Marzocchi fork springs question

Message

tommy · #1 Post by **tommy** » Wed Aug 31, 2011 5:20 pm

Out of interest... Has ony one re sprung thier marzocchi forks? I'm a feather weight, and pretty sure my forks are severly oversprung. I've found loads of fork springs on the net, but im persuming they are the the showa forks. Anyone know if they will fit? Will it be case of take out and measure? (like the rear)

On another note, I put a lighter spring on the rear, (700lb) as to mangocrazys recomendation... and it feels bloody lovely!!

DavShill · #2 Post by **DavShill** » Wed Aug 31, 2011 7:12 pm

Hi Tommy. The mazz forks are cartridge types so it's not a straight forward job of fitting new springs. It can be done - can't remember who, but someone on here has done it - but it's not a cheap mod either. Not much help but it fills you in a little more.

D-Rider · #3 Post by **D-Rider** » Wed Aug 31, 2011 7:56 pm

DavShill wrote:Hi Tommy. The mazz forks are cartridge types so it's not a straight forward job of fitting new springs. It can be done - can't remember who, but someone on here has done it - but it's not a cheap mod either. Not much help but it fills you in a little more.

That shouldn't make re springing more difficult - re-valving would be a problem though.
I'm pretty sure it was Paddy that had his re valved.

anzacinexile · #4 Post by **anzacinexile** » Wed Aug 31, 2011 8:08 pm

D-Rider wrote:
DavShill wrote:Hi Tommy. The mazz forks are cartridge types so it's not a straight forward job of fitting new springs. It can be done - can't remember who, but someone on here has done it - but it's not a cheap mod either. Not much help but it fills you in a little more.
That shouldn't make re springing more difficult - re-valving would be a problem though.
I'm pretty sure it was Paddy that had his re valved.

Correct

tommy · #5 Post by **tommy** » Wed Aug 31, 2011 8:11 pm

I've had a wee look ot the marzocchi manual, and its easy peasy to get the springs out, same as normal forks. I'll be leaving valving alone (thats black magic to me). I just dont want to shell out on new springs if they wont fit. I either need lighter springs, or a diet of suet puddings

#6 Post by **mangocrazy** » Wed Aug 31, 2011 8:47 pm

Hi Tommy, glad to hear that the softer rear spring worked for you - I'm still running it and it's working well for me.

I'm not sure about the Marzocchi forks, but I know the Showas had a spring rate of 1.05 kg/mm (approx 59 lbs/in) and I'd imagine Aprilia would have specified the same rate for the Marzocchis. The spring rate is much lower than for the shock because there's no linkage involved.

Even so, 1.05 kg/mm is a very high rate. Most fork springs are in the range of 0.85 kg/mm to 0.95 kg/mm, depending on rider weight. Personally, I'd go for a rate of about 0.9 kg/mm if you're 'average' weight (around 11 - 13 stones).

If you can get the Marzocchi springs out easily (just one will do), measure its 'free length' (i.e. its uncompressed length) and its outside width. If a damper rod runs up the middle of the spring, I'd also measure the internal width and/or the spring wire diameter.

Then go to these people, giving them all your spring dimensions, and get them to make up a pair of fork springs for you. If they need any further dimensions, they'll let you know.

http://www.dfaulknersprings.com/index.htm

Let them know your requirements and they'll sort you out. They're very helpful and their quality is first-rate.

tommy · #7 Post by **tommy** » Wed Aug 31, 2011 9:00 pm

mangocrazy wrote:Hi Tommy, glad to hear that the softer rear spring worked for you - I'm still running it and it's working well for me.

I'm not sure about the Marzocchi forks, but I know the Showas had a spring rate of 1.05 kg/mm (approx 59 lbs/in) and I'd imagine Aprilia would have specified the same rate for the Marzocchis. The spring rate is much lower than for the shock because there's no linkage involved.

Even so, 1.05 kg/mm is a very high rate. Most fork springs are in the range of 0.85 kg/mm to 0.95 kg/mm, depending on rider weight. Personally, I'd go for a rate of about 0.9 kg/mm if you're 'average' weight (around 11 - 13 stones).

