birdie_xx Posted April 1, 2003 Share Posted April 1, 2003 ...but as we all know, unfortunatelly the terrorists got into our forum as well :evil: I want to upgrade my suspension, but I'm not sure wether to go the easy way (springs and oil) , or the full-on mode (springs, oil, valves - either Race Tech or Ohlin). I seem to remember some of you have done just the first one. Is it enough for the street riding? Are you going to do the valves as well????? Curious mind wants to know :roll: Cheers, Quote Link to comment Share on other sites More sharing options...
Mithrandir Posted April 1, 2003 Share Posted April 1, 2003 The simple answer is - how much cash do you have. Springs are a must do, but valving is less critical. If you have the money definitely spend it on the valves because it makes a huge difference to the front of the bike. I wouldn't bother with the Ohlins valve kits - they're made for racing not road riding. The RaceTech or SuspensionTech are the way to go. I prefer the latter because they're hardened aluminium which means they don't wear as fast as the brass racetechs. Quote Link to comment Share on other sites More sharing options...
Northman Posted April 1, 2003 Share Posted April 1, 2003 If your bike has a few miles on it (20k), then it's time to change out the fork oil, anyway. Replacing the springs is really easy, as is disassembling the forks for cleaning. If you're unsure if you need valving, then you probably don't. Replace the springs first, and judge from there if you'd like to rework the valves later. But, if you've got the cash, then do both now, as it will make a difference in the feel of the suspension, and is no doubt a big improvement over stock. The RaceTech or SuspensionTech are the way to go. I prefer the latter because they're hardened aluminium which means they don't wear as fast as the brass racetechs. Got a link for Suspension Tech? Quote Link to comment Share on other sites More sharing options...
G2 Posted April 1, 2003 Share Posted April 1, 2003 Received a response from Max at Traxxion Dynamics in Georgia http://www.traxxion.com/ and for $725 you get your forks back with compression & rebound kits with 1.0 springs, oil and new seals. I've heard good things about them from a friend who pits for some racing buddies, anyone else familiar with the Axxion valves and this shop's work? G2 Quote Link to comment Share on other sites More sharing options...
RodeRash Posted April 1, 2003 Share Posted April 1, 2003 I am changing fork oil and upgrading to .95 springs today. I'll let you know what I think of these changes after I get a little seat time. Quote Link to comment Share on other sites More sharing options...
GerardoXX Posted April 1, 2003 Share Posted April 1, 2003 That is a lot of money for the job, if you are a mechanic fan, do it your self, it really easy, all you need is to hang the front end of your bike and take the central rod of the forks to do both. A couple of tools and you are set, think about it. With the Valve kit come a VHS video which tells you a lot of how to do it. Quote Link to comment Share on other sites More sharing options...
Mithrandir Posted April 1, 2003 Share Posted April 1, 2003 Got a link for Suspension Tech? http://www.suspensiontech.com They're a NZ based company. The website is quite badly out of date though. I've been talking with them trying to establish where the US dealers are. It's been a slow process as the owner got badly injured in a MX accident about a month ago. He did say at one stage that he has a dealer "in NY" but I have no further information than that. I'd like to do small volume imports of their gear myself, but it's been hard trying to chat with them about it under the current circumstances. The kit I've got coming over is full rebound + compression valves and compression pistons. Total cost is US$150. Hoping they'll be here mid next week and will fit them the weekend after. Quote Link to comment Share on other sites More sharing options...
Mithrandir Posted April 1, 2003 Share Posted April 1, 2003 G2 - That's close to rip-off prices. A fork rebuild should cost no more than $500 absolute maximum. Springs are $110, valves are $160 so he's basically charging you $500 for labour. That's two days worth of work! I can strip, rebuild and refit a set of forks in two hours and I don't do it as my day job. For that cost - send me the forks and I'll do the work for $400.... Well - I'm half serious about the last bit. Seriously - at $730 you're getting reamed really badly. Quote Link to comment Share on other sites More sharing options...
