Suspension help please

[skahigh]

I've just started to look at the suspension setup on my Tuono now that I've had it a couple of months (I know nothing about suspension).

It has a non-original Ohlins rear shock and since the rear ride height seems a bit high I thought I'd try to shorten it a bit. I can't seem to loosen the blue lock nut but in trying I noticed that the whole shock has a fair amount of rotational play, is this normal???

Since I'm a fat git (230 lbs right now), I think the spring on the rear spring is probably too soft, it's marked 01091-31/95 L099, can anyone offer an informed opinion on this?

I think I'm best off getting it checked out and setup professionally, would any bike shop do this or do I need a suspension specialist? If the latter, any recommendations in the south wales area please?

Sorry for all the questions.

[skahigh]

No one?

[Prof Prolapse]

skahigh said:

It has a non-original Ohlins rear shock and since the rear ride height seems a bit high I thought I'd try to shorten it a bit. I can't seem to loosen the blue lock nut but in trying I noticed that the whole shock has a fair amount of rotational play, is this normal???

Since I'm a fat git (230 lbs right now), I think the spring on the rear spring is probably too soft, it's marked 01091-31/95 L099, can anyone offer an informed opinion on this?

I think I'm best off getting it checked out and setup professionally, would any bike shop do this or do I need a suspension specialist? If the latter, any recommendations in the south wales area please?

Sorry for all the questions.

Cant help you get the nut loose. But if you're adjusting your ride hide it will also be making huge changes to the geometry of your bike. So just bear that in mind.

If you have an Ohlins spring, ring Ohlins. They will be able to help you identify the product you have and presumably help you identify the product you need given it's in their interests.

In my limited experience, some motorcycle shops will assist, most won't. A lot of set up is preference, and it's a bit of dark art. Try calling up a dedicated specialist or tuning shop.

Alternatively, there is a book called "Sportsbike Suspension tuning" by Andrew Trevitt, it's very easy to read and gives you a good idea of what is going on, even if you end up paying someone to assist, you'll be better informed as to what you actually want.

Edited by Prof Prolapse on Monday 26th September 10:00

[Private Pile]

Op, I know nothing of suspension but this helped me a bit. Don't know how to do links, but if you google " suspension education program t595 "this should point you in the right direction. HTH

[gareth_r]

skahigh said:

...any recommendations in the south wales area please?...

JHS in Keynsham (that's K E Y N S H A M for older readers ) near Bristol do a static set up for £35. There are a couple of videos - GSX-S1000F and MT10 blogs - on the Fast Bikes YouTube channel.

Local knowledge rather than a recommendation, since I've not had them do any suspension stuff - and obviously not in South Wales.

[moto_traxport]

You could try playing on Racetech's website and using their spring calculator entering your weight etc.

I think that spring is 9.5kg/mm or 95Nmm from the number (which are close enough to each other for basic working out).

[skahigh]

Thanks for the responses guys, much appreciated, can anyone comment on the rotational play in the shock?

I've come across moto pro, anyone ever heard anything about them?

I'll check out the books/sites mentioned, would be good to understand it all a bit better.

[Steve Bass]

Spring is too soft for your weight. As will the forks springs.
Check how much preload the rear shock has wound in..this would explain the high rear end.
Get the correct springs for your weight and you won't believe the difference!

[skahigh]

Steve Bass said:

Spring is too soft for your weight. As will the forks springs.
Check how much preload the rear shock has wound in..this would explain the high rear end.
Get the correct springs for your weight and you won't believe the difference!

Thanks very much, I think I'd better seek professional help.

Here is (I think) a photo of the preload on the rear:



And a photo of the forks (or is this the forks dropped through the yoke??):

[Steve Bass]

skahigh said:

Steve Bass said:

Spring is too soft for your weight. As will the forks springs.
Check how much preload the rear shock has wound in..this would explain the high rear end.
Get the correct springs for your weight and you won't believe the difference!

Thanks very much, I think I'd better seek professional help.

