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View Full Version : Anyone got some old fork springs?



erik
25th January 2006, 16:33
about 30mm to 32mm diameter and 380mm to 500mm long.
they need to be about .90kg/mm at a guess... but would be happy to try whatever is available.

Just thought I'd check before ordering some from Oz. (not many zeal's get wrecked here).

Bonez
25th January 2006, 16:37
Why not get a spring manufacture some? I think WT mentioned he had a contact on that front.

erik
25th January 2006, 16:43
because I'm looking for something cheap.
A while back I cut the original springs in the Zeal to stiffen the front end a bit, it worked (although is still a bit soft). But it's not entirely legal, so since I'm selling the bike soon, I want to get some legal springs for it. I know you can't see them or tell they've been cut, but I'd rather do the right thing.
The thing is the bike has done almost 80,000km and isn't in pristine condition, so I'm not going to get much when I sell it, so it wouldn't make sense to get aftermarket springs for it.

Brian d marge
25th January 2006, 16:50
about 30mm to 32mm diameter and 380mm to 500mm long.
they need to be about .90kg/mm at a guess... but would be happy to try whatever is available.

Just thought I'd check before ordering some from Oz. (not many zeal's get wrecked here).

Eric I am just rushing out the door , I will have a look ..if you are not in a hurry i can probably help

As for cutting down spring
After maket manufactures do exactly that ...and offer a longer spacer to compensate !

but i know what you mean

Stephen

rogson
25th January 2006, 16:52
I have two 37mm OD, 390mm long, about 0.8kg/mm you can have for $20. PM me if you are interested.

Otherwise, I can recommend getting them made by National Springs (09 261 2300). I had a set of 0.95kg/mm made by them that I'm very happy with. Cost $125 for the pair (which is bloody good value IMO).

Motu
25th January 2006, 16:54
So how did you get a WoF with ilegal fork springs? Did you intimidate him,or maybe offer a bribe? I'd like to know please,cause I think I slipped up on the bribe part....

Bonez
25th January 2006, 17:03
So how did you get a WoF with ilegal fork springs? Did you intimidate him,or maybe offer a bribe? I'd like to know please,cause I think I slipped up on the bribe part....:eyepoke: :clap:

erik
25th January 2006, 17:19
Eric I am just rushing out the door , I will have a look ..if you are not in a hurry i can probably help
Cool. I'm not in a hurry, I won't be selling the Zeal for 3 more weeks at least, need to save up a bit more money for a new bike.


I have two 37mm OD, 390mm long, about 0.8kg/mm you can have for $20. PM me if you are interested.

Otherwise, I can recommend getting them made by National Springs (09 261 2300). I had a set of 0.95kg/mm made by them that I'm very happy with. Cost $125 for the pair (which is bloody good value IMO).Thanks, but 37mm OD won't fit. 32 is the max OD that I think will fit.
I'll keep National Springs in mind, that sounds like a better option than getting second hand springs from Oz. :)


So how did you get a WoF with ilegal fork springs? Did you intimidate him,or maybe offer a bribe? I'd like to know please,cause I think I slipped up on the bribe part....:o :sweatdrop :innocent: :D :) ;)

Brian d marge
25th January 2006, 18:00
So how did you get a WoF with ilegal fork springs? Did you intimidate him,or maybe offer a bribe? I'd like to know please,cause I think I slipped up on the bribe part....

Hey can someone run this fork springs and Mot past me ..Cos ALL springs need to be cut ?
They are wound on a mandrel then the ends are cut and folded and ground depending on the end conditions required.

Now I can understand ya boy racer ,,I ve seen dampers with springs that have been cut so they are loose ...

but if you are not altering the height of the vehilcle ( and infact springs suited to your wieght are actually safer )

How does the Law come in to this ...

Stephen

Bonez
25th January 2006, 18:37
Hey can someone run this fork springs and Mot past me ..Cos ALL springs need to be cut ?
They are wound on a mandrel then the ends are cut and folded and ground depending on the end conditions required.

