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-   -   New fork springs - what should i get ? (http://www.advrider.com/forums/showthread.php?t=821392)

Alex_RO 08-28-2012 06:57 AM

New fork springs - what should i get ?
 
Hello,

got a friend going over to the US and he's kind enough to bring back some stuff with him so... i'll be asking him to get me some stiffer springs.

Details:

Bike model:2007 Standard ADV (w ABS), standard .48 springs installed.

Rider weight: 250 now but on a diet, aiming for ...let's say 230 (with gear, no luggage).

Intended Usage: fast street and "fire" roads (these pretty much mean the same thing in Romania, you never know where you're gonna find a pothole), veeery little (and slow) offroad.



I'm hoping to get away with .54 springs since anything thicker/heavier is going to required modifying the forks somehow and there's nobody around I'd trust to get that going (shipping the forks off to SPS isn't much of an option, i'm pretty much half way around the world). If there's a guide somewhere and a "kit" for installing heavier springs, i'd love to hear about it.

Your thoughts? Should i get stiffer springs than .54 ? All input is welcomed.


Thank you !!!

henryroten 08-28-2012 08:15 AM

I have a 2011 R and originally went to .64 springs (with a Superplush revalve) and found that they were still to soft in hard braking and hard, rugged terrain. Went to ;70's and fixed the problem. Much better off road and particularly good on the street. The front end stays up and doesn't dive under hard braking.

If you want to try the .64's let me know and I will try to figure out how to get them to you.

offworlder 08-28-2012 08:41 AM

Weigh approx 175lbs. went with .64. Based on your weight, I'd say .64 should be your minimum.
No modifications are required if using the right springs.

Konflict Motorsports 08-28-2012 09:19 AM

The spring guide will need to be trimmed down for most springs of that rate, if you were having springs put in here at my shop I'd put in .68 front springs.

Alex_RO 08-28-2012 03:25 PM

ok...
 
Since .70 seems to be the way to go... what modifications would be required for thicker springs ? Is there a guide somewhere ?

Thank you, Alex

GZERO 08-28-2012 03:32 PM

Be carefull about hearing other peoples ideas on springs, you don't know how much weight his bike has and how much they weight.
I'll say .70 for a heavy bike with a heavy rider, if not i'll go with the .68.

BTW: i never done it, but .70 springs with stock valving seems crazy.

Alex_RO 08-28-2012 03:56 PM

Quote:

Originally Posted by GZERO (Post 19466276)
Be carefull about hearing other peoples ideas on springs, you don't know how much weight his bike has and how much they weight.
I'll say .70 for a heavy bike with a heavy rider, if not i'll go with the .68.

BTW: i never done it, but .70 springs with stock valving seems crazy.


Yeah, doesn't seem particularly healthy to me either. I'm trying to find a solution to that... maybe a shop in Europe that can do the revalving.

In the meantime, might as well try to get as much information as possible from the OC.

Thank you, Alex

mdfehrmann 08-28-2012 09:49 PM

I'm 165lb's with gear, Safari tanks and running se springs .59's I think?
Works great but my suspension is going to super plush over winter for S spec
and valving.

Konflict Motorsports 08-28-2012 11:16 PM

Quote:

Originally Posted by Noto (Post 19466227)
Since .70 seems to be the way to go... what modifications would be required for thicker springs ? Is there a guide somewhere ?

Thank you, Alex

.70 is a very large increase over the stock .48kg springs. With the stock valving it won't be the best ride (not any worse than you are already experiencing). I'd recommend completing a revalve at the time of a spring swap as well, and would be more than happy to share a few stacks if you are capable of doing the work.
The mid stroke is the major issue on these forks and needs to be addressed as well as the rebound valving when swapping to springs of this rate.
Typically depending on the spring manufacture the I'd of the springs is too large therefore the spring guide needs to be trimmed down 1 to 1.5mm so the guide can travel through without any binding.

