help needed ????

[triker_gal]

Had an email asking for help/advice as follows, can anyone give suggestions please? :


Hi

Hope you don't mind me asking you a question? Just had a Trike built by a company, a 1100 Virago, but it is unsafe. It wobbles vigorously when it goes over the smallest of bumps in the road and it goes out of control, pulling left and right very hard, the whole bike wobbles as does the rider! I am told by the company that this is normal! Could you please tell me if this is so? This is my first Trike but I had two experienced Trikers try it out yesterday and they were horrified by its behaviour, I have been unable to ride it at all and it was only delivered Friday evening!

The company has said they will pay another Trike company to collect it, inspect it and if there is a problem they will pay to fix it. I am desperate to get it sorted ASAP and have no other transport.

Please, please help

[Blackjack]

Phew!

Seeing as it only happens when it hits a bump apparently, does it have rear suspension? And has it got stock forks or something else?

And does it ONLY happen when it hits a bump? Or is it inclined to tank slappers anyway?

[minxy]

Hmm. Dont be fobbed off with this. If the bike / trike is straight it SHOULDNT behave like that. I had a similar problem with my first trike, turned out one of the forks was very slightly bent. If you intend on keeping the machine, fit a steering damper. This should help ward off those nasty shakes. BUT! No - it is not an acceptable excuse that all trikes are like that. If it was custom built, ask what type of jig they used to ensure that the frame was straight. Also enquire re the origins of the donor bike - was it accident damaged?

Keep us updated on this one TG eh :)

[triker_gal]

Have emailed her asking more questions, just waiting on a reply

cheers xx

[dracken1]

i would be interested in knowing the company that built it. i have had a total of 3 trikes all newly built with various serious probs all built by the same company.
please don't post it here, email it to me.

[triker_gal]

The person hasn't given me that information yet, and not responded yet hmmmmm :confused:

[triker_gal]

Got this reply today, If anyone wants her number please pm or email me :

Oh please, please come and look at it for me!!! I live in Abbey Wood, London, near the Dartford tunnel. I really want to sort this out so I can ride it.

As for your questions:

We tried several different air pressures, still now good.
It has suspention
Dont know what 'new head stock' bearings are? But I am given the impression that nothing new has been added to the bike itself
I would say the tubes are about 2ins

I hope this helps

this is my mobile no. 0**** *** ***, if thats easier.

cheers

[Blackjack]

IF, it has independent rear suspension then this COULD be the problem.

Basically, lack of roll stiffness and inadequate damping with an independent set up on a trike can set up a side to side wobble in the suspension.

When you turn left a trike wants to lean to the right, whereas a bike leans to the left. Well with independent rear suspension a flick to the left loads up the right side of the suspension, as this pushes the trike back it can carry on on past the upright and lean to the left. In the mean time the original lean to the right, made the steering want to turn to the right, which makes the trike want to lean to the right which is where it was headed anyway. Then it all happens in reverse and keeps on repeating itself.

Stiffer dampers (preferably adjustable) and an anti roll bar will cure that. Though a trike will generally need less trail than a bike and if the trail's long for a bike then that'll accentuate it too.

If it's the problem.

Try rocking it side to side and see how easily it moves. If it will rock from side to side fairly easily then what I just described could well be the problem.

Has this got a spoked or a cast front wheel?

[triker_gal]

I've sent on your reply and question and have also suggested that she may want to register here as it would be simpler, will let you know on reply......& thankyou

[minxy]

... sounds like a good plan ;) :D

[Choprocker]

I had a similar problem with my first trike, turned out one of the forks was very slightly bent. :)
Do i tell the oldskool boys about this?????

[Choprocker]

i would be interested in knowing the company that built it. i have had a total of 3 trikes all newly built with various serious probs all built by the same company.
please don't post it here, email it to me.
WOT? dint you learn the first time not to use the company again.
Sorry m8 had to say it.

[Choprocker]

I noticed the girl lives in abbey wood (sharp aint i?) well anyway, i not far from there but knoe feck all bout trikes but there are a few trike riders around there.
I not got numbers or names though sorry but Tiny from the old forum (dont know if or what his name is on this 1) should know a few from around there. the 1 that springs to mind is Dusty, i think he had a blue alfa trike that was in 100%, another that comes to mind is alan from deptford, not far from abbey wood.
See if you can get in touch with tiny and see if he can help with names and numbers. Pat might know tiny's forum name.

[Rogue Monkey]

Phew!

Seeing as it only happens when it hits a bump apparently, does it have rear suspension? And has it got stock forks or something else?

