. If you added 2oz of beads but the wheel balance was out by 3oz, it would never balance and you would have a vibration. You mentioned that you went back and performed a static balance, how much weight did you have to add to get it to static balance? did you have at least that much weight in beads in the tyre previously?

I can't think of anything else that would stop the beads from balancing the wheel.

Gary

sportsfreaked
Posts: 370
Joined: Fri Mar 13, 2015 7:23 am
Location: Independence, MO
Motorcycle: 1981 Honda Goldwing Interstate GL1100I
1985 Honda Goldwing Limited Edition gl1200

Re: educate me on fork oil viscosity please

Post by sportsfreaked »

Gary,
I didn't have beads in the previous tire. When I took the beads out I weighed them again and it was 2 oz. When I static balanced the tire it took zero weights. The tire to my surprise was perfectly balanced. It rides fine now except for the harsh to me ride. I'm changing the fork oil today. I don't know why the beads didn't work. Baffling for sure.
Thanks to all who answer and help. It is greatly appreciated!
Ed

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thrasherg
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Re: educate me on fork oil viscosity please

Post by thrasherg »

Best of luck with the fork oil change, remember to put the bike on it's center stand, then jack the front of the engine up so no weight is on the front wheel, before you open the top of the forks to add/drain the oil. :D

No idea why the wheel didn't balance, are you sure the tyre was correctly located on the rim before? If it was not sitting properly on the rim (all the way round the rim) that would cause a vibration that beads could not fix, then when you removed the tyre from the rim to remove the beads, maybe the rim sat correctly the next time and that's why it now runs smoothly? Cant think of any reason the beads would cause a vibration..

Gary

sportsfreaked
Posts: 370
Joined: Fri Mar 13, 2015 7:23 am
Location: Independence, MO
Motorcycle: 1981 Honda Goldwing Interstate GL1100I
1985 Honda Goldwing Limited Edition gl1200

Re: educate me on fork oil viscosity please

Post by sportsfreaked »

Well did the change and just went with ATF. Wow what a difference it made. Nice smooth ride at 85. The 15 wt was just to harsh. Thanks for all the replies. Thank goodnes I'm done upgrading the bike. Now I can just enjoy it. Safe riding.


Thanks to all who answer and help. It is greatly appreciated!
Ed

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