Warchild Posted April 1, 2003 Share Posted April 1, 2003 IMO and from direct experience over the years, to do critical suspension work properly takes a fair amount of experience and, usually, special tools. I normally do all the work on my Blackbird, but fork overhaul I will leave to the expert professionals who have a proven background. I will recieve my Blackbird forks back from Dan Kyle today or tomorrow. I've learned a lot talking with Dan the past couple weeks. Although our Blackbirds have cartridge forks, many are unaware of the complexity of the internal workings of modern USD forks. Here's a shot of Dan's shop where he has torn down the forks of a CBR954 and RC51 and put them side-by-side. Damnation, there's a LOT of little pieces that go into forks! Here's more photos: http://forums.13x.com/showthread.php?s=&threadid=21030 I had heard a rumor that although Dan uses Race Tech springs in his rebuilds, he does NOT use Race Tech valves. Why? Because he says that the factory (Showa) valves are superior to the Race Tech valves! In fact, he says the Showa valves are essentially equivalent to the Ohlins valves. This picture below seems to bear that out; and the Race Tech valves look a little cheap next to the Showa and Ohlin valves: I can't wait to put these Dan Kyle overhauled forks back on Night Train. Between the new forks and the Ohlins rear shock, this is gonna feel like a whole new bike! Quote Link to comment Share on other sites More sharing options...
Warchild Posted April 1, 2003 Share Posted April 1, 2003 BTW, Dan charges $370 to overhaul your forks, $90 more if you need Race Tech springs. Overhauling also includes polishing the fork tubes to further reduce stiction. Dan even has a little machine that actually measures the amount of stiction: Quote Link to comment Share on other sites More sharing options...
RodeRash Posted April 2, 2003 Share Posted April 2, 2003 Dan even has a little machine that actually measures the amount of stiction: Â Actually, that machine measures surface finish, not stiction. Quote Link to comment Share on other sites More sharing options...
Warchild Posted April 2, 2003 Share Posted April 2, 2003 Actually, that machine measures surface finish, not stiction Yeah, poor choice of words on my part. As RodeRash correctly observed, the machine doesn't measure stiction itself, rather, it measures surface finish which can affect stiction. Quote Link to comment Share on other sites More sharing options...
Mithrandir Posted April 2, 2003 Share Posted April 2, 2003 Warchild, as someone who has rebuilt somewhere in the order of 30-40 forks, let me tell you that you're being fed a some pretty big amount of bullshit there. Unless you are pulling apart Ohlins forks, you don't need any special tools whatsoever. Everything you can get at your local sears. That photo - 90% of the parts are the washers in the shimstacks. Also, you don't seem to know what you're looking at with the second picture. Look at the size of the holes in the ohlins compared to the showa. The holes are at least double the diameter, which means 4 times the amount of fluid travelling through them at any one time. When you hit a sharp bump, that makes a huge difference to the front of the bike. When he's saying the showa valves are Ok, he's talking for race bikes on a race track where you don't have to deal with large bumps like street riding. In fact, I think he's talking crap about them being 'as good as' anything else - and so does every other suspension expert (got look at the archives of the wera boards for a discusion in this. The thread was about 2 months ago). For street riding, on street bikes, what you want is the biggest hole size you can get in the valves. This allows a lot of oil to flow as fast as possible in order to deal with big shocks that are typical of road riding (potholes, tar snakes, concrete separators on slab etc). Opening the holes then means you control the damping rates at all points using the shimstack. When you go to a race track, this is not the ideal setup because flowing too much oil will put pressure on the shimstack causing the shims to bend, which then changes the damping characteristics. So race valves use smaller holes to control the oil. The other reason that he's talking crap is that in suspension - particularly race suspension, you want to run as thin an oil as possible. Heating causes the oil to thin, and the thicker the oil to start with, the more difference that makes. As the oil changes viscosity, the damping characteristics change. So the idea is to go really lightweight oil to avoid this as much as possible and then control the damping with the valves and shimstacks. Typically you aim to use 5W oil in the forks and 5-7W in the shock (although some will use 10W). Standard, all Honda forks come with ATF in them, which is about 8W. And, just to let you know I'm not just talking out my arse here, when I was working on my VTR forks I first just changed the springs and played with the oile weights and viscosity. Since I couldn't get it right, I then started tweaking the shimstacks. That helped a bit but not huge amounts. Really sharp bumps still screwed the handling up. Finally I put the ST valves in and that made a huge difference. The freer flowing ports is what really makes a difference. I've been through every state of tune you can do to forks on a single bike and so I know the exact effects of each modification. If you don't believe me, jump straight from your bike onto someone that has had the RT valve treatment done to it (or onto mine if you're ever up this way) and you will notice a big difference in handling. Quote Link to comment Share on other sites More sharing options...
Warchild Posted April 2, 2003 Share Posted April 2, 2003 Warchild, as someone who has rebuilt somewhere in the order of 30-40 forks, let me tell you that you're being fed a some pretty big amount of bullshit there. Shyeah, right. I don't think so, Mithrandir. While I do appreciate you offering your opinion based upon 30-40 fork rebuilds, I think I'll go ahead and take the advice of someone who has overhauled umpteen thousands of forks over the years. I think all can agree that the only real test that matters is when the bike gets back on the road. Quote Link to comment Share on other sites More sharing options...
