Anyone got some old fork springs?

[erik]

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]

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]

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/sh...7&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]

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

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

Stephen