front end chatter...

[joseg1981]

im feeling a shatter when i start going hard on the gas on mid turn and leaning over.. any sugestions.
i havent set up my sack and suspension wise i have racetech emulator,.75 spring from sonic and 15 w fork oil idk the brand and set to 170 mm. my weitgh 170 with gear on, sometimes i was getting away with just giving it more gas.. need some help on this

[alex.s]

set your sags.

[csmith12]

Chatter aye.... front set to hard? That would be a first on a 250 lol. How is your front setup currently?

[joseg1981]

.75 springs
15w fork oil at 170 mm
racetech emulators and no i dint drill the rod

ummm to hard? idk!!! i put a zip tide on the fork and it looks like i have a good travel on them so idk

[mgentz]

Originally Posted by joseg1981

.75 springs
15w fork oil at 170 mm
racetech emulators and no i dint drill the rod

ummm to hard? idk!!! i put a zip tide on the fork and it looks like i have a good travel on them so idk

If you did not drill the rods at all you have about twice the compression damping. Do the install as instructed or remove the emulators.

[alex.s]

not drilling the old oil holes means that the emulators are literally doing almost nothing.

[mgentz]

I verified with racetech and I was correct. You are getting damping from both the rod holes and the emulator.

[Rexbo]

Moar throttle

[psych0hans]

I have front end chatter too, but I think it's because I'm using a fork oil that's too heavy and my oil level is set too high. Need to change those things asap... and @joseg1981 when race tech designed their emulators, I think they might have known what they were doing. So if they ask you to drill the dampening rod, drill the d**n dampening rod... lol Same goes for me, if they ask you to set oil lvl at 140 and use 15w oil, don't set it at 120 and use 20w oil...

[joseg1981]

So phyco what's your current set up on the front end? And what are you planning to change?
Rexbox i did try more gas but after a certain point the shatter came back lol

[psych0hans]

Originally Posted by joseg1981

So phyco what's your current set up on the front end? And what are you planning to change?
Rexbox i did try more gas but after a certain point the shatter came back lol

I did the install as per race tech instructions. Drilled the 6 holes in the rod, put in the valve with the blue spring and 4 turns in. The only thing I did wrong was to set the oil level at 120mm instead of 140mm and used 20w fork oil instead of 10w. The changes I will make are 140mm oil height and 15w oil. Problem is 15w oil is not available in India.

[sierrahotel]

So mix 10W and 20W together.

[psych0hans]

Originally Posted by sierrahotel

So mix 10W and 20W together.

Is it ok to mix two different brands of oils? as no company gives 10w and 20w both. I know Motul sells 20w here, but not 10w. I was planning on using hydraulic oil.

[mgentz]

It is ok to mix oil. That's how I get my 12.5 wt oil.

[alex.s]

Originally Posted by psych0hans

Is it ok to mix two different brands of oils? as no company gives 10w and 20w both. I know Motul sells 20w here, but not 10w. I was planning on using hydraulic oil.

as long as its not a mix of penzoil and motul. motul doesn't like penz so they designed their oil to work like a catalyst to the penzoil. putting both in the same fork will literally explode your bike killing everyone around you.


you could always use 10 in the left fork and 20 in the right fork

[Lychee]

Originally Posted by alex.s

as long as its not a mix of penzoil and motul. motul doesn't like penz so they designed their oil to work like a catalyst to the penzoil. putting both in the same fork will literally explode your bike killing everyone around you.


you could always use 10 in the left fork and 20 in the right fork

genius.

Also check to make sure:
-your steering nut is tight
-all chassis bolts are tight (especially engine bolts)
-your forks are not twisted (undo and redo the upper and lower triple bolts)
-your wheel is properly balanced.

[sierrahotel]

Originally Posted by alex.s

you could always use 10 in the left fork and 20 in the right fork

Erm, without someone with lots of experience on a shock dyno weighing in, I would not do that. Lots on nonlinear effects on damping so that just doing a linear combination may not work out so well.

[alex.s]

Originally Posted by sierrahotel

Erm, without someone with lots of experience on a shock dyno weighing in, I would not do that. Lots on nonlinear effects on damping so that just doing a linear combination may not work out so well.

unless you are talking about the highspeed valve on the emulator.... but the part about penzoil and motul exploding was spot on though.

[smokinsingle]

What tire and pressures?

[csmith12]

Originally Posted by smokinsingle

What tire and pressures?

Yea, I would start there. It's cheaper....

[psych0hans]

I believe I was on stock tires with 28psi front and 30psi rear, but it's only on really bumpy roads.

[HotRedTurbo]

Wassup gents...Jose and I worked on our bikes at the same time. I drilled the left side damper rod and am in the process of removing my right fork. I will be racing PBIR next weekend so hopefully this cures the chatter. Wish me luck.

[cynicalkit]

Originally Posted by alex.s

you could always use 10 in the left fork and 20 in the right fork

That's a terrible idea. Not to be rude but please be careful giving people ideas. Given your record of tinkering and not very positive results.

[cuong-nutz]

Originally Posted by cynicalkit

That's a terrible idea. Not to be rude but please be careful giving people ideas. Given your record of tinkering and not very positive results.

I think the newbs would not be able to distinguish what of his post is true or not

[HotRedTurbo]

Originally Posted by cuong-nutz

I think the newbs would not be able to distinguish what of his post is true or not

G-damn it Alex!!! Now I have to drain my forks again!

