Header's 525EXC refresh

Discussion in 'Thumpers' started by header, Feb 12, 2012.

  1. header

    header Chris

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    I've been riding dirt bikes since I was ten but i've never been really into them until I turned 18 three years ago. For whatever reason I started to obsess dirt bikes. Everything about riding off road from the people to the fresh air I love it all and i've been riding most weekends since. Now as I approach my graduation date from college, two major thoughts contend for space inside that magic of the frontal cortex. The future concerns won't be discussed here, however a lack of time has stopped me from riding this winter but has left me with enough time to refresh/rebuild the 04 525 EXC I found in Tennessee last spring break. :deal That on the other hand will be discussed here.

    Ever since I learned how to ride i've always had sub par setups on the bikes i've ridden. None of them have been bad bikes but they were never smooth in their operation. Some things are still too expensive, like a revalved shock/fork, but others are simply things that most consider general maintenance, rebuilt forks for instance. This spring i'm going to get to ride a truly fresh bike. Not a fresh engine but everything else I can afford will be replaced. I want that feeling you get when you KNOW every bolt has been torqued and inspected. Solid.

    When I was 19 I started my first race, didn't finish, tried another one and wrecked out. But I kept working at it and put in the blood sweat and tears and now I can hold my own with the local B class. I've learned a lot in the last few years and I've found slight differences in setup and suspension or technique mean a huge change in performance. To that end this will be a thread logging all of my maintenance and setup for the following year.

    NOTE: I am not a mechanic, nor do I pretend to be one. I do make mistakes and many of these things ill write about will be incorrect so don't take my word for it. :deal

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    You can see the XR650R behind the KTM. I really liked that bike but as my riding began to be mostly enduro style I had to be honest and get the right tool for the job. I chose the 525 so when I do dualsport riding I can still pull tall gearing without wringing its neck too much. Also I grew up on torque :D

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    Here she is in all her glory after I peeled off the stickers and cleaned her up. She had 290 hours but a fresh top end and didn't have too many real problems besides the regular little things.

    Next up: some singletrack and a years worth of trails. :deal
    #1
  2. header

    header Chris

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    From the time I had my XR I learned the manufacturers do know what they're doing. Everything on the bike has a purpose, foot pegs for instance are optimized for a certain size, something like an 8 I think :scratch. Wish my feet weren't 14s :lol3
    So instead of tearing off the stock stuff its worth the time to ride the bike in its original form and find what doesn't work for you as the rider. I found the ergo's work great for my 6'2" frame but the sag numbers don't like my 200lb naked body. I could lose some weight easily enough but i'm very physically active with weights and if I lost any weight most of it would be muscle so stiffer springs are the answer. I needed the bike to be street legal so I wired up the supplied brake light and added some turn signals. I picked up a oversized gastank from an inmate then threw some oil, filters, and tires at the bike and rode it all summer.

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    I played around on some singletrack.

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    Did some racing.

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    Strapped on the giant loop and took it to what passes for sand riding around here.

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    And just proceeded to enjoy the bike. :ricky

    I found what I liked and what I didn't. Most things I didn't like were things from the previous owner or things that could be mitigated through a different technique or setup. But I also found things I needed to change. I signed up on KTMtalk and read everything I could about suspension. I bought Neduro's PDF on suspension and race tech's suspension bible. I experimented and made mental notes of things I wanted to learn about.
    #2
  3. header

    header Chris

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    I don't have a lot of money. I can only work so much a year before its time to go back to school. I could work during school but my summer work pays literally twice what most college student jobs will ever pay so instead I just save my money and weigh every purchase I make. That combined with working since I was thirteen allows me to afford this hobby while still in school. Though there are limits. This usually keeps me from buying any upgrades I can't get my money out of like bling for the bike :puke1. Instead I put a lot into what I wear, I reasoned if I had gear that let me enjoy riding in winter, rain, mud, whatever means I could do what I enjoy more. Isn't that the idea? Me thinks so :deal

    After riding with a full tank of gas and the giant loop with the stock springs I didn't enjoy it so I decided to put money into something I didn't plan on getting my money out of. I went from .42kg/mm springs to .48kg/mm springs up front and swapped the 8.8N/m spring in the rear for a P30 progressive spring in the rear.

