Strange shimmy on Monarch II trike

[Montana Lee]

First post here and hope to solve a problem. I just bought a 2010 Goldwing with the Monarch II trike. I was surprised that even at slow speeds the trike front end seemed to have a mind of it's own, It wanted to go into an uncontrollable shimmy even at slow speeds. Is there some unique about the suspension that would cause this? Is it normal ? Any help will certainly be welcome. I've had a Motor Trike before this and after 300,000 miles on it, never a problem. But it was an IRS suspension where this one is solid axle.

[rhino 2]

First post here and hope to solve a problem. I just bought a 2010 Goldwing with the Monarch II trike. I was surprised that even at slow speeds the trike front end seemed to have a mind of it's own, It wanted to go into an uncontrollable shimmy even at slow speeds. Is there some unique about the suspension that would cause this? Is it normal ? Any help will certainly be welcome. I've had a Motor Trike before this and after 300,000 miles on it, never a problem. But it was an IRS suspension where this one is solid axle.

Long time between post's' Lee.......

..Besides the shimmy what have you been up to....

[Montana Lee]

Long time between post's' Lee.......

..Besides the shimmy what have you been up to....

For the last few years I been riding all over on my Honda ST1300. Sadly, I have a torn Achilles tendon and they say it will take about 8 months to heal so I didn't want to have to be laid up that long and thus the trike. I can't really steady myself without the use of that right foot. So my precious ST will have to go.

[FuzzyWuzHe]

Check tire balance and pressures ... jack up the front of the trike and check the steering head bearing. Those would be my first thoughts.

[Montana Lee]

Check tire balance and pressures ... jack up the front of the trike and check the steering head bearing. Those would be my first thoughts.

Those are the first things I thought of and have been done. The bike only has 6200 miles since new. I was wondering if there is anything on the trike chassis that might need attention.

[CrystalPistol]

First post here and hope to solve a problem. I just bought a 2010 Goldwing with the Monarch II trike. I was surprised that even at slow speeds the trike front end seemed to have a mind of it's own, It wanted to go into an uncontrollable shimmy even at slow speeds. Is there some unique about the suspension that would cause this? Is it normal ? Any help will certainly be welcome. I've had a Motor Trike before this and after 300,000 miles on it, never a problem. But it was an IRS suspension where this one is solid axle.

Is it "uncontrollable" even with hands on grips? You say "even at slow speeds", does it do it at highway speeds, on smooth highways? Accelerating or decelerating?

[Montana Lee]

Is it "uncontrollable" even with hands on grips? You say "even at slow speeds", does it do it at highway speeds, on smooth highways? Accelerating or decelerating?

It was pretty violent at slow speeds. Enough so that I feared taking it out on the road. Today I will play with rear tire pressure. The book says 26 but I personally think that's way too much. When I had a trike before, I ran the rear tires at 18 pounds and never had a problem. I'll report back once I try a few more things. I think that because of the solid axle and too much air in the rear tires that maybe even the tiniest bump starts this oscillation. Maybe if the tire were more flexible, they would adsorb at least part of the road shock that causes this.

[Montana Lee]

Here is an update to the problem I originally posted about. I ended up checking the tire pressure. It was set at 36 pounds on the rear tires. I reduced that to 20 pounds and you would never know it was the same trike. Consider the fact that these radial tires were actually meant for a vehicle that weighs 3 to 4000 pounds. This trike only has about 350 pounds of weight on each rear tire The tires when inflated correctly for the weight give a much better ride and absorb a good share of the stress from a rough road. I'm wondering if others have thought about this and also how much air is right for your trike. I might mention here that before I had a Motor Trike and kept the pressure on it at 18 pounds for over 60,000 miles and the tires still have plenty of tread.

[CrystalPistol]

I run 22 psi normally, 25 psi if loaded two up & pulling the trailer.

36 psi is really high, makes tire hard and less absorbent of bumps, thus pulling the front off center due to trail.

[paws]

2008 Goldwing GL1800

MotorTrike Adventure kit

Solo rider

24 Rear ... cold

38 Front ... cold ... BT45 in forward rotation

Ride-On in all 3 tires

Fork Brace to stop slight shimmy when barely creeping very slow over driveway bumps

No problems.

[1dn5up]

Front tire cupping will create shakes , due to improper pressures. The previous owner might not of had it right.

[CrystalPistol]

Don't know where you are with this now, but often a change from two wheels to three wheels leads to similar complaints. A bike traverses road elevation changes as it stays vertical. It does not heel over when a wheel is not 100% perpendicular to surface, it stays in a attitude dictated by gravity's pull and balance and whether turning or not. A trike is totally different, if the right rear drops into a dip, the trike will try to turn right. Trail that is good for a bike makes a trike steer heavy and the front end more like a big caster that follows (like shopping cart) so the trike wants to steer right in this case, the bike doesn't even see the dip as a direction influence.

