KDXRIDER.NET

Say, I recently changed the stock springs on my conventional forks to better suit my overweight rearend. I weigh 190 lbs and I followed the Fredette recommendations and put in his .40kg/mm springs using the stock spacer. I finally got to ride this past weekend and I was able to turn up the wick just a bit and the front end felt just great. Very, very happy with the outcome there! However, I now am noticing that the rear end wants to dance around more than I ever noticed before. Any thoughts here? Am I just imagining this? Could the "incorrect" springs up front been masking a problem on the back end? For what it's worth, I've had the bike nearly two years and I've put about 2700 miles on it without touching the rear shock . . . am I simply due for a shock service? Btw, I serviced it tonight and I checked to see if the bearings were tight on the back end; They were!

Chances are...1. It needs rebuilt and B. You need a 5.2 spring on there...

Hey, Doc - just finished a "rebuild" on my rear shock this evening and getting the N2 tomorrow evening. I didn't notice the rear end of things either until the front end was improved. Turns out that I had only a few pounds of gas, the seal was leaking, and the oil was very dark and turbid . . .

the rebuild's not bad at all (at least not with some help from a few here), $25 for seal / wiper / bushing. Another "even JEB can do it so you can too" case study.

I'm looking forward to the improvement just from having the shock performing like it should!

Not to discount the aforementioned advice relative to having your shock serviced (its past due) but if your rear is dancing around too much back off the compression adjuster 3 or 4 clicks than readjust your rebound clicker. Could be too fast or too slow: your description isn't very - well descriptive.

IdahoCharley: Thanks, you made me laugh this morning!! So, you were looking for a more specific dance? . . . twist, square, etc!! :-) Seriously, what sort of description would prove useful here for myself and others in the future? (Consider me a novice in your reply - I won't be insulted!)

There seemed to be a larger than normal bounce over the rough stuff at speed (fast on eastern KY trails might be 30 to 40 mph) on this past ride (and I'm clueless as to whether I'm just now noticing this or if the rear-end woes have been made noticeable with a better front end set-up?!!?). The rear seemed to "loft" more and actually to even dance or whip a bit.

I have already been looking for shock parts to rebuild the critter. Point made on that front!!

There are numerous 'how tos' on the web for suspension tuning. Basically, they amount to this: Ride over some bumps..what happens? Fix it.

A bit of pondering will lead you to what happens with different 'errors' in suspension settings. Say...

As the shock compresses encountering a bump, does it knock your (whatever weight) rearend off the seat? Compression too stiff.

As the shock DEcompresses after the bump..does THAT boing your (ww) rearend off the seat? Rebound too fast.

Do successive bumps get progressively more jarring on that (ww) rearend? Rebound too slow (shock cannot recover from the last compression, the one before that, and the one before that..).


Before you do ANYthing in regard to clicker settings, set the static/race sag on the shock. Suspension changes with those basic settings incorrect is a waste of time.

Start HERE! for basic clicker info.

Sag? You are or are not familiar with that issue?

Cheers!

Again... all the fixing in the world ain't going to help much on a worn out shock.
Do yourself a favor and service it first... this way you are starting with a clean slate.

Indawoods wrote:Again... all the fixing in the world ain't going to help much on a worn out shock.
Do yourself a favor and service it first... this way you are starting with a clean slate.

Sorry...I assumed...

Not that it needs repeating...but to repeat...DO start with something that works in the first place.

Shocks should be serviced annually...bi-annually at the very least.

It's all part of the black hole for $$ that is a dirtbike.

I'll chase down the standard replacement parts and refresh the shock. I happened to be at the dealership this afternoon and they do not recharge the beasts. They gave me the name of just one place within 50 miles that does do it. That seemed odd to me but . . . (Btw, $22 for an OEM headlight bulb - I don't think so!! They later sold me a package of two aftermarket bulbs at a slighter lower output for $4!) What's a reasonable price to recharge the gas if I'm able to do the rest of the shock work?

The sag had been set and the clickers are whatever Fredette suggests on his www site (old and forgetful - I don't recall the specific settings offhand!). I'll start fresh and pay a bit more attention to exactly what feels funny, if anything, after the shock rebuild.

Thanks for all the input . . . as always, this place a wealth of information!

canyncarvr: These toys of ours are indeed black holes for the green stuff . . . but then I try to tell myself that it *is* only money!! :-)

It is indeed only money!

But...given the choice, I'd use yours instead of mine!

The OEM bulb is an 'uncommon' (not available everywhere) wattage..and they get a premium for it.

BTW...the OEM bulb has two filaments..and you use one. If the filament is the problem, tag a bit of wire between the bulb nubbins..and use the 'new' one for awhile!

