soft fork

What would you xjbikeers recommend to stiffen the fork so it doesn't dive quite so much? stiffer fork springs or heavier fork oil or both or something else???

I am a heavy guy over 200lbs and I think it is just a bit too soft.

k

 

The stock fork springs weren't all that good when they were new. I replaced my stock springs with Progressive Suspension units from Dennis Kirk (about $75). I also used a heavier oil,and now the forks are much better suited to handle my 225 lb weight. The stock springs were so sacked out that the bike had to be parked on the centerstand,or it would fall over.The bike rides and handles much better after replacing the springs.

 

I agree with danno, this is a good fix and it is easy.

When I did my forks I had great info from here. There was a girl here who posted some very good threads on this subject.

I think it was fionangie I know thats not right but its close. This a pretty easy project and doable in a week end. I can now do mine in half a day.

 

I'll second that
I'm 260lbs, I changed my fork springs to heavy duty , the kind tou would put on if you added a front fairing. Changed the fork oil to 15w instead of 10w. Rides great and no front end diving under hard braking.

 

My apoligizes mlew but your gonna haft to third it :lol:

 

Please post pics of the '95 FX ... And Happy Holidays !

 

This is your answer.
I have to admit I'm around 210 myself and these are the hot setup for the 550 Seca. The stock springs are about as useful as the original shocks (not.) Quick cheap dramatic upgrade. Highly recommended.

 

I gues I can't count, I can fix any bike but can't count to three

 

Ill see if I can get that done for you danno! Happy Holidays to you as well.

 

Heres a little of what you can expect. Its not all you need to know, but it will show you the basic break down.


http://xjbikes.com/Forums/viewtopic/t=8355/

 

Heres some great insight tubabone

http://roadstarclinic.com/content/view/143/128

Thanx to finnogangela

 

danno I couldn't upload a pick to the thread. I did manage to get a pic uploaded of the 95fxdl in the photo gallery and I blamed it all on you..lol

 

That is one nice bike! Very clean bike,especially for a '95! The Lowrider is my all time favorite Harley model.Wish in one hand,you-know-what in the other...

 

I hear you danno, thanx for the compliments. I wonder if tubabone has checked back in on this thread? I posted some really helpful info on the subject @ hand. I dont want him to think I hijacked his thread. Happy Holidays.

~RIDZ~

 

I weigh-in at over 250. XXXL!

I add a Pre-Load to the Fork Spring.
An Inch and three-quarters of PCV Pipe.

 

Hey guys- How in the world do I do this oil change to my 650G? The top of the fork tubes is a dead metal cap! I don't see a circlip, no air valves, nothing. I've changed the oil, seals and springs on many a MTB DH fork and all of them had some way of popping off the top of the leg and accessing the inside for servicing the thing. I'm reading thread after thread here and looking at my manual, but not seeing an obvious way to pop the tops on the XJ650G forks. I need an oil change and reallly reallly want to stiffen up the ride characteristics of this noodle holding my wheel on, LOL. I bought 10w oil but I'm thinking after my research that I might want to go to 15w, and since I'm poor, it had already occurred to me that a preload spacer might be just what I need to add a little beef to the factory springs. I'm only 170lbs but I still bottom the fork out now and then on these lovely Seattle roads, and experience serious front end dive under braking which I am not loving..

I don't see obvious leaking from my forks, but I have never changed the oil and have had the bike close to two years. No telling when it was last checked or even if the PO had the proper amount of oil in the legs. My riding style is, shall we say, spirited?

Thanks XJ Wizards..

 

DISREGARD- I'm a dullard. Pushed real firmly on the dead metal wafer and saw the circlip holding it in.

I guess I'll take my front wheel off now and get to work. BEFORE I do, however, I still need some ideas on fork oil weight and how to load up these sad ass springs in some fashion that will bestow some version of acceptable handling characteristics to my little pal's front end..

 

Steverino: Why not read back up the thread you so deftly hijacked after it was nearly 11 months old.

Since you don't appear to have nearly as much body mass as some of us, I'd stick with 10W and add about 1" or so of preload (with a hunk of PVC, it's OK, that's how Progressive does it.)

