Have a vibration on my Roadhawk trike

[starrider1946]

I have a 2002 Roadhawk trike. I am getting a vibration when I get to around 1700 rpm. It seems to be from 1700 to around 2100 rpm. It isn't a steady vibration. I am not sure how to explain it. It almost feels like a drive line vibration like a driveshaft bent or something but it can't be that since I don't have one. It is fine below 1700 and seems to go away about 2100 rpm. I can feel it through the handle bars but not through the seat or foot brace. I have had the trike for a year and a half and i didn't notice it doing this until a few months ago. Wonder if it could be my tires causing a vibration at this rpm. Any suggestions or questions would be appreciated. Thanks

[pcombe]

Could be tires? could be steering nut torque?

I am not familiar with the motor mount set up on your bike It will affect my Harley, It is possible if it is rubber mounted for the motor mount to look alright and be broken on the inside of the rubber, The inner metal comes unattached from the rubber.

Also don't lug your bike, Keep it in a gear where the engine is pulling and see what happens?

As I say, I don't know your bike?

[starrider1946]

Thanks for the reply. The trike has a Volkswagon transaxle and motor. Everything vw from the shifter back. I believe the motor is mounted directly to the transaxle. I don't think there are any rubber mounts. The trike has p265/50r 16 radial tires on the rear. They are large tires with 9' of tread and pretty heavy. When I first got the trike at about 50mph the handle bars shook pretty good. I had a new front tire put on and still did it. I called the trike shop and the guy said it was the rear tires causing the vibration through the frame to the front causing the shake. I am wondering if this could be some of the vibration. Like I said it is in the 1700 to 2100 rpm range in fourth gear. I am going to experiment some more and see if I can narrow it down.I don't think it is any kind of bearing issue but not sure. I will try and check the steering torque nut. I need to check all the tin on the motor. It couild be that it is vibrating around a certain rpm.
Thanks for the suggestions. If you have any more I am listening.

Could be tires? could be steering nut torque?

I am not familiar with the motor mount set up on your bike It will affect my Harley, It is possible if it is rubber mounted for the motor mount to look alright and be broken on the inside of the rubber, The inner metal comes unattached from the rubber.

Also don't lug your bike, Keep it in a gear where the engine is pulling and see what happens?

As I say, I don't know your bike?

[peteg59]

Your trike likely has rubber transaxle to frame mounts, unless they've been replaced with polyurethane type mounts.
The rubber mounts do go bad after awhile, or sooner with "spirited" riding. = Something to check, or have checked.
Couple more things to check on:
Was the front tire balanced when it was installed?
Are the rears balanced?

Unfortunately there are many factors to consider when chasing a "ghost"...
Best of luck to you, & post up what is found to be causing the vibe, if/when it is found.

[starrider1946]

I haven't really looked at it that close I guess but I will. I am 70 so I don't do much spirited riding.lol Very seldom do I get up to 55 or 60 but did yesterday. The front tire was balanced when it was put on. Just checked the front and rear.I had the rear wheels balnced after I got the trike. Looks like all the weights are still on. From what the tech guy at The Trike Shop or now Roadsmith said the rear wheels can cause problems especially if they are out of balance. Thanks for the suggestions. I'll post if I find out anything.

Your trike likely has rubber transaxle to frame mounts, unless they've been replaced with polyurethane type mounts.
The rubber mounts do go bad after awhile, or sooner with "spirited" riding. = Something to check, or have checked.
Couple more things to check on:
Was the front tire balanced when it was installed?
Are the rears balanced?

Unfortunately there are many factors to consider when chasing a "ghost"...
Best of luck to you, & post up what is found to be causing the vibe, if/when it is found.

[stinger608]

Does this just happen in 4th gear between 1700 and 2100 or does it happen in all gears at that RPM range?

That may help narrow it down. If it's just in 4th gear then I would suspect something amiss in a wheel balance. Either the front or one/both rear wheels.

I would pull the front wheel and have it checked for balance. After wearing for a couple of years it could be that it has gone out of balance.

It wouldn't take much to notice a vibration.

