Bent Frame?

[ROZZER]

Fitting new chain and set up straight edge to check wheel alignment.
Rear tyre measures 120mm wide and front is 94 mm hence should get equal gap either side of front wheel of 13mm. So far so good, when checking I got 23 mm on left side of bike and 3mm on right - ooer!
Gap is parallel so I reckon wheels are in alignment but it looks like the headstock/frame is twisted.
This would explain the lousy handling and weaving above 80 mph (I know Z1's are reputed to be poor but mine is dangerously unstable). Looking at front forks they appear to be kicked over to the right side of bike (have long thought something looked out of line but others looking at it have said it looks OK and its other parts of bike throwing my eye). I guess what I've found by measurement confirms twisted headstock/frame - can anyone confer with my assumptions? Gonna strip yokes out and stick broom handle down headstock to get better idea of twisting.
Recent article in CMM, Rod Gibson had his Z1A frame straightened in Motoliner jig, anyone know of one in Northwest England cos seastar in Norwich that Rod used is and awful long way from Cumbria?
Its a real shame the guy I bought this moneypit off didn't check the frame before he had it powder coated , the rest of the bike has had full resto done. I guess it looks like a full strip down now, get frame straightened then redo powder coating- so much for a quiet winter!!!!

[steve f]

just buy another frame it will work out loads cheaper

[Steve Cooke]

Hello John, before you strip the forks right down I would just check that both wheels have the correct spacers, and do a check over the vertical plane by setting bike on center stand and measuring from a vertical plumb line to top and bottom of rear wheel, if not the same pack the stand until it is and then do the same on the front wheel it should be the same top and bottom, if not it would indicate a twist in frame or swingarm also I would measure from rim edge rather then tyre edge.
Steve

[ninjajen900]

Hi John,i dont know anyone up there but over the years have had loads of frams motorlined with no problems and always perfect results.check the bottom yoke when you lower the forks down out of the top yoke that distance on top yoke holes are equal,i have found these to be out quite often when the frame is out.good luck

[ROZZER]

Have checked spacers in both wheels and they are correct. Set bike on centre stand, put spirit level across frame rails above air box (only level part I could use) put steel shim under the stand until bike perfectly level. Plummed both wheels, back wheel is spot on, front wheel shows 8 to 10 mm run out thus agreeing with the straight edge findings. Plated section below headstock shows signs of rippling so it looks like there is some twisting at headstock
Looks like full strip is inevitable. Any more ideas for checks before I get stuck in?

[Padders]

No ideas but plenty of sympathy mate.

Keep your chin up.

[steve rees]

Hi John,

A bit of a drive from you (maybe 1 to 1 1/2 hours) but try Blacks Bike Shop at Burscough its 15 mins off junction 27 of the M6 they have a moto liner jig, their number is 01704 897551

They are good lads

They are local to me --if there is anything i can do to help let me know, there is another local guy that might be of use to you after the frame is straightened--John at Elite Powder coating in Aintree another 15 mins away, speedy turn round with excellent quality (i had my frame coated and its very very well done, they are bikers themselves-Z1300 etc)

any way-good luck

Steve Rees

[Davy Doherty]

John, i'd e-mail Jeff Saunders before you do anything, i think he posted about them comming out of the factory a bit out of true... if nothing else he will definatly give you sound advice, he's a sound guy and very very helpful..

[ROZZER]

Davy, Ive heard that these can be a little off when leaving the factory (as most modern stuff is too) but mine is well off and badly affecting the handling, so I'm convinced that the headstock and/or steering stem is bent.
thanks for the heads up tho', Jeff is a top bloke, I spoke at length when I had big engine issues earlier this year and he sourced my oversize pistons/rings at a great price- Top Bloke.
Steve, was told about Blacks at work today and will contact them to see if they have done Zed in recent past. Not too far to travel and I can fit in with visiting my brother (Z1B Alan) in Ellesmere Port at same time (I was born and bred there). Have heard of Elite but never found anyone thats used them, was gonna use Triple S but Elite is closer. It maybe that in straightening the frame, the powder coat may survive (vain hope??) so may not need to get redone. Thanks for the offer of help, much appreciated, I will PM if I need anything

cheers

John

[Steve R]

