A Noobs question on Shock and Sag number

[sen07]

Hi, I've been riding for a year and a half and the shocks needs an upgrade cos we know why. I spent time reading and watching countless 'how to do your sag' videos but i just cant get my head proper on it, sorry im just learning (slow at it). Im 163lbs with gears, i ride to work everyday, getting an Ohlins STX46 Rear Shock and and here's my question :

 

1. Why do we need to put our weight (with gears) on a website prior purchasing a shock? What mods are they going to set on the shock? the spring to match my weight?

2. Say i found my rider sag number, what am i going to do with that? (cos everybody explaining how to do it but not what to do about it? 

[mossrider]

If I understand your questions correctly, in very simple terms;

 

1. They need that info to assemble a shock to suit your stated use. Smooth, compliant ride for street use or a more controlled, firmer action for track use. They will install a spring with the correct spring rate for your weight. They will valve it, if applicable, to achieve the desired performance characteristics.

 

2.  You set your 'sag', the amount the bike's rear end settles with you on it, so the suspension is able to respond to road irregularities in both directions. To keep the ride smooth, safe and controlled (tire on the ground) the wheel needs to be able to both fall into holes as well as rise over bumps. If there was no sag it would skip/slam into every little dip in the road making the ride horrible and possibly causing the tire to lose contact with the ground (lose traction=bad).  If you get a properly sprung shock there is nothing more 'to do about it' other than install it correctly and fine tune your sag number. That's why they need your weight and intended use.

 

For a simple starting point on the street try getting around 1.75 inches of rear end droop when you sit on the bike. This is measured from full up position (shock topped out, pulled full upward, with no weight on bike) to its compressed position with you on it. Too little sag can make the bike feel skittish and will feel like getting kicked hard in the arse when traveling a rough road, assuming the correctly valved and sprung shock is installed.  Too much sag and the bike can handle poorly, wallow, respond slowly to inputs and lack enough remaining travel to soak up bumps causing a loss of traction like a kicking horse. We could go on for ever here but this is a start for you.

[norcal616]

***street valved shock/forks= comfort on the streets/commute...

***track/aggressive valved shocks/forks= firm bumpy ride on street and comfort when on smooth track surface...

 

if you ride majority of the time with a passenger or heavy tail bag alot, let them know... 

[sk8norcal]

http://www.promecha.com.au/springs_basics.htm

http://www.promecha.com.au/sag_preload.htm

 

^ these links might help u understand.

 

From what I understand, getting the right spring for ur weight is the most importantant for starters.

 

What annoys me about the Ohlins STX46 is that there is no info on the web for spring/weight recommendation other than what I found on this forum.  

 

What also bugs me in the variance in spring recommendation from different manufacturers.

From what I understand, there is a formula/software for calculating the spring weight base on your bike linkage design, ur weight, and riding style.

[sk8norcal]

 

 

[sen07]

Thanks guys, keep it coming.. Ill post more question (ahem.. my problems) once i got the shock and installed it

[sk8norcal]

23 hours ago, mossrider said:

For a simple starting point on the street try getting around 1.75 inches of rear end droop when you sit on the bike. This is measured from full up position (shock topped out, pulled full upward, with no weight on bike) to its compressed position with you on it. 

 

1.75 inches = 45mm 

that is quite a bit, most sources I have read says 30-35mm rider sag for street bikes.  

Or 25% of rear shock travel.  

FZ07 is 5.1" rear.  25%=32mm

[blackout]

1.75" is fine for comfy street riding.  That's what my buddy runs on his fz07.  I would run 1.5" to 1.75" for comfy street riding, 1.25" to 1.5" for spirited street riding, or 1" to 1.25" for track.  Your results may vary, but I have tried different numbers and these make sense to me.

[blackout]

On a side note, I think an awesome street setup might be a shorter suspension link from AP Motoarts and 1.75" of sag.  You get the added droop travel with the higher sag number so your tire can follow the large bumps, but your swingarm angle remains high so not to lose rear anti-squat.  Shallow swingarm angles cause the front to lose weight in corner exit under acceleration, front grip is lost, and the bike wants to go wide.