[pcombe]

I haven't really looked at it that close I guess but I will. I am 70 so I don't do much spirited riding.lol Very seldom do I get up to 55 or 60 but did yesterday. The front tire was balanced when it was put on. Just checked the front and rear.I had the rear wheels balnced after I got the trike. Looks like all the weights are still on. From what the tech guy at The Trike Shop or now Roadsmith said the rear wheels can cause problems especially if they are out of balance. Thanks for the suggestions. I'll post if I find out anything.

Check your tire inflation for sure, I guess you know you don't run them fully inflated in the back?

[starrider1946]

I am going to get out on the road tomorrow and do some testing. I was on a ride the other day and couldn't do much. I did run it up to around 1700 rpm in third and I think I started picking up the vibration but not sure. I am going to check it for sure tomorrow. I am also going to run it up to 1900 rpm and kick it in neutral and see if I feel anything. I am running 28 lbs pressure in rear and 40 in the front. I could lower the pressure and see if that makes any difference. If I have the vibration in third gear also what would that mean? I am also going to run it up to 1700 rpm or so in netural sitting still and see if I hear anything. Some time it almost seems like I hear some of the tin making a noise. I just wonder if it could be some of the tin vibrating in this rpm range. I'll post tomorrow what I found out. If I don't find anything I'll go ahead and have all the tires reblanced. I'll post tomorrow. Thanks for the suggestions.

Check your tire inflation for sure, I guess you know you don't run them fully inflated in the back?

[starrider1946]

I forgot to ask if anyone is using Dyna Beads in their tires. I had my tires balanced on my trike and they just used the stick on weights front and rear. Well on the front it is the weights that clip on the spokes. Wonder if I might get a better balance with beads. I had them in my motorcycle tires and they worked ok. Anyone use them?

I am going to get out on the road tomorrow and do some testing. I was on a ride the other day and couldn't do much. I did run it up to around 1700 rpm in third and I think I started picking up the vibration but not sure. I am going to check it for sure tomorrow. I am also going to run it up to 1900 rpm and kick it in neutral and see if I feel anything. I am running 28 lbs pressure in rear and 40 in the front. I could lower the pressure and see if that makes any difference. If I have the vibration in third gear also what would that mean? I am also going to run it up to 1700 rpm or so in netural sitting still and see if I hear anything. Some time it almost seems like I hear some of the tin making a noise. I just wonder if it could be some of the tin vibrating in this rpm range. I'll post tomorrow what I found out. If I don't find anything I'll go ahead and have all the tires reblanced. I'll post tomorrow. Thanks for the suggestions.

[MR TRIKE]

Hello- I would say your rear tires are out of round. Egg shaped. A tire can be in balance but out or round. To check this, place a floor jack under lower rear shock tower, raise tire just off ground and use a white caulk held next to center of tread. Now rotate tire by hand, if the tire is round, it will leave a white mark all around tire. If out of round, you will have voids in the white line. The only way to fix this is to have the rear tires shaved or trued on the trike with a trueing machine or replace tires. This can and will happen with brand new tires sometimes. Because most of the weight is on the rear wheels, any vibration will get transferred to the front. I have seen this hundreds of times. You will have to call tire shops or race car shops to find someone that does this service on tires. Always best to shave and balance on the trike if you can. Dick KEEP-ON-TRIKIN

[starrider1946]

I live in Pineville Lousiana and after I first got the trike and was having trouble with handle bar shake about 50 or so I called the Trike Shop and talked to them about it. They said I probably need the tires shaved and trued and I checked on it. I can't find anyplace in Louisiana that does this so I just gave up on that. I will do what you said and see what it shows. I know it is hard to get a round tire. I'll do what you said and repost. Thanks

Hello- I would say your rear tires are out of round. Egg shaped. A tire can be in balance but out or round. To check this, place a floor jack under lower rear shock tower, raise tire just off ground and use a white caulk held next to center of tread. Now rotate tire by hand, if the tire is round, it will leave a white mark all around tire.