Here is (I think) a photo of the preload on the rear:



And a photo of the forks (or is this the forks dropped through the yoke??):

Yep.. Someone has wound up the preload trying to compensate for the wrong spring. All this actually does is increase the initial force required to move the spring. And raise the rear comically. Which you know. correct springs and a set up will transform the bike.
And very little preload in the front. Must be an interesting handling bike

[skahigh]

Steve Bass said:

Yep.. Someone has wound up the preload trying to compensate for the wrong spring. All this actually does is increase the initial force required to move the spring. And raise the rear comically. Which you know. correct springs and a set up will transform the bike

Thank you, should my local bike shop be able to sort me out or am I best off with a suspension specialist?

[Steve Bass]

skahigh said:

Thank you, should my local bike shop be able to sort me out or am I best off with a suspension specialist?

If you are changing the springs look at refreshing the suspension overall. Depending on the age of the bike it might benefit from new bearings and sliders, seals and fluid as well as a recharge to the gas.
A semi decent suspension shop would be a good place to start. Springs are easy to source from an authorised Ohlins retailer. Or go with ktech or similar if you aren't worried about the spring being yellow.
It'll be the best money you ever spend on the bike.

Edited by Steve Bass on Monday 26th September 14:52

[skahigh]

Will do, have just called moto pro who are not far down the road from me so just awaiting a call back from them.

He is an Ohlins service centre I think.

Thanks everyone for the help.

[skahigh]

Steve Bass said:

Must be an interesting handling bike

Just noticed this. It probably speaks volumes to my lack of experience and type of riding that I havn't noticed it being particularly poor handling wise. Then again, my other bike is a Thruxton which is also not set up for my weight so handles even worse.

[Steve Bass]

skahigh said:

Will do, have just called moto pro who are not far down the road from me so just awaiting a call back from them.

He is an Ohlins service centre I think.

Thanks everyone for the help.

Simple guideline is you don't want to have more than 15mm of threads above the top ring on the rear shock. 10 is the correct amount but you can go a little bit more to get the correct sag.
Don't get too worried about static sag but make sure you have about 1/3rd of the total suspension stroke taken up when you are on the bike in your gear. So front forks should lose about 40mm of stroke. Rear needs to be measured in a line above the rear axle but same rule applies. Plenty of information out there to provide guidance.

[skahigh]

Hi guys, took the bike to moto pro on Tuesday and he did a setup for me.

He agreed that there was too much preload on the back and that it really needed a slightly heavier spring. He also said that the front was really soft and could do with going up possibly as much as three spring stiffnesses on the front.

There was no static sag at all and barely any rider sag. He set this up with 35mm rider sag on the rear and added a fair bit of rebound damping. He added some preload on the front and tweaked the damping.

I havn't had a hard ride yet, only commuting to work. Yesterday I didn't notice anything wrong but this morning on the way to work the front end felt very strange.

The front wheel felt like it wanted to pull away from straight ahead as I turned through corners at relatively low speeds (20-30) and a couple of times it felt like it wanted to run wide quite badly in slightly faster corners.

I'll check the tyre pressures later but in the mean time any idea if the changes mentioned might be likely to cause this feeling?

[Steve Bass]

skahigh said:

Hi guys, took the bike to moto pro on Tuesday and he did a setup for me.

He agreed that there was too much preload on the back and that it really needed a slightly heavier spring. He also said that the front was really soft and could do with going up possibly as much as three spring stiffnesses on the front.

There was no static sag at all and barely any rider sag. He set this up with 35mm rider sag on the rear and added a fair bit of rebound damping. He added some preload on the front and tweaked the damping.

I havn't had a hard ride yet, only commuting to work. Yesterday I didn't notice anything wrong but this morning on the way to work the front end felt very strange.

The front wheel felt like it wanted to pull away from straight ahead as I turned through corners at relatively low speeds (20-30) and a couple of times it felt like it wanted to run wide quite badly in slightly faster corners.