[psych0hans]

Originally Posted by cynicalkit

That's a terrible idea. Not to be rude but please be careful giving people ideas. Given your record of tinkering and not very positive results.

[psych0hans]

I ordered 15w fork oil off amazon prime, coz my friend was coming down from the states. Guess my fantastic luck... They sent me 5w oil... They were nice enough to give me a refund AND let me keep the oil, but It's not what I needed... Ahh well, 21% 5w and 79% 20w will give me what I need...

[cuong-nutz]

Dont mean to thread jack, but which spring rate should I go with? 170 lb without gear. 185-187 with gear. 75 or 80 kg/mm? kind of conflicting rates between Race-tech and Sonic Springs calculators.

[psych0hans]

Originally Posted by cuong-nutz

Dont mean to thread jack, but which spring rate should I go with? 170 lb without gear. 185-187 with gear. 75 or 80 kg/mm? kind of conflicting rates between Race-tech and Sonic Springs calculators.

Yeah, I had the same issue. .75 and .70 between Sonic and race tech respectively. I landed up with .70, but I hear race tech spring rates are generally on the softer side. If you want a stiffer ride, take .80 and if you want something softer take .75...

[HotRedTurbo]

IMO, the softer option might be a wiser choice. If you want a stiffer feel, you can always add preloaders. What would you do if you went with the stiffer option and found that you need to reduce stiffness a tad? You probably can't...try calling them. I've spoken to both and they seem helpful on the phone.

[cuong-nutz]

Originally Posted by HotRedTurbo

IMO, the softer option might be a wiser choice. If you want a stiffer feel, you can always add preloaders. What would you do if you went with the stiffer option and found that you need to reduce stiffness a tad? You probably can't...try calling them. I've spoken to both and they seem helpful on the phone.

Preload has nothing to do with spring rate, though. All preload does is affect your sag so finding the correct spring rate is important first.

[KazMan]

Originally Posted by HotRedTurbo

IMO, the softer option might be a wiser choice. If you want a stiffer feel, you can always add preloaders. What would you do if you went with the stiffer option and found that you need to reduce stiffness a tad? You probably can't...try calling them. I've spoken to both and they seem helpful on the phone.

You could try a different size spacer, or are you not running one? Get some PVC and cut different lengths and you can go softer/stiffer a bit. And this can help dial in sag.

[HotRedTurbo]

Originally Posted by cuong-nutz

Preload has nothing to do with spring rate, though. All preload does is affect your sag so finding the correct spring rate is important first.

Oh, I'm still trying to absorb all the suspension setup information I've read. I think I finally understand more. For some reason, I was only thinking in terms of "stiffness". Now I understand...preload (compressing the springs thus changing sag/initial position of suspension) is different from spring rate (rate the spring compresses). So will adding more preload give you a stiffer feel up front? I know spring rate does of course.

I haven't made any adjustments on my preload since I wanted to take it one step at a time in trouble-shooting the chatter issue.

[HotRedTurbo]

Originally Posted by KazMan

You could try a different size spacer, or are you not running one? Get some PVC and cut different lengths and you can go softer/stiffer a bit. And this can help dial in sag.

I got the Sling Shot Racing preloaders.

[iZapp]

ok, this is a bit eye opening... we're running bone stock front end. are there things that should be tweaked? i'm just the sponsor/mechanic/tuner and have the disadvantage of not being the actual rider - my son is, and the rider feedback is limited. like, "so how'd it feel out there?" answer: "good". yah thanks...

[cuong-nutz]

Originally Posted by HotRedTurbo

Oh, I'm still trying to absorb all the suspension setup information I've read. I think I finally understand more. For some reason, I was only thinking in terms of "stiffness". Now I understand...preload (compressing the springs thus changing sag/initial position of suspension) is different from spring rate (rate the spring compresses). So will adding more preload give you a stiffer feel up front? I know spring rate does of course.

I haven't made any adjustments on my preload since I wanted to take it one step at a time in trouble-shooting the chatter issue.

Say you have a 100 lb/in spring. That means it takes 100 lb to compress the spring one inch. So 200 lbs will compress the spring 2 inches. If you add one inch of preload, 100 lbs will not compress the spring so the fork will not move because the spring has already compressed. The next 100 lb will compress the spring down one inch.

[HotRedTurbo]

Originally Posted by cuong-nutz

Say you have a 100 lb/in spring. That means it takes 100 lb to compress the spring one inch. So 200 lbs will compress the spring 2 inches. If you add one inch of preload, 100 lbs will not compress the spring so the fork will not move because the spring has already compressed. The next 100 lb will compress the spring down one inch.

Ahhhhhh, I see. That's easier to understand.

[Rexbo]

Originally Posted by cynicalkit

That's a terrible idea. Not to be rude but please be careful giving people ideas. Given your record of tinkering and not very positive results.

REAL. TALK.

[alex.s]

its easy to call something a bad idea. its harder to explain accurately why its a bad idea. theres nothing wrong with mixing oil weights. 50/50 10/20 makes 15.

[KazMan]

Originally Posted by HotRedTurbo

I got the Sling Shot Racing preloaders.

In the stock forks there is a metal spacer (& washer) that sit under the cap. They should have been re-intalled unless uour pre-load caps had spacers. You can fine tune you front end, in particular, your pre-load adjustment by changing different spacers lengths.