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General Category => General Discussion => Topic started by: dxhall on August 15, 2015, 02:22:13 PM
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After getting a speeding ticket on my Le Mans a few weeks ago going up Independence Pass, I find myself riding the '71 Ambassador. The stock forks on the Ambo are pretty harsh compared to the Ohlins on the Le Mans. What's the best way to improve the Ambo forks? I can't remember what fork oil I used.
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Something's wrong with them...
Most (drum-brake) Loop owner's will have the opposite complaint - too mushy or soft. Maybe your springs are so sacked that it's bottoming out, or the bushings are so worn that they're binding? Could be fork alignment as well. I'd loosen up all 4 pinch bolts and see if it gets any better.
There's really only two improvements for drum-brake forks: 1) Wirth springs and heavier fork oil. I use 8 oz. of 30w fork oil in each leg. The extra 2.6 oz. over factory specs helps in two ways: a) damping for the entire stroke of the fork and b) less air gap for slightly firmer effective springing.
http://www.mgcycle.com/index.php?main_page=product_info&cPath=197_199&products_id=1147
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Sounds like I should hit up the MG Cycle guys. Charlie, do you know what Moe Moore puts in the Cycle Garden bikes?
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No, I don't.
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Sounds like I should hit up the MG Cycle guys. Charlie, do you know what Moe Moore puts in the Cycle Garden bikes?
synthetic saline 30w skank oil.
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Something's wrong with them...
Most (drum-brake) Loop owner's will have the opposite complaint - too mushy or soft.
:1:
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Sounds like I should hit up the MG Cycle guys. Charlie, do you know what Moe Moore puts in the Cycle Garden bikes?
considering his prices, I'd guess unicorn tears :laugh:
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There's really only two improvements for drum-brake forks: 1) Wirth springs and heavier fork oil. I use 8 oz. of 30w fork oil in each leg. The extra 2.6 oz. over factory specs helps in two ways: a) damping for the entire stroke of the fork and b) less air gap for slightly firmer effective springing.
http://www.mgcycle.com/index.php?main_page=product_info&cPath=197_199&products_id=1147
:thumb: :thumb: :thumb:
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I used 30w VR1 in the forks of my Eldo. It was all I had handy at the time and it seems to be working good for the last 2 or 3 years.
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I'm getting ready to change fork oil and it's been long enough that I don't remember the process from last time. But my '72 Eldo doesn't seem to have drain screws so I'm thinking I'll have to remove and invert the fork tubes instead. Does that make sense, or am I just not seeing the screws? :sad:
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I'm getting ready to change fork oil and it's been long enough that I don't remember the process from last time. But my '72 Eldo doesn't seem to have drain screws so I'm thinking I'll have to remove and invert the fork tubes instead. Does that make sense, or am I just not seeing the screws? :sad:
The screws are there - they're "hidden" under the the "lug" where the rear fender brace attaches to the slider.
(https://i.ibb.co/LzSPmsj/Loop-forks.jpg) (https://ibb.co/LzSPmsj)
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Charlie
can you drain and then refill using same hole while on the bike? I'm thinking of a syringe and squirting it in and then plugging back up.
Mark
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Thanks Charlie
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Charlie
can you drain and then refill using same hole while on the bike? I'm thinking of a syringe and squirting it in and then plugging back up.
Mark
[/quote
Interesting question, Mark. I imagine you may be able to if you rig up some kind of threaded nipple to screw into the little hole, then about a 10CC minimum syringe with tubing attached , after draining all the oil, use a clamp to block the hose while you reload your syringe for the next "injection " of oil.
What Charlie advised is 100%. I used a full 10 oz of 50 wt "Harley" oil in each fork leg of my 73 eldo, and it helped the forks work better. When finished, you will have to be quick in reinstalling the bolt, to keep the oil from leaking out.. Of course ,its always better to take them all apart and clean them up, but in a pinch, just doing an oil change like that may get you by.
Good luck,
Rick.
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(https://photos.imageevent.com/time_warp1959/motorcycle/mgmods/bts.jpg)
(https://photos.imageevent.com/time_warp1959/motorcycle/mgmods/p1.jpg)
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Charlie
can you drain and then refill using same hole while on the bike? I'm thinking of a syringe and squirting it in and then plugging back up.
Mark
I've never tried, but my suspicion is that it could get very messy. The oil that you're squirting in would be trying to displace air within the fork, compressing it. The compressed air will force whatever oil you manage to get in, back out again.
But, here's a thought, as Rick surmises, if one had a fitting to thread into the drain plug hole, it might be possible to compress the forks to drain the old oil, compress them as much as possible again, hook up the fitting and a hose going into a container of whatever fork oil you want to fill it with. Extending the forks fully should create enough of a vacuum to draw the oil into the forks. Will it draw in even the original 5.4 ounces, much less 8 or 10? Good question. Trying to draw fork through a small (3 mm?) hole likely won't go well. All hypothetical.
But, is it really so difficult to lift up the dash, take the top plugs out and pour the oil in? I guess for a Loop with certain windshield brackets it could be.
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I agree with ACC and his recommendations. I go a little farther and pour some leftover 5wt fork oil in to flush the tubes a little more, usually get some more dirt out the drains. And use 8 oz. of 15w-50 Mobil 1 engine oil. Forks don't know the difference and seem to ride well, done yearly. :bike-037:
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synthetic saline 30w skank oil.
Bwahaha.
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The way I do it is to open the drain plugs and let the oil drain out completely then pour in some kerosene from the top; let it drain out completely and move the bike from side to side and pump the forks with your hands on the handlebar further emptying it, then let it sit over night and button up everything the next morning and put in Bel Ray 30wt. Put in an ounce extra and make sure you have Wirth springs in there. I simply do not know why motorcycle manufacturers don't put drain plugs on their forks.
