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DRZ400SM fork springs?

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I'm looking to upgrade my SM's suspension and so far have the parts for the rear, but am having a b!tch of a time finding fork springs. Racetech doesn't seem to have anything for the supermoto; I've checked their site and talked to two local shops who called. Nada. Progressive is showing nothing in their lineup, both current and forthcoming,

ARG.

Has anyone upgraded the front forks of their SM? Where on earth did you find springs?! I've been looking half-assedly for about a month but really trying in the last week. My canyon carving experience this weekend where I felt every single bump has really moved up my timeline.

I have the parts for the rear, can anyone point me in a specific direction (part numbers would be BOMB) for heavier SM springs? Pretty please?

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Cannon Racecraft makes custom springs at a reasonable price if you can't find any else where...

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Racetech does have front springs

PartNumber FRSP 434949

Mine were just shipped last week

Call them directly

Get their gold valves too

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Racetech does have front springs

PartNumber FRSP 434949

Mine were just shipped last week

Call them directly

Get their gold valves too

I believe the stock SM springs are ~450 mm long and ~43 mm in diameter. The racetech springs you quoted are ~490 mm long... way too long and you'll end up with a ton of preload.

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forks are designed to be used with a specific length of spring. To change the spring rate they change the diameter of the wire or the wind of the wire or the length. Changing length of a wire by this much would not be ideal as it would give too much preload. 40mm is about 1 3/4". Too much preload makes the springs harsh at the beginning of the stroke. If the forks have a spacer inside that could be removed then longer would be Ok to do. So, when they sold you longer springs did they explain to remove a spacer or was it talked about at all? I dont know the length of the stock springs, Im just going off whats mentioned here and general spring thots.

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So essentially, you're saying I should jack the preload up a bit to help with the front end diving? I'm still trying to figure out all the adjustments on the forks, keep finding new screws to click and turn.  :ride:  Now to just figure out what all of them do...

 

I managed to find these progressive springs from Hyperpro on Ebay, would they give me any help or should I stick with making stock adjustments? 

 

http://www.ebay.com/itm/Hyperpro-Progressive-Front-Fork-Spring-Kit-Suzuki-DRZ400-SM-05-/141270748201?pt=UK_Motorcycle_Parts_13&hash=item20e4648c29

 

I've already bought a spring for my rear shock and plan to get that worked on very soon, but I'd thought to rebuild the front as well. Is there a detailed breakdown of how to tune a DRZ front end? I've played with the screws at the top of the triple but not yet the ones down by the axle, mostly I'm just messing around with things since I don't know what does, well, what.  :smashpc:

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I managed to find these progressive springs from Hyperpro on Ebay, would they give me any help or should I stick with making stock adjustments? 

 

http://www.ebay.com/itm/Hyperpro-Progressive-Front-Fork-Spring-Kit-Suzuki-DRZ400-SM-05-/141270748201?pt=UK_Motorcycle_Parts_13&hash=item20e4648c29

 

:smashpc:

I was looking into these as well and from what I read, the reviews seem mixed. Some describe them as a "fix all' that mean you don't need to re-valve, others describe them as old technology that does very little.

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I'm keen to hear how this works out for you. Please advise after your suspension mods are complete and tested.

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I got mine from cannon race craft. Changed to 7 wt fork oil and I like the way it came out a lot. I am 225 lbs and I put .50 or .52 kg/mm in. There is a good write up on super moto junkie. Search fork spring swap mega pic dial up beware. Was very helpful to me.

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cannon race craft is the only source for correctly fitting SM springs far as I know. (correct being not a other application spring chopped off to "fit")

 

RT grabbing the right diameter and length spring for an RM and cutting it to length to fit an SM fork is.. well different at best. Sounds like something a teenager would do in his dads garage with a hacksaw and pair of vice grips. :devil: 

 

​What spring rate are they quoting for a modified FRSP 434949? 

 

I think most would be better off calling cannon race craft and getting a set of springs that correctly fit from the get go. 

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Got off the phone with Racetech and the only springs they have for the right weight range are, as several people pointed out earlier, longer than stock. There was no mention of modifying them to be any shorter, so I'm not sure what to do. Should I get the longer springs in maybe one weight-range down and cut off that extra inch or so, or should I stuff the extra length into the shocks and use spacers to make up the difference?

My original plan had been to lower the bike a bit in the front and rear with spacers, so I'm not sure what I'd do with longer front forks. :( The current ride height is actually good for me, I just wanted the ability to have a taller seat (the peg-to-seat distance feels cramped to me). Plus, that stiffer rear spring is going to make it seem taller than current.

Anyway, thanks for all the answers! It's nice to see I'm not the only one who's looked into this, there's a surprising lack of fork spring questions for the SM.

ETA: Here's the Cannon Racing parts chart Eddie mentioned. They do seem thorough!

http://www.cannonracecraft.com/wp-content/uploads/2014/03/CannonRacecraft-Application-Chart.pdf

Edited by Ladyeclectic

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I know this thread is a couple of months old, but I thought I'd add some info.

Wilber's, in Germany, makes 0.51kg/mm front springs for the SM. Correct length and diameter. But, it appears that they only sell it as a kit with a couple of bottles of SAE 10 fork oil. Because of the oil, not sure if they would ship over here.

http://www.wilbers-shop.de/Motorrad/Suzuki/DR-Z-400-SM-WVB8/Wilbers-Gabelfeder-linear.html?manufacturer=4o026b35cee799af75d296ff64ae81b3&year=2006&catname=s2ida29c85b5314da693740d7d85e749

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Since the thread had been bumped, I will give an update on my setup

0.51kg/mm is what RT quoted me that the modified springs are.

Installed about 6 weeks or so ago, and the new suspension setup is awesome. The springs themselves are extremely well manufactured and don't look at all "hacked". In fact side by side with the stock spring you couldn't tell the difference

My DRZ is no longer mushy, and it handles like a dream. This upgrade was definitely worth the money

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I'm glad they have options. They should add those options to their website for easier ordering.

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