Mithrandir Posted April 2, 2003 Share Posted April 2, 2003 So you're going to take the advice from a guy that earns his money rebuilding forks for a living, and therefore it is in his vested interest to convince you to pay him money? Not only that but every other suspension expert in that thread (and elsewhere) completely disagree with his solutions. Sure your bike will feel better after the rework, but for the same amount of money that you've spent on it, it could feel vastly better than what you'll be getting. All I'm trying to say, is don't believe everything that you're told. Research first, particularly when you have other people contradicting what one person was saying. Go look about on the net for pages on how to rebuild forks. Give me a couple of weeks and my stuff to turn up, and I'll write up and show you exactly what tools are needed to do fork rebuilds - all of about 6 things. Quote Link to comment Share on other sites More sharing options...
SwampNut Posted April 2, 2003 Share Posted April 2, 2003 Everything I've read, and everything the local tuners and racers have told me, goes along with what Mithrandir has said. While I respect Dan's opinion to some point, it's that--an opinion. He's also got a stake in the whole thing. The "flow more oil" point is something everyone talks about. Looking at the RaceTech kit, I saw nothing but excellent craftsmanship and machining. Even the competing kits from Traxxion feature larger oil flow holes. Quote Link to comment Share on other sites More sharing options...
G2 Posted April 2, 2003 Share Posted April 2, 2003 Mith, are the Suspension Tech kits XX specific? This thread has changed my mind about doing the work myself, I just need to be steered in the right direction. How do you feel about documenting your mod with instructions and pics? G2 Quote Link to comment Share on other sites More sharing options...
Mithrandir Posted April 2, 2003 Share Posted April 2, 2003 The SuspensionTech kits I've got coming are: BP Road Compression Kit: BP Rebound compression kit. In addition to the 1.0kg/mm springs. Right now, because of the availabilty issues direct from the manufacturer, I've got my gear from one of the aussie suppliers. If you would like to contact him directly, send an email to nick@teknikmotorsport.com and tell him I sent you (Justin Couch). All the parts hopefully will be in the mail this week, so if you're interested, you may be able to get the purchased and put into the same bundle as mine. Then, when they get here, I'll divvy the bits up and send them on to people. Means you'll end up paying a bit more for them though, but at least you'll get a full kit for less price than the same from RaceTech (aussie dollar conversion helps greatly too!) The only "special" tool that you'll need for these valves is a 1.0mm drill bit (ie metric, not SAE). In the racetech valves you drill the compression pistons out to make them bigger, whereas with the ST valves, you work on the rebound side, hence the much smaller drillbit needed. If you've never done valves before but reasonably confident weilding a set of spanners, set aside probably a half a day. He'll send valves over with the shimstacks already set up for you. Personally, I'm going to be playing with them quite a bit so it will take me much longer to find something that I'm really happy with. Also, since I'm doing the F3 conversion, it will be marginally simpler for me than you because I just drop out a couple of bolts and the whole fork internals just slide out and drop in new ones. And yes, as stated before, this is going to be very well documented. Doing RaceTech valves is pretty much the same, but minor differences, such as where you drill out holes etc. In all honesty, I don't think it really matter which kit you go with for road riding - ST or RT. They're both orders of magnitude better than the stock valving. The rest comes down to little details like the construction materials. Oh, and the other thing - if you got the ST race valves, they are a direct knockoff of the Ohlins valves pictured above, but just using different materials. Quote Link to comment Share on other sites More sharing options...
