got a track day pic lets see

[Excalibre]

Nice pics there. What mods have you done on your TRX? I'm planning some cosmetic mods at the moment and looking for some inspiration.

Caution - thread drift follows:

For that particular bike I wanted to keep the original look so the mods have all been performance related i.e. handling, braking and power. The major ones have been Racetech fork springs and Gold Valve emulators, R6 shock, R1 gold spots and master cylinder, Keihin FCR 41s, Toby steering damper.

My track bike build will be heavily modified in all areas. Cosmetically the frame has been modified to fit an R6 rear end which I think looks cool and is a fairly common mod for TRXs. Credit to the previous owner for starting the frame alterations before I took over the project.

Here's some teasers:









Cheers

[Excalibre]

And a video!
This was the first outing with the quickshifter (thanks Cobba) and it was a ton of fun once I got used to it.
https://www.youtube.com/watch?v=-k5JyjJfFvg

[dandywarhol]

Looks very composed out there.
Did you drill an additional hole in the damper tube for the rebound damping with the emulators?

[Excalibre]

Looks very composed out there.
Did you drill an additional hole in the damper tube for the rebound damping with the emulators?

Hi,

Short answer, yes.

Long answer:
The red track bike (aka 'Track Thunder') has a complete R1 front end so it has fully adjustable cartridge forks.
My black 'street' TRX has the Racetech emulators. I did use it on the track half a dozen times before building the track bike. In my opinion, properly set up stock forks with Racetech springs and emulators feel just as good as the R1 forks.

After brazing all the rebound damping adjustment and indexing holes


I fitted drill bits into the holes on the adjuster sleeve to see what size equated to what damping. i.e. the largest hole/bit = position 1, through to no hole = position 4


I selected a bit size in between 2 and 3 and drilled a hole in the tube here (from memory it is opposite the existing rebound hole) . Effectively the rebound damping is set at the equivalent of 2 1/2 which is a nice compromise between street and track.


Cheers

[dandywarhol]

Thanks for that. I drilled a hole in exactly the same position - 2mm from memory but I have to use 20W oil to get decent rebound damping which means that the emulator spring (yellow) is only about 1 turn in to get the compression damping right. I'm still not happy with the rebound and wondered if I didn't need the additional hole drilled. My thoughts behind this is that I liked running maximum rebound (4th click, no hole) with the original damper rods. I have a spare set of damper rods and I was thinking of keeping the adjustable sleeve in there (having added the additional 8mm holes for compression oil access), setting it to fully closed (no hole) and not drilling a hole in the waisted part of the tube. In theory, on the fork extension, the low speed damping plate will open and allow the oil to flow past the plate to control rebound damping (along with oil viscosity). If need be, if the damping was too strong on rebound, I could remove the emulator and adjust the rotary collar with the old "D" shaped rod to allow the rebound to be softer.

I hope that all makes sense - I'm running on the road, weight 65kg and reverted back to stock 0.7 Euro springs as the 0.9 Racetechs were too firm for me.

Any thoughts?

[Excalibre]

Thanks for that. I drilled a hole in exactly the same position - 2mm from memory but I have to use 20W oil to get decent rebound damping which means that the emulator spring (yellow) is only about 1 turn in to get the compression damping right. I'm still not happy with the rebound and wondered if I didn't need the additional hole drilled. My thoughts behind this is that I liked running maximum rebound (4th click, no hole) with the original damper rods. I have a spare set of damper rods and I was thinking of keeping the adjustable sleeve in there (having added the additional 8mm holes for compression oil access), setting it to fully closed (no hole) and not drilling a hole in the waisted part of the tube. In theory, on the fork extension, the low speed damping plate will open and allow the oil to flow past the plate to control rebound damping (along with oil viscosity). If need be, if the damping was too strong on rebound, I could remove the emulator and adjust the rotary collar with the old "D" shaped rod to allow the rebound to be softer.

I hope that all makes sense - I'm running on the road, weight 65kg and reverted back to stock 0.7 Euro springs as the 0.9 Racetechs were too firm for me.

Any thoughts?

I think we may have hijacked this thread.
That set up should give you heaps of rebound damping. I'm a bit more chunky than you at 90kg so we can't make a direct comparison with our settings. I have 0.9 springs, the 0.7 springs should be pretty close for your weight.
Did you adjust the pre-load for correct sag? You probably want around 32-35 mm for the street. If the pre-load is too strong it will make the fork springs seem stiff and also cause the forks to rebound too quickly.
NB. The emulator does not control/affect rebound damping at all, it only controls compression damping. Rebound damping is controlled by a combination of the size of the small hole(s) drilled in the top of the damping tube and the oil viscosity. See the bottom of this link: http://www.racetech.com/HTML_FILES/DampingRodForks.HTML
If you liked your rebound damping at position 4 before fitting the emulators, then having no extra rebound hole drilled will give exactly the same rebound damping with the emulators installed.

Cheers

[dandywarhol]

That's where I've gone wrong. I've converted a lot of TDMs to Racetech and been happy. Preload/sag all good. I've got an Ohlins on the rear, maybe that's why I'm finding the front so sensitive.
I understand how the rebound is essentially controlled by oil weight but what do you think of leaving the sleeve in place, setting it to position 4 but having the option to adjust it by taking the emulator out and turning the sleeve? All the other holes, including the detent will be blocked by the sleeve so oil shouldn't flow past the damper rod top.
Sorry to hijack the thread, maybe we should discuss this by PM?