Shock recharge: It's not uncommon for a shop to not charge a shock they didn't put together. About the time some shade-tree mech's shock blows up in their face 'cuz it wasn't put together correctly is about the time you would agree such a stance is reasonable.

$20 is ballpark. If you pay less...good deal!

You could just buy a regulator and nitrogen bottle! You could pay for it within a couple years 'cuz all your buddies would be bringing you beer and pizza to charge THEIR shocks!

Of course...there's that 'blow up' problem.........

Re: 'The sag had been set.'

Had? I take that to mean you have not? If it's not set for you, it's not set. Same applies to clickers.

As long as you're taking the spring off, might as well resolve that.

BTW...loosen the locking ring with a drift (cheap screwdriver will do), spray the spring seat/shock threads with something suitable (soapy water, WD 'fer example) and 'uscrew' the spring with your hands. Reinstall the same way.

You will likely save some time if you take the pipe off....

It's a good time to service the Unitrak linkage and the swingarm!

More money down the hole................

canyncarvr wrote:
. . . You will likely save some time if you take the pipe off . . .

I got away with loosening the SA and the two pipe mounts and shifted everything just enough . . . maybe save even more time!

My pipe has been tweaked so many times, it sealing with the o-rings is not going to happen. RTV is required to deal the headpipe to the cylinder.

I wouldn't suppose that is TOO rare....so any movement of the pipe after the RTV cures means it has to come off anyways........

To each his own!

canyncarvr wrote:My pipe has been tweaked so many times, it sealing with the o-rings is not going to happen. RTV is required to deal the headpipe to the cylinder.

I wouldn't suppose that is TOO rare....so any movement of the pipe after the RTV cures means it has to come off anyways........

To each his own!

That's a great point, Mr. Carvyr . . . won't hurt to apply a fresh sealing any ol' way . . .

I can't remember the last time I fiddled with the bike and didn't end up fiddlin' with something else!

Please...this is not the forum for jokes pertaining to the wife........

Hey Kirk. Ever tryed like Tire Discounters? The advertise nitrogen inflation for tires????????? Maybee........

The manual calls for 142 lbs of nitro for the shock. It would be nice if the tire shop could do that. I did run into one shop that would not recharge my shock after I rebuilt it, but I really wouldn't trust them to do it anyway. Another shop did it for $20. I told them I had already checked it with air at 10 lbs , waited a half hour to see if it leaked , then up to 80 lbs.

After doing this rebuild, I'm certain that my shock has been bad for a good long time. Probably since I put my KX forks on, since I remember being pretty happy with them , and noting how now the rear sucked worser.

I figure to be doing the rebuild more often now, and I probably will just buy the complete seal head from RaceTech. Looks like they charge $39 for the whole thing assembled , versus me screwing around for an hour and a half to save $10 over the cost of the replaceable soft parts.

Colorado Mike wrote: . . . I figure to be doing the rebuild more often now . . .

Same here; it's so simple, a caveman can do it . . .

Say, could I trouble one of you to check out the www page

http://www.mx-tech.com/?id=bike_informa ... ght_type=1

and tell me which of the parts listed at the bottom would be considered standard replacement parts for a shock rebuild?

I read on an old thread here that someone indicated that they were just going to start buying seal heads rather than separate parts to make life easier on themselves . . . if that route is taken, then what would one additionally need to complete the rebuild?

Jeb: What did you end up paying for your nitro recharge in L'ville?

Btw, the article

http://www.mx-tech.com/?id=articles_news&news_id=81

suggested by canyncarvr above is a wealth of information!!

Well, of course it depends on how bad your shock got before the rebuild. Now if I was rebuilding the seal head again (which I probably wouldn't), I would buy the following:

"O" Ring: 2.0mm x 38mm o-ring 90 buna HMOR203890 $1.99
Oil Seal: KYB 14mm Oil Seal SKOS14 $16.00
Dust Seal: KYB 14mm Dust Seal SKDS14 $14.00
Shaft Bushing (DU): Shaft Bush 1415 SMSB1415 $9.99

But looking at those prices and my own time in getting all of that stuff out of the seal head, I would buy this:

Seal Head: MXT KYB Sealhead 44x14 SKSH4414 $49.99

But I would get it from RaceTech because they charge $10 less. And I called them and they said all the rubber parts are already in it.

Keep in mind getting the seal head apart is not just a "unclip it and go" type of operation. It's not ridiculously hard either, but it is a bit time consuming to do a good job. To me, swapping the assembly makes sense. In my case though, I just changed the oil seal on my 3 year old shock, and everything was fine. Getting all this stuff apart and reassembled to find another part was bad would have been very much not fine though.

BTW, I paid about $12 for the seal from Rocky Mountain. They call it a "Kit" that contains one part. I thought I was getting all of the soft parts.