Rear Spring

I was torn between going to 0.80 and 0.85 on an 899 racebike. I tend to like the bike stiffer, so I went 0.85, and I'm about 165 lb with no gear. So far, the rear end is working great, and tire wear is fine. I'm able to pull off 2nd and 3rd gear corners and hang with everybody who is doing my lap times in an open class, where many of the bikes are liter machines, so it's hooking up fine. I've never seen a traction control light come on at any point. My forks are sucking it though under braking.

tcelano said:

I was torn between going to 0.80 and 0.85 on an 899 racebike. I tend to like the bike stiffer, so I went 0.85, and I'm about 165 lb with no gear. So far, the rear end is working great, and tire wear is fine. I'm able to pull off 2nd and 3rd gear corners and hang with everybody who is doing my lap times in an open class, where many of the bikes are liter machines, so it's hooking up fine. I've never seen a traction control light come on at any point. My forks are sucking it though under braking.

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What sag values are you using front and rear?

Thanks for posting Jarel. I've had DTC problems the whole time on track and mountain roads but never thought of changing springs. I've swapped tire brands, raised, lowered pressures, made some suspension adjustments all with no better results. The bike handles very well and shows decent tire wear so I've been apprehensive making or seeking improvements. I'm 175 lbs plus gear, so maybe 190ish. I'm now thinking that my sag was not set as well as the dealer said, and maybe my spring is a touch stiff.

Try this...

mali said:

Just curious, where can I find the recommended spring rates by Ohlins anyway? Its not on their website, do you have any literature from them that says which spring for which weight?

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Mali, turn your compression and rebound all the way out front and rear and then measure your front and rear sag. To determine if you need a softer rear spring, try setting your rear sag at 35mm (and forks to 40mm). If you run out of shock shaft threads, then you need to go down a rate (at least). I'm approximately 200 lbs. with gear and the 90N/m spring on my 'R does not allow me to get proper sag with the preload spun all the way out. I'm going down to an 85N/m soon because of this.

Jarelj, do you have a source for a reasonably priced Ti 85N/m coil?

Pilot, I thought you would change preload to set your sag, not compression and rebounding damping, no? The damping should not have an effect on how much sag would get, is that not correct?

Pilot said:

Jarelj, do you have a source for a reasonably priced Ti 85N/m coil?

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Ohlins doesn't sell them anymore, you might be able to get one from RCS:

http://www.rentoncoilspring.com

mali said:

Pilot, I thought you would change preload to set your sag, not compression and rebounding damping, no? The damping should not have an effect on how much sag would get, is that not correct?

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I does affect it a bit. Backing out all the damping isolates the spring resistance as much as you possibly can. Plus, by doing this, you are setting it up in the same state each time you check it.

Pilot said:

I does affect it a bit. Backing out all the damping isolates the spring resistance as much as you possibly can. Plus, by doing this, you are setting it up in the same state each time you check it.

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How would damping settings affect a shock or fork that is static (not in motion)? Backing out the damping settings would allow you to "bounce" a bike through a longer range of travel, but shouldn't affect static spring effect in any way that I can think of.

jarelj said:

How would damping settings affect a shock or fork that is static (not in motion)? Backing out the damping settings would allow you to "bounce" a bike through a longer range of travel, but shouldn't affect static spring effect in any way that I can think of.

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I agree with you mostly. Will at Ducati Westlake does it this way. It makes sense to me after thinking about it. Taking all damping out of the loop will allow the spring the highest probability of settling quickly, and allows the coil to move as minor movement from the rider is encountered during the balancing and measuring. I don't think it's wrong to not change the clickers, but doing so allows an accurate reading quickly every time. Do you think there's any downsides to taking out the damping during sag measurement?

jarelj said:

90 Nm is the stock spring rate on the 1199R. At around 210 lbs. or so the stock spring rates on the S/R are usually pretty good (90 Nm rear spring, 1.0 Kg front springs), so you might just be one of the lucky guys who doesn't need to change anything! If you feel it's too stiff, you can go to an 85 on the rear and/or a .95kg in the front but I wouldn't change anything unless you have a solid reason for doing it.

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This is both excellent feedback and good news! I did not know that the 90Nm is the "stock" spring rate. I assumed I'd need a stiffer spring, because my MTS1200S was under-sprung when purchased. Thank you for your counsel, Good Sir. Much appreciated.

All the suspension experts I've spoken to is not agreeing with the 80N/mm springs for a 170 lb. rider with gear, for RACING or Level 3 track day pace.

90N/mm spring is what is recommended for RACING for smooth and semi-smooth tracks
and 85N/mm for Track day and/or aggressive canyon riding, OR... if the track is very bumpy (like Auto Club, Buttonwillow [not sure how bumpy after repaving it recently], and Streets of Willow)

This is coming from the most established names here in the west - all of whom make a full time living in the motorcycle tuning and suspension world.

