comparison of different emulators and fork springs

Muneio

Muneio

XS650 Argonaut
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So I want to upgrade my front suspension and have been looking on Mike's XS and 650 Central. I notice that there is quite a difference in price between the Front fork springs and emulators/fork damper valves. Is there a big difference, is it worth spending the extra money? I don't race and dont plan on starting but would like to have decent suspension.

Mikes XS650
27-1086.jpg

$49.00 pair
27-1088.jpg

$59.00 set

650 Central
gv.jpg

$169.95 pair

Progressive Suspension" Late Model Fork Springs
$83.00 pair

Thanks for your help
Bill
 
Depends on what you want, really. For starters, Race-Tech emulators are the original product, designed, produced, and patented in the USA. They're a known factor. Mike's are knock-offs reengineered in either Peoples Republic of China or Republic of China (Taiwan), I'm not sure which. The only part that might differ from the Race-Tech product is the preload spring, but it's critical to the functioning of the valve. To date I haven't been able to get test comparisons of spring rate and durability. Race-Tech also supplies detailed installation instructions, setup suggestions, and tech support. Mike's does not.

Re. springs, emulator valves are designed to do well what dual-rate springs do badly, which is to modulate response of the forks to different sizes and profiles of bumps. They perform best with straight-rate springs selected for your weight, your bike's weight, and your riding style. Off-the-shelf straight rate springs aren't available in the diameter we require, but Traxxion Dynamics will suggest a rate for you and produce a custom-wound spring for less than you'd expect--the price was around $125 a few years ago, and I doubt it's significantly more now. If the springs don't deliver the right sag in a viable range of preload, they'll have another pair wound and sent to you with shipping paid both ways--can't beat their customer service and ethics.
 
Thanks for the info grizld1 looks like Traxxion Dynamics web site is down right now I'll try again later. But anyways what your saying is the progressive springs offered by both Mikes and Central really are not compatible with the emulators? Funny they don't mention that :shrug:
 
Thanx, inxs. Muneio, emulators will work with dual rate springs, but they won't work optimally. IMO there's no point installing a performance enhancement with components that won't let it work to potential. There are other alternatives to custom springs if you really know what you're doing; dual-rate springs for 35 mm. forks are available with second-coil rates of 35 lbs./in. and 50 lbs./in. They have sufficient travel before coil bind to allow you to cut the close (soft) windings off--you need an angle grinder (and frequent splashes of water) or other serious cutter for this, the trusty hacksaw won't scratch that steel. You can get a bit into the main coil of the spring if you need to; rate increases in straight inverse proportion to length, so shortening a spring by 5% yields a 5% increase in rate. The formula for how much you can shorten a spring before coil bind go like this.

Spring travel before bind = Free length - (coil count x wire diameter) - preload

Spring travel should at least equal the rated travel of your forks.

With combined bike (wet) and rider weight of around 575 lbs., I use .80 kg/mm. springs (from Traxxion). They dial in to 25 mm. of laden sag at about 1/2" of preload, so I'm guessing they'd easily handle another 50-60 lbs. combined weight within their adjustable range.

Approximate conversions: .70 kg/mm=39 lb/in .80 kg/mm=45 lb/in .90 kg/mm=50 lb/in
 
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One more thing worth noting is that you need to work with front and rear suspension together; sag should be approximately equal in front and rear. For a sport-oriented ride, 25 mm. of laden sag is a good number, and I don't find it uncomfortable doing long hauls of 500 miles a day (or I should say any more uncomfortable than anything else at 500 miles a day, at my age). 35 mm. is a good number for more touring-oriented use. If you have to do one or the other, IMO it's best to get a pair of properly-sprung premium shocks on the back end first, then do the front. I've installed premium shocks the rear and straight-rate springs with Race-Tech emulators on both of my personal rides (Ohlins on the SV650 Zook, Works Performance on the XS650D); but I've also gotten considerable improvement by adding premium shocks with 13-1/4 to 13-1/2 length and taking 4" off the "soft" end (closely wound part) of the OEM fork springs, most recently on a rescued D-model that I'm prepping for sale. One advantage to working with Michael Morse is that he can take your information and give you a good recipe for shock springs that'll do what needs to be done. His Progressive Series 14 shocks are a lot of bang for the buck.
 
hmmm lots to think about. Thanks again for all the great info, I appreciate it! So it sounds like a good budget set up is the Series 14 rear shocks and modifying the OEM fork springs as well as adding Race-Tech emulators. And you think Micheal Morse can help me determine how much to cut off the OEM fork springs or who would be able to help with that?