    (can't find any pictures of swapping the spring so here's a XRR)

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    I liked the feel of the springs up front, they soaked up a lot more of everything and the rear spring being progressive kept me from bottoming on some fast G-outs. Unfortunately its not perfect. The progressive spring still doesn't give me the right sag for the 04/03 model EXC's. It sags too much chopping out the bike which is made worse by having the, now, correct springs up front. The front handles bumps better but now I have to straddle the gas cap to turn the thing :bluduh

    Next up: a lesson in suspension.
    #3
  4. header

    header Chris

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    When I first contemplated KTM's my riding buddies told me they handled weird but didn't know why. They said it was something with the steering angle or some other geometry thing. I think a lot of the confusion is in the shock. Its not that it is going to handle any different but the way it works is different which causes people to freak out and attack the thing they don't understand. :nono this is why we read books folks.

    KTM's use what is called a link-less rear end. This means there is no link system that connects the shock to the swingarm. Instead the shock attaches directly to a heim bearing on the swingarm. This keeps the service down to only one bearing. It also allows trail riders to slide over the tree that is covering their favorite trail and you don't drag the links over the bark...or get the bike stuck on the hitch carrier like I did with the XRR because I didn't want to unhook the ramp and roll it off :lol3

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    Thats not the only function of the link system though. The links provide a very predictable amount of increased damping. This means the linkless system on KTM's has a lower rising rate of compression ie, it bottoms easier. To fix this WP (the suspension KTM uses) uses what is called PDS suspension. This means progressive dampening system. Suspension is affected by the velocity the shaft has to move to get out of the way of say, a rock, but doesn't matter about where the shaft is. Not so much with PDS. When the PDS shock compresses so far it engages a needle into the orifice that allows the oil to flow out of the way during movement. This forces the flow to move into a second circuit with another valve body and valve stack that adds compression. WP also runs a progressive spring that has a soft initial force but uses thicker coils that causes an increase in compression force when further through the stroke.

    This all adds up to a very fussy setup that is picky on springs, sag dimensions, and makes for a harder tuning process. But it does still work, and man is it nice to be able to pull the shock off with two bolts :D

    More tomorrow.
    #4
  5. sashapave

    sashapave riders on the strom

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    Awesome thread! Keep 'er going!
    #5
  6. header

    header Chris

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    Alright, next up is how to enjoy wrenching :deal

    I am not good enough with a wrench to really enjoy working on things. I do to an extent but it doesn't take too big of a problem before i'm out there cussing and yelling. But it seems dirt bikes will be a part of my life for the unforeseeable future so I better learn to like it. First step in this process is to reduce the amount of problems i'm going to run into. Basic routine maintenance is the best way to keep your bike in working order but also it is important because it allows you to find problems and fix them before they develop. If you look over every bolt after each ride you will only have loose bolts, not missing bolts :deal

    To enjoy wrenching it has to be easy. For me the most annoying thing is when i'm working on something and i'm not getting anywhere, a rounded off bolt for instance. To combat this every bolt needs to have something on it, locktite, grease, anti seize, whatever it is they all need something. Heavily cleaning the bike before working on things really helps keep the damages you do to the bike down and having the proper tools helps a bunch too. All of these things help to ease the wrenching process.

    Here is Neduro's thread, Spring bike maintenance guide which is really useful and has some good tips in it.

    The next step is to remember to learn from what i'm doing wrong. Why is that problem happening, what am I doing wrong and how could I avoid this in the future? Every time I pinch a tube I remind myself its just more practice for the next tire change, then I think what went wrong. I do my best to stay calm and avoid loosing control. Everything I do is better when i'm still in control. There's a reason its called being emotional :lol3.

    With that in mind I set to work on the rear tire first. I had been limping it along for a while but with winter setting in I decided to pull off the old rubber and swap in some new bearings while I was at it.

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    I always have a really hard time removing the rear axle and decided to replace the wheel spacers with steel ones that wouldn't wear out and let a bunch of crap into my wheel. I had to make a punch and push out the spacer since it had gotten stuck on the bearing. That worked so well it pulled the bearing out as well, except when I put the new bearings in I found a bunch of material had been removed from the hub :bluduh. Anyone got a spare hub they don't need?