Are you guys RACING with these 80N/mm & 85N/mm springs at your 170 - 190 lb. weight (with gear) or track days?

Do you happen do know the rear ride height on these springs?

I'm 170 with gear and for RACING/Level 3 track days on an 1199R, recommendations that are given to me are:

* 90N/mm spring (stock spring)
* Drop the rear ride height with 2 full turns in on the shock length adjuster (this lowers ride height by ~ 1mm since the ratio is 2:1, I'm told)
* Pivot the swing arm -2 (not avail. on the base or S unfortunately) and adjust chain slack
* Move forks up, flush with the Triple (effectively raising the front to increase trail & help hold line + traction driving out of corners
* As we all know, the fastest way around the track on these bikes is NOT to focus on braking crazy late and entering a corner extremely HOT, but to throttle up ASAP and drag race to the next corner. Braking late helps with passing, but we all know that lap times are all about driving out of corners. The 1199 is setup to flick extremely well, but the stock geometry spins the rear with aggressive throttle out of corners. I guess, everyone competitive on this bike is slightly giving up on the "flickability" for added stability for much better drives out of corners with the added trail (raising the front and lowering the rear.) For casual trackdays, they say to experiment with softer springs, but when racing and running in the fastest track day group (170 lb. rider with gear on a 400 wet bike) I'm told "NOT suggested to go below an 85N/mm spring."

These guys also tell me "It's always the newbs who want to drop the front and raise the rear for 'maximum flickability and handling' and these are the same guys that enter corners hot with the rear lifted 12" off the ground thinking this is the fastest way around the track, because they see this in MotoGP" <--- NOT MY WORDS

This is what I'm told and we shall see on the next shake down.

Suggestions differ from suspension expert to expert, but hope this helps as this info. was challenging to gather.

I can see some logic re higher rate spring for track as their will be more weight transfer, but if the rear suspension doesn't have sufficient sag with a lightweight like myself @ 155 then this is a compromise on available traction for the price of a spring we can afford to experiment, I'm going with an 80 & report back + -2 on s/arm stk front ride height

Pilot said:

I agree with you mostly. Will at Ducati Westlake does it this way. It makes sense to me after thinking about it. Taking all damping out of the loop will allow the spring the highest probability of settling quickly, and allows the coil to move as minor movement from the rider is encountered during the balancing and measuring. I don't think it's wrong to not change the clickers, but doing so allows an accurate reading quickly every time. Do you think there's any downsides to taking out the damping during sag measurement?

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I don't think there are any downsides OR upsides to doing it that way, I think the damping settings are irrelevant when setting the spring preload. You don't want to "bounce" the bike when setting preload, you want it to be static. And when it's static, the damping settings have no effect on the range of travel. The only thing that keeps the suspension moving to an exact position is stiction created by the drag of the seals, damping has no effect. This is why when setting sag the most accurate way possible we lift-and-settle, measure, press-and-settle, measure, and average the two. That accounts for stiction. It also gives you a clue if something is wrong, in the case of stiction outside a normal range. Usually more than 8mm in the front and 4mm in the rear and there's a problem, either a bent triple clamp, axle not centered, forks twisted in triple, etc.

sean999r said:

I can see some logic re higher rate spring for track as their will be more weight transfer, but if the rear suspension doesn't have sufficient sag with a lightweight like myself @ 155 then this is a compromise on available traction for the price of a spring we can afford to experiment, I'm going with an 80 & report back + -2 on s/arm stk front ride height

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So how did the 80N/mm spring work out at the track? (I'm assuming this setup is for track)

I run an 80 Nm shock spring and I weigh 185 w/o gear. I use the flat rate, and have had the shock softened WAY up in both compression and rebound. It works much better than stock.

Rear shock

Hi!

We are racing the bike in Norway, with some luck. Our rider is about 85kg(187LBS) with gear.

Settings we are using is very similar to thoose recomended by Ducati.

We use a Ohlins TTX GP shock

Link: Flat
Pivot: -4
Spring: 85
Ride height: 222 mm
Preload: 12 mm
Comp:14
Reb: 16
Lenght of the swing arm: 545 mm

Works very well!

jarelj said:

Ohlins doesn't sell them anymore, you might be able to get one from RCS:

http://www.rentoncoilspring.com

Click to expand...

I am into lightening my bike so I gave RCS a call but they do not do Ti springs for road bikes anymore. Their range is actually fairly limited. They can make a custom spring from $950 USD. Bit too much for me. I wonder how much the part number for the SL Ti spring is ?

Keen to talk to my local suspension guy who supplies Ohlins and see whether a 85nm may take some of the harshness out of my rear suspension.

jamesz3 said:

All the suspension experts I've spoken to is not agreeing with the 80N/mm springs for a 170 lb. rider with gear, for RACING or Level 3 track day pace.

