Hawk - Rear Shock
 

Does anyone know of a heavy duty replacement shock with preload adjustment? The stock one is pretty weak

the RX3 shock is being used on the TT250 i believe.

measure the length eye to eye/fork...
then head for e-bay.....



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Please do reply back with your measurements and findings.

Stock NXR Bros (& copies) = up Ø10 low Ø10
http://img.alicdn.com/imgextra/i3/22...2260914611.jpg

Once you find one with the correct length, mount style & size, and travel you'll have to figure out spring and damping rates. If the stock shock can be drained and filled you could just play with oil weight.

Change spring :wtf:
http://www.motorfans.com.cn/forum.ph...d=75082&page=1

I assumed he's after stiffer damping since he's asking about a heavy duty shock, he also mentions preload adjustment so maybe he's after a stiffer spring...or maybe both...or maybe he doesn't know what he needs to achieve the feel he's after.

That's neat. It would be even better if I could read it.

Yes, I'm looking for a stiffer spring. Any weight and this thing bottoms out

This is the first I've seen posted about the spring being too soft; unless it's a common problem, or you're heavier than the average rider, maybe you just got a defective one and a stock replacement could fix it. The one human being posted has an adjuster, if yours is the same size you could get one of those. Adjusting isn't the right way to fix a spring being too soft, but it at least it can keep you from bottoming out.

I changed out the f/r springs in my main KLR and it made a 'huge' difference (I am heavy) but having some additional dampening wouldn't hurt also. that can be done by rebuiding the shock and using different valving and oil but it's a looong way from easy for the typical rider and probably a waste of money. you should be able to find an inexpensive replacement from another hawk like chinese supplier. I've seen em in the orient carrying a family of four on their bikes, someone HAS to be making what you want. hell the rear on my 200 Zong is so stiff it jars my teeth:)

Maybe similar syrnome as http://www.chinariders.net/showpost....5&postcount=90 (No oil ...bad seal) btw. Beta Alp 200 copy (Loncin, Kinlon...) = http://www.cnabsorber.cn/products_de...uctId=137.html | Honda KRH (NXR bros "KRE" is quite similar)http://www.cnabsorber.cn/products_de...uctId=396.html

I might have found a shock that could work, but I can't figure out how to get the Chuannan Shock Absorber site to tell me the weight of the spring, the eye-to-eye length of the shock, or the size of the mounting holes. The shock number is XY 211.

Im looking to lower the rear suspension by one inch, i just hate the way it keeps you up againt the tank, too high in the rear, and i cant slide back when i need to shift my weight to the rear.

i think it looks stupid soo high in the rear anyway,.

I will likely add a second shock mount lower on the swing arm.. also closer to the fulcrum so likely to make the suspension softer by increasing the leverage on the shock. ill need an adjustable shock..

has anyone identified a good or great replacement?

or the stats on the stock shock to help with shopping for one.

I'm looking forward to that!

I hadnt thought of how to install the bolt with the mount in the ideal position its right between the rails of the swing arm,,

using a steel plate i tested the leverage change that occurs when moving the fulcrum either forward or backward.

with the fulcrum 1 inch forward seat hieght is up about 2" the shock is way too soft, bottoms right out on a light bounce, and i only weigh 165.

with the fulcrum moved back 1 inch, shock is in the way of the tire.. so most of the chain adjustment is gone , but the shock is stiffer and about 2.5 inches lower..

if you look at pictures of a honda nxr 150 thats about the spot is sits now and i like it..


what i discovered while looking this all over is the hawk has a common issue where the chain gets tighter as the suspension compresses. so if you run your chain too tight it will likely streach.

i suspect a snaller rear sprocket will lessen. the effect. now im looking at a 45 rear, and going back to 15 fromt to see if that helps.

more later,

All bikes do that... why yer have a lose chain..
as the suspension travels the chain gets tighter then
when the engine sprocket/swing arm pivot/ rear axle
come in to alinement that is the tightest point , then as it travels
passed that point the chain starts getting lose again..
there should be a rollor on the frame above the swing arm pivot
that takes up the slack chain under full suspension compression..

there are so meany shocks out there that are suitable but the
big issue for a china bike is they cost half or more than the prise of the bike..
So to make it afordable yer stuck with nasty chinese ones..

It may be best to look for a used named brand one if yer want a shock
that works....


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not this much they dont. i have owned hundreds of bikes.

The hawk goes from sloppy to tight in 2 inches of travel.. its a geometry flaw..
fulcrUm of the swing arm is a bit to high.

I know a few things about it. i drive a classic car with a custom one off tube frame chassis designed and built by me.

I understand all concepts of suspension geometry.

so while your right the chain should be adjusted for the longest point in travel, the chain should not fall off at rest..

I Have built a chain tensioner to take up the slack at rest. but the amount of change is still too much i didnt notice it untill i had the shock off and moved the arm through its path a few times.

this is why peoples chains fall off. and why it seems to streach soo much, i really thought the 420 was too weak but in this case a 520 would do the same.

Ive had bikes with no chain stay of any kind that never tossed a chain. and the tension change hardy perceivable.