And does it ONLY happen when it hits a bump? Or is it inclined to tank slappers anyway?
1100 Virago is solid as a rock on two weels! I rode one long enough! :rolleyes: I cant see why it would be any less stable if ya stick an extra weel on :confused: I`ve rode a few trikes and Ive found em all t be a bit skittish round corners but I havent the expierience to really comment. Jsut try taking into a bike shop on the pretence of a part ex or you wanna sell it to em an se wot faults they come up with! At least they wont charge for the advice! Ride Safe!

[Gypsy]

IF, it has independent rear suspension then this COULD be the problem.

Basically, lack of roll stiffness and inadequate damping with an independent set up on a trike can set up a side to side wobble in the suspension.

When you turn left a trike wants to lean to the right, whereas a bike leans to the left. Well with independent rear suspension a flick to the left loads up the right side of the suspension, as this pushes the trike back it can carry on on past the upright and lean to the left. In the mean time the original lean to the right, made the steering want to turn to the right, which makes the trike want to lean to the right which is where it was headed anyway. Then it all happens in reverse and keeps on repeating itself.

Stiffer dampers (preferably adjustable) and an anti roll bar will cure that. Though a trike will generally need less trail than a bike and if the trail's long for a bike then that'll accentuate it too.

If it's the problem.

Try rocking it side to side and see how easily it moves. If it will rock from side to side fairly easily then what I just described could well be the problem.

Has this got a spoked or a cast front wheel?

we had to stick more pressure in our rear on our trike to stop a lot of the "drifting" as i call it... i know what blackjack is on about .. feels like the trike is going against the camber ... was also told by someone (can remeber who now) that a sidecar tyre on the front can help big time

[Mad Dog]

... was also told by someone (can remeber who now) that a sidecar tyre on the front can help big time

That would be me wot told you that. Really does make a big difference.

[titusni]

IF, it has independent rear suspension then this COULD be the problem.

Basically, lack of roll stiffness and inadequate damping with an independent set up on a trike can set up a side to side wobble in the suspension.

When you turn left a trike wants to lean to the right, whereas a bike leans to the left. Well with independent rear suspension a flick to the left loads up the right side of the suspension, as this pushes the trike back it can carry on on past the upright and lean to the left. In the mean time the original lean to the right, made the steering want to turn to the right, which makes the trike want to lean to the right which is where it was headed anyway. Then it all happens in reverse and keeps on repeating itself.

Stiffer dampers (preferably adjustable) and an anti roll bar will cure that. Though a trike will generally need less trail than a bike and if the trail's long for a bike then that'll accentuate it too.


I was actually going to post a question about IRS trikes and cornering so your info interested me.

I've got a V-Max trike (http://www.oldcolo.com/~bradley/trike) with a BMW 5 Series backend with Avo shocks and a GSX-R1100 USD frontend (lengthened). I've had the trike for 6 months now and its understeers on corners - I've gotten used to dropping my speed and pushing/pulling the handlebars to force it round.

The shocks do have hand-turnable damper adjusters with a range of 20 "clicks" and at present they're set to 2 clicks away from the "-" end of the scale (so minimal damping?). I've been meaning to head out some night and experiment with different damper settings to see what effect they have on cornering, if any...

I'm not sure if the trike's got an anti-roll bar(s).

So Blackjack, do you reckon that if I turn the dampinging on more it will ease my cornering?

[Blackjack]

1100 Virago is solid as a rock on two weels! I rode one long enough! :rolleyes: I cant see why it would be any less stable if ya stick an extra weel on :confused: I`ve rode a few trikes and Ive found em all t be a bit skittish round corners but I havent the expierience to really comment. Jsut try taking into a bike shop on the pretence of a part ex or you wanna sell it to em an se wot faults they come up with! At least they wont charge for the advice! Ride Safe!

Yes, I know. But part of the reason it feels solid as a rock on two wheels is probably that it has a lot of trail. Which isn't a good idea on a trike. The reason it's different with a trike is like this, you know the dynamics of a bike cornering and where all the vectors are pointing?

No?

Well then take my word for it it's a LOT different with a trike.

(And if the answer was "yes" then you ought to know why a trike is different)

And for the same reason don't take it to a bike shop as they will have absolutely no idea about it. The advice may cost nothing, but that's exactly what it's worth.

[Blackjack]

I was actually going to post a question about IRS trikes and cornering so your info interested me.

