2020 V4s suspension discussion

I thought the OP had recently spent time getting advise with the forum expert....?

Here are some comparison settings. Note I changed the rear spring from 85Nm to 95Nm for better support with less preload. IMO, preload, especially a lot of it, is not a good way to adjust the suspension unless you have no other adjustments available. The fork compressed travel limit is the fork foot itself. You measure travel amount from fully extended. However, Ohlins includes a top-out travel spring that is effectively addition travel, but is only in play as the fork tops out over bumps, or wheelie effect. To see that travel while forks/front wheel are mounted for use, unweight the front of the bike, measure the length of the fork tube showing, then physically pull down on the wheel/forks to compress the top-out spring fully. You will see that the Ohlins on my ‘21 SP have 4mm of top-out extension travel. I can’t say for SURE about other Ohlins models, but I think all their superbike forks have top-out travel. The Bitubo fork carts I installed into my Aprilia RS660 use a rubber top-out “spring” for only 2mm of top-out travel. Anyway for comparison on what I “like” weighing ~180lbs here’s my baseline. I’ve also tweaked the dynamic and manual settings in each ride mode, but not more than a few steps from their defaults.

Suspension Baseline Settings:

REAR: Ohlins DU9480 172609 016
Spring = 95Nm (trvl spec 130mm)
Shock sag w/me = 37mm
Shock sag static = 18mm
Shock preload = 13mm

FRONT: Ohlins FL9670 0021L/0017R
Springs = 10Nm (trvl spec 120/4mm)
Fork sag w/me = 32mm
Fork sag static = 18mm
Fork preload = 9mm
Fork height from lower triple top = 257mm
Fork cap height above upper triple = 10mm

Updated numbers with more precise slacker tool

Front and rear:


An oddity: max preload not the same on both forks. Will correct when I rebuild them






Rear preload:


Question: how much pre-

how much preload will the rear shock take before binding is an issue?

so I’m curious as to how much preload this stock 85 Newton rear shock can take.

And 12 of 15 front preload seems pretty extreme.

I think it’s obvious. I can go a size higher in the front and to a 105 in the rear.

@bp_SFV4

SirJAG said:

so I’m curious as to how much preload this stock 85 Newton rear shock can take.

And 12 of 15 front preload seems pretty extreme.

I think it’s obvious. I can go a size higher in the front and to a 105 in the rear.

@bp_SFV4

Click to expand...

You need to measure the free length of the spring away from the shock then you shorten it eg 10 mm, that’s 10 mm of preload .
You can keep winding load on to them but at some point it’ll get coil bound
Much better to have a stronger spring with less load on it as long as it keeps bike sag

SirJAG said:

An oddity: max preload not the same on both forks. Will correct when I rebuild them

Click to expand...

Do you mean you don't get the same number of turns out of the preload adjustment for the right and left fork? From full out, I have just under 15 turns. I vaguely recall there being a slight difference between right and left. I don't think it's a huge issue though and likely just a slight difference in machining.

SirJAG said:

so I’m curious as to how much preload this stock 85 Newton rear shock can take.

And 12 of 15 front preload seems pretty extreme.

I think it’s obvious. I can go a size higher in the front and to a 105 in the rear.

@bp_SFV4

Click to expand...

I think 11.0 Nm front and 105 Nm rear will work for you. You definitely want to be in the middle of the adjustment range ideally.

andyb said:

You need to measure the free length of the spring away from the shock then you shorten it eg 10 mm, that’s 10 mm of preload .
You can keep winding load on to them but at some point it’ll get coil bound
Much better to have a stronger spring with less load on it as long as it keeps bike sag

Click to expand...

Surely this stock free length number is available somewhere….

bp_SFV4 said:

Do you mean you don't get the same number of turns out of the preload adjustment for the right and left fork? From full out, I have just under 15 turns. I vaguely recall there being a slight difference between right and left. I don't think it's a huge issue though and likely just a slight difference in machining.



I think 11.0 Nm front and 105 Nm rear will work for you. You definitely want to be in the middle of the adjustment range ideally.

Click to expand...

No, I get 15 turns on both, but the right fork is about 45° rotated compared to the left.

I don’t believe it’s any issue. You just can’t have the cap lineup visually perfect / symmetrical

All ensure they are symmetrical when I remount the forks

Springs on order!!

Any idea on stock 85N Spring free length?

Jag

That's the problem I've always had with expressing the rear shock preload that way. It works IF you measured YOUR spring. I'd even speculate it could change over time as the spring settles.

I measured my 85 Nm spring that was in my parts box, it's 158mm.

Make sure the 105 Nm spring you get is about the same length as your 85 Nm. I ordered a 105 Nm from Superbike Unlimited and the one they sent was much longer, but the same diameter. They said it was listed as being for a V4R but had a different p/n on it. Who knows...either way, I returned it and got the correct 21040 p/n. On my order, the Ohlins 21040-XX is listed as being 160mm.

SirJAG said:

Surely this stock free length number is available somewhere….

Click to expand...

They are all not the same and vary

SirJAG said:

so I’m curious as to how much preload this stock 85 Newton rear shock can take.

And 12 of 15 front preload seems pretty extreme.

I think it’s obvious. I can go a size higher in the front and to a 105 in the rear.

@bp_SFV4

Click to expand...

Clearly an 11 in the front. So in the front if you went to an 11 that's 10%. In the rear 10.5/8.5 = 23.5 %. The reason they went to the 8.5 was to add preload in an attempt to keep the front down with less DWC intervention. A stiffer spring (assuming we're in the same range) set at the same sag allows a little more weight transfer. You may want to try a 9.5 first.

And get the linear rear rocker addiction motorsport …. Just saying

@bp_SFV4 @andyb @baggerman
And others!

I really appreciate all of the input and information in this thread guys! Thank you so very much!

Special thanks to BP for lending me tools!!!

Jag

I used a 95 Nm (not 9.5 ) in my 2020 Streetfighter V4. @roadracerx recommended the 105 Nm for my 2021 Panigale V4S and it was spot on.

bp_SFV4 said:

I used a 95 Nm (not 9.5 ) in my 2020 Streetfighter V4. @roadracerx recommended the 105 Nm for my 2021 Panigale V4S and it was spot on.

Click to expand...

Fair enough 95. I'm old and my mind is feeble. I have a 105 in my 21 SF. But I carry about 30-40 lbs in the bags right under me and would not want it stiffer. Recognize that a 2020 SF is not set up like a 2020 Pani totally different animal. They're like 2018 Pani's with slow steering and a long wheelbase and with more of your weight rearwards. My entire point was the guy who rides those all the time (who's the current lead test rider?) thought it worked a bit better with more preload with the stock gearing. Bike needed more ant-squat that's why the next change was pivot height. If you gear it down you get more ant-squat anyway. Most likely none of us could actually discern the difference anyway. Key thing is to get the front stiffer.

does rear subframe have to be removed to remove the rear shock?

can anyone recommend anchor points for supporting the front end without a front end stand? 11/12 '99 bikes were easy, just looped strap under the frame/air box...

JAG

no need to remove rear subframe

ideally foot peg stands do you have rear sets or std pegs?

I have an Akrapovic full system. No need to remove the subframe. I remove the cans and with the bike supported on stands, I take the weight off of the rear by using a floor jack and a piece of a 4x4 on the "lower holder," which is part 13 in the diagram.

You'll want to take the preload out of the shock to make compressing the spring easier. If that's easier on or off the bike is up to you.