Topic: Emulators

[maxheadflow]

Anyone using this emulator?

https://www.vintagecb750.com/products/3/suspension-wheel/52/fork-tubes-springs-seals-boots

I've used the RT's for a few setups.  Price for the valve does seem a little high for a 40 year old mod. 

[seanbarney41]

Main thing you are paying for from RaceTech is access to knowledge of how to set these parts up for your specific needs.  If you are not knowledgeable with how to adjust your emulators, you can actually make your suspension worse.  Not saying you are or you are not, but real good help is available from RaceTech.

[maxheadflow]

One thing to note is that I've done RT emulators on 4 different bikes, also had them setup front and rear forks for my XR400 and have used one gold valve kit.  Some of their recommendations were off and I ended up going back into the forks.  Instructions have been getting better tho.

[Steve_K]

I have used RT emulators in my 86 750 GIXXER and a SVS650 and I got great results and was very happy with them.  The instructions were good, though I did need to work with spring pre load.  I also used the RT springs for my weight in the forks.
Steve

[The Lone Builder]

Ignorant and curious; what are emulators?

[maxheadflow]

Ignorant and curious; what are emulators?

https://www.racetech.com/page/title/Emulators-How%20They%20Work

[JoeDuc]

Emulators take our old, simple forks and "emulate" more modern cartridge forks. A real improvement.

[maxheadflow]

I think one point to note is that the emulator only "emulates" a cartridge fork on compression.  Rebound is still the same. 

[andy750]

How much does it cost (approx) to send forks to RaceTech for emulator install? Anyone done this? I have 2 sets of spare forks lying around.

thanks
Andy

[maxheadflow]

How much does it cost (approx) to send forks to RaceTech for emulator install? Anyone done this? I have 2 sets of spare forks lying around.

thanks
Andy

https://racetech.com/ProductSearch/12/Honda/CB750K/1977-78  About mid page.

[seanbarney41]

The install is pretty easy, especially with provided instructions.  The adjustment is more difficult, but really just requires careful and honest measurement.  And once again, technical help and basic instructions are provided, with additional just a phone call or email away.  This is why I recommend spending the extra money for genuine racetech stuff.

[andy750]

How much does it cost (approx) to send forks to RaceTech for emulator install? Anyone done this? I have 2 sets of spare forks lying around.

thanks
Andy

https://racetech.com/ProductSearch/12/Honda/CB750K/1977-78  About mid page.

Thank you!

[maxheadflow]

FWIW, I bought the cheaper emulators.. Machining on the parts was good but IMO they had the wrong springs for the top valve.  The springs included were 64lb/inch which are a little stiff.   For the street RT suggests 40 lb/inch which I happened to have from another install.   Measurements were taken at 0.3 inch compression. Given that the gauge resolution is only 2 lbs. The springs were real close to advertised if you add 2 lbs to each reading.

I also added a second low speed hole.

I also added a brass spacer at the top to get a more consistent reading on spring compression and polished the screw shaft.

[maxheadflow]

I drilled the holes in the damping rod.

I checked the stock springs for rate and volume. The rate is about 0.79 kg/mm which is closed to what is recommended but the spring were to long when the emulators were added. Also the springs are much thicker than what you get from RT so I had to measure the volume the spring occupies to adjust the oil level in the tube. Found some PVC that had the same ID as the fork tube. It turns out that the spring fills up about 152mm of the tube for the 130nn recommended 130 they had was way too small volume. I added 24mm for the cap and spacer then a little more and figure 185mm was a better number.

[maxheadflow]

Forks have about 130mm travel. I measured the sag before disassemble and got 40mm. 

Adding the emulator added about 12mm of preload so I cut it off the spring and made a spring holder that added about 4mm of preload. Sag with the new forks came out to about 36mm.

Only about 40 miles on the bike, the front end feels good. Still need to get some Ikons.

[SKTP]

Race tech did my forks. It was expensive and every time I called they acted like I was really bothering them. I did not think they had very good customer service at all. My forks feel fine. They squeak if I hit a driveway slope at low speed. They are definitely better than they were (stock untouched for 30-40 years) but they are nothing to write home about...