I've got a V-Max trike (http://www.oldcolo.com/~bradley/trike) with a BMW 5 Series backend with Avo shocks and a GSX-R1100 USD frontend (lengthened). I've had the trike for 6 months now and its understeers on corners - I've gotten used to dropping my speed and pushing/pulling the handlebars to force it round.

The shocks do have hand-turnable damper adjusters with a range of 20 "clicks" and at present they're set to 2 clicks away from the "-" end of the scale (so minimal damping?). I've been meaning to head out some night and experiment with different damper settings to see what effect they have on cornering, if any...

I'm not sure if the trike's got an anti-roll bar(s).

So Blackjack, do you reckon that if I turn the dampinging on more it will ease my cornering?

Well I looked at the pic and it does seem a little long in the wheelbase, so it's not ever going to be the most nimble thing in the world. Plus the longer the wheel base the greater the angle you need to turn the bars through to go round any given radius of bend.

Understeer is pretty much the normal state of play for a trike, mostly because you have a small tyre contact patch at the front trying to steer two larger contact patches at the rear arranged in an inherently stable wheel plan.

With a bike you make very small steering inputs as the whole thing is inherently unstable and that's used to get the thing to go where you want (simplistic explanation). With a trike you actually have to deflect the steering wheel like with a car. Which is why you need to push/pull the bars.

I'd say that your biggest problem is the forks. A pair of leading links with a 15" car wheel and shorter trail would probably be the biggest improvement you could make. And when I say a big improvement I'm talking you wouldn't recognise it. You'll still need to turn the bars, but the effort involved will be a lot lower, and using a tyre that is designed to work when it's upright should go a long way towards solving the understeer problem.

Failing that you ought to find that braking later in to a bend and fading the brakes out as you steer goes some way towards reducing the problem. I'd suggest you try that out in a car park and not actually in a bend, as if you over cook it it'll run extremely wide!!!

[dracken1]

by choprocker
WOT? dint you learn the first time not to use the company again.

the trikes were owned by my customers not me.
i only make vw ones, these were bike engined

[titusni]

Understeer is pretty much the normal state of play for a trike, mostly because you have a small tyre contact patch at the front trying to steer two larger contact patches at the rear arranged in an inherently stable wheel plan.

In my case it probably doesn't help that my rear tyres are 265s so lots of road contact.

With a trike you actually have to deflect the steering wheel like with a car. Which is why you need to push/pull the bars.

Its not having to push/pull that bothers me - its the amount of force required - going round a roundabout I feel like I'm fighting to keep it on course.

You'll still need to turn the bars, but the effort involved will be a lot lower, and using a tyre that is designed to work when it's upright should go a long way towards solving the understeer problem.

I'll chat to my trike builder about a sidecar tyre as they're squarer aren't they?

Failing that you ought to find that braking later in to a bend and fading the brakes out as you steer goes some way towards reducing the problem. I'd suggest you try that out in a car park and not actually in a bend, as if you over cook it it'll run extremely wide!!!

So you mean that I start to turn into the bend, ease on the brakes whilst cornering and then ease off the brakes further into the corner?

I still plan to tweak the dampers at some stage to see how it affects handling in general.

One additional point to mention - when I brake I normally use just the foot pedal which is linked to both the rear discs AND also to one of the front discs (via a bias value). I think the bias is some like 80% rear, 20% front. I'm not sure what extra effect the linked brakes may have on cornering.

[Blackjack]

Yep, wide tyres on the rear can be a bad thing on a trike. A quick check would be to take a 12" ruler to the garage and put about 40-50 psi in the rear tyres until there is a bulge across the tread (the ruler is to use as a straight edge to check for the curvature!)

Try it then, if its noticeably lighter to steer then the rear tyres are having an effect.

The high steering effort can result from too much trail as well. Essentialy if you have longish trail then the contact patch has more leverage about the steering axis. You can reduce this by changing the offset in the yokes, more offset between the legs and the steering stem will give less trail.

Far as I know you can only get a limited selection of square section motorcycle/sidecar tyres. But if you can get one on there, it should make things better. Though the sidecar tyres I've seen are all made out of concrete so you don't get sexy levels of grip.

What I was talking about with the braking was use the weight transfer to load up the front tyre BEFORE you start to turn, then ease off the brake as you start to turn. If you get "dive" under braking then that also shortens the trail and may make the steering lighter, at least initially. The idea is that putting the extra weight on the front helps to "plant" it on the tarmac, it's a technique used by offroad quad racers and seems to run against all logic but it also lightens the rear tires and reduces their resistance to changing direction. Of course it can also result in a big skid and total failure to negotiate the bend!!!!

