June 8th, 2010, 04:08 PM | #1 |
ninjette.org guru
Name: Joel
Location: Orlando, FL
Join Date: Dec 2008 Motorcycle(s): 08 Ninja 250 Posts: 256
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External, fork preload adjusters.
Talking to some 250 racers this weekend at Roebling Road I found out about Slingshot Racing.
They make a set of billet aluminum preload adjusters for the 250 that replace the stock caps. Adjustments range from 5mm to 20mm. I just ordered a set since I am getting ready to do some suspension work on the bike. They look pretty slick. Link: http://www.slingshotracing.net/catal...-ad-p-191.html |
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June 8th, 2010, 04:14 PM | #2 |
ninjette.org sage
Name: J.G.
Location: Austin
Join Date: Oct 2009 Motorcycle(s): '09 zx6r Green/Black, (ex-)Diablo Black '09 Ninja 250r Posts: 959
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I have been eyeing those for a while - look forward to photos and review.
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June 8th, 2010, 05:25 PM | #3 |
self wrencher
Name: john
Location: houston
Join Date: Dec 2008 Motorcycle(s): 08 250r and 07 600r Posts: A lot.
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Nice piece. Looking forward to your review.
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June 8th, 2010, 06:33 PM | #4 |
ninjette.org member
Name: Ed
Location: NJ
Join Date: Dec 2009 Motorcycle(s): 2009 250r Posts: 157
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Nice! Guess now you can do a DIY and give us your impressions!
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June 8th, 2010, 07:06 PM | #5 |
Join Date: Nov 2008 Posts: Too much.
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why would one need preload adjusters?
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June 8th, 2010, 07:31 PM | #6 |
ninjette.org guru
Name: Joel
Location: Orlando, FL
Join Date: Dec 2008 Motorcycle(s): 08 Ninja 250 Posts: 256
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Is that a trick question, Kelly? lol. Want to be able to experiment with the forks at the track. Yes, I could do it by changing spacers, but don't want to take the thing apart every time I want a small change if I can avoid it.
Also if I make a preload adjustment to the shock, this will affect the front, which might need adjusting to compensate for the change at the rear. |
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June 8th, 2010, 08:27 PM | #7 |
Join Date: Nov 2008 Posts: Too much.
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sorry, no trick question. I guess I meant, what problem do you hope the preload adjusters will help combat/fix?
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June 8th, 2010, 08:58 PM | #8 |
self wrencher
Name: john
Location: houston
Join Date: Dec 2008 Motorcycle(s): 08 250r and 07 600r Posts: A lot.
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For me, cuz it's purrrdieee
Posted via Mobile Device |
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June 8th, 2010, 09:02 PM | #9 | |
ninjette.org guru
Name: Joel
Location: Orlando, FL
Join Date: Dec 2008 Motorcycle(s): 08 Ninja 250 Posts: 256
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Quote:
I am interested in learning about suspension setting/adjustments. If there is a way to at least adjust one setting in the forks without having to disassemble anything, I'll take it. |
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June 8th, 2010, 10:19 PM | #10 | |
ninjette.org member
Name: John
Location: Nashua NH
Join Date: May 2010 Motorcycle(s): 2004 Hayabusa, 2008 Ninja 250r Posts: 16
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Quote:
With having 2 bikes with Ohlins forks, im spoiled, for track applications, these adjusters are great! The suspension, here on my girlfriends is very soft, but im going to leave it alone for now. But in the future i will be adding these! All of my bikes have allways had extensive suspension work done to them, as well as having geometry work done by the GMD Computrack shop here locally! There is so much more confidence you can have with your bike with good suspension work! |
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June 9th, 2010, 08:13 AM | #11 |
ninjette.org member
Name: Jerry
Location: Ontario, Canada
Join Date: Jun 2009 Motorcycle(s): 09 EX250 LE Posts: 117
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I just bouht a set of these. Just shipped yesterday. Should have them in a week.
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June 9th, 2010, 09:46 AM | #12 |
ninjette.org certified postwhore
Name: Rick
Location: Alexandria, Louisiana
Join Date: Jan 2009 Motorcycle(s): 05 Blue Ninja 250 Posts: Too much.
MOTY - 2017, MOTM - Jan '19, Oct '16, May '14
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June 9th, 2010, 12:16 PM | #13 |
Join Date: Nov 2008 Posts: Too much.
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June 9th, 2010, 01:13 PM | #14 |
self wrencher
Name: john
Location: houston
Join Date: Dec 2008 Motorcycle(s): 08 250r and 07 600r Posts: A lot.
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June 9th, 2010, 01:27 PM | #15 |
ninjette.org guru
Name: Andrew
Location: Vancouver, BC
Join Date: Jul 2009 Motorcycle(s): 2009 Kawasaki Ninja 250R Posts: 410
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Ok these are a cool idea. I'd like the ability to tune the preload front and rear between track days and days riding distance with loaded panniers and a backpack.
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June 9th, 2010, 01:41 PM | #16 |
Join Date: Nov 2008 Posts: Too much.
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so, does a preload adjuster only allow for adjusting the static fork sag due to differing weights of riders/load or does it actually stiffen up the front end through it's travel, effectively "upping" the front fork springs ability to resist load throughout the entire fork stroke?
ie: will the forks feel stiffer throughout its entire travel? |
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June 9th, 2010, 03:21 PM | #17 | |
ninjette.org guru
Name: Joel
Location: Orlando, FL
Join Date: Dec 2008 Motorcycle(s): 08 Ninja 250 Posts: 256
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Quote:
Sag adjustments are individual for each rider as it depends on rider weight. |
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June 9th, 2010, 03:29 PM | #18 | |
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Quote:
so taking your explanation one step further, when we adjust the preload on our rear shock, why does the bike feel so harsh over bumps if preload does not affect spring rate? |
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June 9th, 2010, 03:36 PM | #19 | |
ninjette.org guru
Name: Joel
Location: Orlando, FL
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Quote:
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June 9th, 2010, 03:38 PM | #20 |
Join Date: Nov 2008 Posts: Too much.