If our of round, you will have voids in the white line. The only way to fix this is to have the rear tires shaved or trued on the trike with a trueing machine or replace tires. This can and will happen with brand new tires sometimes. Because most of the weight is on the rear wheels, any vibration will get transferred to the front. I have seen this hundreds of times. You will have to call tire shops or race car shops to find someone that does this service on tires. Always best to shave and balance on the trike if you can. Dick KEEP-ON-TRIKIN

[stinger608]

Hello- I would say your rear tires are out of round. Egg shaped. A tire can be in balance but out or round. To check this, place a floor jack under lower rear shock tower, raise tire just off ground and use a white caulk held next to center of tread. Now rotate tire by hand, if the tire is round, it will leave a white mark all around tire. If our of round, you will have voids in the white line. The only way to fix this is to have the rear tires shaved or trued on the trike with a trueing machine or replace tires. This can and will happen with brand new tires sometimes. Because most of the weight is on the rear wheels, any vibration will get transferred to the front. I have seen this hundreds of times.

You will have to call tire shops or race car shops to find someone that does this service on tires. Always best to shave and balance on the trike if you can. Dick KEEP-ON-TRIKIN

An excellent point Dick!!!

I hadn't thought of that, however, it would sure cause the problem if it's just in 4th gear.

If however, it is in all gears then I would suspect a bad crank pulley, clutch pressure plate, or out of balance flywheel.

If the engine has one of them cheap aftermarket "power" pulley's on it, that would be the first thing I would replace. Spend the little extra and get a good one.

Of course, this is all pending the vibration is in every gear between 1700 and 2100 rpm.

[starrider1946]

Well I checkd my fan belt this morning and it was definitely too tight so I adjusted it. I think I have it about right now. I went to 23 psi on the rear and 30 on the front and took it for a ride. I second gear at a steady 1700 to 1800rpm it sounded good. I ran it up to about the same rpm in 3rd and it sounded ok. Really couldn't feel anything.Got it up to 1700 or so at a steday speed and I really couldn't feel anything. I ran it up to 2500 or so rpm just in netural to see if I could feel anything and I couldn't. I wore my novlety type helmet today so I would be apt to hear more. I usually wear a helmet that covers my ears ( have intercom system). I don't know what to think.

Gonna ride some more later on today and see what happens. I'll post. Thanks for the help.

An excellent point Dick!!!

I hadn't thought of that, however, it would sure cause the problem if it's just in 4th gear.

If however, it is in all gears then I would suspect a bad crank pulley, clutch pressure plate, or out of balance flywheel.

If the engine has one of them cheap aftermarket "power" pulley's on it, that would be the first thing I would replace. Spend the little extra and get a good one.

Of course, this is all pending the vibration is in every gear between 1700 and 2100 rpm.

[starrider1946]

Well I'm back. My wife and I rode yesterday and I could still feel some vibration. I rode for just a minute in my subdivision this afternoon. I ran it up to 1700 or 1800 in first and I hear the sound. It sounds like to me it is in the tin or metal vibrating sound. The motor has no covers on the bottom, just the ones on top. Should I have the ones on the bottom anyway. The motor has never ran hot that I know of and I guess that is the way it came. I may call Roadsmith tomorrow and ask them if it came with bottom tins. Any more suggestions appreciated.

Well I checkd my fan belt this morning and it was definitely too tight so I adjusted it.

I think I have it about right now. I went to 23 psi on the rear and 30 on the front and took it for a ride. I second gear at a steady 1700 to 1800rpm it sounded good. I ran it up to about the same rpm in 3rd and it sounded ok. Really couldn't feel anything.Got it up to 1700 or so at a steday speed and I really couldn't feel anything. I ran it up to 2500 or so rpm just in netural to see if I could feel anything and I couldn't. I wore my novlety type helmet today so I would be apt to hear more. I usually wear a helmet that covers my ears ( have intercom system). I don't know what to think. Gonna ride some more later on today and see what happens.

I'll post. Thanks for the help.

[peteg59]

Being as you're down south, I wouldn't run any bottom tin on your trike. They don't help in 100 degree stop & go traffic.
There is no reason to unless you're running the stock heat exchanger type exhaust. Most if not all "open" VW trikes don't need heat nor have it hooked up to the stock factory exhaust exchange system.