Thanks
Bill
 
Bill, MMM may have some advice for you there. When you're dealing with old OEM springs the actual rate is a guess (due to wear they'll have less pressure than new) unless you have the equipment to measure rate (pressure at given compression distances). Comparison of free length to book free length gives you some idea of the shape the springs are in, but modding the springs is still pretty much a cut-and-try process and may not yield the desired results. You'd calculate max allowable preload before bind after removal of the closely-wound coils, using the formula above. Check sag after the first cut with max preload, and work your way down the spring if sag is still excessive, recalculating max preload each time and adjusting the spacer as needed. Minimum allowable preload is ~1/2", so when you hit that point in your calculations the spring has been shortened and the rate increased to the max pressure the spring will deliver.

It's a bit of work. You need to keep the spring cool as you cut and flatten the coil on a grinder after each cut, again keeping it cool in the process. You may still wind up needing a pair of springs from Traxxion. But it's a great learning experience, and if you can't get the results you want, you're only out a little time--you needed those Traxxion springs anyway!
 
Harley used a 35 mm Showa fork from mid 70's to mid 80's. There springs are very close to our springs.
Our springs____________ H-D
O.D._.957_____________.950
Length _18.52__________19.625
Wire Dia. _.158_________.1875
I don't have the spring rate. They used this fork on the Sporster's and FX bikes.
I thought the difference in length could be accomadated by cutting the adjuster part off the fork cap of just below the threads and using the right length spacer to get the correct sag.
Would this work? Or would these springs be to stiff?
At about $50 it may be a viable option.
 
It's unlikely that they'd be too stiff. The HD's were heavier machines, but the XS650 OEM springs are far too soft for sporting use, somewhere in the neighborhood of .650 kg/mm. in the stiff portion of the OEM dual-rate; but you won't know if the HD springs are appropriate until you either try a pair and measure sag or get the figures on rate; you could have a cheap option or a waste of $50. Bear in mind too that most OEM Showa springs were dual rate, so the Hardly springs might put you right back to Square One. A better way to go than cutting up an adjustable cap would be to use a cap from a D-model. IIRC caps from the late 34's will also install, but my memory ain't what it was.
 
I saw a pair of flat caps on ebay. They use a big allen wrench to remove and install. I like the adjustable caps because they use a socket to remove and install. Thats why I was thinking of cutting an adjustable set down.
I might try the H-D springs, I've wasted more money on things with a poor result. I did learn somthing from those expirences.
I'll see if I can find out more about them first.
Thanks
 
I have them on my 79 some talk about it here

Have a put a couple thousand on it now, I found the clicking issue I reported was cured with a few rounds of "setting" the tapered steering bearings. The damping is noticeably better. I was riding with a guy that had a stock "special", we swapped and I liked the "mikes" set up a lot better. The other rider preferred the soft stock ride of his bike. I can hear the emulators when the valves "release". This bike rides on Shinko's and stock rear shocks. Hopefully this year I will continue to explore some more front end and handling options.
I have checked quite a few "stock" rear shocks and if the shafts aren't rusted I found most of them still have good damping action.
 
Call Doug at DEK Performance - http://www.facebook.com/DEKPerformance

I had him set my XS650 front end up with Race Tech emulators and springs last October during our get together at the Barber festival in Alabama. Awesome setup and it performed very well on the backroads of Alabama and the track at Barber.

I had the springs and emulators from Mikes in there before. I'd say the Race Tech genuine parts are better, but I'm no pro. For the money you can't go wrong with the Mikes parts. But remember you need to drill out the dampening rods to effectively disable them.
 
I got the HD springs, did the Minton mods on the dampers. ATF for oil, six inches down from the top. With the adjustable caps on the first step I get about 25 mm sag, the second step about 12 mm, Can't get to third step.
I tried several weight oils and settled on the ATF because it feels as good as any I tried.
They are firm, almost a bit to firm. I have a set of the flat caps and I will try them with spacers cut to give me about 30 mm sag. I might also get a set of the emulators. They are about 14 mm thick and with the flat caps I might not need a spacer. I'll update as I try things.
Leo
 
I have Race Tech springs and emulators on my SV650 (Awesome). It has a GSX-R750 rear shock on it with a Race Tech straight rate spring. No more chicken strips! I got RT springs and emulators for my Road Star for Christmas, which will get a Gold Wing 1800 rear shock with electric/hydraulic preload adjustment, and the stock spring rate on the Gold Wing shock is right at the 1.0 Kg-MM that suits my fat ass. I am currently buying Race Tech parts for my XS. Not sure what I'm doing with the back of the XS yet, but I will probably start with a phone call to 650Central. I will be updating as that is done.
I can't hear the Race Tech emulators release. I can't imagine that stock springs, original or NOS, would come close the the consistient performance of a new spring, be it progressive, straight rate, or dual rate. The damping and spring have to be in the same ballpark for it to work well. Anyone that has ever tried to ride with a blown shock can tell you that. The spring being sacked out causes a lot of hobby horse action that over heats the damper as well, and can cause it to blow out.
 

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