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Put in an ounce extra and make sure you have Wirth springs in there. I simply do not know why motorcycle manufacturers don't put drain plugs on their forks.
I have Wirth springs in my V700 and while it doesn't bottom out as badly as my Ambo with (50 year old) stock springs, it also doesn't ride as well. I may try a set of new stock type springs and see if I like them better.
Up until fairly recently almost all manufacturers did put drain plugs on their forks (except maybe on USD type forks). I guess it costs too much to drill a hole, tap it and fit a plug and sealing washer. :wink:
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But, is it really so difficult to lift up the dash, take the top plugs out and pour the oil in? I guess for a Loop with certain windshield brackets it could be.
Trust me, if I can manage to do that job, just about anyone can!
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I have Wirth springs in my V700 and while it doesn't bottom out as badly as my Ambo with (50 year old) stock springs, it also doesn't ride as well. I may try a set of new stock type springs and see if I like them better.
Great to know before replacing springs on mine. Thanks, Charlie.
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When I overhauled the forks on my 70 ambo I used synthetic trany fluid in them. The guts on them are pretty basic so if they are stiff somethings wrong. My old ambo is the smoothest riding bike I own. I also have IKON shocks on the back. I can ride the old beast all day with no problem'
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When I overhauled the forks on my 70 ambo I used synthetic trany fluid in them. The guts on them are pretty basic so if they are stiff somethings wrong. My old ambo is the smoothest riding bike I own. I also have IKON shocks on the back. I can ride the old beast all day with no problem'
I've rebuilt dozens of these forks so I know my way around them by now. :wink: I didn't write "stiff" - the "something wrong" is just that the ride is firmer than my old Ambo. Not a bad thing, just different. Does make for better handling. :azn:
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Hello.
Need some advice, i shall change the fork oil on my V7 Special -1971.
-Do i need to remove the front wheel, fender etc? Or it is enough to drain the oil and then refill?
-Any other oil that can be used except 30W fork oil?
Regards,
Fredrik
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Hello.
Need some advice, i shall change the fork oil on my V7 Special -1971.
-Do i need to remove the front wheel, fender etc? Or it is enough to drain the oil and then refill?
-Any other oil that can be used except 30W fork oil?
Regards,
Fredrik
No need to remove the wheel and fender, etc. Remove the drain screws and pump the forks to eject the old oil.
Drum brake Loop forks are so crude that it really doesn't matter what you use (almost). I've heard of motor oil, gear oil, transmission fluid and hydraulic oil being used. I tried 80w90 gear oil recently and it works just fine, perhaps a bit more damping. Do use more than the original specified 5.4 oz. - with that amount there's a huge "dead spot" in the fork travel where there is absolutely zero damping. 8 oz. is my preferred amount.
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FWIW...
I just replaced the fork seals on my '72 Eldo. I re-installed the forks with new springs ($58/pr.) and added 7oz. of Belray 30w to each leg.
So, I haven't rode the bike yet but the springs are definitely better than what I had, no front end dive when taking it off the side stand. I only put 7oz in each leg because I've read where you guys (having way more experience with this) claim 5.4 was insufficient and I can always add more. I poured the fork oil into the forks using a funnel and after I installed them. In the past, I have always added fork oil and then pump them to bleed out air, toss in the spring, screw on cap and re-install into the bike. This time I completely forgot to first add oil and pump air before installing legs back into bike so I hope it doesn't make too much difference.
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FWIW...
I just replaced the fork seals on my '72 Eldo. I re-installed the forks with new springs ($58/pr.) and added 7oz. of Belray 30w to each leg.
So, I haven't rode the bike yet but the springs are definitely better than what I had, no front end dive when taking it off the side stand. I only put 7oz in each leg because I've read where you guys (having way more experience with this) claim 5.4 was insufficient and I can always add more. I poured the fork oil into the forks using a funnel and after I installed them. In the past, I have always added fork oil and then pump them to bleed out air, toss in the spring, screw on cap and re-install into the bike. This time I completely forgot to first add oil and pump air before installing legs back into bike so I hope it doesn't make too much difference.
No need to "bleed out air" - the damping system is so crude (basically just a prong at the bottom of the slider that goes into a hole in the nut securing the bottom bushing, and a hole in the side of the tube - that's all) that no air is likely to be trapped anywhere. Nor can one "toss in the springs" since on drum-brake forks the springs are external to the tubes.
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So i can more or less use ordinary mineral SAE30 engine oil? "Lawnmover oil"? :afro:
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So i can more or less use ordinary mineral SAE30 engine oil? "Lawnmover oil"? :afro:
Yep, you can use multi viscosity as well.
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No need to "bleed out air" - the damping system is so crude (basically just a prong at the bottom of the slider that goes into a hole in the nut securing the bottom bushing, and a hole in the side of the tube - that's all) that no air is likely to be trapped anywhere.
Thanks Charlie! I'll commit this to my failing memory for future reference. Anyway, I'm looking forward to trying out the new springs and higher fluid level as soon as the weather becomes milder here.
Art
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Yep, you can use multi viscosity as well.
What i can see is a 10W40 oil at 40 degrees almost same mm/s (90-100) as a 30W forkoil.
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Thanks Charlie! I'll commit this to my failing memory for future reference. Anyway, I'm looking forward to trying out the new springs and higher fluid level as soon as the weather becomes milder here.
Art
You're welcome. If you used the "Stucchi improved" springs, I think you'll like them.
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Changed the fork oil today, what came out looked like coffee with cream rather than oil. :shocked:
(https://i.ibb.co/JtP5Fgg/314124-F4-7-BB7-4603-86-B7-2-A970010-F272.jpg) (https://ibb.co/JtP5Fgg)
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Looks thin too.