[Mincehead]

I don`t see anyone complaining, crack on lads it`s interesting reading.

[Excalibre]

I understand how the rebound is essentially controlled by oil weight but what do you think of leaving the sleeve in place, setting it to position 4 but having the option to adjust it by taking the emulator out and turning the sleeve? All the other holes, including the detent will be blocked by the sleeve so oil shouldn't flow past the damper rod top.

Theoretically that could work and give you adjustable rebound damping, however;
I think that the sleeve would restrict the flow of oil through the emulator when a high flow rate is needed for high speed compression damping. I.e. it would undermine the purpose of drilling the extra 8mm holes in the bottom of the tube. See fig 3.16 in the previous link.
The cut-outs in the sleeve would be controlling the rate of compression damping which would defeat the purpose of installing the emulator in the first place.

[dandywarhol]

Yep, you're absolutely right - kinda losing the plot here, of course the sleeve assembly would interrupt the compression damping Duh!

Think I'll make up another set of modified rods without the additional hole and try to get down to 10W oil to make the compression damping work better.

Thanks for re-opening my ageing brain again..........................

[dandywarhol]

I understand how the rebound is essentially controlled by oil weight but what do you think of leaving the sleeve in place, setting it to position 4 but having the option to adjust it by taking the emulator out and turning the sleeve? All the other holes, including the detent will be blocked by the sleeve so oil shouldn't flow past the damper rod top.

Theoretically that could work and give you adjustable rebound damping, however;
I think that the sleeve would restrict the flow of oil through the emulator when a high flow rate is needed for high speed compression damping. I.e. it would undermine the purpose of drilling the extra 8mm holes in the bottom of the tube. See fig 3.16 in the previous link.
The cut-outs in the sleeve would be controlling the rate of compression damping which would defeat the purpose of installing the emulator in the first place.

I had another look at the sleeve today and I think I'll open up the segment cut out holes in the adjuster sleeve - there should be enough room to get the oil past there to the emulator. I blocked off the holes in the damper rod and the lower cap screw and blew down the top of the (dry) damper rod - it didn't let much air past in the minimum damper position. With oil adding additional sealing, I reckon the old, modified, rebound adjuster could be left in place without brazing up the holes and a finer tuning could be made to the rebound damping combined with oil weight - your thoughts Excalibre? Do you think the small hole in the waist of the damper rod would still be required for rebound?

[Excalibre]

I had another look at the sleeve today and I think I'll open up the segment cut out holes in the adjuster sleeve - there should be enough room to get the oil past there to the emulator. I blocked off the holes in the damper rod and the lower cap screw and blew down the top of the (dry) damper rod - it didn't let much air past in the minimum damper position. With oil adding additional sealing, I reckon the old, modified, rebound adjuster could be left in place without brazing up the holes and a finer tuning could be made to the rebound damping combined with oil weight - your thoughts Excalibre? Do you think the small hole in the waist of the damper rod would still be required for rebound?

Hello again,
In my opinion you'd need to remove virtually all of the material around the cut-outs to ensure there was no resistance during high speed compression damping to allow the emulator to work as designed.

How about this for an idea?:
Remove most of the metal around the cut-outs, including the central section, leaving 3 small lugs around the perimeter. Make a special tool using an appropriate diameter pipe or old socket with notches cut in the end to engage the lugs. This tool would be used to rotate the sleeve to adjust rebound damping (fork spring and emulator removed).

You do need to leave the original small hole in the waist open otherwise the fork will essentially not be able to rebound at all (with adjuster set to 4). The only way for the oil to return would be past the bushes. See figure 3.19 at the bottom of this page http://www.racetech.com/HTML_FILES/DampingRodForks.HTML
During the rebound cycle the oil flows from chamber 'B' through the centre of the damping tube to chamber 'A'. The waist hole plus the selected adjuster hole control the rebound damping rate.
When the adjuster sleeve is set to position 4 the waist hole is the only available passageway.

I'm really interested to hear how it works out, you could revolutionise the emulator rebound damping world!

If that all seems like too much trouble, just braze closed the extra holes you drilled in the waists of your original tubes and you'll be back to the equivalent of position 4.

Cheers

[dandywarhol]

Thanks, we're thinking along the same lines. Good to get another opinion.
When I get this done I hope to be able to use 10 weight oil, then I'll need to refit the low speed plate with 2 holes rather than the 4 hole one fitted at the moment
Cheers

[cobbadiggabuddyblooo]

Nice pics there. What mods have you done on your TRX? I'm planning some cosmetic mods at the moment and looking for some inspiration.

Caution - thread drift follows:

For that particular bike I wanted to keep the original look so the mods have all been performance related i.e. handling, braking and power. The major ones have been Racetech fork springs and Gold Valve emulators, R6 shock, R1 gold spots and master cylinder, Keihin FCR 41s, Toby steering damper.

My track bike build will be heavily modified in all areas. Cosmetically the frame has been modified to fit an R6 rear end which I think looks cool and is a fairly common mod for TRXs. Credit to the previous owner for starting the frame alterations before I took over the project.

Here's some teasers:









Cheers

Is that a satin black paint job on your motor Wayne???

[Excalibre]

Is that a satin black paint job on your motor Wayne???

Hi Cobba,

The head and block are Dupli-Color Engine enamel Low Gloss Black DE1634
Some of the other engine casings were touched up with Dupli-Color Engine enamel Gloss Black DE1613

I bought it from Supercheap Auto

Cheers