The absolute best way to "fix" your forks is to spend the $70 or so on a set of Progressive suspension fork springs. I've got two 550 Secas, one with a pair of nearly new stock springs and one with Progressives. The difference is amazing. The Progressive fork works much better; it responds to the tiniest imperfection in the road surface whereas the stock fork takes a certain size bump before it responds. The front end feels much more firmly planted in corners as a result. I'm going to upgrade the other bike over the winter.

I run 15W in both bikes, but as I said back in my post from a few months back I weigh over 200.

 

Does it really count as a hijack when the question is still on topic and the thread is as old as this one?

Thanks for the feedback, I would spring for the progressives if I had the cash, but alas that is not in the cards right now.

I took some ID measurements today with my calipers, I'll find some PVC in the next few days and give it a shot.

 

Hi Huck, New to this forum but not new to bikes. Since cash is the issue of the day, for all of us , why don't you try shortening the springs? I know it doesn't sound right but it works. Use a grinder and cut off wheel,forget about a hacksaw,and cut maybe a half inch off at a time. Heat the end with a propane torch and squeeze it down with a pair of channel locks. Level out the end with a grinder. Make up the difference and maybe a little more with a spacer. PVC or steel, I prefer steel, and change the oil.
Now that you have a heavier spring you'll need a heavier oil. I'd just go one wieght at a time to the factory spec on volume and level.
What your trying to achieve is lots of travel without bottoming or topping out.
Let us know what you think. Good luck . RG

 

The springs have the same rate all the way through, so I don't have a clue how shortening them will help at all.

 

He may be right about the non progressive nature of the stock springs on the American maxim 650's.. I'll let you know when I pull them next week, on my days off.

Thanks for the help, I'm leaning towards shimming without cutting as a first step, and using standar weight oil, as I don't want to slow the fork down too much, an 15w could feel sluggish during the chilly NW winter.

 

Think about the spring as a piece of wire that's not coiled up. Take a 4' piece and a 10' piece. Which one's harder to bend?
Here, look at this site. Lots of good info. http://www.peterverdonedesigns.com/springs.htm
This site is interesting too.
http://www.activeboard.com/forum.spark? ... 105037&p=2

 

Excellent point. That seems to make some sense to me..

 

And with respect to Cooter,I'm sure there's limit to this theory. But I have done this and much to my suprise it worked.

 

cutting coils off a spring will not increase the spring rate, sorry
it just makes it shorter

 

Sorry Polock, but cutting a spring WILL increase its spring rate. wera90ex's explanation is right on. Here's a quote from one of the links he posted:

 

Suspension is magical stuff, ain't it? Thanks for the lively conversation and debate, this is what I was looking for out of my bumping this thread. Though I don't have the math to back it up, or the eloquence to explain it, my gut feeling is that cutting the springs will indeed tend to firm up the suspension to a degree. I will try a short (1") PVC dowel first without cutting if possible, and see where that gets me. After that, if positive results are not obtained perhaps I'll try cutting them because at this point, I'm fooling around with a 30 year old fork and whatever happens happens. If I screw it all up and have to buy springs then, so be it. I guess I'll risk incurring the wrath of the Old Lady when I come to that crossroads. That is, if my hacked up forks don't energetically disassemble on me at highway speed, in which case you may not be hearing much more from me on this subject..

 

Cutting the springs WILL stiffen them up; preloading will stiffen the suspension without actually stiffening the springs themselves. Cutting the springs to make them stiffer will result in a harsher, less-compliant fork; simply preloading them will not.

 

If your head isn't hurting for those other sites,here's another http://www.carbibles.com/suspension_bible_bikes.html

 

some piece of metal at some angle will deflect some distance when some force is applied = spring rate
if our spring 20 coils and 100 lbs on it, it might move 2 inches, each coil has moved .1 inches, now same 100 lbs same spring minus 5 coils will only move
1.5 inches, each coil has moved the same amount but there 's not as many to move but the RATE is the same (1 coil moves .1 inch @ 100 lbs)
when we cut coils off a spring, what changes is called, Spring Constant
check this out, all that changes is the free length
this is really more about grammar than suspension