I'll check the tyre pressures later but in the mean time any idea if the changes mentioned might be likely to cause this feeling?

Firstly, did you have new springs fitted as he suggested? ? If not, you're really wasting your time trying to get it right. With the excessive rebound removed you will now be much lower at the back making the bike understeer/ not hold a line. Go back and get the right springs fitted.....
If you did get the springs fitted......
The rebound is probably too slow which causes the suspension to pack down.
Simple rule is to set it around the first 1/3rd of the clicks.
So get a pen and paper and follow:
From under the shock turn the rebound adjuster anti clockwise until it either stops or goes very vague and you can't feel the clicks.
Now turn it clockwise until it stops. Don't force the end pount and DO count the number of clicks from open to closed.
Now divide that number of clicks into 3. Turn the rebound adjuster anti clockwise to a number equal to 2 thirds of the total clicks.
Repeat on the front.
Biggest mistake people make is to have the suspension much too slow which prevents it from working properly.

[skahigh]

Steve Bass said:

Firstly, did you have new springs fitted as he suggested? ? If not, you're really wasting your time trying to get it right. With the excessive rebound removed you will now be much lower at the back making the bike understeer/ not hold a line. Go back and get the right springs fitted.....
If you did get the springs fitted......
The rebound is probably too slow which causes the suspension to pack down.
Simple rule is to set it around the first 1/3rd of the clicks.
So get a pen and paper and follow:
From under the shock turn the rebound adjuster anti clockwise until it either stops or goes very vague and you can't feel the clicks.
Now turn it clockwise until it stops. Don't force the end pount and DO count the number of clicks from open to closed.
Now divide that number of clicks into 3. Turn the rebound adjuster anti clockwise to a number equal to 2 thirds of the total clicks.
Repeat on the front.
Biggest mistake people make is to have the suspension much too slow which prevents it from working properly.

Thanks again Steve.

I havn't had new springs fitted yet as it was just a quick adjustment job he was doing for me at short notice, he's given me a price for all new springs and I'll be getting that sorted soon. I understand that spending too much time faffing with this with the wrong springs is pissing into the wind somewhat.

I see what you're saying about the rebound causing the tendency to run wide, would that also explain the front wheel trying to pull away from centre on light steering at slowish speeds?

It felt a bit like the effect of having one flat tyre on the front of your car.

[Steve Bass]

skahigh said:

Thanks again Steve.

I havn't had new springs fitted yet as it was just a quick adjustment job he was doing for me at short notice, he's given me a price for all new springs and I'll be getting that sorted soon. I understand that spending too much time faffing with this with the wrong springs is pissing into the wind somewhat.

I see what you're saying about the rebound causing the tendency to run wide, would that also explain the front wheel trying to pull away from centre on light steering at slowish speeds?

It felt a bit like the effect of having one flat tyre on the front of your car.

So by reducing the preload in the rear the back has effectively dropped.
By adding preload in the forks the front has effectively lifted.
Now you have a fundamental change to the overall geometry which will feel weird enough but to slow down the rebound just makes the suspension slow to respond and stay in the compressed condition even longer, exacerbating the exaggerated geometry.
At 230lb youre a fair bit over the target range of the standard springs. Italians have a habit of under springing their bikes. But adding preload isnt the answer. Preload doesn't stiffen the spring, just changes how much force is required to deflect it from its static position. Once it's moving its still a 9.5kg per mm spring. Nothing has changed in that respect. So now with less preload the spring will be quicker to move as less initial force is required but with the weight of you pressing it down and the slow rebound it's packing down and staying there too long. With this the front geo changes causing the vague and wandering sensation you're describing.
I really can't stress enough the importance of the correct springs if youre outside the"normal" range of standard suspension. 65 to 75kgs is the average spring weight but you can extend this with a bit of preload if you understand the byproducts.

[skahigh]

Thanks Steve, there's a bloody screw sticking out of the front tyre so that'll explain the steering pull!

Wasn't flat this morning but it certainly is now!!