Z1OwnersClub GB

Anyone here ride or race Eddie Lawson reps or J`s.

Need advice regards setting up suspension on my ELR(2).

I rarely ride this bike now which is a shame as having put new flatsides on in 2019, it goes very well indeed. However, I seem to have upset the handling by putting on a pair of KYB piggy back shocks.
The original shocks were leaking (still got them), so I tried a couple of non piggyback shocks and whilst the handling was pretty sweet; they didn’t look right, so I gave them away and replaced them with the KYB`s

Despite having some adjustment, I just cannot get the bike set up correctly. No matter what I do the front feels too heavy, tips in too quickly and understeers - odd mix I know.

The frame is straight, the tyres good and the front fork oil 2 yrs fresh, still on original springs.
If it helps I’m just about 6 ft and weigh just over 13 stone…..all muscle 

The poor handling drove me nuts to the point where I didn’t bother riding it last year.

Penny for your thoughts.

Hi Wardy

I can see in the picture that the preload of the spring is at the lowest. Perhaps you can start by giving it a bit more preload, try to put it in the middle and see what that gives. It's not much work and it's not irreversible...give it a try.
Is there enough play at the steering tapered bearing? Didn't it became rusty and do you have to replace it? Check it out.
GrtZ
Philippe

There are many on here who either do track days on a J or ELR, or have very sorted versions. Also, there is a raft of info about suspension setup, in particular a thread by Al showing the path he went down to get his J to where it is.

Knowing a bit more about your bike would help: -
- Are you running the stock 19" front wheel?
- What condition are the tyres? Squared off? Are you using the same tyres front and rear?
- Do you know the rate for your front springs? (A standard J is waaaaaaaay too soft...)
- Are your forks stock otherwise, and what grade and make of fork oil are you using? (Consider that Silkolene make two versions of fork oil, but the Centistokes value for both types of 10w are significantly different!)
- Do your rear shocks (1100 Zephyr?) have damping?
- Are the shock damping adjusters free?
- What length are the shocks, eye-to-eye unladen?
- Are your swinging arm and steering head bearings in good condition?

Then, have you checked the rear static and laden sag?
How have you gone about setting the rear damping?

Although heavily modified, my J is very susceptible to tyre profiles. Previously I used Avon Roadriders and they were very good on the road, very neutral.
In the photo below I had just fitted a 130/80-18 Continental Road Attack 3 to the rear and it was awful - the profile was too triangular and it felt like the rear was washing out. I have a Conti Road Attack 3CR in 110/80-18 on the front, and have since fitted a 150/70-18 Dunlop Alpha 13 (on a 3.5" rim) and we're now hack to normal, but much stickier.

Link to Al's interesting suspension thread: - viewtopic.php?f=4&t=27150

What type pressures are you running and what are the tyres?

Hi All.
Thanks for your feedback, sorry for late reply as I don’t use a computer on weekends due to spending all working week sat in front of the bloody thing.
I will answer questions in order from:

Phillippe.
Yes I have had the spring pre load in a variety of settings, worked better in the middle but not like it should, tried them on both higher and lower setting which was worst but left them there. Steering bearings are all good, not lose or too tight.

Coose.
Boy you ask a lot of questions, but all relevant. To answer them, Yes stock wheels. Tyres Bridgestone Battllax BT45`s front and rear, two yrs old with very little use so profile is good. Before that Avon Roadriders with good but more triangular profile. But same handling issues remained with both makes of tyre
Front fork spring rate, I have no idea what is standard for the 1983 ELR(2) – however before I started messing with the rear suspension the front was very good.
Front forks are stock, I cannot remember the make of fork oil but grade was 10W20 with 7 psi air pressure.
Rear KYB shocks do have compression adjustment / damping currently set on one (1) also rebound adjustment is set on one (1). However have dialled in many variations and to be honest whatever settings the shocks are on it makes little difference.
Eye to eye length of rear shocks. Now if I remember there were two different length Zephr KYB shocks and I made sure I got the ones that were closet eye to eye length as the original showa shocks being 14inches if memory serves me right.
Steering head bearings are good; swing arm bearing could do with a clean to be honest.
Suspension sag. I have never adjusted this as found it hard to do when working on my own, but I think the unladen / laden sag is just over 1/3rd of available travel at front, although I personally feel I need more travel at the front…but I do ride large trailies most of the time.

Chris.
Tyre pressures tend to be about 32 psi front 34 psi rear.

Thanks All and I really hope my replies helps continue the discussion to work out the simple little thing I need do to put my suspension set up back to where it used to be.
I will look at Al` Interesting Suspension Thread later this evening.

Yeah, sorry about all of the questions but it's tricky to diagnose the issue without being able to prod the bike.

The first thing that springs(!) to mind is whether the shocks have any damping? If you bounce on the seat does it spring straight back up, no matter the rebound setting (the rebound is the adjuster at the bottom)? If so, you have no damping.

No worries about the questions ,it’s tricky for me to diagnose even though I have access to the bike.