It's important to understand that any suspension set up has various elements which can be changed and they all affect each other to a greater or lesser extent. This basically means that there isn't always a magic cure!! It's also fairly important to mention that I'm conjecturing from looking at some photos, if i was taking a few measurements and a test ride. there'd be less "probably", "ought to", and "should" dotted about the place!

[BikerGran]

I had this problem with my GT550 trike at first - playing around with the tyre pressures front and rear helped a bit, as did letting most of the air out of the air-assisted forks. But the thing that made the most difference was replacing the half-worn front tyre with a brand new one - the difference was incredible!

Have since been told that this was because the tyre was worn when being ridden as a bike, which is not a suitable profile for a trike, if that makes sense....


The other thing that made a big difference was just experience - same as on a bike, if you get tense about it and try to hang on tight to the bars, it exaggerates the problem. But with a bit of experience (3 months for me now) you begin to anticipate how it's going to behave. On mine the problem virtually disappears once you're over 20mph.

[minxy]

Do i tell the oldskool boys about this?????

rearrange these words

orf arse short feck

:eek: :p

[ratwing]

I bought a Beetle steering damper from Bigboystoys, the VW people in Breach Road near Lakeside this week. Cost 12pounds50p :D :D and they're pretty close to you so worth considering if you decide to fit one. Can you borrow some different rear tyres or dampers to try - the amount of flex in the sidewalls varies from one brand to another and can make a huge difference.

[xjtriker666]

i had similar probs wi trike i have..but mine was rear end wobble if ya wakked it open fastish..prob was rear wheel lost balance weights was very scary at 55-70 ish ..front end wobble really wants sortin try usin steerin damper m+p do one for about 40quids kawasaki universal fit...or try fittin wider bars ..if that fails widen front end out that shud stop it....

[Blackjack]

It's a dumb idea to try and solve a bad steering wobble by fitting a steering damper.

They are'nt really intended for that, just for stopping the sort of "shimmy" you get occasionally. Really bad shakes that threaten your control of the vehicle and are caused by bad geometry can eventually cause the mounts to fail (or worse the frame member its mounted too) and that's not fun, because you suddenly find yourself with a major wobble and a lump of metal dangling around in the area of the forks.

Plus it just makes the steering heavier.

[dracken1]

fitting a steering damper to try to eliminate bad shake may work to a degree.
but as blackjack stated it is not a good idea as theres obviously an inherent problem which if left will eventually show itself in another way maybe more serious.
i run 42 degs of rake but i don't have the weight of an engine as well as myself on the front end. so i'm used to the trail effect i get.

but i'm now going to start making upside down springers designed to fit standard yokes which will pull the trail back into the 4" ballpark

[oggers80]

:rolleyes: my 1100 virago trike has original forks with slab yokes widened out to take car wheel (i.e. 3 matching wheels) bike wheel wont steer as well as a car wheel as theyre designed to lean. builder suggested this to me as he said it would handle better.

[odie]

never heard so much crap in my life, "try fittin wider bars ..if that fails widen front end out that shud stop it....
If your front end wobbles that means some-thing is wrong!

[triker_gal]

never heard so much crap in my life, "try fittin wider bars ..if that fails widen front end out that shud stop it....
If your front end wobbles that means some-thing is wrong!
me front end has wobbled nearly all my life, fnar fnar :D

[odie]

Yes, true my dear but your front end IS SUPPOSED TO WOBBLE! (and very nice it looks too!) ;) :D

[triker_gal]

come to think of it, me rear end wobbles alot too , hehehe :D

[triker_gal]

Yes, true my dear but your front end IS SUPPOSED TO WOBBLE! (and very nice it looks too!) ;) :D
Ooohh I say :o

[odie]

You must be honey, cos jelly dont wobble like that! :eek:

[titusni]

Yep, wide tyres on the rear can be a bad thing on a trike. A quick check would be to take a 12" ruler to the garage and put about 40-50 psi in the rear tyres until there is a bulge across the tread (the ruler is to use as a straight edge to check for the curvature!)

Try it then, if its noticeably lighter to steer then the rear tyres are having an effect.

I tweaked the rear tyres ever so slightly from 38-39 to 40psi and also checked out the damping adjusters on my rear shocks - they were set to ZERO damping so I turned them to half-way along the scale.

The trike seems to corner a bit better now - not sure whether it was the lack of damping or the tyre pressures.

If I check the rears with a rule then its obvious that about 3/4 of the tread is touching the ruler with it curving away on both sides...