TXC 310 Fork oil

I am changing my fork seals and oil and was wondering if the manual is correct. Seems a little off. What I am seeing is heavy oil and lower volume then most Kayaba recomendations. Usally it is 5 wt and 340ml of oil. When I search for Kayaba KHL-15 all I get is a cross referance for Yamaha S1 which is more like 0wt.

I plan on using Maxima racing Fork Fluid (5wt) (A standard in other brands KYB Closed cartrige fork). I will start with the recomended 325 ml of oil and see how it works. Anyone eles use 5wt and have good results? I belive it will work very well wiht the 5wt maxima.

Manual says
Front fork oil KAYABA KHL15-11 (SAE 7,5; SAE 5 for extremely cold weather)

TC: 325 cu cm

TXC: 325 cu cm

I figured I would follow this up for people using the search engine.

The service manual for the 250 TXC stated 325 cu cm for the outer cartrige (as in the above post). I found in the owners manual it states 360 cu cm for the outer cartrige and no recomended viscosity, only the same Kayaba KHL-15 recomendation.

I went with 325 ml and it works well (feels very simalar to stock, only a little better beacuse it is freshly serviced). I will use 360ml as a maximum if I feel I need to up the oil level to up the bottming resistance (5-10 ml at a time.)

So for my referance I am fine recomending 325-360 ml of 5wt Maxima racing Fork Fluid on these forks (fyi Yahmha recomends 330ml on these forks on a yz 250)

I will see how it does at the MX track and if it bottoms hard I will add oil 5ml at a time. But for right now it worked wel for me at 325 off-road.

I also found it suprising that I could get both forks done with one bottle of oil. (bottle says 1L but contained 1060ml) so if you do not waste a drop of oil you can do both forks with one at 325ml. Still buy 2 because you may come up a little short. After I was done I took apart the first leg and remesured in order to make sure I did not measure wrong teh first time . I didn't.

Also Motion Pro's "Ringer" fork seal driver is a work of art, most well desigened tool I have used. Beats the ones that are held together by pins hands down.



OIL QUANTITY IN EACH FORK LEG

- TE: 674 cm

3 (41.13 in3)
- TXC: 556 cm

3 (33.93 in3)
Cartridge: 196 cm

3 (11.96 in3)
Fork sleeve: 360 cm

3 (21.97 in3)

After a few outings to the MX track and a bunch off off road stuff, I finally settled on 350 ml of oil in the otter chamber

At the recomandation of MikeB I installed a set of Merge racing RRS http://www.mergeracing.com/store/index.php?app=ccp0&ns=prodshow&ref=00-036

This was a missing piece of the puzzle. Rode them today. Improved plushness on the small nasty stuff (the rocks and trail nasties just disapeared). It added fantastic front end traction and control in the corners (what I was looking for). The stock forks were very good but I some times had the front end climbing out of ruts in the corners. I have not tried the forks on the MX track but they were unbelivable on single track.

Took me about 20 mins to install them pretty straight forward if you have been in your forks before (and have the correct tools).

Hi ive been after some of these but im in the UK so expensive to ship.

My question is did u stay witht the stock valving and large spring as my 2013 wayyy too stiff.

Also did u remove the inner chamber to fit and then just drop back in without refilling/bleeding as mine wont come out with a strip?

Thanks

The initial install I did it without taking the whole fork apart as I had just serviced it. I just took off the top of the inner cartage and remove/replaced the springs. I initially used the stock springs and valuing; I just changed the pressure springs.

On my next service I changed seals, bushings and main springs (went softer to .42 springs). I also did the free piston mod (drilled 4 holes in each) totally changed the bike as it was much more forgiving and the front end tracked better in the ruts and was not as prone to washing out.

I tried removing 2 shims from the comp stack and was great, i also dropped the forks to the 2nd line, a mate thought it was too soft so i added the thicker 2nd one back and now its terrible again.

