trike geometry

[chaza]

hi guys
does anyone know if or how to check the geometry of a trike.
i have a virago 535 1996, the steering wobbles when driving, i havent gone too far. so its maybe needing a damper. but i wondered about the geometry, does that effect the steering wobble.


cheer guys
chaza

[WD Forte]

Geometry eh?
the square on the hippoptanus is sum of the sumfin from the
summat or other and all that rassis fake science shit.


I'd be looking at steering bearings, wheel bearings, forks etc first
plus tyre pressure and damage
Stick a jack under the engine and check it out

The longitudinal axis of the bike should be at 90 degrees
to the axis of the axle so
I'd say any variance may cause a tendency to wander but not wobble
Ditto the vertical axis.

Rake angle also comes to mind.
If the builder left it be and just stuck an axle on the back, I'd tend to discount it
but if they 'improved' it then it may be an issue

I'd still start at the forks though
____________________
bikers smell of wee

[stinkwheel]

Contrary contraptions and some of them can be horribly unstable.

I'd check tyre pressures first off though.

The geometry is pretty specialist stuff. Is it a home-built trike or a kit? If it's a kit, I'd get in touch with the manufacturer and see if they can help.

If it's home built, make sure it's actually put together properly because I've seen some death-traps.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[chaza]

hi guys
its not home built contraption. ill take a look at the bearings and pressure as you say....
it has passed mots before so it cant be the geometry really i think.

there is one other issue,
it has passed its mot before,,, but the handbrake only goes to one wheel..... should it not brake both wheels ??????

thanks guys

[Nobby the Bastard]

they aren't ridden for an MOT so dodgy steering geometry could still exist.

Ask anyone who's ridden a 70s/80s era bike. You don't know what a speed wobble is if you've never ridden one of them and they would hapopily pass an MOT today.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[WD Forte]

Pics might help
if it's got a ferkin great tool box n shit on the back
that wont help
but if it drove/rode ok previously, go for the simple obvious stuff first
____________________
bikers smell of wee

[stinkwheel]

As above, the MOT is not a test of frame design/geometry. Although in theory if the frame has been modified, it should have passed an SVA test before going on the road which is a lot stricter.

If it's a bolt on kit, no SVA but they are usually made by people who know what they are doing.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Nobby the Bastard]

Depends on how old it is. Viragos are old....
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Ste]

Post a link to what you bought.

[MCN]

Bearings were the first thing I would consider.
Shocks/forks.
Wear parts.
Out of round tyres if it's been sitting on its tyres in a shed for a long time. More than 6 moths for example. The rubber will deform and stay in that shape.
The people who MOTed may be able to help if you get stuck.
____________________
Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[chaza]

thanks guys
ill check what you have commented on...
the trike is a 96 model. cant say much more about it yet.
but thanks for your views.


chaza[/img]

[A100man]

[Ste]

At least it wasn't a 1986 model sold as an unfinished project.

https://www.ebay.co.uk/itm/1986-yamaha-virago-xv-1000-trike-unfinished-project-/325346389647?nma=true&orig_cvip=true

[chaza]

no its not that one. mine is complete and running.

[WD Forte]

Before you jack it up.
Get it on level ground, grab the bars, put the front brake on hard
and push it forward and back to see if there is any play in the top stem bearings.
They may just need adjusting/nipping up but
I see it uses typical ball and cup type bearings, so if they seem in need of replacement then personally I'd put tapered rollers in there.
____________________
bikers smell of wee

[chaza]

cheers WD

[Lone-Wolf]

[The Shaggy D.A.]

I'd get some straight edges and check the alignment of the rear wheels, and take some measurements from the headstock to the rear axles to see if there's any wonky frame issues.
____________________
Chances are quite high you are not in my Monkeysphere, and I don't care about you. Don't take it personally.
Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[chaza]

hi guys
ive checked the headstock bearings, they seem fine and tight. ill have to wait till better weather to go road testing. maybe it will reveal something.

thanks for all your advice

chaza

[ThatDippyTwat]

A scary amount of trikes shake their head. Shit geometry at best, and being built by a company isnt a guarantee, it just means it'll look half-decent. A steering damper is a sticking paster. Ideally, flog it and get one from a half decent builder. If it's got a steering damper, walk away. If you happen to be in/around N.Wales I can point you to a trike specialist that knows his stuff.
____________________
'98 VFR800 (touring) - '12 VFR800 Crosrunner (Commuting) - '01 KDX220 (Big Green Antisocial Machine)

[chaza]

thanks dippy
no im no where near...its winter now so its not going anywhere quick. do you know why they wobble.....i was going to put a damper on .


cheers
chaza

[ThatDippyTwat]

[chaza]

well i guess ill have to ride it and try to find out, but it will have to wait till spring.
ive got other shit to get on with.

thanks anyway

chaza