My fizzer needs major surgery... again

[riffer]

All right - I've just about come to the end of my tether with this bike.

You guessed it - my eternal problem has resurfaced - the bloody steering head. To sum the problem up in a few words - its knackered.

The bike has had two major prangs in its life - once while under my control (control - yeah right) - in which it's taken a fair beating in the front end. In the first bin it had new forks and triple clamps. In the second it had new forks and had the triples straightened.

The legacy of all this is there is a degree of ovalisation in the steering head socket races.

I have pulled the races out of the steering head and attempted to fix this with loctite 660 quickmetal (an expoxy resin fortified with aluminium shavings) which I really am not too sure is up to the job with a steering head on a 90-odd horsepower 220 kg behemoth of a late-eighties 750.

If I have the steering head tightened to the correct amount it goes "clunk" when I put the brakes on. If I tighten it more, it "binds" in the centre which gives you that awkward feeling as it's stiff when going straight ahead and then a touch loose as you turn. The main problem with that is its too stiff going in a straight line at slow (< 20km/hr ie slow lanesplitting) - and its hard to explain away come warrant time.

It got a warrant on Thursday but I am more particular than the Vehicle Testing chaps so I want it sorted.

So the way I see it I have two options.

1. Pull the bike apart and take it to someone who can weld in filler into the race sockets, then get the sockets milled out smooth again.

2. Get a new frame, pull the bike apart, rebuild it with the new frame, then go through the whole revinning/recertification thing.

Yes, I know I can just pull the VIN plate of one frame and chuck it on the new bike, but all it takes is one vigilant person and I'm in trouble, so I may as well do it legal.

I've been quote $200 for a replacement frame which I reckon is pretty damn good. I'm not too sure if you could get the frame welded and new sockets milled for that.

What do you guys reckon is the best solution, and what does the process of recertification with a replacement frame entail. Does anyone out there know the answer?

[FlyingDutchMan]

Go for the new second frame I recon... I agree that $200 is cheap - its not bent already is it? revinning/registering the bike will cost a pretty penny on top. But I recon you'd be better off with a bike that'll turn when you need it too, than one that might run you in a straight line off road when trying to corner.

[カワサキキド]

It's a good excuse to pull the fizzer completely apart and put it together again. Working on your is bike is almost as satisfying as riding it, (except when you loose a bolt and it drives you crazy for hours looking for the st#p!d l!ttl* f#ck*r errr....

How much is it worth to get the vin changed?

[Motu]

An alloy frame and it weighs 220kg? How the hell did they manage that? I've never liked the idea of alloy frames,and you've just given me a reason to stay clear of them.For $200 I presume your 'new' frame is used? I'd still go for another frame,the repair work is going to cost more than that,but check it out well first.

[Antallica]

New frame I reckon.

[James Deuce]

I'm with Motu, except for the reactionary rant about alloy frames :)

$200 is cheap!! The RC30 frame after my shunt was going to cost $12k to replace and that was a similar era bike.

Hire an engine lifter for the weekend, let us know when your doing it, and we can make it a KB BBQ to do the swap.

Hang on - BBQ - Beer - bike rebuild. A bunch of pissed no hopers armed with a socket set and the collected "wisdom" of 20 odd drunken backyard mechanics. You may want to have a think about that before accepting.

[Antallica]

Hang on - BBQ - Beer - bike rebuild. A bunch of pissed no hopers armed with a socket set and the collected "wisdom" of 20 odd drunken backyard mechanics. You may want to have a think about that before accepting.

Haha, right on mate ;)

[riffer]

Hire an engine lifter for the weekend, let us know when your doing it, and we can make it a KB BBQ to do the swap.

Yup. Sounds good.

And Motu - 220 kgs. Yup. Amazing when you consider the frame itself only weighs 12 kilos!!!



I dunno where the weight comes from. But it's a big bike. Around the same size as a GSX1200.

[SPman]

Yup. Sounds good.
I dunno where the weight comes from. But it's a big bike. Around the same size as a GSX1200.

Big but comfy - better than the YZF. Go with the replacement frame.

[Blakamin]

I'll come give you a hand!

[F5 Dave]

220kg isn’t that heavy really. It’s just we are getting blasé believing all the quoted crap that comes from the manufacturers & their lies about weight. Get a pair of bathroom scales under each wheel & prepare to be disappointed, better yet try a calibrated scale & a bike with a full tank.

[bungbung]

New frame. $200 is cheap

[Paul in NZ]

You might just wanna hang on a second here….

Replacement frame for $200? Chances are it has issues as well?? Be really certain it’s the old frame first. Have you measured it?