Im going to remove the added one and try again it was my rebound not wound in enough making it boing about not my compression. I also did the 4 holes.

Ive also been given some .42 springs and im 79kg without gear, how is yours on big jumps now?

thanks

I have taken a break from the MX track so I have not had it on big jumps all that much (actually only one trip to the track since the change). Still worked well for me then but the big improvement was the front end handling entering a corner.


Current setting

4.2n/mm springs and 325 ml of Maxima Racing Fork Fluid

I am having a hard time with roots and nasty stuff as well.. Lots of deflecting... My TXC 310 is @ 2014.. Same forks as the 12 correct?

My plan is to try some lighter weight fluid with less volume first.. I am running comp all the way out and I am a solid 200lbs. Thanks.

Yes they are the same fork. The Merge racing spring made the largest improvement overall for me.

A different viscosity oil only matters in the inner chamber. The outer chamber dose not have shims or valves, only a bottoming cone that influences the last 1/2" of travel. The holes in the spring cups have a little bit to do with damping but not much over all.

So oil in the outer chamber mainly effects the volume of the trapped air which acts as an air spring. Less oil = softer. More oil = harder.

Thanks.. I will do the Merge spring.. Now I need to find some bottom end power.. It makes great power but it seems to be a mid to top end thing.. Not the best for trials type enduro..Suggestions.?

The Black head motors (2012) make better low end then the Red heads do; (Red Heads make more top end power). My 2012 did pick up some good HP and more torque from a Full FMF system (Power bomb and an Q4) the 2013 -2014 may benefit from a better exhaust as well.

Power Bomb it will have to be.. Thanks..

I've got a Powerbomb/Q4 setup on my '12 model as well, and I agree. It lugs much better now and pulls out of it strongly.

Hi i found lighter springs (.43) and lighter fork oil ( i mixed rock oil 5w with 2.5 50/50) and removal of 2 compression shims helped ALOT. ALSO if u want FULL TRAVEL use 290ML of oil!!

What exactly do these springs do? Will the merge springs affect my sag numbers? What tools do I need?

My 2012 TXC has too much preload on the springs. is there a spacer under the spring I can shorten?

Its a progressive rate ICS, or cartridge spring. IMO, better to adjust valving and retain a higher initial cartridge pressure with stock springs so the oil is more stable. The reason they feel soft initially is not the rate difference directly, that accounts for very little. Its because the cartridge oil is more aerated and cavitation more prevalent at lower pressure and higher top stroke velocities. I have a lot of experience with the Marzocchi PFP fork that uses an adjustable cartridge spring and runs MUCH higher pressure than a KYB even at its minimum setting. You run light valving and adjust the ICS preload externally, the difference is quite dramatic and you can demonstrate this to yourself in seconds with the turn of a wrench.

The Merge Racing springs soften the first 3" of travel then they ramp up deeper in the stroke and the valving gets progressively stiffer. They are a polarizing product for some reason people "hate" them and say they do not work, but whoever uses them seems to love them.

Tools needed are the KYB cartridge wrench which you need to service them anyway. http://www.rockymountainatvmc.com/p/731/17693/Tusk-KYB-Dual-Chamber-Fork-Cap-Wrench?term=kyb wrench


http://www.rockymountainatvmc.com/images/prod/275/t/tus_08_kyb_dua_cha_for_cap_wre.jpg

No hate, just pointing out to previous poster they have nothing to do with main spring rate. Many tuners choose to install softer ICS as part of a revalve, which do the same thing in the initial stroke, valving being equal. If you like the feel thats good then. Problem is it blows through this part of the stroke too fast because the oil is full of bubbles. Rebound is also compromised, which causes the bike to stand up in a turn. I noticed this immediately on a TXC I rode set up like this. Light ICS with no preload is like an OC fork in the first few inches. I've had good results with a higher initial pressure, and less preload on the main springs. Firm and controlled. Just another way to approach it thats all.

Thanks! I already have that wrench!