Hi Everyone,
Just fitted new progressive springs to front forks. Garage told me the front has dropped by 50mm. Checked parts number with supplier and confirmed all is correct. Has anyone heard of this or something similar?
The back has a 155 jack up kit which was already on the bike before so shouldn't effect the 50mm drop.
Ive read about spaces but doesn't that change the preloads?
Can someone advise me if just fitting spaces say 40-50mm. Most people use pvc ones which can be made.
Most articles about FZR 1000 fork rebuilds state to use Race Tech Gold Valve Cartridge Fork Emulators. Does this add anything to the over height as i want to make up 50mm.
Is it possible to fit adjustable fork caps these forks?
Thanks for any info
1990 FZR 100 Exup Front forks rebuild
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FZR 1000 Ex up
- Brolly Dolly
- Posts: 5
- Joined: Sat Aug 15, 2015 9:44 pm
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willandrip
- Test Rider
- Posts: 291
- Joined: Fri Aug 10, 2012 8:50 am
- Location: Tyne & Wear
Firstly what make of springs were used.?
If you can find out the spring length of the progressive spring and compare it with the service limit of the original spring in the Yamaha service manual then you will soon see what is wrong with the replacement.
Most spring sets come with the correct length spacer...or use the original or advise a length.
The spacer will change preload if it is made longer than what is recommended.
If the correct spacer is fitted the preload should be in the range for starting to make changes to suit the individual.
The Racetech valve is circa 30mm in height and would add to the preload when used fitted to an already correctly set up fork.
If you can find out the spring length of the progressive spring and compare it with the service limit of the original spring in the Yamaha service manual then you will soon see what is wrong with the replacement.
Most spring sets come with the correct length spacer...or use the original or advise a length.
The spacer will change preload if it is made longer than what is recommended.
If the correct spacer is fitted the preload should be in the range for starting to make changes to suit the individual.
The Racetech valve is circa 30mm in height and would add to the preload when used fitted to an already correctly set up fork.
Endeavour to persevere.
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FZR 1000 Ex up
- Brolly Dolly
- Posts: 5
- Joined: Sat Aug 15, 2015 9:44 pm
Hi all,
Thanks for your response.
I used Hyperpro Progressive Front Fork Spring Kit Yamaha FZR 1000 EXUP 89-90. Ive checked the parts with the supplier and confirmed the parts are correct using the chassis number. The supplier says its
1. Parts are not fitted correctly. (Fitting at garage,they say its as it should be and can't understand why they are 50mm lower than the last ones?)
2.Measure the new springs and they will check to make sure they haven't sent out the wrong ones!
Like you said if i put spaces in there i would increase the preload making them too stiff i imagine!!
Ill get you updated on how it goes, speak to garage tomorrow!
Thanks guys this is a great site for us ex up lovers
Kevin
Thanks for your response.
I used Hyperpro Progressive Front Fork Spring Kit Yamaha FZR 1000 EXUP 89-90. Ive checked the parts with the supplier and confirmed the parts are correct using the chassis number. The supplier says its
1. Parts are not fitted correctly. (Fitting at garage,they say its as it should be and can't understand why they are 50mm lower than the last ones?)
2.Measure the new springs and they will check to make sure they haven't sent out the wrong ones!
Like you said if i put spaces in there i would increase the preload making them too stiff i imagine!!
Ill get you updated on how it goes, speak to garage tomorrow!
Thanks guys this is a great site for us ex up lovers
Kevin
-
willandrip
- Test Rider
- Posts: 291
- Joined: Fri Aug 10, 2012 8:50 am
- Location: Tyne & Wear
Most springs require a pre load spacer.
If the bike has lost 50mm then the springs are incorrect or
no/incorrect spacer has been fitted.
Generally the spring and spacer length is such that it is just possible to screw the top nut on by hand with very little downward pressure with the fork fully extended.
This is then corrected by adjustment to the spec you require for static sag.
If the bike has lost 50mm then the springs are incorrect or
no/incorrect spacer has been fitted.
Generally the spring and spacer length is such that it is just possible to screw the top nut on by hand with very little downward pressure with the fork fully extended.
This is then corrected by adjustment to the spec you require for static sag.
Endeavour to persevere.
When I first bought my Exup-R I thought the problem with the setup was with the forks. So I bought some springs from 'Progressive Suspension' via a UK supplier & had to cut down the standard spacer/tube to the specified length. But the new springs didn't help & the way I used to ride the bike made the ride worse, no matter what I did with pre-load, air gap, fork oil weight etc.
So the next mod was to buy some Race-Tech emulators, which, with a bit of fiddling, improved the fork action, but it still wasn't right. Then I increased the rear damping on the OEM shock to one click back from max & changed the rear spring pre-load to max. This stopped the back end from sqatting under acceleration, which stopped the front fromrising, which had made me suspect the forks.
Once i'd spent more money on an EMC 'RACE' shock, which was rubbish as it came with no instructions for setup except how to adjust SAG & it blew it's guts during a spirited ride along the A272, I reinstalled the standard shock just in time to go to Assen WSB.
Having installed various lengths of dog bones I settled on 160mm, which raised the rear by about 28mm, instead of the 155s which raised the rear by about 35mm & caused the chain to chew through the slider & would've caused damage to the swingarm if i'd not changed them back to the 160s.
But the biggest change was to buy an Ohlins shock & once that was set up, I complemented that by installing Ohlins straight rate fork springs, 7.5w Ohlins fork oil as well as a slightly heavier spring on the emulators. Now it's as good as it's going to get, but no where near as good as the R1, which has Ohlins fork springs & shock.
With the 160 dog bones & the bike on the stand, the back tyre nearly touches the floor
If 155s were fitted, i'd have real problems using that stand
So the next mod was to buy some Race-Tech emulators, which, with a bit of fiddling, improved the fork action, but it still wasn't right. Then I increased the rear damping on the OEM shock to one click back from max & changed the rear spring pre-load to max. This stopped the back end from sqatting under acceleration, which stopped the front fromrising, which had made me suspect the forks.
Once i'd spent more money on an EMC 'RACE' shock, which was rubbish as it came with no instructions for setup except how to adjust SAG & it blew it's guts during a spirited ride along the A272, I reinstalled the standard shock just in time to go to Assen WSB.
Having installed various lengths of dog bones I settled on 160mm, which raised the rear by about 28mm, instead of the 155s which raised the rear by about 35mm & caused the chain to chew through the slider & would've caused damage to the swingarm if i'd not changed them back to the 160s.
But the biggest change was to buy an Ohlins shock & once that was set up, I complemented that by installing Ohlins straight rate fork springs, 7.5w Ohlins fork oil as well as a slightly heavier spring on the emulators. Now it's as good as it's going to get, but no where near as good as the R1, which has Ohlins fork springs & shock.
With the 160 dog bones & the bike on the stand, the back tyre nearly touches the floor
If 155s were fitted, i'd have real problems using that stand