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[Pard]

This is a great tool.  Makes the job so easy and accurate for you to do alone or with help.

The only challenge is recording unweighted sag for the front and rear.  A triple tree head stand in front does the job, but you need to use a jack under the battery (lower fairing removed) to unweight the rear wheel.

For street settings:

40 mm rider sag front forks (difference between unweighted sag and full gear rider on bike = rider sag)

30 mm rider sag rear shock.


The app is terrific as well. Bluetooth connection to the measuring unit allows one touch recording of measurements.

If you have not set up the proper preload front and back, (may even require some fork height adjustments or spring rate changes to the shock,)  to get the baseline sag numbers, your ride quality and handling are not as good as they can be.  This is true even if you have a premium suspension setup.

Get it done.

Plenty of videoes out there explaining how to set up correct sag.  This tool makes the process much easier if you don't have a team to help.


https://getslacker.com/

[Specter]

If you are going to be doing any spirited riding, you really should have the suspension set correctly.  The bike will handle so much better when set right, not to mention when you Do start getting up to speed, it's not fun having stuff starting to get squirrely at 130 mph.  Even when driving normal on the road, having it all set right will give you a smoother more in control ride.  You never know when some dumbass pulls in front of you or you need to make a reflexive type evasive maneuver.. and having a suspension that can handle it, and not jitter you into a lowside literally can be a life saver.

Aaron

[jotjotde]

The only challenge is recording unweighted sag for the front and rear.  A triple tree head stand in front does the job, but you need to use a jack under the battery (lower fairing removed) to unweight the rear wheel.

Just a thought: If you had the means to lift the rear from above, e.g. by a hoist looped through the pillion rider footrests, wouldn't that do the trick as well?

Just a question: There is the rule of thumb that your fork is properly adjusted if the travel is approx. 2/3 of the overall travel (see pic). Do you agree?

[Pard]

The only challenge is recording unweighted sag for the front and rear.  A triple tree head stand in front does the job, but you need to use a jack under the battery (lower fairing removed) to unweight the rear wheel.

Just a thought: If you had the means to lift the rear from above, e.g. by a hoist looped through the pillion rider footrests, wouldn't that do the trick as well?

Just a question: There is the rule of thumb that your fork is properly adjusted if the travel is approx. 2/3 of the overall travel (see pic). Do you agree?

Sure, anything that gets the rear wheel off the ground for top out measurement. 

The 1/3 of overall travel rule of thumb has been around forever, so it likely works well enough.   

Depending on what the total travel available might be for a given fork, a particular preload setting, and a particular rider weight, that 2/3 could be a very wide range of travel (10-60 mm for example). 

The 35-40mm rider sag in the fork is a precise starting point from which to make additional adjustments to fine tune the bike's behavior, yet, sure,  you could set it for 1/3 travel and make adjustments from there as well to suit your needs.

"A general rule of thumb is that the front sag should be about 30-35% of travel, while the back should be at about 25%. That works out to be 30-40mm at the front and 25-35mm at the back, for most bikes."

https://www.promecha.net/sag-and-preload

[smithy]

"A general rule of thumb is that the front sag should be about 30-35% of travel, while the back should be at about 25%. That works out to be 30-40mm at the front and 25-35mm at the back, for most bikes."
https://www.promecha.net/sag-and-preload

I can't get anywhere near the 30-35% on the front of my Experia which has 150mm of travel, this equates to 45-52.5mm of sag, I'm lucky to get just 30mm of sag...even with the preload wound all the way out...I'm a bit of a lightweight at only 70kg though...maybe lighter springs would help..??

The lower part of the fork travel never gets used unfortunately...bit of a waste really.

Smithy.

[Phaedrus]

I think on forks, the internet gurus run the mm of sag together with the % of compression - without talking about the fact that the fully extended lower fork tube is just that - it's just a reference point not the travel.  The fork tubes do not fully compress to the end. 

So, for instance, with my Ego+ RS with Marzocchi forks, the fully extended forks measure at about 150mm - but the spec'd travel for the forks is only 4.33" = 110mm

Most of the percent of travel measurements out there seem to be based on the fairly common 110mm of fork travel of many forks.

I'm at the opposite end of the scale though from Smithy - I need heavier fork springs to get to my desired 30mm of front sag.

[Pard]

I think on forks, the internet gurus run the mm of sag together with the % of compression - without talking about the fact that the fully extended lower fork tube is just that - it's just a reference point not the travel.  The fork tubes do not fully compress to the end. 

So, for instance, with my Ego+ RS with Marzocchi forks, the fully extended forks measure at about 150mm - but the spec'd travel for the forks is only 4.33" = 110mm

Most of the percent of travel measurements out there seem to be based on the fairly common 110mm of fork travel of many forks.

I'm at the opposite end of the scale though from Smithy - I need heavier fork springs to get to my desired 30mm of front sag.

Indeed, that is a good point.  There is a bottom out on the fork before the upper tube swallows the whole lower tube.  That data exists online for most forks.

I have the Ohlins front forks and a custom rear Ohlins shock. 

I will get stiffer springs on the forks when I service them next because I have the preload all the way in, and the forks dropped all the way down in the triple tree (1 mm left above the front of the top triple face) to get the 40mm rider sag in the front.

Almost all the preload out in the rear to get 35mm rider sag on the shock.

Handles like a dream as is, so I may not change the spring rate if it holds up.

[Specter]

When you do figure it out, try to set your 'liking' in the middle of range if possible.  That way if you need to make adjustments, as it wears / ages, as your weight changes (holiday fatass syndrome   )  etc, you can tick it in and out as necessary.

yes only 10 to 15 lbs CAN make a difference when riding for optimal performance on a bike.

also, if you are working on a race bike, or for higher performing situations,  if you are sitting on the bike to see what your tonnage does to deflect the shocks, make sure you are dressed as you would normally be dressed to ride the bike to make the measurements.  Meaning if you are racing the bike,  make sure you have your entire set of leathers on, helmet, gloves, boots, armor inserted etc. when checking it, because YES that shit DOES get heavy. I think I last weighed my setup at about 22 lbs or so.  22 lbs is enough that you very possibly may need to notch a spring adjustment etc.  If you are going thru this trouble, make sure you do it absolutely right, for the absolute best results.

Just saying.

Aaron

[Pard]

Absolutely Aaron.

I wear 30 lbs of gear when I ride street or track.  Leather Suit, airbag, helmet, gloves and boots are heavy.

Rider sag should be measured with full rider gear for accuracy.

Indeed, the preload should ideally be in the middle position so you can adjusted either way, exactly why I am considering getting a higher spring rate set in the forks.

[Specter]

or go on a diet, might be cheaper than new springs     

Aaron

[Pard]

or go on a diet, might be cheaper than new springs     

Aaron

 

[Pard]

[Specter]

I like my ohlins too, they saved my ass once or twice.  came down hard off a wheelie and almost started a slapper but the shocks grabbed and dampened it in one or two oscillations so that was a good thing.  im thinking of upgrading my ribelle a bit here, not sure how far i want to go with it but the brakes for sure, maybe the suspension too so I have it as a backup on the track, maybe not as fast but still a bike to ride.

aaron