Konflict Motorsports 08-28-2012 11:28 PM

Quote:

Originally Posted by Noto (Post 19466227)
Since .70 seems to be the way to go... what modifications would be required for thicker springs ? Is there a guide somewhere ?

Thank you, Alex

This black spring guide needs to be trimmed down, just the ridges that guide it trough the spring itself.



http://konflict.smugmug.com/Other/su...mingCone-M.jpg

The midstroke harshness you feel (deflection) is due to the poor valving without enough float if you do not modify the midstroke tap and piston:

http://konflict.smugmug.com/Other/su...eckPlate-M.jpg

These pictures are courtesy of KTMtalk.com located in the suspension form. These are not ADV forks, but very close in design.

Konflict Motorsports 08-28-2012 11:29 PM

[QUOTE=Noto;19462541]Hello,



Rider weight: 250 now but on a diet, aiming for ...let's say 230 (with gear, no luggage).

Intended Usage: fast street and "fire" roads (these pretty much mean the same thing in Romania, you never know where you're gonna find a pothole), veeery little (and slow) offroad.

How much luggage do you carry, and how much weight? Are you using hard bags or a giant loop type system?

Yascher 08-28-2012 11:41 PM

Thats a great thread)))
intresting to see what the end result will be

slackmeyer 08-28-2012 11:50 PM

Quote:

Originally Posted by Konflict Motorsports (Post 19469610)
The midstroke harshness you feel (deflection) is due to the poor valving without enough float if you do not modify the midstroke tap and piston

That's not something I expected to hear. Didn't think that midstroke harshness was a problem on my stock forks, thought they were more likely to blow through the midstroke. Are you referring to adventure forks or SE forks?

I wish I had time to try a bunch of different variations on forks, I think there's a lot of ways to skin this cat.

syzygy9 08-29-2012 03:06 AM

.70s?? really
 
I am struggling to see how an increase form the stock 0.48 to 0.70 is required. I had my own (2011 990 Adv) forks resprung to 0.56 with a revalve to suit - that's an ~17% increase in spring rate and it seems fine for my 85kg 'naked' + gear + load.

On a recent trip across Australia with lots of fast and slow dirt roads (and some really gnarly sections) I am not aware of ever bottoming the forks but did use all of the suspension travel. Front and rear were set to 'max payload'; with no load this setting feels quite stiff.

I am no suspension guru so happy to defer to the experts, but my understanding was that if you are using all of your travel and not bottoming, you're pretty close to the mark. Of course, if all you are doing is riding on smooth roads than compliance may not be your primary concern, rather things like fork dive under braking, and you can get away with much stiffer and less compliant forks.

Alex_RO 08-29-2012 03:57 AM

Quote:

Originally Posted by syzygy9 (Post 19470061)
I am struggling to see how an increase form the stock 0.48 to 0.70 is required. I had my own (2011 990 Adv) forks resprung to 0.56 with a revalve to suit - that's an ~17% increase in spring rate and it seems fine for my 85kg 'naked' + gear + load.

On a recent trip across Australia with lots of fast and slow dirt roads (and some really gnarly sections) I am not aware of ever bottoming the forks but did use all of the suspension travel. Front and rear were set to 'max payload'; with no load this setting feels quite stiff.

I am no suspension guru so happy to defer to the experts, but my understanding was that if you are using all of your travel and not bottoming, you're pretty close to the mark. Of course, if all you are doing is riding on smooth roads than compliance may not be your primary concern, rather things like fork dive under braking, and you can get away with much stiffer and less compliant forks.

Well.. there's no way I'm ever going to be under 200 pounds (hell, i might go back to 280 if i leave the exercise/diet thing) and i do end up on the slab a lot (i still wouldn't call romanian roads smooth). Might as well accept it and prepare for it. Either way, slab or offroad, it's still underspung.

Now, I *might* have a way to send the forks to SPS without paying an obscene amount for shipping but it's not something definite so ... might as well learn as much as possible.


Thank you, Alex


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