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2Smoke

 
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Mon Apr 05, 2010 11:00 pm » Post: #1 » Download Post

I think I need some more preload, or new springs.


I've seen them racetech things, recon they'll stop this happening? Back end was quite interesting, think I managed to knock someone off with it
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Hermit

 
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Tue Apr 06, 2010 5:27 am » Post: #2 » Download Post

what are we looking at? The rear looks high and the front looks low as though you're braking in the shot. If you're referring to having too little front preload then i'd recommend you first wrap a cable tie around a stanchion tube to see how much travel you're using. If you aren't actually bottoming the fork out then shes probably fine as she is.

Have you measured static and rider loaded sag?

You'd need stiffer fork springs or a smaller air gap in the forks to prevent them from bottoming whilst on the brakes.

I'm currently using all but the last 20mm of travel on my fork when braking hard in the dry and my preload is set to sag under my weight (with riding gear) by about 35mm if i remember right. That figure is recommended in my Ohlins guide thing for 'dry road race'.
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2Smoke

 
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Tue Apr 06, 2010 9:31 am » Post: #3 » Download Post

Thanks, yes its bottoming out completely on the brakes.

I've been a bit lazy (read: short of time) to set up the sag thoroughly, hopefully get it done before the Llandow meeting..

What sort of sag do you reccomend on the rear?

Thanks
Paul
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cgallant
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Tue Apr 06, 2010 12:22 pm » Post: #4 » Download Post

If your bottoming the front on braking, setting sag with your current setup (spring/oil/valving) isn't going to do much for you, as you will still bottom out the front on braking.

Have you gone through the front end to check the fluid, check the spring weight, compared to your body/bike weight? What about valving? Could be reduced to slow the oil movement to keep the bike up while braking.

RaceTech has some good products, as does other companies that provide inserts (Traxxon, Ohlins, etc..)

However, with proper springs/oil you should be able to tune the suspension and not need to go with expensive upgrades.

For sag, you want to measure both static (just the bike under it's own weight) and rider sag (rider/gear). If my memory isn't all the way shot, I useally set my rider sag at around 25-35mm (front and rear). Don't recall what I set my static sag at without digging into my notes.
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2Smoke

 
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Tue Apr 06, 2010 12:43 pm » Post: #5 » Download Post

Thanks Charles, I've had the forks apart and re-oiled them as good as I could, getting the balance between rebound and hydraulic lock right. Felt pretty good but its fairly soft.

I've just bought a pair of racetech springs and I may well get one of their emulator kits although they only list for the mc28, do you know if the '18 and '28 share similar internals?

Paul
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cgallant
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Tue Apr 06, 2010 12:55 pm » Post: #6 » Download Post

The MC18 and MC28 internals are a good bit different in terms of stock internals. Not sure if the emulators will fit in the MC18 (as a good amount of the internal parts are discarded).
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Neal

 
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Tue Apr 06, 2010 5:59 pm » Post: #7 » Download Post

Hi Paul , i sent my forks in for a full service , they used the correct oil and quantity ( is it 120mm from the top ? ) with all the standard parts and the suspension is great . I could feel the difference and was 2 seconds quicker !
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Hermit

 
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Wed Apr 07, 2010 5:56 am » Post: #8 » Download Post

Just a note on spring stiffness - i've got RVF400 forks on my MC21 race bike - standard springs seem about right for my application and considering they are weighted for a 170kg road bike i guess it makes sense that they'd be somewhere close for a 120kg race machine. Apparently they're about the same stiffness as Honda RS250 fork springs. Dunno about valving.

I'm running 30mm sag (with rider) at the rear. That's on an Ohlins shock.
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mike1972

 
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Wed Apr 07, 2010 8:06 am » Post: #9 » Download Post

2Smoke wrote:Thanks Charles, I've had the forks apart and re-oiled them as good as I could, getting the balance between rebound and hydraulic lock right. Felt pretty good but its fairly soft.

I've just bought a pair of racetech springs and I may well get one of their emulator kits although they only list for the mc28, do you know if the '18 and '28 share similar internals?

Paul


here,s the part number for the mc18 emulators FEGV-S4101 , got mine from pdq1 , they share the same part number with other bikes
the emulators are good , just a pain as you have to remove them to adjust them
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2Smoke

 
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Wed Apr 07, 2010 8:27 am » Post: #10 » Download Post

Cheers mike, what did they charge for them?
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mike1972

 
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Wed Apr 07, 2010 9:21 am » Post: #11 » Download Post

there were £102 , 2 years ago
but it says from £145 on the website , seem to have gone up a bit
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mike1972

 
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Wed Apr 07, 2010 9:29 am » Post: #12 » Download Post

$138 here , works out around £90

http://www.powersportsuperstore.com/Race-Tech-GOLD-VALVE-CART-EMULATOR-FEGV-S4101-p/tr77-2132.htm
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2Smoke

 
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Wed Apr 07, 2010 11:00 am » Post: #13 » Download Post

Cool! Think I'll buy a set of them then!

cheers mike Cool
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2Smoke

 
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Wed Apr 07, 2010 1:05 pm » Post: #14 » Download Post

I'm wondering if it'll be possible to setup some sort of adjusters in the fork tops that could be connected to the emulator. I think one of the nc30's came with rebound damping adjustment for the front so maybe using the caps and rods off one of those might work.

Be interesting to see if anyone else has done it?
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cgallant
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Wed Apr 07, 2010 1:39 pm » Post: #15 » Download Post

I know Ohlins makes inserts that include new caps/bolts with rebound adjusters built in... not sure if there is anythign for the NSR forks?
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