Now I can understand ya boy racer ,,I ve seen dampers with springs that have been cut so they are loose ...

but if you are not altering the height of the vehilcle ( and infact springs suited to your wieght are actually safer )

How does the Law come in to this ...

Stephen
IT WAS A PISS TAKE!!!

Brian d marge
25th January 2006, 18:40
IT WAS A PISS TAKE!!!


Well it went steaming past me ........Must be that famous Kiwi humour I ve read so much about !!!

Stephen

erik
25th January 2006, 19:18
It's not entirely a piss take, as far as I know it's illegal to either heat suspension springs or cut them, I'm not entirely sure, I haven't seen the actual legislation.
I should probably go look it up...

Here we go, found it:
http://www.ltsa.govt.nz/publications/vir-manual/general-vehicles/9-1-steering-and-suspension-sys-v2-1a.pdf

On page 4 it says that LVV certification (Low Volume Vehicle certification) is not required if...
"replacement springs have not been heated or cut"

Which mine have. Therefore they are illegal unless I can get LVV certification.

Motu
25th January 2006, 19:36
I've had fork springs made several times,they are usualy very cheap compared to new OE.Back in the 70s I had new springs made for my Ceriani's for $2 each! But last time I had some made,for my KT250,I was told they weren't able to get the correct grade of steel for fork springs so couldm't offer any sort of guarantee...it was only for an old trials bike so I didn't care.

Bonez
25th January 2006, 21:00
It's not entirely a piss take, as far as I know it's illegal to either heat suspension springs or cut them, I'm not entirely sure, I haven't seen the actual legislation.
I should probably go look it up...

Here we go, found it:
http://www.ltsa.govt.nz/publications/vir-manual/general-vehicles/9-1-steering-and-suspension-sys-v2-1a.pdf

On page 4 it says that LVV certification (Low Volume Vehicle certification) is not required if...
"replacement springs have not been heated or cut"

Which mine have. Therefore they are illegal unless I can get LVV certification.How the hell are they going to know that's been done on the springs in front forks of a m/c?

Motu
25th January 2006, 21:17
LTNZ confirs upon WoF testers certain powers not available to mortal men,one is the ability to look right through metal,to see it's very structure.Heated and cut fork springs are easy to pick - that's why I suspect Erik was able to somehow bribe the doddery old fool who inspected his bike...but he mislaid the bribe I think.

Bonez
25th January 2006, 21:21
LTNZ confirs upon WoF testers certain powers not available to mortal men,one is the ability to look right through metal,to see it's very structure.Heated and cut fork springs are easy to pick - that's why I suspect Erik was able to somehow bribe the doddery old fool who inspected his bike...but he mislaid the bribe I think.
Thank you for clearing that up Motu. I'll line mine with lead next time I go in for a WOF.

Motu
25th January 2006, 21:39
And don't use Kryptonite either...it makes me go all weak in the knees.....

Bonez
25th January 2006, 21:44
And don't use Kryptonite either...it makes me go all weak in the knees.....How is Lex these days?

Brian d marge
26th January 2006, 02:19
It's not entirely a piss take
"replacement springs have not been heated or cut"

Which mine have. Therefore they are illegal unless I can get LVV certification.

Didnt think it was Eric,,, and that has to be the wackiest bit of law I have ever heard of.

unless they are cold formed which would induce tensile and compressive stresses in the region of the bend, which would caused a localised high stress point on the inside?

I know its to try and stop the boy racers ,,,but this bit of rubbish says if you replace your springs * if they have been cut* , you have to get an engineers report !( unless it OE
or they are a direct replacement ?? whats a direct replacement ???

Anyway I will have a look what I have lying around tomorrow and let you know !

Stephen

Kickaha
26th January 2006, 05:59
or they are a direct replacement ?? whats a direct replacement ???

Stephen

Something made by an aftermarket manufacturer specifically for that vehicle, but it may be a different spring rate or length

erik
26th January 2006, 07:24
unless they are cold formed which would induce tensile and compressive stresses in the region of the bend, which would caused a localised high stress point on the inside?
...