My Lifan 200 had the same problem where chain had to have about 3.5" of slack while on the stand so it wouldn't be too tight at the tightest point in suspension movement. My solution was to move the swing arm pivot bolt down about 3/4" which required some welding and grinding on the frame. Works like it should now.

Odd that whoever designed the frame didn't realise that the swing arm pivot should be as close to the countershaft sprocket as possible, and in the same plane. That geometry was figured out about 75 years ago, and is in the text books of the time. And maybe even longer ago than that, come to think of it - the 1918 Indian Chief had swing arm suspension, and I've never heard of them throwing chains.

In todays mixmatch world the frame may well have been concieved with a different engine in mind. on the way to production, some substitutions can be made with cost or availability in mind.

The engineers may not have had the forsight to see the problem they introduce. this is a common problem in manufacturing.

or they just messed up. sounds like that Lifan had it even worse.

solved my problem by making a set of adapters that move the shock mountpoint 3/4" forward and 1/2 inch lower. by bolting them instead of welding, I can install the shock bolt then swimg it downward and clamp it with the bolts.

the result is the bike is about an inch lower at rest. and about 2" lower with me on it, im 5' 10" tall and can easily touch both feet standing still.

the change of the fulcrum has the suspension a bit softer and it really feels great. I cant make it bottom out with my 165 pounds of rider.

the bike feels better and the forks dont seem too short anymore, my first impression of the hawk was forks are too short, later I realized the rear is just too high..

here are some pics of the modification, i also added a grease zerk to the swing arm for the bushings and shaft.

this pic is the peices cut from the front of the existing shock mount.

this is the adapters I fabricated.

the chain tensioner I Fabricated.

another angle of the suspension work.

from underneath

I am happy with this and it cost me nothing but my time, and some electricity.

one more

sounds just like a pitbike... swing arm pivot way to high
On my boys pit bike I had to put a nylon disc each side of
the rear sprocket to guide the chain on & stop it jumping the sprocket & run the chain
all but tight when the suspension was un loaded to keep the slack chain under full compression
to a minimin..

What stops the 2 plates you made from pivoting on
the old shock mounts on the swing arm...?
Is it relieing on the plates sitting against the swing arm.
it looks as if what was a compression loading on the shock
brackets is now a tentsion loading by the way of the plates acting as a lever...
Or is there something ealse that is unseen in the pictures..

Hundreds.. thats a lot of bikes...
I'm still new to bikes then in would seem..., only had 36..




...

its locked in place by the two bolts and the pressure they apply, if itbdoes mobe Illl tack weld it in place, just bave to grind that off to take it apart then, so I really didnt want to weld it..

yeah im 54 and have been riding since i was 9. sold my last motocross bike about 5 years ago, bought the hawk to force me yo be more mellow on the trail. I also like the exhaust note, can't stand a screaming 2 stroke these days, its like an ice pick in your ear.

motorcycles gave me my start in mechanic's. These days there isnt much Ill leave alone.

wouldn't like to see it fold up on yer...

I'm 57... still ride enduros.... old dirt riders don't give up we just get slower..
but I now ride the clubmans class & the odd B grade ..
use to have national A grade ranking.." seems a life time ago now"
got my first bike for my 7th birthday.... now been riding for 50 years...
I'm a tool maker...

This is what I'm playing around with at the moment...
http://www.chinariders.net/showthread.php?t=16036




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thats a great project! ill be following the progress. its been 3 or 4 years since ive done a big project.

Pete, yes the plates rest on the swing arm, so the only movement possible is upward. all the bike weight rests on the swing arm.

if airborne the weight of the arm and wheel would be applied to that clamping point, I think it will hold it but I will keep a close eye on it.

how dose it handle now seems like the back is higher than the front

not at all. actually its 1 inch lower than stock. I couldnt touch both feet at a red light. now I can easily. the bike is a bunch better and I can go over the curb in front of my house without even feeling it. so the ride is much softer.

I havent had it to my local dirt track to see if it bottoms on a jump. It seems like it wont, I only weight 163 so this wont work so well for a big guy.

my first impression of the hawk was its got too small of front forks. but really its more that its too high in the rear, and only compressed about half an inch when I sat on it..

now its softer and compresses about 3 inches when I sit down.

I used to get my motocross suspensions dialed in for my weight range. That is the feel I Wanted to achive with the hawk and its close.

so if your light like me this is a good mod, and totally removeable.

Jimwildman,tried your set up and ended up with a 3/4 rise,I'm not joking.

how is it with your weight on it?

I took it off road yesterday and 8m thinking its a bit soft.

I cut away a bit of the old mount so that it can get more angle, as well as to shape the part to,allow more angle before touching the swing arm.
so my mount is 3/4" forward but 1/2 imch lower.

again the amount of change in leverage is a bit extreme.

i might make a change at the top of the mount to try a bit less leverage.

tonight in an effort to reduce the effect of leverage i did basically the same thing at the top of the shock, the part required alot more shaping and I plan to weld this one, bolt is good for testing but alot of weight goes against the tank mount, so welding it to the old mount will solve that.

im almost flatfooted siting on the bike now. and its about half as soft. so better.
its probly as good as its gonna get with this shock.

even after welding this my old top mount will still be usable, there will just be a second placement for it.

I'm looking forward to pics of that, Jim.