Rear Pre Load setting question. - SV650.org

Nick_69 · 19-08-10, 10:12 AM

This may sound a stupid question but i want to make my rear shock harder so i would want to increase my pre load right not decrease it

19-08-10, 10:32 AM

Yes. More pre-load = more compression on the spring = harder rear suspension

Sid Squid · 19-08-10, 04:35 PM

Not so.

Same spring, same load, same 'hardness'.

Preload does not change anything except where you are in the suspension's available travel under any given load.

Stu · 19-08-10, 05:23 PM

Quote:

Originally Posted by Sid Squid

Not so.

Same spring, same load, same 'hardness'.

Preload does not change anything except where you are in the suspension's available travel under any given load.

Doesn't preload reduce the the available travel by simply compressing the spring? - i.e. making it harder? That is intuitively how it works by looking at it, from a numpties POV i.e. me cf. you knowing how it works.

Sid Squid · 19-08-10, 05:55 PM

No.

As above, there's you the rider, that is; the load, apply that load to the spring it compresses the same amount no matter what you do to the spring setting.
Suspension is a dynamic system, the spring is not constrained to a given length in use - the length in use, (forget about that the suspension may 'top out' when you're not on the bike - you never use the suspension when you're not on the bike) is dictated by the load. Again; preload, (as previously discussed - the wrong word, but the one we have), adjusts ONLY the position in the available travel under any given load. Raising the preload does not make the suspension harder*.
Same spring, same bike, same load; same suspension stiffness.
Want harder or softer suspension? Change the spring/s, the only way.

*On the rear due to the way the linkage works raising the spring preload actually softens the suspension slightly as the linkage will be in a a lower part of the rate curve, by an tiny amount there's no doubt, but that is does so is not in doubt.

I did a series of pictures detailing how this works a while ago - I will need to find a suitable again bike to demonstrate beyond doubt what's happening.

19-08-10, 06:00 PM

Quote:

Originally Posted by Stu

Doesn't preload reduce the the available travel by simply compressing the spring? - i.e. making it harder? That is intuitively how it works by looking at it, from a numpties POV i.e. me cf. you knowing how it works.

Would increase the travel as the more preload the less the shock compresses under rider and bike weight so leaves more travel to be used when you actuly need it

Sid Squid · 19-08-10, 06:34 PM

Doesn't increase travel - only changes the position in whatever travel there is.

19-08-10, 09:42 PM

yeh thats what i was trying to get at

yorkie_chris · 19-08-10, 10:27 PM

Quote:

Originally Posted by Sid Squid

(forget about that the suspension may 'top out' when you're not on the bike - you never use the suspension when you're not on the bike)

Never ride over a dip?

19-08-10, 10:32 PM

Ok, I'm going to be really thick here and demonstrate thati know feck all about how thus works.

Does a spring with equally spaced winds travel the same distance not matter how much it is already loaded?

I keep thinking that the more a spring is compressed the harder it us to compress it further.

Hence the assumption pre-loading a spring makes it stiffer.

Sorry. Noob.

19-08-10, 10:12 AM	#1
Nick_69 Member Join Date: Jul 2009 Location: Guildford, surrey Posts: 785	Rear Pre Load setting question. This may sound a stupid question but i want to make my rear shock harder so i would want to increase my pre load right not decrease it __________________ Was SV650S K9 Now GSXR 600 K9

19-08-10, 10:32 AM	#2
christian1000 Guest Posts: n/a	Re: Rear Pre Load Yes. More pre-load = more compression on the spring = harder rear suspension

19-08-10, 04:35 PM	#3
Sid Squid No, I don't lend tools. Mega Poster Join Date: Jul 2003 Location: Skunk Works, Nth London Posts: 8,680	Re: Rear Pre Load Not so. Same spring, same load, same 'hardness'. Preload does not change anything except where you are in the suspension's available travel under any given load. __________________ If an SV650 has a flat tyre in the forest and no-one is there to blow it up, how long will it be 'til someone posts that the reg/rec is duff and the world will end unless a CBR unit is fitted? A little bit of knowledge = a dangerous thing. "a deathless anthem of nuclear-strength romantic angst"

19-08-10, 05:55 PM	#5
Sid Squid No, I don't lend tools. Mega Poster Join Date: Jul 2003 Location: Skunk Works, Nth London Posts: 8,680	Re: Rear Pre Load setting question. No. As above, there's you the rider, that is; the load, apply that load to the spring it compresses the same amount no matter what you do to the spring setting. Suspension is a dynamic system, the spring is not constrained to a given length in use - the length in use, (forget about that the suspension may 'top out' when you're not on the bike - you never use the suspension when you're not on the bike) is dictated by the load. Again; preload, (as previously discussed - the wrong word, but the one we have), adjusts ONLY the position in the available travel under any given load. Raising the preload does not make the suspension harder. Same spring, same bike, same load; same suspension stiffness. Want harder or softer suspension? Change the spring/s, the only way. On the rear due to the way the linkage works raising the spring preload actually softens the suspension slightly as the linkage will be in a a lower part of the rate curve, by an tiny amount there's no doubt, but that is does so is not in doubt. I did a series of pictures detailing how this works a while ago - I will need to find a suitable again bike to demonstrate beyond doubt what's happening. __________________ If an SV650 has a flat tyre in the forest and no-one is there to blow it up, how long will it be 'til someone posts that the reg/rec is duff and the world will end unless a CBR unit is fitted? A little bit of knowledge = a dangerous thing. "a deathless anthem of nuclear-strength romantic angst"

19-08-10, 06:34 PM	#7
Sid Squid No, I don't lend tools. Mega Poster Join Date: Jul 2003 Location: Skunk Works, Nth London Posts: 8,680	Re: Rear Pre Load setting question. Doesn't increase travel - only changes the position in whatever travel there is. __________________ If an SV650 has a flat tyre in the forest and no-one is there to blow it up, how long will it be 'til someone posts that the reg/rec is duff and the world will end unless a CBR unit is fitted? A little bit of knowledge = a dangerous thing. "a deathless anthem of nuclear-strength romantic angst"

19-08-10, 09:42 PM	#8
barwel1992 Guest Posts: n/a	Re: Rear Pre Load setting question. yeh thats what i was trying to get at

19-08-10, 10:32 PM	#10
hongman Guest Posts: n/a	Re: Rear Pre Load setting question. Ok, I'm going to be really thick here and demonstrate thati know feck all about how thus works. Does a spring with equally spaced winds travel the same distance not matter how much it is already loaded? I keep thinking that the more a spring is compressed the harder it us to compress it further. Hence the assumption pre-loading a spring makes it stiffer. Sorry. Noob.

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