Suspension questions...

**Maido** · 10th December 2007, 12:08

A couple of things I would like cleared up, I have heard contradicting statements.

When installing a harder spring in your front forks (eg going from 9.0 to a 9.5 rate), to achieve the same cornering geometry do you have to lift the forks through the triple clamp to offset the increased force required to compress them.
Obviously the being a harder spring the forks will naturally sit higher and take more force to compress. (depending on preload of course, and assuming the fork protusion is the same for both spring rates)
In theory if you set the same overall sag with both spring rates, the higher rate will have a different height it settles into at any given corner? (meaning the bike would be inclined to run wider as the front is sitting higher?)
Is this correct?

Also, how much effect does oil level have on how the bike sits in the corner?, it obviously has a dramatic effect on the final bit of travel.

I have often been to chicken to ask questions as I have been pedling for a wee while and I don't want people to think I don't know stuff, but bugger it, that doesn't make you go faster!

I have probably explained this really badly but I can't get a straight answer, If you answer this well I might throw another one at you!

Thanks in advance.

cookie for the best answer!

**codgyoleracer** · 10th December 2007, 12:46

Is this for the track or road ?, Usually leave the bike set up (ride heights, reb / comp/preload) exactly the same to begin with so that you have a reference to work from - then go from there. If you change 3-4 things in one hit - you can chase your tail a wee bit trying to find which bit worked best for you & your riding style.

**tri boy** · 10th December 2007, 13:01

"Paging Dr Bob"..."Dr Bob required in surgery".....

**Maido** · 10th December 2007, 14:07

for track

so far triboy has the cookie.....

**Maido** · 10th December 2007, 14:39

Originally Posted by tri boy

"Paging Dr Bob"..."Dr Bob required in surgery".....

I tried emailing Dr Bob about similar things the other day but got a very limited reply.

**codgyoleracer** · 10th December 2007, 14:42

Originally Posted by Maido

I tried emailing Dr Bob about similar things the other day but got a very limited reply.

Try sending him some money instead - works well every time

**Robert Taylor** · 10th December 2007, 16:22

Originally Posted by Maido

I tried emailing Dr Bob about similar things the other day but got a very limited reply.

When you are moving business, moving house and have the workload from hell then perhaps the ''very limited'' reply is somewhat understandable....

**Robert Taylor** · 10th December 2007, 16:24

Originally Posted by codgyoleracer

Try sending him some money instead - works well every time

And you know that I have been very accomodating with advice over the years. Forums do have a little bit of a kangaroo court demeanour at times, dont you think?

**Robert Taylor** · 10th December 2007, 16:35

Originally Posted by Maido

A couple of things I would like cleared up, I have heard contradicting statements.

When installing a harder spring in your front forks (eg going from 9.0 to a 9.5 rate), to achieve the same cornering geometry do you have to lift the forks through the triple clamp to offset the increased force required to compress them.
Obviously the being a harder spring the forks will naturally sit higher and take more force to compress. (depending on preload of course, and assuming the fork protusion is the same for both spring rates)
In theory if you set the same overall sag with both spring rates, the higher rate will have a different height it settles into at any given corner? (meaning the bike would be inclined to run wider as the front is sitting higher?)
Is this correct?

Also, how much effect does oil level have on how the bike sits in the corner?, it obviously has a dramatic effect on the final bit of travel.

I have often been to chicken to ask questions as I have been pedling for a wee while and I don't want people to think I don't know stuff, but bugger it, that doesn't make you go faster!

I have probably explained this really badly but I can't get a straight answer, If you answer this well I might throw another one at you!

Thanks in advance.

cookie for the best answer!

This is all 'relativity' If you had the desired ride height with the softer springs then firmer springs will indeed need a little less preload. As they are compressed more and more there will be more total spring force ( we are talking compressed force, not spring rate )

If you make a change that affects dynamic ride height then you will have to compensate, e.g fork position.

Oil level is really all about secondary air spring and affects primarily the last third of travel. If you read the mounting instructions that came with your Ohlins fork cartridges ( or have a look at www.ohlins.com ) it describes it very well and will ease the strain on my two typing fingers.

In truth the change you propse is not that large so I would just seta s per thye 9s and fine tune from there.

