Replacement Fork Springs

[BBB]

Had a good search on the forum and plenty of info but...

Was thinking of either Ohlins (.80 for 70kg rider on road) or Hyperpro / Hagon progressive springs.

What are peoples experiences of progressive over standard winding?
Heart says Ohlins, wallet says Hagon.

Help

[bazzee]

According to the racetech calculator

http://old.racetech.com/evalving/Spring ... gType=Fork

you need 0.87kg/mm.

cheers,

bazzee

[cobbadiggabuddyblooo]

Just replaced my front springs bout a mth ago and weighing in around 76/80kg fully suited I went for a .9kg/mm linear Eibach spring. I found the tranformation compared to the old std progressive springs like chalk and cheese. The little discomfort I have to put up with under 60k's every now and then is well and truly outweighed by the stability and performance gained when the TRX is utilised for its true sports bike nature. Another handy point I learnt from here was about the damping affect upon progressive and linear springs. What may be a desired damp/rebound on the upper part of the springs will be different the more you compress the spring or visa versa.. Where as the linear spring is a constant.. giving you a constant comp/rebound all the way thro the working of the spring. There are a lot better explainations to this on here as such but the it seems like common sense ... you have two constants working together you have the same feel all the way thro the range as such...or one constant(damp/rebound)and one progressive.... well... just have to compromise...once again... Good luck with the tinkering I only replaced the springs last month and am about to replace the oil as i wanted to feel the difference each time another improvement was made...(and with new tyres fitted f&r last week) Now I'll try a 10 weight oil instead of the 5weight to see how that feels ...

[BBB]

ohlins it is then

Is it a case of fork caps off, lift out the old spring and plop the new one in like my old FZR or is there more to it?

Forks out kind of a job?

Fork oil was changed when I had the seals done a month ago.

[cobbadiggabuddyblooo]

don't forget to allow for the extra weight of your leathers as such ...Extra 7-8kg when I'm fully suited up as such..

[cobbadiggabuddyblooo]

yes simple as... spring length may be an issue as such as I found as I found and had to cut a spacer to fill the gap, I think one of the lads here stated the olins actually were longer and had to cut the metal spacer that lives under the cap as such.. But if you refer back to the thread I posted last month on spring lengths this will give you an idea of what the optimum length is(as I found anyhow)from the workshop manual... Let us know how you go and some feedback once fitted

[G Beale]

I've got Hyperpro progressive springs fitted to FZR600 forks & either the springs or the sleeves were too long when it all went together. I managed to back the preload adjusters off all the way & force the springs down with the end caps enough to screw them on but it was bloody hard work. My front end feels very firm now to the point where I might have to syringe a bit of oil out & maybe cut the sleeves down while I'm at it so I can have a play with the preload adjusters & I don't have end caps flying all over my garage when they slip off the socket. No danger of the forks bottoming out now, ever & I'm 198lb + all my gear. Not sure what weight the springs are suited to (bought 2nd hand,unused) so I'm off to find the box now out of curiosity.

[dandywarhol]

I've got Hyperpro progressive springs fitted to FZR600 forks & either the springs or the sleeves were too long when it all went together. I managed to back the preload adjusters off all the way & force the springs down with the end caps enough to screw them on but it was bloody hard work. My front end feels very firm now to the point where I might have to syringe a bit of oil out & maybe cut the sleeves down while I'm at it so I can have a play with the preload adjusters & I don't have end caps flying all over my garage when they slip off the socket. No danger of the forks bottoming out now, ever & I'm 198lb + all my gear. Not sure what weight the springs are suited to (bought 2nd hand,unused) so I'm off to find the box now out of curiosity.

Do you have any sag Mr B? (not personally, the bike y'understand )

[G Beale]

I've got 12mm of static (bike only weight) sag which I'm led to believe is about right ? But only 22mm of loaded (me on it) sag which I'm betting is not enough. Would like to have at least 30mm with my weight so I'm assuming I've either put too much oil in or the springs are for a right fatty. Hope it's the 1st one but I will trim my spacer tubes down a wee bit so the top caps can be fitted without loading the spring & see what happens.
Sorry for jumping all over your thread BBB but some of the above might be useful... . . maybe ?

[dandywarhol]

The oil level won't affect the sag (unless it's filled to the very top!) More oil just gives a stronger "spring" effect as there's less air to compress. Trimming the tube10mm would sort it out.

[OFD]

Hi. I fitted a pair of Hagon Progressives at the weekend with 10wt oil with an Air gap of 140ml. I have done about 200 miles on them and the difference is worth it, less dive on the brakes but still a comfortable ride quality and I would reccomend them without question.

One thing though they held different amount of oil in each leg but i have the same air gaGood luck

Gary.

[Killerwhale]

Hi. I fitted a pair of Hagon Progressives at the weekend with 10wt oil with an Air gap of 140ml. I have done about 200 miles on them and the difference is worth it, less dive on the brakes but still a comfortable ride quality and I would reccomend them without question.

One thing though they held different amount of oil in each leg but i have the same air gaGood luck

Gary.

Did you leave them upside down over the night and did you give them a good handjob (to take out air bubbles) when pouring in the oil??

[G Beale]

As above Gary you need to errmmm... . manipulate ? each leg whilst filling them but it also helps to do it during the draining process. Sounds like you left a bit of the old oil in one of the forks.

[BBB]

looking in the haynes manual and it mentions slackening the damper rod bolt. Does the whole damper need to come out , looks a bit awkward if it does.

[G Beale]

Not if you're just changing the oil & springs BBB but I think this is why you're advised to leave them over night ? I completely stripped my forks so I could see they were empty but I had to make a tool to hold the damper whilst I loosened the bolt. I think you can loosen it with the forks in the bike before you do anything ? I would imagine the weight of the bike putting pressure on the springs would hold it in place then.