[Montana Lee]

I am well aware of how a trike handles versus a bike. Thanks for your input. I have travelled about 600,000 on Motor Trike before I got this one. Both Motor Trikes were the Adventure models which have independant suspension. This new (to me) trike has a solid axle. They respond very differently from an IRS trike. My problem turned out to be way too much air in the rear tires. The Lehman factory advised 26 # in the rear. That is way too much in my opinion. Those rear tires are rated to hold up over 3000 pounds of car. On a trike they hold up about 350# each. I reduced the air pressure to 20 #. They are after all radial tires. This cured the problem completely. It steers and rides now like a trike should.

[CrystalPistol]

OooohKay

[Lee H. Mann]

I am well aware of how a trike handles versus a bike. Thanks for your input. I have travelled about 600,000 on Motor Trike before I got this one. Both Motor Trikes were the Adventure models which have independant suspension. This new (to me) trike has a solid axle. They respond very differently from an IRS trike. My problem turned out to be way too much air in the rear tires. The Lehman factory advised 26 # in the rear. That is way too much in my opinion. Those rear tires are rated to hold up over 3000 pounds of car. On a trike they hold up about 350# each. I reduced the air pressure to 20 #. They are after all radial tires. This cured the problem completely. It steers and rides now like a trike should.

From Lehman Trikes.......... WHAT IS THE CORRECT TIRE PRESSURE FOR MY TRIKE?

There has been a lot of confusion and misinformation out there when it comes to tire pressures for trike riders. Most all trikes have a motorcycle tire up front and automotive tires in the rear. The motorcycle compliance label has a recommended pressure for both the front and the rear tires. Now that your motorcycle is a trike are these still the pressures to use?

Since we are trying to clear up the confusion and misinformation... the answer is yes and no!

Let me explain more fully. We, Lehman Trikes, have always recommended that you maintain the same pressure the motorcycle manufacturer lists on the compliance label for the front wheel. There is no reason to change this pressure. That’s the “yes”. The “no” is a bit more involved.

First of all, the two automotive tires like those installed on the rear of your trike are a completely different design than the single motorcycle tire they replace.

Now for some history. Lehman Trikes has been building and riding trikes for 25 years. Our founder, John Lehman, and many of the dedicated trike riders that work here have experimented for years trying to find what air pressure in the rear tires gives you the best ride, handling and tire life. What they found and recommended for years was an air pressure in the 20 to 22 psi range worked best.

So why, if you look at a current Lehman Trikes Owner’s Manual or the Owner’s Manual for a H-D Tri Glide, do you see a 26 psi recommendation for the rear tires? When I came to Lehman Trikes several years ago one of the things I was asked to do was to confirm with the manufacturer of our tires that they would support our recommendation of 20 to 22 psi air pressures for our application. What I learned is that no tire manufacturer will recommend anything less than 26 psi for standard automotive tires.

[brianl]

Here is an update to the problem I originally posted about. I ended up checking the tire pressure. It was set at 36 pounds on the rear tires. I reduced that to 20 pounds and you would never know it was the same trike. Consider the fact that these radial tires were actually meant for a vehicle that weighs 3 to 4000 pounds. This trike only has about 350 pounds of weight on each rear tire The tires when inflated correctly for the weight give a much better ride and absorb a good share of the stress from a rough road. I'm wondering if others have thought about this and also how much air is right for your trike. I might mention here that before I had a Motor Trike and kept the pressure on it at 18 pounds for over 60,000 miles and the tires still have plenty of tread.

I recently had service done at a dealer I'd never been to before. Trikes are not their specialty but for some reason they checked the tire pressures and set the rear tires at 35 psi. They said that's what a trike is supposed to run at. This trike is a 2017 Goldwing with a brand new Roadsmith kit. I'm not sure what the out of state builder had the tires set at. I picked it up and drove it home on the interstate. Felt like the bike was all over the place. First thing I did when I got home was lower them to 25 and 23 psi. Made all the difference. I put over 30,000 miles on my previous trike and if it rode like this one did with the increased tire pressure I never would have gotten another one.

[CrystalPistol]

I recently had service done at a dealer I'd never been to before. Trikes are not their specialty but for some reason they checked the tire pressures and set the rear tires at 35 psi. They said that's what a trike is supposed to run at ...etc...

LOL …. I have cars that show lower pressures on the door jamb sticker. 35 psi in car tires on a trike = Krazy!

[Papa Zook]

Steering stem being under torqued can also present this same issue.

[rhino 2]

LOL …. I have cars that show lower pressures on the door jamb sticker. 35 psi in car tires on a trike = Krazy!

My 2002 Suzuki Vitara, Has 26 psi on the door sticker.....But ever since the Firestone/Explorer fiasco no tire dealer in his right mind [Legally] would put less than 35psi in any tire....What you do once you get home thats your business...