fork modifications and rebuild valving

[1973cb750]

here is my write up on the Racetec gold valve install and a set of .95 kg springs for my weight 

I will add to this post as I rebuild and add the gold valve.

first I removed the wheel and fender brakes.

Then remove the 6mm allen cap out of the bottom of the fork leg have a drain pan ready 

 

next gently pry up the dust cover 

next remove the spring retainer clip do not scratch the chrome on the fork tube 

next break the fork cap loose then unscrew the preload adjuster 

Here is how I remove the lower leg and fork seal

I do all this with the forks in the triple trees once I remove the lower legs then take the legs off the triple trees 

Here is a quick video of the fork assembly and the race web valve fits in

I will have more to add soon keep an eye out for part 2

 

[Karidis]

I thought I had read that the top of the damping tube had to be machined for the emulator to fit. I hope this is incorrect. I have the emulators in my KX250 and it made a difference.

 

[rdprdp01]

Great write-up and much appreciated! David

 

[1973cb750]

I thought I had read that the top of the damping tube had to be machined for the emulator to fit. I hope this is incorrect. I have the emulators in my KX250 and it made a difference.

the newer ones have a machined adaptor we will find out for sure !

 

[1973cb750]

got the emulators ordered now i got make some more cash olla to get the springs

 

[The_Crackerdog]

here is my write up on the Racetec gold valve install and a set of .95 kg springs for my weight 

I will add to this post as I rebuild and add the gold valve.

first I removed the wheel and fender brakes.

Then remove the 6mm allen cap out of the bottom of the fork leg have a drain pan ready 

 

next gently pry up the dust cover 

next remove the spring retainer clip do not scratch the chrome on the fork tube 

next break the fork cap loose then unscrew the preload adjuster 

here is how I remove the lower leg and fork seal

I do all this with the forks in the triple trees once I remove the lower legs then take the legs off the triple trees 



here is a quick video of the fork assembly and where the race tec valve fits in 


I will have more to add soon keep an eye out for part 2

Thanks for posting this info and the video. I’m going to be doing the same soon, so very helpful. Looking forward to part 2 ?

 

[1973cb750]

video of seal install how too

 

[1973cb750]

ok i got the new valves installed pretty easy not modifications other that the dampening rods.  make sure to use a locking compound on the dampening rod bolt and torque to 15 ft lbs install spring if it wont tighten.



Gold Valve install

---

here is a few of the enlarged holes and adding 2 holes per rod 

here i drilled one hole in the 2 blank plates my set up called for only 1 hole per side 

helps to drill a small hole after measuring and center punching a spot for the new holes. I used a cheap step bit and made them all 5/16. that worked fine I deburred the inside with a wooden dowl and sand paper then cleaned them out with carb cleaner followed by compressed air 

this is what comes in the box
2 valve assemblies 
2 blank plates 
3 sets of springs 
2 circlips not used in the case of the cb1100

---

here is a detailed video the cb is not much diff than our bikes

 

[1973cb750]

each fork took exactly 16 oz to get the right oil height measurement of 140mm that race tec recomends that spec is not what the manual states fyi 

almost done tire and springs next

 

[Cormanus]

Really helpful stuff. Thanks.

 

[pdedse]

Very interesting to see this done on the CB1100. I just put a new shock and springs with drop-in damper cartdridges for my DR650. I don't claim to understand how they work, but many dr650 owners vouch for their improved handling for off-road riding. Hopefully, I get the chance to find out soon.

 

[1973cb750]

welp everything is together with the springs forks feel great I may need to stiffen the low speed damping

 

[Tev62]

Very interesting to see this done on the CB1100.  I just put a new shock and springs with drop-in damper cartdridges for my DR650.  I don't claim to understand how they work, but many dr650 owners vouch for their improved handling for off-road riding.  Hopefully, I get the chance to find out soon.

A lot of the older bikes, and still many new ones, use a simple hole in a damping rod. The oil must get through that hole, the resistance though is very mutch based on the velocity of the oil going through the hole. Very little damping at low speed but increasing by the square of the velocity at higher speeds (damping speeds i'm talking about). That can lead to underdamped bikes at low speed damping and harsh suspension at high shock speeds. Either way there will always be some compromise. The cartidge damper gives back a certain proportionality, linearality to damping and hence much better tuned performance.  

SHOWA made a bit of a big deal of markeing their "dual bending valve" fork technology as used in the 2017MY EX and I think the later NC750X's, I have to say it is excellent fork in that respect but it is actually not a full cartridge fork. A great solution for a non adjustable fork though with great intermediate performance. It's design goal was to bridge low and high speed damping transitions.

 

[rdprdp01]

Brilliant!!