The brevity of my e-mail reply to you was because of an extremely heavy workload. Try an 18 hour day for size sometime and you will understand!

**Maido** · 11th December 2007, 07:55

supprisingly, on the odd time over certain periods of the year I have to work crazy hour overtime also, so I understand that you were busy, especially as you are moving shop, sorting out sam and andrew as well as 100 others, there are a thousand and one jobs that need done yesterday! (I hate the fact that you have to explain this sort of nonsence on the internet forum, its a little huggy kissy don't you think, i suppose that is the nature of the beast)

this is why I branched out to the forums to see if anyone elso was available to answer some questions as we both know guys like shaun and oz frequent them the odd time.

Anyways, I managed to sort most of the stuff out by myself, so I was just trying to get some idea that I was on the right track theory wise.
As we live at the complete other end of the country we cannot approach you in the pits at the club days, or get you to come testing in the weekend, Me and john end up bouncing ideas that sound good off each other which sometimes works!, I email rather than call so you can reply when you have time, (and email, like internet forums, is so impersonal and you don't get the true jist of wht is actually being asked), that leaves only the national series to actually talk to you, but then you are flat out sorting half the road race series riders.

we have talked before about the "fical" nature of faceless internet postings, when I posted "limited reply" it was not meant in a derogatory sence, i forgot to insert the appropriate emoticon!

Just so we are clear, this is not an angry posting, or it wasn't meant to be worded grumpy, it is not intended to read that way, i don't want to offend people or burn bridges, i am a pretty easy going person, just like you robert i enjoy a heinekin (not sure about the opera thought)

I need a hug.

**codgyoleracer** · 11th December 2007, 08:27

Originally Posted by Robert Taylor

And you know that I have been very accomodating with advice over the years. Forums do have a little bit of a kangaroo court demeanour at times, dont you think?

Kangaroos are springy bouncy things as well Robert, - all in fun as always. P.S kerry is to make some changes to the front end & we should be on the right track.

**Robert Taylor** · 11th December 2007, 18:50

Originally Posted by Maido

supprisingly, on the odd time over certain periods of the year I have to work crazy hour overtime also, so I understand that you were busy, especially as you are moving shop, sorting out sam and andrew as well as 100 others, there are a thousand and one jobs that need done yesterday! (I hate the fact that you have to explain this sort of nonsence on the internet forum, its a little huggy kissy don't you think, i suppose that is the nature of the beast)

this is why I branched out to the forums to see if anyone elso was available to answer some questions as we both know guys like shaun and oz frequent them the odd time.

Anyways, I managed to sort most of the stuff out by myself, so I was just trying to get some idea that I was on the right track theory wise.
As we live at the complete other end of the country we cannot approach you in the pits at the club days, or get you to come testing in the weekend, Me and john end up bouncing ideas that sound good off each other which sometimes works!, I email rather than call so you can reply when you have time, (and email, like internet forums, is so impersonal and you don't get the true jist of wht is actually being asked), that leaves only the national series to actually talk to you, but then you are flat out sorting half the road race series riders.

we have talked before about the "fical" nature of faceless internet postings, when I posted "limited reply" it was not meant in a derogatory sence, i forgot to insert the appropriate emoticon!

Just so we are clear, this is not an angry posting, or it wasn't meant to be worded grumpy, it is not intended to read that way, i don't want to offend people or burn bridges, i am a pretty easy going person, just like you robert i enjoy a heinekin (not sure about the opera thought)

I need a hug.

Becks ( not Heineken ) Isnt that piece of water a curse? We do actually enjoy coming down to Invergiggles, its ( in a very positive way ) a little like turning the clock back.

**Robert Taylor** · 11th December 2007, 18:53

Originally Posted by codgyoleracer

Kangaroos are springy bouncy things as well Robert, - all in fun as always. P.S kerry is to make some changes to the front end & we should be on the right track.

Yes I am well aware of your wicked sense of humour! Glad to hear your tumble didnt damage you too much. Shims and an alternative valving spec are being despatched tommorrow.

**Maido** · 12th December 2007, 07:56

Originally Posted by Robert Taylor

Becks ( not Heineken ) Isnt that piece of water a curse? We do actually enjoy coming down to Invergiggles, its ( in a very positive way ) a little like turning the clock back.

we say that about Gore!