[sen07]

On my first ride right after swaping the shock it was plush and comfy. I didnt do any preload or rebound for that matters. Next morning on a 35km commute, the shock was way stiff and killing my back! (I run bumps on purpose) Nobody told me about break-in period? Later this evening i get to do the sag measurement and i was on 26mm. Reduce it to 31mm and do some run, feels better, not finish tho. Tmrw going to work will be the real test

[blackout]

3 hours ago, sen07 said:

On my first ride right after swaping the shock it was plush and comfy. I didnt do any preload or rebound for that matters. Next morning on a 35km commute, the shock was way stiff and killing my back! (I run bumps on purpose) Nobody told me about break-in period? Later this evening i get to do the sag measurement and i was on 26mm. Reduce it to 31mm and do some run, feels better, not finish tho. Tmrw going to work will be the real test

No break-in needed.  Some roads just plain suck and you have to lift your butt off the seat a little.  With cars,  bad suspension is masked by comfy seats that support our bodies much better than a motobike seat.

[sen07]

7 hours ago, blackout said:

No break-in needed.  Some roads just plain suck and you have to lift your butt off the seat a little.  With cars,  bad suspension is masked by comfy seats that support our bodies much better than a motobike seat.

Not being in the know how or anything but yes i felt it. 

[sk8norcal]

Yeah 26mm is too little.  Mine was 26mm when l got it used.  Way too firm.  Went to 35mm sag.  Still too firm on bumpy roads for me.

 

Play around with the rebound dampening also.  More clicks = more comfort.  Urs is already at 14 clicks.

[sk8norcal]

On 8/14/2018 at 12:45 PM, blackout said:

1.75" is fine for comfy street riding.  That's what my buddy runs on his fz07.  

 

I should have tried that out.  But just sold my fz07 yesterday.   I wish they have the mt07 tracer here.

[sen07]

11 hours ago, sk8norcal said:

 

I should have tried that out.  But just sold my fz07 yesterday.   I wish they have the mt07 tracer here.

Sorry u couldnt work it out man. Im probably trying to to 33 and how it feels. Is there any limit clicks for rebound?

[sk8norcal]

I believe the manual recommends not to go beyond + or - 5 clicks from 14 clicks stock.  

[sk8norcal]

Btw, if u read up on the suspension stuff.  The experts recommends that both the front and rear suspension needs to be balanced.   So keep that in mind.

[sen07]

10 hours ago, sk8norcal said:

Btw, if u read up on the suspension stuff.  The experts recommends that both the front and rear suspension needs to be balanced.   So keep that in mind.

Yeah read that too. Need to get the rear sort out first then i need to sell my kidney for the front

[pattonme]

some shocks claim 22-30 clicks of this or that. But assuming 4 clicks/turn it's typically the case that 4 turns (16) is about the limit of effectiveness and the rest do squat. Springs have +/-20lb weight range and you can utilize a spring rate "off" by one and probably two increments without hating the experience.

[sen07]

6 hours ago, pattonme said:

some shocks claim 22-30 clicks of this or that. But assuming 4 clicks/turn it's typically the case that 4 turns (16) is about the limit of effectiveness and the rest do squat. Springs have +/-20lb weight range and you can utilize a spring rate "off" by one and probably two increments without hating the experience.

Rebound right? 

[r1limited]

On 8/13/2018 at 12:07 AM, sk8norcal said:

 

 

Kieth Code Good video but jeeprs wally why not a 10 lbs sledge hammer over a shocker spanner tool? 

LOL

[sk8norcal]

On 8/16/2018 at 9:49 AM, sk8norcal said:

I believe the manual recommends not to go beyond + or - 5 clicks from 14 clicks stock.  

^ ignore the above, I don't see it in the manual.

 

couple of pages from the manual,
notice the drawing for the shock is wrong (preload locknut is not on the bottom)

 

 

[howworkclutch]

On 8/15/2018 at 8:42 AM, sen07 said:

On my first ride right after swaping the shock it was plush and comfy. I didnt do any preload or rebound for that matters. Next morning on a 35km commute, the shock was way stiff and killing my back! (I run bumps on purpose) Nobody told me about break-in period? Later this evening i get to do the sag measurement and i was on 26mm. Reduce it to 31mm and do some run, feels better, not finish tho. Tmrw going to work will be the real test

was it a cold morning? suspension behavior changes with temperature.

on my old buell, riding below 62 degrees F was harsh and miserable. Above 70 degrees F it was excellent. Between the two temps it was a mixed bag of good/bad performance.

i was at the track recently on the fz07 with ohlins shock. early morning temps were very cold and the suspension was wonky. late afternoon temps were warmer and the bike felt considerably better.

[r1limited]

At 62, I am pretty shocked at my sag

 

Er uh never mind

[elmo]

I hear ya, 61 in few months and to much sag, and fixed it with a stiffer spring.

I am 210# with gear and just changed my Penske shock 700# spring to 750#  and now have 8mm static and 35mm rider sag.