John,
Triple s are very good i have used them for years they are 3 miles down the road from me so if you need me to take /pick up stuff during the week then you can bring/ collect stuff to mine evening or weekend if that helps.
Otherwise if you are going there drop in for a coffee.
regards Steve R

[simon gilling]

John
My '72 Z1 has the same issue the headstock is twisted to the right by a visible amount.
Be very careful about the frame change route, I tried it ,even MoTd the bike and sent off the log book to DLVA with the updated number. Big mistake. Frame passed the VIC, (Vehicle Identity check), had it inspected by VOSA,but DVLA could not handle the same reg with a different chassis no.
They insisted I register it from scratch. Managed to get my original (frame no.) log book back, then in the same post came a letter from DVLA saying my MoT chassis number is different from my log book details aaargh!!
I can now strip a Z1 down and change the frame over in 3 hours flat, put it back together in about the same time and will get the MoT station to update the MoT. That shoudl get DVLA off my back, but I still have a bent frame. I hope the above will save other members from making the same mistake.

Anyway I would like to hear how you get on with the Motoliner on your frame, I had an XS650 trued up in the 80s with no damage to paintwork, it was a technical rather than brutal pushing on the frame.

Good luck!

Simon

[ROZZER]

Simon, I suspected that getting a differnt frame may be problematic with DVLA (let alone the fact that the replacement frame could be as bad or worse if buying off Ebay) so I will forge ahead with the motoliner route. Will let you all know how it goes (when I can afford the expense). I am confident it can be rectified, based on Dr Rods bike and comments from lads in the club, its just a case of the breaking out the old money spanner again- I'm an expert with that particular tool now!!!!!

[simon gilling]

John
You are probably right about frames on eBay, a bit of an unknown. I got a Jan '73 frame from a club member it checked out straight and did handle a lot better.

The way I check the frame is similar to you in that I ensure that it is flat on the centre stand. I use a digital angle finder (?25) of ebay 'Digital Angle Gauge - Set Mitre Saw Blade to 0.1? '). It is acurate to 0.1 degrees so I take the swingarm pivot as the baseline, set to 0 degrees and check that both wheel spindles = 0 degrees and the headstock lateral is 90 degrees to the swig arm pivot. I remember when I had my XS650 motoliner'd the guy locked down on the swing arm bolt as the main datum then took all the other readings.

I was wondering whether I could set some big bolts down in the garage floor the make a holding frame for the partly stipped Z1 and find a big bar to 'tweak' the headstock then recheck with the angle finder.

Has any other member experience of frame strsaightening?

Simon

[Garn 1]

Spurred on by Simon's method, I have a similar method that basically checks that my headstock is at right-angles to the swing-arm pivot bolt.
The design has been modified from the drawing, in that I have adapted a laser pointer to an old steering stem and it takes taper roller or plain ball bearings and can be collimated by simply rotating.

You can see by moving the platform in an arc around the swing-arm pivot a laser pointer will travel along the perspex surface and any gradual move away from the engraved line will show a miss-alignment. I accept a maximum of 1 to 2mm max deviation. The rake angle can also be checked by inserting a location pin in the front LHS mounting bolt position.

RegardZ

[simon gilling]

Garn1
That looks neat, I wanted to know which point(s) on the frame to level to then check the rake angle. Can you confirm that the level is from the l/h swingarm to the l/h front engine mount.

Does anyone out in Zed land have the specs of the various models?

p.s. I have put my origianal (slightly bent) frame back on the road, it really handles weird after a few months with straight frame. Even stranger I managed to track day it at the Cadwell Park full circuit and kept up with a few classic race bikes.

I expect the weather in Sydney is better than UK!

Simon