Remember there's also the problems of changing the temper of the steel by heating and cooling them, the increased stress in the spring if coils are removed for the same amount of travel and the difficulty of getting the ends of the springs square while keeping their temper if they are cut.
I think in forks it's not such a big issue since the springs are long, are fully supported in a tube and for stiffening them, only an end is altered.
I'd say you're right that the law is targetted towards boy racers.

FlyingDutchMan
26th January 2006, 10:19
I have a pair of MC19 (CBR250R) springs that might do the job. I'll check when I get home, but I think OD is 30mm, length is ~304mm, dunno the spring rate from the top of my head though. Good as new - looked identical to the brand new OEM ones I replaced them with.

Pixie
26th January 2006, 11:09
So how did you get a WoF with ilegal fork springs? Did you intimidate him,or maybe offer a bribe? I'd like to know please,cause I think I slipped up on the bribe part....
Chief Wiggum to Homer - "I'm Looking for my friend 'Bill',Have you seen him?":killingme

FlyingDutchMan
26th January 2006, 16:30
Well they're actually 303mm long and 29mm OD. You'll need to use a spacer if you put them in (the MC19 has a spacer about 200mm long -- I think).

Brian d marge
26th January 2006, 18:11
ok
I rumaged through my fork /spring sets

I have a set of VFR 400 front forks 30 x 390 x 4 ( 3.98) mm

all the othere are cr 250 and are 38 mm ( 86 cr250 ) od

hope this helps in some way

Stephen

erik
1st February 2006, 18:25
Thanks for the offers, FlyingDutchMan and Stephen.
I thought about it heaps and decided to get some springs made up.

The guy at National Spring and Wire Products didn't seem too keen to make some springs for me, he said that motorcycle springs are often made out of a higher strength (I think he said higher chromium content?) that was in short supply and he thought that he'd run into problems with the springs binding if he tried making them out of the standard materials he uses.

So I phoned CMI Springs who put me onto their design guy. I gave him the required dimensions and spring rate and he said he could make them for about $60 each which beats aftermarket springs from a bike shop, so I'm happy.
Just there is a bit of a wait before they can be made, they should call back in a week or so.
If all goes well, they should fit right in there with the original steel tube spacers.

While I was checking the spring dimensions again on monday with the front wheel off the ground I checked the front wheel bearings. I was surprised to find a whole lot of slop in them, the wheel wobbled around a fair bit :eek5:
I'd been riding it the day before having fun in the twisties around SH22. I thought it felt a bit funny going in a straight line, but wasn't sure if it was the road or the bike.
Anyway, I was able to get a new pair of bearings and new seals from Automotive Engineering Bearing Supplies in Henderson and have put them in today.
Here's a photo of the left hand old bearing, it was the worse of the two.
I think water got in there somehow, possibly through the speedo cable, but I'm not sure how it got into the speedo cable in the first place.
Things were a bit rusted in there but cleaned up ok :sweatdrop
It's all back together now. Just have to wait for the springs and decide if the clutch is bad enough to require replacing (and how much it'll cost and if it's worth it considering I'm probably not going to get much for the bike when I sell it in a few weeks time :wacko: ).

Bonez
1st February 2006, 18:51
Do you use a water blaster on the bike Eric?

Brian d marge
1st February 2006, 18:55
So for less than 100 dollars you can get the correct spring rate for your wieght.

The poor guy is going to get swamped with enquiries !!!!

Stephen

erik
1st February 2006, 19:34
Do you use a water blaster on the bike Eric?
Nope, hardly ever even clean it. ;)

When I've disconnected the speedo cable in the past for changing the front tyre etc, I've noticed what I think was water dripping out of it a bit. Only a small amount. That's what led me to think that the water got in there through the speedo. But I had a look at the speedo, took it off the bike and put some water on the glass (it can pool on top of it because there is a lip around the edge of the glass) but none of it leaked through, and besides the speedo seems to have a drain hole at the lowest point.
So I think maybe it got through the speedo cable itself? The cable has an outer sheath that covers most of the cable except for a small section near one end. The uncovered bit was at the top of the speedo, so I wonder if water may have collected in between the outer sheath and inner sheath and somehow got through? I don't know if this is possible as the inner sheath is also plastic/rubber coated.
Anyway, I've put the break in the outer sheath at the bottom end so that any water that gets inbetween the sheaths will just drain out.