90N/mm spring is what is recommended for RACING for smooth and semi-smooth tracks
and 85N/mm for Track day and/or aggressive canyon riding, OR... if the track is very bumpy (like Auto Club, Buttonwillow [not sure how bumpy after repaving it recently], and Streets of Willow)

This is coming from the most established names here in the west - all of whom make a full time living in the motorcycle tuning and suspension world.

Are you guys RACING with these 80N/mm & 85N/mm springs at your 170 - 190 lb. weight (with gear) or track days?

Do you happen do know the rear ride height on these springs?

I'm 170 with gear and for RACING/Level 3 track days on an 1199R, recommendations that are given to me are:

* 90N/mm spring (stock spring)
* Drop the rear ride height with 2 full turns in on the shock length adjuster (this lowers ride height by ~ 1mm since the ratio is 2:1, I'm told)
* Pivot the swing arm -2 (not avail. on the base or S unfortunately) and adjust chain slack
* Move forks up, flush with the Triple (effectively raising the front to increase trail & help hold line + traction driving out of corners
* As we all know, the fastest way around the track on these bikes is NOT to focus on braking crazy late and entering a corner extremely HOT, but to throttle up ASAP and drag race to the next corner. Braking late helps with passing, but we all know that lap times are all about driving out of corners. The 1199 is setup to flick extremely well, but the stock geometry spins the rear with aggressive throttle out of corners. I guess, everyone competitive on this bike is slightly giving up on the "flickability" for added stability for much better drives out of corners with the added trail (raising the front and lowering the rear.) For casual trackdays, they say to experiment with softer springs, but when racing and running in the fastest track day group (170 lb. rider with gear on a 400 wet bike) I'm told "NOT suggested to go below an 85N/mm spring."

These guys also tell me "It's always the newbs who want to drop the front and raise the rear for 'maximum flickability and handling' and these are the same guys that enter corners hot with the rear lifted 12" off the ground thinking this is the fastest way around the track, because they see this in MotoGP" <--- NOT MY WORDS

This is what I'm told and we shall see on the next shake down.

Suggestions differ from suspension expert to expert, but hope this helps as this info. was challenging to gather.

Click to expand...

So much conflicting information, who is right and who is wrong? Unless this spring business is all a subjective matter..

I have ordered an 80 spring anyway, lets see if that will change things by much.

A static spring recommendation for "racing" is a bit silly. The faster the rider is, the more likely it is that they're going to change spring rates for different tracks. So the questions is if you're "racing" what PACE are you racing at? Are you 2 secs off the lap record, 12 secs off, or 22 secs off? The guy who's 2 secs off is going to have a wide variety of spring rates he can use for different tracks to get the response from the bike he wants. He's not going to have just one spring. I would never take our baseline spring recommendations for track riders and apply them to a top-level club racer who's racing for a championship. That guy is normally working with a local suspension tuner who can provide much more precise recommendations for that rider, his bike, specific tires and the local tracks. So if you're at that pace, you're probably not on the internet looking for spring rate recommendations. Now the guy who's 12 secs off the track record, you're at around an A or fast-I track day pace, or mid-pack Novice race pace. That guy can usually stick with a spring and ride with it for the season, he's not at the level where he needs to change suspension at every track other than a click or two of damping change to compensate for conditions. That guy might prefer a rate higher than our baseline, depending on how he rides, but 2 rates higher I'd be worried about too much tire spin and tearing the rear tire (we've seen it as a big problem on these bikes with too stiff of a rear spring). The guy who's 22 secs off (which is still a solid I track day pace, not a beginner) is the basic target for our baselines, and we've had great success with it. I'm not sure if there's another shop in the country that builds as many Ducati track bikes as we do, there might be, but certainly we build a lot more than most. We have dozens of Ducati track bikes that are ridden at our track day events, and we have around 24 track days on our calendar every year, so that's a lot of laps being ran on these bikes. We've been using those spring rates on Panigale track bikes for 3 years now and it works well, which is why I'm comfortable sharing it with you all. If I wasn't sure, I'd say "I don't know". The ultimate no-........ deciding factor is what does the tire wear look like? If you're going quicker and getting better life out of your tires, then your suspension is set up well. That's what I use on my own bike to decide on my setup, I want my tires to last. I'm running a 90Nm rear spring on my 899 (which is light) and I weigh about 205 in full gear. I can comfortably run about 10 secs off the track record at my home tracks if I have a faster student I'm working with, normally I'd run 12-14 secs off for a normal A track day pace. At that pace, the 90Nm spring works well and I'm getting good life from my rear Bridgestone slicks, usually 5-6 days.

^^^ Good to know and thank you. Much of the info given to me are from folks who build and setup AMA bikes. They're talking about for racers who are running about 7-10 seconds off track records.

I'm going to try all the options from 8.00 - 9.00N/mm springs with the various geometry settings and we shall see...