Test Drive.....

[mick stobbs]

Well,having sorted the electrics and the handbrake(thanks for all the help),I test drove the trike on Friday morning before booking an mot and.....
It rode like an absolute pig,pulling quite badly to one side so back to the garage for some investigation.
A quick measure from the centre of the swingarm bearing to the flat bit on the end of both axle flanges revealed that the axle frame is 8mm out of alignment due to the A frame being poorly made(not by me mind you).
Absolute heart breaker cos i thought the job was finished but now i'm gonna have to chop and weld the frame after i strip the lot down again.
Oh well,i'll probobly find knackered swingarm bearings and a duff shock the way this job is going.....

Thanks for listening ...
Mick.

[terry t]

Hi Mick sorry to hear the trike handles like a pig. you say its 8mm out from centre of swing arm bearings to flat plates. have you checked the axle from the centre line of the trike to each side of the axle plates. what trike have you built

[mick stobbs]

Ay Terry, still doin checks on the trike (its a yamaha xj900 diversion with a reliant axle on).
I didnt make the swingarm frame and i assumed(wrongly as it turned out ) that it was ok.
I've took the swingarm off this afternoon so i will check it side to side when i put it back on, but the 2 mounting points on the frame appear to be out of alignment.
I'm gonna have to sort that out first and redo some of the welding which is cr#p.
To be honest i'm starting to feel like getting a bog standard swing arm and starting again, but a nights sleep might change my mind.....
Cheers,
Mick.

[markju]

Hi mick,
Been an avid reader of this forum for a while but don't think I've posted owt  yet.
Anyway, I ride a trike, cx500, and when I first got it on the road it too pulled badly to one side. So much so that it was no pleasure and felt dangerous.
Over the next couple of weeks, after checking measurements like you have and finding it a few mill out, which for something made in someone's garage probably ain't that bad, I changed the wheel bearings (knackered) the headstock bearings ( totally knackered) the fork seals cos they were letting any pressure out and finally balanced up and played with tyre pressures.
Complete difference. Absolute joy to ride now. So either one of the things I did or a combination helped.
You've probably already checked these things but just in case you haven't might be worth a look at before starting major metal surgery?

Edit. Wow I'm good. This is my third whole post

[Manky Monkey]

Have to agree with that, (Hi Mark    ).
I'm certainly no expert, but have built, or had a hand in, a dozen trikes. None were built on a jig -obviously it's best to if you can, but it's perfectly possible without. It just takes a lot of measuring & re-measuring to make sure everything's just right, (see the frame building chapters in the Trike Tech section of the main website)
http://www.mankymonkeymotors.co.uk/trikes.htm
At the end of the day though, as long as your rear wheels are equi-distant from the centre line, the rear axle's sitting at 90 degrees to the headstock & the headstock sits vertically, (not leaning to one side or the other), it should run straight & true. On a hardtail trike, a few millimetres shouldn't be that noticeable.
Headstock & wheel bearings can make a big difference & running the rear tyres too hard can make the trike really skittery.
So as Professor Markju says, maybe spend a few days replacing knackered bearings & just experimenting before pulling the whole thing apart.

[BikerGran]

When I first had my trike, I tried to ride it round the circular road round our estate, managed to get back to our road and thought 'I just can't do this'.  It would only go in a straight line or round in circles.

Then I thought, well the bloke who built it rode it here so it can't be that bad.  So I had another go, then consulted anyone I knew with a trike, and as a result, played with tyre pressures, also let all the air out of the air-assisted forks - result!  It did still wobble a lot at speeds below 25-30 mph, but I got used to that the more I rode it - it was always a good idea to keep both hands on the bars!  After a while I didn't even notice the wobble.

Till I got older and the arthritis got worse and I was finding it too much like hard work.  Then I had the front end modified, extended yokes to change the steering geometry, and wider and higher bars - problem solved!

Lately it's started to wobble again but only since I had the fork seals replaced - I have an idea that it may be down to the headstock bearings being too loose.  It's going in to a bloke from our club soon to have the valves looked at so I'll get him to look at the head bearings too.  It's still rideable but i want it back to the way it was before!

[Olds]

Wouldn't have thought the 8mm difference would make it pull so badly to one side. Would have thought it would crab and have a tendency to turn one way easier than the other. I would look at the vertical geometry the headstock relative to the axle. Check the axle isn't bent.  Also as everyone else has pointed out bearings, forks etc. One other thing that can make a trike pull to one side is a dragging rear brake.
Hope you can get this sorted.

[BikerGran]

Another question - which side did it pull to?  If it was the gutter side, is there a lot of camber where you tried it as this can make a difference.

[mick stobbs]

Hey,cheers for the replies everyone,  right....
never thought about the headstock bearings,will check them next,fork seals are new,rear wheel bearings are new,hav'nt checked the tyre pressures yet but gonna run them on 15 psi is this ok?
What i have found is;
the swingarm bearings are shot,new uns coming tomorrow but dunno how i'm gonna get the outer races out of the tubes yet.
i reckon the axle was mounted about 11 mm out of line cos the mounting points for the axle are out of centre,also one of them is lying over to one side so the axle might have been bending when clamped up.
Don't know if theres any difference parallel wise between the swing bearing line and the axle line so i will put that right as well if its out.
The back of the A frame is gonna have to be redone so my idea is to make a sort of jig on a bit of plywood to see if i can do a better job than the last bloke.
Okay, gonna have a read of the trike building section.......
Thanks again,
Mick.

[ROD]

Only just read this thread.Hope youre progressing.Any news yet?

[spanners]

it may all boil dowm to geometery,  if you build enough you find out that its best for one rear wheel to ,,lead,, by a few millimeters,,

those  on here that have built enough trikes will understand , 

[mick stobbs]

Good evening,sorry about the late reply...night shift 
Right,i've ground out and redone all the welding thats gonna stay.
I'm going to cut the old axle mounts off and lose about 250mm after them along the frame legs where they start to go out of line.
I've 'borrowed' some 40 mm box section for the frame legs from work, and have started making a couple of 2 piece axle mounts for the back.
The mounts will have one half welded to the legs and the other half will bolt to it to clamp the axle tube.
Looks like i'm gonna be busy on nights for a while......

Cheers.
Mick.

[Manky Monkey]

Same method I used -don't forget to add a tab somewhere to stop the axle rotating in the clamps.

[mick stobbs]

Yeah, i reckon i'll weld a tab on the axle when i put it on .