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Santa brought my Progressive fork springs for Christmas to finish out my hybrid fork mods, and the results seemed worth sharing with the group.



I got Progressive springs 11-1114, listed for the TT500, based off the technical specs on their website, and installed them this afternoon. On road feel was definitely improved, particularly over the little bumps in the road & quarter round curbs. Can't say much for the off road performance yet, but I sincerely doubt that I'll bottom out the front end as often as I have been.



In the pic below are three sets of springs/spacers:



Top: '87 YZ80

Middle: '06 TW200

Bottom: Progressive 11-1114 & spacer cut to match the YZ80 total length



Notice that the Progressive springs sans spacer are the same length as the TW spring & spacer.



So for those of you looking for an alternative to the OE front suspension, these might be worth looking at.









Cheers,

 
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Great idea. When you are done, please include fork mod & springs all together so we won't loose track of a super upgrade........... For those that are less confident, you can get a nice set of progressive springs for the stock fork from HyperPro. Gerry/



 

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Great idea. When you are done, please include fork mod & springs all together so we won't loose track of a super upgrade........... For those that are less confident, you can get a nice set of progressive springs for the stock fork from HypePro. Gerry/




Gerry,



How'd the Hyperpro progressive rear go? I've been waiting to tackle the back end pending your reports on it...



Thanks,

 

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The rear HyperPro spring is 14mm thick, though some of that is likely epoxy paint. In any event, I felt compelled to make a larger O.D. base & spacer. Had the machinist at work turn down my marginal welds and make the spacer look nicer. Should be able to take pictures and install the shock over New Years. Given the rain, likey my first review will not be more than a couple of "butt slams" to the seat. I suspect it will be stiffer, but hope the 'progressive' part will still make for comfort. Should I be wrong, not sure if I would try the stock spring or just go back to the V-Star, which worked great for me. Gerry
 

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The HyperPro spring is 14mm thick, though some of that is likely epoxy paint. In any event, I felt compelled to make a larger O.D. base & spacer. Had the machinist at work turn down my marginal welds and make the spacer look nicer. Should be able to take pictures and install the shock over New Years. Given the rain, likey my first review will not be more than a couple of "butt slams" to the seat. I suspect it will be stiffer, but hope the 'progressive' part will still make for comfort. Should I be wrong, not sure if I would try the stock spring or just go back to the V-Star, which worked great for me. Gerry


Well, I'm looking forward to your updates. I've found a local offroad park here and while hardcore dirt riding is certainly not yet in my repertoire of skillsets or the TW's capabilities, I was bottoming out repeatedly on mild jumps on the last trip. If the new springs did anything for me, it was to make me realize how weak the rear end is.



I've been really happy with the increased rake the YZ forks yielded and somewhat reluctant to lift the rear. However, a fellow tweaker by nature and now poignantly aware of how inadequate the rear suspension is for my desires, I'm sure I won't be able to leave well enough alone for long...



Thanks,

 

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All,



In regards to the stock fork, what does the progressive spring do, (advantage), over the stock spring?
 

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All,



In regards to the stock fork, what does the progressive spring do, (advantage), over the stock spring?


In theory the spring allows a softer suspension in the first stages of travel, stiffening progressively as travel is used up.



Through the use of spacers you can also somewhat control this characteristic to suit your needs.



My lame explanation of springs (also applies to front springs. If the wire diameter, length and coil spacing are correct they work well):





http://tw200forum.com/index.php?/topic/1013-need-rear-shock-info/



This all kind of case-by-case, relative to your own weight and riding style. Also keep in mind that Abyss is running longer fork tubes. I have the same front end as Abyssdancer but run stock TW springs, longer spacers and ATF filled to the same level as called for on stock forks. For me, my front end is ""fixed", permanently. It's the rear that blows for us light guys.



If you outweigh or outride me (170, slow
) you'll need some other setup. Or none. Lighter or heavier fork oil might be all you need.



Fork oil, (and fork oil level) is generally one of the most neglected maintenence items items on any bike cuz it's a PITA to some. Sometimes just flushing and replacing the oil and setting the oil level properly can wake your fork up if it's been neglected.
 

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The only TW springs I saw on the Hyperpro site were listed for a TW125. Are they the same as the TW200? If so, they should replace the OEM front springs without other modifications?



Thanks,

Dusty
 

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Great idea. When you are done, please include fork mod & springs all together so we won't loose track of a super upgrade........... For those that are less confident, you can get a nice set of progressive springs for the stock fork from HyperPro. Gerry/





The only TW springs I saw on the Hyperpro site were listed for a TW125. Are they the same as the TW200? If so, they should replace the OEM front springs without other modifications?



Thanks,

Dusty
 

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The only TW springs I saw on the Hyperpro site were listed for a TW125. Are they the same as the TW200? If so, they should replace the OEM front springs without other modifications?