Most sterring head bearings have an outer and inner race. Both have to fit properly, since various parts have been substituted onto you bike are you sure the bottom / top yokes are a good fit? Perhaps the inner bearing is loose on them?

Is there anyway to ream the stem (on the frame) to take an oversize bearing. Bloody Yamaha charges a fortune for theirs but any bearing factor will have a tapered roller bearing in a slight oversize that should tighten things up if you can remake the hole.

Frankly, there is something odd about this. For it to be that bad, it should be pretty obvious whats wrong. You sure it’s not something daft like undersized balls (if it has loose (uncaged) bearings?

[riffer]

You might just wanna hang on a second here….

Replacement frame for $200? Chances are it has issues as well?? Be really certain it’s the old frame first. Have you measured it?
Good call. It's a frame from a 1987 FZR1000T. Absolutely identical. However, I have not looked at it yet. It was mentioned yesterday in a conversation with the local bike wrecker when he turned up to buy a parts bike I was selling on trademe for my father-in-law.


Most sterring head bearings have an outer and inner race. Both have to fit properly, since various parts have been substituted onto you bike are you sure the bottom / top yokes are a good fit? Perhaps the inner bearing is loose on them?
I've had a damn good look at the triple clamps. They were straightened back in June. The top triple was twisted in the crash. The forks are the third set (that I know of) that are on the bike. The bearings and races are supplied by Sawyers. I asked for the Yamaha ones and, while they didn't come in the usual semi-opaque Yamaha-labelled parts bag, I was certainly charged the usual Yamaha price for them (ouch). I have talked over my technique for "pressing" on the bottom bearing onto the lower triple, and while we both agree its pretty bloody dodgy, it most likely has not caused a problem. However, I'm fairly certain the "clunk" is coming from the bottom of the steering head.


Is there anyway to ream the stem (on the frame) to take an oversize bearing. Bloody Yamaha charges a fortune for theirs but any bearing factor will have a tapered roller bearing in a slight oversize that should tighten things up if you can remake the hole.
Definitely not my area of expertise. Ask me about photoretouching, design or offset lithography and I'll give you a better answer. However the steering head is pretty large. Although made of alloy. IMHO it could be machined out. It depends on the kind of bearings you can get. Again, I'm not an expert on bearing sizes. I will talk to Graham Berry RaceCars tomorrow. They have some pretty cool equipment down there and they're local. They build replica AC Cobras and have done some work previously for me on an old VH SS Commodore I had trouble with. Perhaps maybe some machining and a different race could make a difference too.


Frankly, there is something odd about this. For it to be that bad, it should be pretty obvious whats wrong. You sure it’s not something daft like undersized balls (if it has loose (uncaged) bearings?
I dunno Paul. I've had it apart five times now. Maybe I'm missing something. It has tapered roller bearings. The bearings themselves seem pretty loose at the bottom though. How much movement should there be in a bottom taper roller bearing?

[F5 Dave]

Probably not a bad choice. The younger of the 2 Grahams (ie: not Berry) has an R6 & is a bucket racer (when allowed out).

[FROSTY]

Mate-i think I've got it sussed for you.
I've been talking to a real expert or two for you.
Both are VERY doubtfull that you need to repair the steering head
I need to start with the assumption that when you tighten the bearings down you have the top triple clamp loosened off on the forks and you dont have stuff like handle bars clamping things down
I know you said there were sighns of previous damage but even so a possibility is that when fitting the new outer race you fitted it slightly skewiff and you have a small lump of shaved ally jammed under either the top or bottom race. sorry to say it but you need to dissasemble and examine very carefully the frame stem. You are looking for anything that will prevent the bearings pulling down flush. -that includes that epoxy stuff.
You will need to clear it all out and put it all together again.
The other bit of advise i have is that no matter how well you think you have taper roller bearings tightened down you WILL need to retighten them at least once as they pull down into place --more likely 2 or 3 times.
Do that before looking at alternatives.
Ohh and go easy on the grease--it may be making matters worse.
Good luck bro.

[riffer]

I pulled the whole assembly apart yet again and checked the bearing races for position, movement, etc.


Just for good measure I changed the top roller bearing and then torqued the whole assembly up as tight as I could (until I could not move the forks at all), and then undo until there is no clunk and (hopefully) no binding.

Yes, I take the top triple clamp off first, remove the tank, undo the clipons, etc.

I have the front of the bike off the ground so I can grab the forks and give it a good yank and ensure that there is no clunk.

There's only a little bit of binding now and no clunk.

So, maybe the frame is okay. I'm now looking at the possibility that the bearing on the bottom triple clamp is not entirely on straight.

It might be worth looking into getting the bearing ripped off and put a new one on properly. It could be the cause of the binding. :spudwhat: