Front Forks

[The Stranger]

Ok as you may be aware I have just purchased a YZF750.

Now this thing needs a little work, the main thing being the front forks. if you hold the front brake and give it a shove down it bounced 5 or 6 times before coming to rest.

So I am thinking I need to replace the front dampers and after the result with the X11, the front springs too. Not after anything fancy for the dampers as it is an old bike.

Does anyone know where abouts I can get the existing dampers rebuilt or some reasonably priced replacement ones please?

[bugjuice]

could it be a possibility to change the oil to a heavier weight before splashing out on new dampers/spring? Just a thought.

Else I use Spectrum for everything (top blokes), but they're more Kawa based.. They have done Suzuki shocks for me before tho, so they're up for anything

[SimJen]

Of all the forks I've done, they only ever needed a cleanout and new oil/seals.
Easy job just a pain to get the front end out. Last time I roped it to the ceiling of the shed. :)

[R6_kid]

I could take it in to Cycletreads and have a chat to Budgie (the big guy) - rumour has it he's a bit of a suspension pro :yes:

[The Stranger]

No would rather go strait to a rebuild thanks, I expected to spend about a $1,000.00 to bring it up to scratch and I want the front end good.

Want to use it for track days etc too

Got to look at the brakes and a few other things also. It has 6 pot calipers on the front and I would expect it to stop on a dime, but nooo.

Do you have a contact for Spectrum please?

[R6_kid]

Spectrum Motorcycles - 09 489 5355

[SimJen]

Yeah calipers always gunk up, get a nice ring of shit around the piston and cause them to stick nicely.
A sealkit, new fluid and a toothbrush makes quick work and gets them back in good working order.

[bugjuice]

calipers are easy to clean up, done a few and got them working sweet. Isn't hard to do, so just go for it (or can help if you need). I just don't do forks yet, cos there's things in there that I don't know where they live, and I don't want to fork them up

[The Stranger]

Hey thank you guys, much appreciated.

Ok, just spoke to Spectrum and he say prob just fork oil. So it looks like I better bloody listen to you in future aye Buggy.

Off to Henderson Motorcycles now to see what a seal kit for the calipers and forks are worth.

[bugjuice]

lol.. what can I say?

shop around for the caliper kits too, some places can double the price of bits of rubber bands.. and check the condition of the brake lines too. If they're looking a bit tired, they'll flex when you squeeze the lever, which will make the brakes feel spongy. Ask about a master cylinder kit cost too, just for piece of mind. If the rubber in there is old too, then that can also cause a bit of loss of feel too. If you want good brakes, it's best to just redo the lot..

[Mental Trousers]

Got to look at the brakes and a few other things also. It has 6 pot calipers on the front and I would expect it to stop on a dime, but nooo.

Thought they only put those on the SP. Oh well. They do stop bloody well, but I'd highly recommend changing the fork springs cos the standard ones bottom out if you brake really hard, even with plenty of preload.

[R1madness]

Give Ray Clee a call at Ray Clee Motorcycle Performance in Keumu(sorry about the spelling). He will sort out the front end. Go for WP fork springs and a reoil. New bushes would help reduce binding and stiction along with new seals. If you were planning to do it anyway and had the money it would be a great investment.
But like you say just a flush/reoil will help heaps.

[The Stranger]

Ok, takena few days due to time constraints, but I now have the forks apart.

The oils was black and thin as water.

One thing I hadn't expected was the amount of crap in suspension in the oil and the sludge that had collected in the bottom of the slider.

On the positive side the bushes all appear sound and the springs are well within limit, so they will go back together soon with new seals being about all I will replace.

One issue though. There is rust and pitting starting on the slider just below max travel. I suspect this is futile, but is there any way to hold this in check?

[CLEAN CUT]

Ok as you may be aware I have just purchased a YZF750.

Now this thing needs a little work, the main thing being the front forks. if you hold the front brake and give it a shove down it bounced 5 or 6 times before coming to rest.

So I am thinking I need to replace the front dampers and after the result with the X11, the front springs too. Not after anything fancy for the dampers as it is an old bike.

Does anyone know where abouts I can get the existing dampers rebuilt or some reasonably priced replacement ones please?

Reasonably priced means they will be there for decoration rather than proper damping, roadholding, your safety and everyone elses. Doesnt matter whether its a cheap bike or an expensive one, it will still benefit the same from quality ( not cheap ) suspension. Forget about trying to get your standard shock rebuilt, the body is not hard anodised and it will be worn like crazy inside. This bike is currently capable of killing you and other road users.....

[FROSTY]

Dude--sorry ive been busy with my own shite.
Ive got the manual here for ya to borrow.
Starting with the brakes -push each piston completely out -one at a time and give em a really good clean up.in my opinion the best way is using a brass wire wheel in a bench grinder. -The brass is softer than the chrome but harder than the craop stuck on the pistons.Give the seal a huck out with your finger and apply a smear of rubberlube.do this to all 12 pistons then bleed the crappy fluid out and replace it with good clean stuff.Bleed em up of course.
The reccomended fork oil is 10 weight and 464ml-471ml -measured from top of fork tube to oil level with spring removed and spring removed--
Id use 15w and 460ml but thats my gut feeling only.
Fork tube cleanup is possible.
I use 2000 grit wet and dry paper -wet to clean up the rust -if a pit is left you can fill it with 2 pot epoxy and linish it smooth.Never perfect but its actually the sharp edges that rip the fork seals out more than the pits.
Rear shock wise-it does sound like the daming is a gonzod--Tyebbe bruin may be able to reoil it for you --given ya aint proddy racing he can fit a bleed nipple in the side to change the oil
Dude that bike is a bllody bonzer--I tregret selling mine almost every day

[Brian d marge]

Reasonably priced means they will be there for decoration rather than proper damping, roadholding, your safety and everyone elses. Doesnt matter whether its a cheap bike or an expensive one, it will still benefit the same from quality ( not cheap ) suspension. Forget about trying to get your standard shock rebuilt, the body is not hard anodised and it will be worn like crazy inside. This bike is currently capable of killing you and other road users.....

I have my MX rear shock infront of me , Piston measures 44.02mm internal diam of shock body 44.03 ( no signs of wear , one smaal scratch mark , but not enoughto worry about
At working temp of say 100 deg ( bit hot ) I make it an expansion of 44.10 for the piston and as the body is exposed to some sort of coolant it will run ever so slightly cooler it the clearance will if anything close up a bit
That shock is from a 92 cr ,,,and is well abused

The piston is a 6060 or higher as is it dark black the body is a sand cast LM3 or some such ( thats a guess base on other stuff I have had tested )

Stock isnt always bad, it just needs abit of help sometimes !

Stephen

I have just thought , higher silicone alloys would be less suitable to hard anodize.