AlphaBird Posted April 5, 2003 Share Posted April 5, 2003 I find it curious what a debate this has become. Most AFM racers(in Norcal) that ride Hondas use either Lindemann or Dan Kyle.Warchilds perspective comes from the experience of close to 250 very satisfied customers at www.fireblades.org---NOT one has had an issue with their forks. There are MANY stories of people having there forks done by others---or doing it themselves with very substandard results. On the XX you may not even notice these as you are not pushing the enevelope as one would on the racetrack---go to an AFM race and try to find Racetech valves in a racebike-you wont find very many--I wonder why?---Although I respect Mirths skills/experience---I havent heard hundreds of awesome reviews of his forks. For example---one of the really big issues with Honda forks is there suseptibility to stiction--I hear no mention of this in any XX threads. Furthermore---No one has seen a "picture" of these valves---why would you buy something sight unseen---One of the uses with "big valves" is high loading chatter. The fluid dynamics behind valve sizing/performance are of the variety of a 5th order differential equation. Ohlins/Showa spends a ton of R&D researching these---so the bigger is better philosphy aint that simple or everyone, especially Ohlins would be using it---and I gaurantee it aint present in the beloved Ohlins rear shock. My buddy did his own 929 forks with Rcatech valving(both comp/rebound) and was NOT a happy camper---he went straight to Ohlins after that and was quite happy. He has ridden my 929 and says that it is loads better than the Racetech setup. I push my 929 to mid-pack AFM times and have yet to notice any performance limitations of the forks than Dan Kyle rebuilt---ie NO chatter, no understeer/over steer, wierd tire behaviour, etc. I know numerous RC51/929/954 users that have the same Dan Kyle rebuilt forks with the same results. What I find interesting is that everyone seems to ignore the Moriwaki RC51 link that Dan has has such good results with---and has worked its way into the production RC51----yet Max/others pooppo this as a "work of fiction". I am not trying to promote anyones specific agenda here--I encourage all to make a very informed decision. Below is a rather interesting review of the "fork issue" from a pretty respectable indiviual that has spent along time racing Hondas "There seems to be much discussion of hydra-lock on Max's part, yet no one has discussed cavitation in that entire debacle. In a sealed space as long as there is air, force, movement and fluid, there will be cavitation and the larger holes will allow the "air charged" fluid to percolate whereas with the smaller holes, the cavitation factor will be reduced through an increased straining effect. As LTL pointed out, the valve face contour will have a profound impact on damping reaction time as well as efficiency as the face of the valve has to slice through the fluid wall as the suspension moves in and out. Most of these valves wouldn't last 10 seconds on a flow bench, so I wonder how their fluid dynamics rate from one type to another??? At any rate, methinks Max said a lot last year when he admitted that he rarely get's on the WERA board until he's "had a few . . .". Review of Stock/DK,Ohlins http://www.fireblades.org/forums/arcmessag...=ohlins%20forks Quote Link to comment Share on other sites More sharing options...
Warchild Posted April 5, 2003 Share Posted April 5, 2003 I find it curious what a debate this has become. Me too. I'm beginning to think the subject of fork rebuilds ought to join the ranks of the never-ending oil and tire threads. My experience with Dan Kyle was nothing short of amazing. When I called him up to discuss my fork rebuilds, Dan interogated me for 30 minutes, extracting information he needed: body weight, riding style, weight of typical touring gear, he asked me what I didn't like about the stock forks, and what I was expecting out of my rebuilt forks, etc, etc. Since my Blackbird is pretty much regulated to Endurance Rally work throughout the Desert West (always with a 4.7 auxillary fuel cell on the back, and a good 30 lbs of rally gear in addition to my 230-lb linebacker ass), the bike tends to stay fairly near max carrying capacity the majority of the time. Dan said he would obviously not be setting up my forks like he does his racebikes, rather, he will orient the rebuild more for heavy-duty combat touring over a wide range of road conditions. Still.... I wasn't prepare for the results. I re-installed the forks and went for a test ride. HOLY FUCK! The front end has never felt so planted, never rolled over bumps and road irregularities and so totally sucked them up like they weren't even there! Fork "dive" under heavy braking is now quite minimal. The ride seems both firm and plush at the same time. This is everything I was expecting, and more. Without question, this has got to be the best $370 I ever spent on Night Train. The only slight complaint I have is now I am forced to look at this shiny silver component that is too CLEAN (ugh!) compare to the rest of the combat-touring Blackbird (a couple thousand miles in the rain oughta fix that): Quote Link to comment Share on other sites More sharing options...
AlphaBird Posted April 6, 2003 Share Posted April 6, 2003 Thanks for the review Warchild---finances depending--Im next Quote Link to comment Share on other sites More sharing options...
tomek Posted April 6, 2003 Share Posted April 6, 2003 Just one thing to remember,LIndemann,or Kyle modified Showa or whatever forks or valves are not your stock parts anymore. Valves are polished,holes are enlarged and reshaped,shimes are polished and altered. The only thing those valves and stock parts have in common are the fact they started from the same piece of metal. Now, if you live near by or can afford timewise to ship your forks, it is a valid option but can you achive the same results using stock valves by yourself?No way. For those of us tring to do forks ourself aftermarket valves are the only option. Also if I remember correctly many racing classes in various racing organizations (AFM) prohibit using non-stock fork intervals ( to keep cost down). Quote Link to comment Share on other sites More sharing options...
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