View Full Version : Front springs spacers & oil
I have looked arround and seen that most people are recomending a front spring spacer of about 15mm.
Is this assuming that all aftermarket springs are the same length?
If so i guess that it is the same for all. What about if your bike has preloader caps, how does that change the spacer length?
Ive got a set of progressive springs from (progressive), they are installed at the moment with a spacer of 3cm and the pre-load caps to highest setting (7 bars), it feals firm but a bit to much so. Sould the spacer be less?
In the box came a little peice of paper with diffrent bikes and spacer lengths, but for the sv650 is does not say what it should be, without a spacer the spring would be free to bounce in the fork.
I did a reasonable brake test and the front seems to compress to about 30mm from top, is this ment to be less.
Should the spacer be less? Any ideas?
Progressive springs are definitely longer than single rate springs and therefore the 12-15mm spacer will be incorrect. This was noticed at the ForkFest last year but I can't remember who had progressives though I think it was either Mr Toad or Billy C.
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I originaly tried to put the whole of the spacer that they gave into the fork, but was impossable to put the cap on, the i trimmed about 1.5cm off and the was able to get the cap on with a little help. Glad i did not put the whole thing in otherwise it would be rock hard.
Mabey a trim of 1cm of the spacer should help a bit more, 1cm off should not be a big problem as i do have preload caps which can compensate enough, considering that at the moment is as hard as i will ever have it.
I originaly tried to put the whole of the spacer that they gave into the fork, but was impossable to put the cap on, the i trimmed about 1.5cm off and the was able to get the cap on with a little help. Glad i did not put the whole thing in otherwise it would be rock hard.
Mabey a trim of 1cm of the spacer should help a bit more, 1cm off should not be a big problem as i do have preload caps which can compensate enough, considering that at the moment is as hard as i will ever have it.
Did you drop the forks off, so there was no weight on them from the headstock going down to the front wheel. It is difficult to get the preload cap on. They may of given you the correct spacers for the bikes, i remeber the maxtons at the forkfest had some very long spacers with them
Dan
Took the front forks off completley as i wanted to turn them upside down for all the oil to come out. I also had to twist one of the forks arround because it was bent (as per SidSquid's recomendation for temporary fix).
With the full length spacers they gave i could not get the caps on at all, i noticed that i had a bruse on my hand where i tried to get the cap on, that why i think (i know that they have to be shortened).
Sid Squid
26-06-05, 06:31 PM
as per SidSquid's recomendation for temporary fix.
It's not a fix, it's a rule of thumb way of finding out if they're bent or not. If you want to reassemble your bike when you know the forks are bent, you may well need to line up the bends so to speak, so that you can get the wheel spindle in for instance. I would hesitate to call it any sort of fix.
It seems like one is (the left one), the bend is now facing inwards to the other fork, now the wheel goes on properly. When i have some free time i will sort it out properly and get the forks to be both checked properly.
Sid Squid any ideas on the spacer, should it be enough to put a little pressure on the spring when the cap is on, then use the preload adjusters?
Found this regarding spacer length. (TT from SVRider.com)
http://www.svrider.com/tips/emulators.htm
Now you need to calculate the length of the new spacer. I got some Schedule 40 one inch PVC pipe to make my spacers. Measure from the top of the fork tube to the top of the washers inside — in mine, with the emulators, Progressive springs, and both washers, the distance was 1.81 inches. The fork cap extends down into the fork tube about 0.70 inch, so that must be subtracted from the distance measured. Finally, you have to decide how much preload you want — I aimed for 20 mm (0.79 inch), based on Racetech’s recommendation. So the length of my spacer was: 1.81 — 0.70 + 0.79 = 1.90 inches.
What i found odd was this:
Carefully add fork oil (I used 20 weight, for a stiffer ride use a heavier weight) to the proper level, which is measured as distance from the top of the fork tube to the oil level. Race-Tech suggests 130 mm (5.1 inches); Progressive Suspension suggests a minimum of 140 mm (5.5 inches) with their springs, and that’s where I set mine. A homemade dipstick and a penlight help here. I made a crude dipstick out of a piece of wood and a nail to set the proper depth. Make a dipstick that you are sure you can't drop into the fork!
Most other people on here recomend 100mm from top with oil.
northwind
27-06-05, 06:32 PM
If you're using PVC pipe for your preload spacers your air volume is reduced, so that could account for some of it... Alternatively, it could be for the wrong model :?:
I took my spacers out and trimed them down to 30mm from 45mm.
Will ride out tommorow but now atleast i know that when i had 45mm spacer with no added preload from caps and it was too hard, now with 30mm of spacer, if i need i have the range of about 2cm from the caps.
Also it seems that my sag is probaby off, by my calculations, this is after the spacer was adjusted.
Fully Extended = 128mm
Sag with rider = 90mm
Sag without rider = 100mm
Static Sag = 28mm (a bit off, adjust with added preload)
Loaded Sag = 38mm (within limits, probably not enough)
Loaded Sag to aim for = 128x0.3(third of total extention) = 38.4mm
Fully loaded under braking before reduced spacer = 35mm
Fully loaded under braking after reduced spacer (expected) = 20mm
I took some of this info from a page about speed triples.
Correct me if i am wrong on this
Riccardo,
bearing in mind that you weigh hardly anything at all... 15mm of spacer will be far too hard for you. In the forks this can be a real problem, not only in the ride quality, but may also adversely affect the handling - the classic being understear - not good on the twisties.
In summary, it's better to have it too soft, than too hard. I think so anyway!
Mr Toad and I used Maxton Springs, which are not progressive, but the resulting length of the kit is 10mm longer than the stock springs that we removed. This effectively gave us the preload we needed, and that is now all I am using - anything extra with the preload caps became too much.
I suggest you PM Raf, as I'm certain he put progressive springs in his, and his weight may give you a guide as to the spacer size you need.
Just be aware that the spacer sizes we're talking about, concern the difference in length between the original stock springs and spacer, and what you're putting back in.
I think 20wt oil for me would be murder, and it would be sheer torture for you Riccardo. I even find the 15wt stuff very firm... so I'm guessing you'd be best of staying with 10wt.
Then there's the air gap... mine was set to 92mm, and again I think this adds to the firm ride.
I am using 100mm air gap as recomended and 10w oil.
The spacer is now 30mm down from 45mm with minimum preload on the caps, after a ride this morning it seems much better, but i will test it more tommorow to selkent.
I dont think i can go any lower otherwise when i put the caps on there will be no pressure on the spring at full extention.
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