Thanks,

Dusty


Yes, the 125cc fork springs are what I used (same bike different cylinder). I made a shorter PVC spacer for the longer springs as I did not want to cut (shorten) the stock spacer. Someone else on the forum is useing them as well. Gerry
 

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The fork of pre-2001 TW200 is a tiny bit shorter than the TW125's... I don't know about the springs though, maybe it's just boots that are different due to the drum/disc brake change.

I need to open up a TW125 fork that I used to install a disc brake on a TW200 and I was just wondering if I could use the old TW200 springs in it... not 100% sure they are the same length.
 

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Yes, the 125cc fork springs are what I used (same bike different cylinder). I made a shorter PVC spacer for the longer springs as I did not want to cut (shorten) the stock spacer. Someone else on the forum is useing them as well. Gerry


Thanks for the reply. Can the springs be replaced without removing the down tubes from the steering assembly?
 

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Yes, yes. Simply remove the caps, put a hook in a length or wire. Fish the old springs out, replace with new. Gerry
 

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Yes, yes. Simply remove the caps, put a hook in a length or wire. Fish the old springs out, replace with new. Gerry


Thanks again for the reply. It's great to have such knowledgeable and helpful users on this forum. I'm going to order the springs and install in the spring with the rest of my projects.



Dusty
 

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Thanks again for the reply. It's great to have such knowledgeable and helpful users on this forum. I'm going to order the springs and install in the spring with the rest of my projects.



Dusty
Ordered the progressive springs today. Any recommendations on getting the OEM fork oil out or anything else I should be aware of. I have a hand siphon pump I am planning on using. I am not going to remove the downtubes for spring installation.



Dusty
 

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Once you have a look at the gack that comes out of there you may want to consider removing and flushing the fork tubes anyway. It really is much easier than siphoning.



I use cheap by-the-gallon ATF for flushing. If you're not going to remove them I'd suck out as much of the old stuff as possible, refill with ATF to at least the height of the lower tubes, cycle the forks without springs repeatedly, siphon, fill, repeat until you get clean fluid.



Save your old spacers. If it turns out that the springs work better with spacers, experiment with PVC spacers til you get the length right, then cut permanent ones from one of your TW spacers.
 

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I concur with Lizrdbrth, removing your fork tubes is a better way of getting all the gunk out of there. Also, easier to work in (cycle) the new fork oil.



This past winter/spring I had to replace my fork boots, thus having to remove the forks. I'm glad I had too, as there was a ton of gunk mired in the bottom of the tubes which didn't come out with just dumping out the oil. I suspect siphoning or vacuuming out the old oil wouldn't get it all the gunk either without a good flush. Flushing the tubes works best, but can be done without removal.



That's my recommendation.
 

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To get all geeky about it, light oils tend to be hygroscopic.



In other words they attract moisture from the air. In use, forks don't generate enough heat to drive this moisture away, so the fork oil combines with the moisture from the air, condenses in the airspace, then emulsifies in the tubes and settles in the lower legs.



Basically it's always raining inside your fork tubes. This will rust the top of the springs and spacers, and the little chunks and flakes of rust will go immediately downstairs as well. This problem gets worse, not better, on stored or little-used bikes.



BTW, it ""rains" to some extent inside your crank case as well, every time you start your bike after a few days of it being parked. The difference is that the engine heat quickly evaporates the moisture and floats it harmlessly out of the crank case vent as water vapor. In a fork tube it has nowhere to go, and no heat source to ever evaporate it.



A lot of people panic thinking that the gray gack is aluminum shavings, and in some of it is, but it's mostly emulsified oil. In either case it needs to be cleaned out of there on a semi-regular basis.



I'm not sure exactly what year they did it, but Yamaha eliminated the fork drain bolts from the lower tubes, then no doubt gave the bike its usual annual price increase to celebrate the "improvement".
 

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Lizrdbrth, admiral, good advice on flushig the tubes. I think I will go the gallon of ATF fluid route: filling, cycling, siphoning, and repeating until clean.
 

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Buy the type specified "Dexron/Mercon" rather than "Mercon" only.



Mercon is about 6wt. Dexron/Mercon tends to be about 9wt. You can use the same jug to fill your forks. ATF is excellent fork oil, in fact it's overkill compared to most fork oils, 1000 percent less expensive. and about equal to the factory's 10wt.



Its only drawback is that it's not available in heavier weights. after which the fork oil guys take over, producing essentially the same thing, but with higher viscosities.



This may start one of those oil wars, but I haven't bought a bottle of actual "fork" oil in 30 years, unless I really, really needed to stiffen a fork.



If your forks seem too soft for your liking you may need to buy heavier fork oil, but if not you can use the ATF forever without worry.



In a fork there is no advantage to buying the more expensive brands of ATF. So long as it's Dexron/Mercon the cheap house brand type is fine for both flushing and refilling.



Even if you're not quite ready to accept some internet screwball's opinion on the oil, the viscosity is about right. So you could take your first rides with the ATF and bypass the expense of the 10wt. and jump directly to something heavier.
 
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