So for less than 100 dollars you can get the correct spring rate for your wieght.

The poor guy is going to get swamped with enquiries !!!!

Stephen
Not quite less than $100. He said approximately $60 per spring, so about $120. Still good though :yes:

erik
3rd February 2006, 20:11
The new bearings are nice. :) The bike feels more precise. And the front brakes work better! I don't have to pull the lever in so far to get them to grab. I guess the movement in the old bearings made the disc push the pads further into the caliper, requiring more movement at the lever.

erik
21st February 2006, 20:54
Got a call yesterday morning that the springs were ready, so I went today and picked them up.
I'd asked for 32mm dia, 373mm long and 0.95kg/mm springs. The engineer guy I talked to said he'd make the length 375mm, I guess just to round it up. Anyway, the length came out at exactly 373mm on the one I measured and the other looked the same, so I'm not sure if I misunderstood or if it was just a fluke.
I'd said the diameter had to be no larger than 32mm, that they needed to work inside a 32.9mm tube. But when I measured the new spring dia, it was 32.5mm!
Luckily it seems ok with just the 0.4mm clearance.
The new springs are a fair bit heavier than the old ones, weighing 600g each compared to 400g for the originals. Not that this has any significant effect as far as I can see.

Anyway, I put them in the bike and there's a huge difference, the front feels way firmer and nicer. Not too hard though, I think.
It's funny though, the second rate of the original springs was 0.95kg/mm, the same as the new ones. But there was about 8mm travel of the first rate from the laden position.
I don't know if it's the 8mm travel that made the difference, or if the original springs weakened since I last measured them (just after cutting them, a year or more ago, iirc. I should measure them again). I measured the rate on the new springs and came up with 0.96kg/mm but I don't think that'd be noticeable plus my measurements might have been slightly out.

Since the new springs were the exact length I asked for I was able to put them straight in with the original steel spacers which was nice. It's way easier putting single rate springs in than dual rate springs.

Brian d marge
22nd February 2006, 14:12
The springs are nice !!

and yes they do make such a difference ,! BTW Eric did you give the Engineers a drawing or just word of mouth ? And how did you measure the spring rate ?

I use a press with a dial guage , and a set of digital bathroom scales.

If you measure and calculate , you have to be SUPER careful with the measuring, ( From memory its the wire dia that causes the hiccups !)

I have completely resprung , revalved , rebuilt both shocks on the cr , cnt wait to see what the difference will be

Stephen
BTW Well done that man !

erik
22nd February 2006, 20:27
The springs are nice !!

and yes they do make such a difference ,! BTW Eric did you give the Engineers a drawing or just word of mouth ? And how did you measure the spring rate ?

I use a press with a dial guage , and a set of digital bathroom scales.


I told one of their design guys the required dimensions (outer dia, length and spring rate) over the phone, they did the rest from there.

I measured the spring rate using the contraption in the last pic of this post:
http://www.kiwibiker.co.nz/forums/showpost.php?p=141017&postcount=19

I made it up when I was getting ready to cut the original springs a year or so ago. I just used a measuring tape for the spring length/compression.
A dial gauge and digital scales sounds fancy. ;) :)

Cheers :)

Brian d marge
23rd February 2006, 02:10
I told one of their design guys the required dimensions (outer dia, length and spring rate) over the phone, they did the rest from there
A dial gauge and digital scales sounds fancy. ;) :)

Cheers :)

Hey that tester you made is the same load/distance . I use a cheap digital scales, and I have a dial guage !!, but the results will be very similar to yours ( I checked using Tony foales Suspention progame and I think I was 3 percent out , or something silly ) enough not to worry

You know what happened , they guy wrote on the job sheet 34mm with no tolerance , I reckon . Do a drawing lot safer and you have a come back if it didnt fit, ( or like me, foget to edit a dimension and it comes back Way to big , so you rush to drawing to find out you havent toleranced it properly- or edited the tolerance :shit::doh:

any way enjoy the new springs, .....boing ........

Stephen