    So I dismissed that and went onto the rear tire. Swapped out the old tube and spooned on a new M12 and proceeded to make swiss cheese out of the tube :baldy. But I stayed calm and didn't let it get to me. Instead I ordered a Ultra Heavy Duty tube like I should have done in the first place, and moved onto the forks.
    #6
  7. header

    header Chris

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    I have replaced fork seals before but i've never rebuilt any before so this was a learning experience for sure. I went from a perfectly working pair of forks to this in two days:

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    I wanted to take the forks apart as far as you can. I have read enough that it was time to see this stuff first hand. I was surprised it isn't as difficult as I thought it would be.

    I don't have time to do the fork page tonight so ill save that for later this week.
    #7
  8. header

    header Chris

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    Where was I? :scratch

    I decided earlier this year money put into suspension is never wasted but before that I knew I had to know what the suspension in my bike was supposed to feel like. I doubt any of the internals were still working properly or gave the same plush feel they are supposed to offer when broken in. So I took them all the way down as far as they could go. It wasn't all that hard.

    I took the forks out and did all the easy dis-assembly.

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    Went a little further to get the base valve, spring guide and all the other internals out.

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    Then started taking apart the base valve to see what the stock valving is.

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    When you take the valve body and shims off the base valve holder looks like this:

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    You must be careful when removing though, the top of the threads are penned so you need to carefully file the area down before you remove the stack. Also when you remove them it helps to slide the whole stack onto a wire so you won't get things out of order.

    After I had it apart I laid everything out and measured everything to see what the valving is. This is very important and makes the bike what it is. Dirt bikes are not about how much power they make or how fast they are. They are ALL about suspension and tire selection. IMHO of course.

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    Racetech's suspension bible (get one before opening your bike up) says to lay everything on a piece of glass to check if the steel has been bent. If it has the shims need replacing. They're cheap so once you know what stack is in there you can order a bunch and replace them all and start over with your suspension. This will give you a good base line when you want a revalve.

    After the base valve I moved on to the rebound side. I wanted to do the same thing as before but I also wanted to remove the needle that controls the bleed ie. the piece that your rebound clicker presses down on.

    Here is the entire assembly:

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    And when you remove the valving:

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    The needle resides inside the valve holder. This time called the rebound tap. It is held in with locktite and requires generous amounts of heat to remove. Not a flame, just heat for a long time. When removed and laid out everything looks like this:

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    After I recorded everything I buttoned it all back up and started assembling everything with the new bushings, seals, and sliders. This is what worn out bushings look like compared to good ones on the outside. :bluduh

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    Do it all again and your done!

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    Next up, the rest of the bearings.
    #8
  9. header

    header Chris

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    Earlier this year I tore the front end down to the steering stem bearings and cleaned and repacked them as well as I could, I had never ridden a bike with fresh greased steering bearings. :whoa if you haven't greased them before you are really hampering yourself by not doing it. It makes line selection and adjustment so much better. I figured if I got that much of an improvement from just greasing them I wondered what a new set would do.

    About halfway through greasing the lower.

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    I pulled the old ones out, knocked out the races and pressed all new freshly greased ones in :thumb

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    All finished up waiting on the forks

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    I figured I should go through all the wiring behind the mask before I put it all together. After taking a long detailed cleaning of all the little stuff up front I cleaned up the wiring a bit and started putting the front end back together.

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    Here is how the bike was when I stopped working.
    #9
  10. header

    header Chris

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    The next morning I jumped in again hoping to get everything wrapped up and get the bike back together. I should have known better to think I would be able to get the swingarm bearings out without a problem :bluduh

    I still got a lot done, I received my rear tube and the hard anodized wheel spacers from Enduro Engineering so I finished up the wheels.

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    I then moved back to the front end and finished that up. Then rolled the bike over into the sun where I could see.

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    With the front end and wheels all done the only thing left was the swingarm. Getting the rod out took all of about ten seconds which is a first. But the bearings had been neglected and were probably the originals so I had to cut them out. :bluduh

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    After taking them out I did my best to clean everything up before pressing in the new bearings. I made a simple press out of some sockets and a large clamp. It worked great and I was able to press the new bearings in easily.