The bike is up against a wall in my garage, surrounded by lots of stuff, so I can’t get to her and give it a bounce, also shamefully I haven’t ridden her for about a year, a waste in anybody’s book.
However, if memory serves me correctly which it doesn’t always, I vaguely recollect that the rear was perhaps a bit slow to bounce back.
Weather permitting, I will empty the garage this weekend and give it a bounce test.

Its hard to find shocks that look right on the ELR, for me they have got to be the same gold colour as the wheels. Anybody know if the original Showa shocks can be rebuilt as they look the part. The KYB`s look ok, can they be rebuilt as well or am I simply chucking away good money and best invest in something new even though it might not quite look right.

Aiming to give Al a ring when I get the chance.

Hmmm.... It's sounding like you may have too much rebound damping and the rear could be pumping down. What this means is the shock compresses when it hits a bump, but too much rebound means that it doesn't properly extend again so when it hits the next bump it compresses even further and so on. This could cause the rear to squat, which will increase the rake angle and cause slower steering.

If you're saying the adjusters are free to turn I'm assuming they're all clicking between the four(?) settings, but the rebound adjusters could have failed internally if you're not noticing a difference.

What I would do is set all of the damping adjusters to 1 (minimum) with the preload on minimum, bounce on the back and check the rebound. It should spring straight back up and bounce.
Then, wind the rebound to max on one shock and bounce the bike to see if there is a difference. Then, reverse by setting the shock with max rebound to min and the other to max to check the other shock for rebound. Reset both shocks to min if you are seeing a change on both when they're individually on max and then increase one step at a time until the rear extends quickly but only just doesn't bounce. If you can't get the shocks to do this and they extend too slowly with the adjusters at min, then they're over damped to start with.
Leave the compression damping on min at this point (the upper damping adjusters).

Then, check to see that you have a little static sag and a little more laden sag, increase the preload if your laden sag is more than a third of the shock stroke, wait for the snow to melt and then take it for a spin to see how it feels. I always put a small tie-wrap on the damper rods so that I can see how much travel is being used.

If, when you hit a bump the rear springs up quickly, add another click of rebound to each shock.

Compression damping; if, when you hit a bump you're bring bucked out of the seat and it feels like the shocks aren't compressing, you have too much compression damping. But, at this point your shocks should be set to minimum so all being well you'll not have enough.
If it feels ok but the rear wheel is leaving the ground on a bumpy road, add a click or two to see if it improves.
You can also often feel if the compression damping is right when you drive out of a corner - if it squats and runs wide (as you were complaining about) you might not have enough. If it doesn't squat but then skips over bumps you have too much. It should squat a little but "drive" out of a corner.

I know this sounds like War & Peace, but hopefully it gives you some pointers. But remember, with damping less is more!

You wont get a better explaination than that. Suspension set-up at a track would have just relieved you of £40 for it as well!
For the front end; if you follow the set-up in the manual it just plays into the hands of an out of adjustment rear end. Last time i was using air assist in the air over oil forks i was at 3 PSI. All the air really does is extend the free length of the forks and make feedback vague and difficult to interpret. Air is a poor substance on which to base suspension. 7 PSI probably just adds about 1 inch or so to the length of the forks without making any real contribution for any other reason. I needed something different so started progressively cutting down on the air and increasing the oil level thereby reducing the air gap. An extra inch or so of fork length also screws up the rake angle.
Something you can take from the comments in the Emulator thread is that oil has a different viscosity and by implication different suspension characteristics at different temperatures. This can be incredibly confusing if youre on the trail of something but dont know exactly where to look. Small volume of oil in the rear shocks VS large volume of oil in the front gives a different rate of change too. How can you win. Well, i guess you cant but you really can get a decent set-up even with these primitive design of forks.

To illustrate Coose's point; i bought some really expensive rear shocks for mine just recently. I was given the settings of a guy who was racing with them. That must be ok then, right? Put them on thinking i was going to be entering Moto GP soon and the ride was dangerous. I dont mean dodgy i mean seriously dangerous. Eveything that happened was focussed on the 'front end' and that is exactly where the problem wasnt,...... it turned out. It is really easy to come to the conclusion that the front is at fault even with something as innocuous as fitting different rears.
Another of Coose's great tricks is an inclinometer on a smart phone. Download it for free. You can place the phone against the front fork legs (upper or lower) and directly read off youre current rake angle. Tune the forks rake angle with the air pressure setting and match it with laden sag and static sag. You, like me would probably be amazed by what this tells you. The inclinometer is great for DIY too and i use mine at work at least every couple of days. What a phenomenal thing.
As a matter of interest; is the position of the rear shocks lower mounting point approx the same distance from the swingarm pivot as it was with the original steel swing arm?

AL

If you want to know if your shocks can be rebuilt talk to MCT suspension
https://www.mctsuspension.com/

Or Brooks
https://www.brooksuspension.co.uk/

I have heard good things about both.