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isn't that upping the spring rate, then?
how does a spring give the "impression" of being stiffer w/o actually being stiffer? |
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June 9th, 2010, 03:55 PM | #21 | |
ninjette.org guru
Name: Joel
Location: Orlando, FL
Join Date: Dec 2008 Motorcycle(s): 08 Ninja 250 Posts: 256
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Quote:
So, we put the 200lbs load back and the spring will only compress 1 inch. The spring however, is still compressed a total of 2 inches and it's still doing the necessary work to hold 200lbs, no more no less. Spring stiffness is determined by the materials used and the manufacturing process. |
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June 9th, 2010, 03:58 PM | #22 | |
FORMER MOTORCYCLE RIDER
Name: Steve
Location: On a Trek SU200 or in my CRX
Join Date: Dec 2008 Motorcycle(s): Rode an 08 250r then rode an 08 ZX-6R until i totaled it on 7/10/10 Posts: 758
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Quote:
If the spring would've fully compressed with say 300 lbs. it still would still regardless of the preload. |
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June 9th, 2010, 04:01 PM | #23 |
Join Date: Nov 2008 Posts: Too much.
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so, with the preloaded spring, the stroke/travel through the fork will feel the same as a spring with no preload?
I guess what I'm after is, will the fork's travel feel the same or feel harder/stiffer? I know you can't change the inherent spring properties, but can you change the "effective" rate by preloading? |
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June 9th, 2010, 04:14 PM | #24 | |
ninjette.org guru
Name: Joel
Location: Orlando, FL
Join Date: Dec 2008 Motorcycle(s): 08 Ninja 250 Posts: 256
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Quote:
That's why it's important that the sag be set correctly to avoid "hitting the stops" of your suspension if you go too far either way with the preload. |
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June 9th, 2010, 04:18 PM | #25 |
Join Date: Nov 2008 Posts: Too much.
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June 9th, 2010, 04:19 PM | #26 |
ninjette.org guru
Name: Joel
Location: Orlando, FL
Join Date: Dec 2008 Motorcycle(s): 08 Ninja 250 Posts: 256
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June 9th, 2010, 04:25 PM | #27 |
Join Date: Nov 2008 Posts: Too much.
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June 9th, 2010, 04:39 PM | #28 | |
ninjette.org guru
Name: Joel
Location: Orlando, FL
Join Date: Dec 2008 Motorcycle(s): 08 Ninja 250 Posts: 256
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Quote:
You were just asking the right questions to keep me rambling Yes, it would benefit them, however changing preload affects ride height. So if you increase it at the front, you'll have to move the forks up on the tripple to maintain the original height and F/R weight balance of the bike. See, there you did it again |
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June 9th, 2010, 04:43 PM | #29 |
ninjette.org guru
Name: Andrew
Location: Vancouver, BC
Join Date: Jul 2009 Motorcycle(s): 2009 Kawasaki Ninja 250R Posts: 410
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Preload on forks / rear shocks like the stock 250R "packs" the spring as described here which makes it stiffer, affecting both determined sag and fork stiffness.
In a perfect world this would allow for correct sag setup and proportional stiffness for fork action and diving characteristics, but isn't a perfect formula but can get close enough for the type of riding I do. |
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June 9th, 2010, 04:53 PM | #30 | |
ninjette.org guru
Name: Joel
Location: Orlando, FL
Join Date: Dec 2008 Motorcycle(s): 08 Ninja 250 Posts: 256
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Quote:
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June 9th, 2010, 04:54 PM | #31 |
Join Date: Nov 2008 Posts: Too much.
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Joel,
Actually, I thought I knew the answers, but in another thread on how to stiffen up the front end, when I mentioned increasing the preload, I was told it wouldn't do a thing and the way to correct for the front end dive would be to replace the springs with the correct rate ones... whatever they might be. Mine was a cheap trick with washers vs $100 for springs. Glad to finally know the forks I preloaded on the dirtbike is actually stiffer than when I started. Couldn't figure out how the front end on that bike got stiffer if preloading didn't stiffen up the feel. Good luck with racing... now that's where a minute difference in suspension setup can mean the difference between being first or doing a soil/tarmac sample. |
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June 9th, 2010, 05:02 PM | #32 |
ninjette.org dude
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Relevant link on Sport Rider's site:
http://www.sportrider.com/tech/146_9510_tech/index.html With pretty graphs!
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June 9th, 2010, 05:08 PM | #33 | |
ninjette.org guru
Name: Joel
Location: Orlando, FL
Join Date: Dec 2008 Motorcycle(s): 08 Ninja 250 Posts: 256
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Quote:
Thanks, I plan on doing my first race in the Sept WERA round at JGP. |
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June 9th, 2010, 05:13 PM | #34 | |
ninjette.org guru
Name: Joel
Location: Orlando, FL
Join Date: Dec 2008 Motorcycle(s): 08 Ninja 250 Posts: 256
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Quote:
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June 20th, 2010, 08:25 PM | #35 |
ninjette.org guru
Name: Dude!!
Location: Southern California
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Anyone install these yet? Just curious as to how easy (or difficult) they are to install...
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