Death wobble

I have a 1983 xj750 maxim. It was converted to a trike before I bought it. Its sitting on a 1985 Chevy s10 rear. When I get to about 24 mph, until about 30mph, it gets a terrible death wobble. I have balanced the wheel, put a new tire on it, and checked the bearings. I'm out of ideas. Any help?

 

head bearings tight enough?

 

Yea, all the bearings are tight.

 

has it always done this or is it a new issue?
balanced rear wheels?
checked the rear wheel bearings?
check the rear end and how it is attached . a bad swing arm can cause a death wobble.


got a photo?

what was used as a drive shaft

 

Likely none of the above - if the head bearings are tight it's all to do with rake and trail - it's difficult to get right, most converted bikes to trikes have it. My z750 wobbled exactly like yours, when I bought it it was almost impossible to stop it. After rebuilding the whole frame, and stiffening it up considerably it still wobbled, but you could steady it with one hand. My vmax doesn't wobble at all, but it's really heavy to steer. The sweet spot is very narrow, ultimate fix is a leading link front end, but you could try lowering the front tyre pressure to almost ridiculous levels.

 

What do you mean by leading link front end

 

what he is showing in photo

 

Do you not know google?

 

Is that really the best way to answer an honest question?


@James R Downs,
A leading link front works just like a conventional swingarm that you'd find on the rear of a motorcycle, but the pivot for the swinging arm is behind the wheel. The geometry of such an arrangment makes for a very stable front-end, but at the cost of weight and some minor handling differences (which won't be noticeable on a trike).

 

No, it was a bit short. But google did a far better job than I could have done (I checked). Nevertheless, I have noticed that because sitting behind a keboard is easy it means people don't bother thinking for themselves, and ultimately, you know me, I love being helpful, but spoonfeeding is not my thing - life's too short.

 

I've done some Google searching, where would info about finding an earl fork system for my bike. I haven't been able to ride it because the wobble is literally at speed limit

 

http://www.vk6fh.com/vk6fh/earlesfork.htm

Hope this helps?

 

https://www.m.lumleyengineering.co.uk/page_41.php?pgenme=bespoke-leading-link-forks&totwid=412

 

You are from the USA just noticed that lol.

 

Yea, good ol us of a lol.

 

If anyone has any sites as ti where I could order parts for this type of front end for my bike, I would be most appreciative.

 

There you go - you taught me something - I never knew they were called Earle forks.
No one will have these in stock - you'll have to comission someone to make a set for you, or make you own!
One thing though - you say it wobles at the speed limit - normally trike heads woble at low speed, and it reduces as you go faster. If this isn't happening I would suggest there is something else amiss?

 

he should check anything and everything to do with the bike that may be loose or mis adjusted, before buying a new front end.

still want to know if this is a new issue or he got it that way.

how is motor connected to the rear end can we see a photo of the set up

 

I got it this way. It's a home made trike.

 

What about a steering damper kit?

 

I'll show you mine if you show me yours. This is my earlier (sold last year) Kawasaki 750). Hard tail, wobbled a bit between 0 and 20 mph, no big issue to stop it, for some reason worse from cold - could be stiff tyre?
The one below it is my current one Yam Vmax full power, IRS back end, doesn't wobble at all, but is heavy on the 'bars, so I'm going to make a new front end for it.
If you want help you have to do your bit - I asked you what speed yours wobbles at? Strike this - I re-read your original post. Wobbling up to 30 mph is higher than normal though.
Now, you could also try to upload a couple of pics - let's see what the front and back looks like - some home made trikes are nothing but badly welded death traps, not suggesting yours is but they really do vary.
And @XJ550H asked you weather this problem developed or did you buy it like this - I suspect someone sold you a failed build, but confirmation please?
A leading link front end is an expensive fix, and you should try all options first, including a damper, even a quallity version will be a loads cheaper alternative.

 

Fair enough.