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    After pressing in the new ones I ziptied them so I wouldn't lose anything.

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    Did it all again and set the swingarm aside. I was feeling ambitious so I pulled the shock off and cleaned it off while taking a preload measurement.

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    I also decided I wanted a clean muffler. I figured I had the shock, swingarm, and mudflap off so why not take the header and mid pipe off and give them a nice clean.

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    About halfway through.

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    I don't have any pictures of it finished but I know there was a lot of mud cooked on there based off of the amount of cleaning I had to do the next day :lol3 All the vehicles needed a good cleaning and the garage had to be leaf-blown out. Dad was not thrilled :D
    #10
  11. header

    header Chris

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    After cleaning up the garage I rolled the bike outside, after knocking off all the big bits of dirt, and aggressively cleaned everything under the plastics. After a second detailing I let it dry off and took out the air filter. I oiled up a new one and cleaned the old one, setting it aside to dry and be re-oiled. I went ahead and checked the valves and adjusted the intakes. Then changed the oil and filters and replaced the rusted bolts that were holding the skid plate on. I wanted to pull the carb and give it a good cleaning while I was at it but I decided it can wait.

    With everything under the hood adjusted I went back to cleaning it all up again, then added the plastics and put a light coat of armor all on everything to give it a nice sheen :D

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    Here is how it sits now with one final looking over the front end for a clicking that is being elusive :scratch then its ready for a shake down ride this Friday and Saturday.
    #11
  12. header

    header Chris

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    A list of the things I did:

    Bearings including
    --Swingarm
    --Upper and Lower triple clamps
    --Wheel bearings and seals

    --Rebuilt forks with new bushings, wipers, and seals

    --Hard anodized wheel spacers (front and rear)
    --New air filter
    --BRP threaded bar inserts
    --Oil change and filters
    --Lots of lock-tight and antisceze

    --Loads of cleaning, checking, and greasing
    --Cleaned up any dodgy electrical connections
    --Rerouted many wires to avoid future electrical issues

    And overall did a close inspection of everything I could. My goal was to give the bike that secure feeling. I knew I would be unsatisfied if I didn't do AT LEAST everything I did here, anything less and I would have felt that I just changed the limiting factor. I could have gone further as well. The heim joint for the shock could have been replaced, the spokes i'm sure are stuck where there at now, i'll need new front brake pads and a front tire soon as well but I did what I felt was necessary right now and I am very excited to try the bike out with fresh components.

    Its like getting a new bike, just without any of the problems from the previous owner! :D
    #12
  13. lstzephyr

    lstzephyr Solo con rambo

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    :clap It always makes a big difference when I do maintenance on my bikes. I like your approach to it too, I will have to remember some of your sayings.
    #13
  14. header

    header Chris

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    Thanks, though i'm sure any of the good quotes came from other people's threads. There are some good ones out there though!
    #14
  15. Mark_S

    Mark_S Fair Weather Faggot

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    a good read
    will watch this thread with interest

    cheers


    Mark
    #15
  16. header

    header Chris

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    Alright, I took the bike out to the local riding spot on Friday and Saturday. Friday I just made sure everything was working well and I didn't fubar anything up.

    Friday I did my normal ten mile warm up. I find this very useful to do first thing, I would equate it to the road bike guy's "100 miles before breakfast" kind of thing. A quick ten mile jaunt gives me enough time to warm up, get stiff, and loosen up. I hit a normal loop that I am used to then start into the stuff that makes me a bit nervous. As long as I don't stop for anything, especially that nervous part, I get it out of the way and for the rest of the day I don't have a problem hitting anything that's hard.

    After my warm up I started playing around with the clickers on the forks. I ended up with the compression set as soft as it would go :eek1 I guess I need to figure out a stack for the mid-valve and base-valve the next time I have them apart. I don't remember where I ended up with rebound but I remember its in the middle roughly which surprised me. Three clicks either way felt like crap. I played with the shock a bit but couldn't make it any better, just different. More testing for that. I wanted to play with a little preload but felt like I should ride some more miles in the attempt to knock off my rust. That way I will have a better idea of what is actually better and not just something covering up my inability to ride :D

    Overall the bike tracks pretty well in the we have rocks around here. When I bottom its predictable enough but i'm not hitting jumps either. The front will dive a little more than I wanted with the clickers set the way they are but I don't have any deflection from the front in rocks. The rear does a little but I think I can make it better, but even the way it is now I have no kicking.