If you can get the Marzocchi springs out easily (just one will do), measure its 'free length' (i.e. its uncompressed length) and its outside width. If a damper rod runs up the middle of the spring, I'd also measure the internal width and/or the spring wire diameter.

Then go to these people, giving them all your spring dimensions, and get them to make up a pair of fork springs for you. If they need any further dimensions, they'll let you know.

http://www.dfaulknersprings.com/index.htm

Let them know your requirements and they'll sort you out. They're very helpful and their quality is first-rate.

I think I may just do that. I used several spring rate calculators on the net. All said I need around 0.55 5o 0.65. But then i'm only 9 1/2 stone. The standard ones are way to much for my girly frame

#8 Post by **mangocrazy** » Wed Aug 31, 2011 9:28 pm

If you're a sylph-like 9.5 stone, you might be better off with 0.85 kg/mm. 0.55 - 0.6 kg/mm are really very, VERY soft. The Race-Tech calculator reckons as follows for your weight on a Falco and for street use:

FRONT FORK SPRINGS
Recommended Fork Spring Rate: 0.898 kg/mm (use closest available)
Stock Fork Spring Rate: 1.050 kg/mm(stock)

Fork spring dimensions: 36.7 x 34.5 x 315 (bear in mind these are probably Showa spring dimensions - I'd measure your own)

So Race-Tech reckon 0.9 kg/mm. Your call really - you know whether you prefer a more softly or firmly sprung motorcycle. Even so, there won't be a big difference between 0.85 and 0.9. A suspension guy I know reckons that you need around a 10% difference in spring rate to really notice the difference.

tommy · #9 Post by **tommy** » Wed Aug 31, 2011 9:37 pm

As it happens, I just found the racetec calculator. Will probably go with some 0.9 ones. Will pop my fork caps off at some point once i've got some pennies together (i'm probably due to change the oil anyway) Out of interest, how much did it cost to get your ohlins revalved to falco spec? I'd be interested to do this as the 700lb spring we have is what is fitted to the falco ohlins shock...

DavShill · #10 Post by **DavShill** » Thu Sep 01, 2011 10:01 am

Oops! That'll teach me to not to talk about techie stuff that I really don't know too much about.

D-Rider · #11 Post by **D-Rider** » Thu Sep 01, 2011 5:24 pm

DavShill wrote:Oops! That'll teach me to not to talk about techie stuff that I really don't know too much about.

LOL - no join in the party Dave. I think you remembered paddy posting up but just forgot which bits were the hassle

#12 Post by **mangocrazy** » Thu Sep 01, 2011 7:51 pm

Hi Tommy, John at Revs Racing in Halesowen did my Ohlins shock. He re-valved the Mille Ohlins to Falco spec and I think it cost about 90 drinking vouchers (plus P&P). Might be a few quid more now as it was 2 years ago.

I'm thinking about getting him to re-do it as the compression damping still feels a bit harsh, but that's probably me just being picky. It's worlds better than before he re-valved and re-sprung it.

I reckon 0.9 kg/mm should be about right for the forks. I had a set of Hyperpro progressive springs put in mine, so they don't have a set spring rate as such. The standard forks are well over-sprung in my opinion...

D-Rider · #13 Post by **D-Rider** » Thu Sep 01, 2011 8:09 pm

John at Revs serviced and re-sprung my Ohlins forks for me before I fitted them.
He's a good chap

tommy · #14 Post by **tommy** » Thu Sep 01, 2011 8:43 pm

That's alot cheaper than i thought. I'll have to do that I think. Just need to get some reddies together first

paddyz1 · #15 Post by **paddyz1** » Fri Sep 02, 2011 6:20 am

Cost me £270 a few years back. That was a complete changeover of all internal baddies to goodies springs, valves etc.

Also had my rear shock fixed some months back. I bound up the adjusting rings (soft git) and they would not move so i took it back to Maxton and had them fix it as well as a shock service. It cost £120 all in. £90 for the service, £30 to remove the rings and replace with an updated one piece adjuster).