I'm in NH & ride from about April~early Dec. with no lower tins & motor runs fine without them, even in moderate & hot weather situations, (think Laconia national bike rally stop n go traffic in mid June).

So the bottom line is: it's really 100% your call if lower tins are necessary.

They do look good all in chrome though...

[stinger608]

I rode for just a minute in my subdivision this afternoon. I ran it up to 1700 or 1800 in first and I hear the sound.

Well, if your feeling it and hearing it in 1st gear then it ISN'T a tire issue.

That would indicate it is going on in all gears. You mentioned that the engine belt was too tight and you loosened it up some. I am wondering if you're not getting some bearing vibration from the Alternator/generator.

That could be what your hearing is the dog house rattling at a certain rpm due to a bad or going bad bearing in the alternator/generator.

[starrider1946]

Thanks for the information on the tin. I'll probably leave it off. I put a new alternator on several months ago. I think what I will do is pull the belt of and run through the gears before it gets hot and see if the sound is still there. If the sound is still there I believe it is the tin if not I guess I need to look at the alternator. I'll feel for any slack in the shaft when I take the belt off. I'll post what I find.

Well, if your feeling it and hearing it in 1st gear then it ISN'T a tire issue.

That would indicate it is going on in all gears. You mentioned that the engine belt was too tight and you loosened it up some. I am wondering if you're not getting some bearing vibration from the Alternator/generator.



That could be what your hearing is the dog house rattling at a certain rpm due to a bad or going bad bearing in the alternator/generator.

[stinger608]

Thanks for the information on the tin. I'll probably leave it off. I put a new alternator on several months ago. I think what I will do is pull the belt of and run through the gears before it gets hot and see if the sound is still there. If the sound is still there I believe it is the tin if not I guess I need to look at the alternator. I'll feel for any slack in the shaft when I take the belt off. I'll post what I find.

Oh man, I would NOT suggest running without the belt. It will get very hot in a hurry without the doghouse fan running!!!

[starrider1946]

Well I had to try it. Took the belt off started it up ran through first and second and shut it off. Probably 45 seconds. With the belt off I don' t get the vibration. I put the belt back on and it does it. So that tell me it has something to do with that. I can be in neutral and rev the motor up by hand and feel the tin on the cylinders and the dog house and it feels like I can feel some vibration with my hand on the dog house. I believe if it had anything to do with the fan itself seems like I would hear something at lower rpm also. Without the belt on the fan spins free and no noise that I can hear. I went to a fellow that fools with VW's to get his opinion.

He said it sounds eternal to him. Said it could the the aftermarket tin and to recheck the belt. He felt it is a little to tight. Said he had trouble with that once. Going to keep trying.

Oh man, I would NOT suggest running without the belt. It will get very hot in a hurry without the doghouse fan running!!!

[stinger608]

Well I had to try it. Took the belt off started it up ran through first and second and shut it off. Probably 45 seconds. With the belt off I don' t get the vibration. I put the belt back on and it does it. So that tell me it has something to do with that. I can be in neutral and rev the motor up by hand and feel the tin on the cylinders and the dog house and it feels like I can feel some vibration with my hand on the dog house. I believe if it had anything to do with the fan itself seems like I would hear something at lower rpm also. Without the belt on the fan spins free and no noise that I can hear. I went to a fellow that fools with VW's to get his opinion.

He said it sounds eternal to him. Said it could the the aftermarket tin and to recheck the belt. He felt it is a little to tight. Said he had trouble with that once. Going to keep trying.

It's Good you only ran it for a few seconds.

That is pretty much narrowing it down then. You might pull, or have someone pull the Alternator and fan out and take a good look at the fan. It could be a broken or loose blade that causing it also. I had that happen many years ago on a Baja bug. Also, if the trike sat for any length of time, it could be part of a birds nest or mouse nest. Seen that several times on bugs that sat for a long time.

It will throw the balance way off.

If there isn't anything odd in or about the fan, then I have to suspect it being the alternator.

See if that that fella that deals with VW's has an extra alternator and fan set up to give it a try.