    Note: I'm currently using springs and oil height to control bottoming more than valving. I plan on making the forks more compliant on rocks (high speed compression type hits) but I would like to firm up the slow speed actions like diving at the same time. From what I know enduro/singletrack suspension should use oil height and springs to control bottoming then have the valving blow off fairly fast to deal with trail junk like roots and rocks but be stiff enough for the riders given speed (C, B, A, AA etc..). Also reducing stiction would seem to be the only way to deal will little things like chop, or small roots that you will still feel in the handlebars. That's my thinking at least, :dunno i'm just thinking out loud now.
    #16
  17. header

    header Chris

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    On Saturday I knew everything was working so the goal was to get some miles in. Indiana and the surrounding states (besides Michigan, they have the best trail systems east of the Rockies IMO) don't have real "trails" to ride on. We have what are basically parks with trails on them but most long trails in the parks are still around ten miles at most and your going to cross seven or eight trails along the way all the while you'll be within five minutes of the truck. Its kind of disappointing the lack of cross country riding around here. You can take a mountain bike through the national parks and they're some nice trails there but nothing for bikes. We simply don't have the ground for it. :bluduh It may not be as fun as cross country or trail riding can be, but I still enjoy playing around in the hills we do have here.

    I got up and headed out, did my normal warm up then met up with a good riding buddy and had him lead for a while. I found my timing to be way off when I rode with someone else because I haven't ridden with anyone else for a long time. Most people put the bike up for the winter, I don't put it away until the ground freezes but with all the warm weather I was able to ride a lot this winter. It seemed to rain a lot but that's why you need good (versatile) gear. It took me about an hour to get used to looking past the leader so I didn't follow all their mistakes :lol3

    About another hour after that I felt like the rust had been knocked off and I was back to my normal speeds. I did have to remind myself to look a bit farther ahead but otherwise I didn't feel all that slow.

    Throughout the day I made a mental list of things I need to work on or look into. For myself I know I need to look at my form. Its ok but I know it can be better. When I go down hills I have to consciously remind myself to hold my body up with my legs not my arms or if i'm standing to stand up a little higher, otherwise I stand just above the seat which is using too much energy for anything but the most technical down hill sections. My body position is also off for fast uphill sections as well. For starters i'm not looking far enough ahead but I also don't have the front to back balance for hills yet, I used to but now that i'm getting faster i'm a little off. For instance when I hit a hill and it has a steep section that then has a water bar I try to ride the wall instead of jumping the water bar, that works great until I am too far forward for the slight flat section following the water bar, this is fine until there is another obstacle like a rock ledge or large root that needs to be cleared with speed.

    For the bike I absolutely have to get into the Carb. When it gets hot there is a slight stumble right off idle. I found this to be a real problem going through turns with trail junk in them that require very predictable power delivery. This has also made me want to get a G2 Ergonomics throttle cam system. These replace your existing throttle tube with an aluminium one that has interchangeable cams for the throttle pulls. You get to select a couple different softer/milder cams or one faster one I think. Sucker costs $100 though.

    This is, to me, why a slower bike is easier to ride or race at a fast pace. Too often I hear people talking about a bike being heavy or a pig which does make a difference but I had better race results on my XRR than I have on the KTM yet. I think its more about how much power the bike has that wears you out, on my 525 I have to constantly manage the throttle unless i'm in perfect dirt. If I were on a 400 I wouldn't have to think about it, allowing me to think about line selection or other obstacles. But, and here's the catch, a big powerful bike is fun to ride. That's why I ride big bore's :D

    Sorry no pics for either days. I was a little busy :ricky

    More later in the week. Maybe :scratch
    #17
  18. Foot dragger

    Foot dragger singletracker

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    Nice,your doing a great job of learning how bikes work,it amazes me that so many people take dirtbikes to the shop to get basic stuff done,you really have to do it your self to understand how it all works together. It takes a bunch of time to dig in and just go through a bike but its very satisfying once done.
    #18