2010 Sach Fork Questions.

[hallam76]

Hi firstly i am new to gasgas and this forum and will be greatful for any feed back, after many years riding Hondas I have got my first gasgas a 2010 250 CC. I am very happy with the bike and the suspension is not too bad, i have decided to service the forks, and at the same time check what the shimming and other things are set to. I have previously done a lot of revalving work on showa and WP forks but these are my first set of Sach and would like to confirm what the base settings are, as on close inspection it seems that there are some bleed holes in the compression piston are these std? (I could attach photos if anybody is intrested)
Therefore can anybody confirm the exact shim stack in std fork in the compression rebound and midvalve stack? I must point out that i bought the bike second hand so i dont know exactly if they have been modified or not.
Also can anybody give there feedback on which make of of oil seems to work best and what air gap? it seems they were presently set at 110mm ish?
Thanks in advance for your input.

[twowheels]

Originally Posted by hallam76

Hi firstly i am new to gasgas and this forum and will be greatful for any feed back, after many years riding Hondas I have got my first gasgas a 2010 250 CC. I am very happy with the bike and the suspension is not too bad, i have decided to service the forks, and at the same time check what the shimming and other things are set to. I have previously done a lot of revalving work on showa and WP forks but these are my first set of Sach and would like to confirm what the base settings are, as on close inspection it seems that there are some bleed holes in the compression piston are these std? (I could attach photos if anybody is intrested)
Therefore can anybody confirm the exact shim stack in std fork in the compression rebound and midvalve stack? I must point out that i bought the bike second hand so i dont know exactly if they have been modified or not.
Also can anybody give there feedback on which make of of oil seems to work best and what air gap? it seems they were presently set at 110mm ish?
Thanks in advance for your input.

Hallam: Welcome aboard! We don't get a CC here in the States, but our XC settings should be similar.

There are indeed two bleed holes in the compression pistons (1.35mm)

Sticking with compression, from the base valve
24x0.15
12x0.15 crossover
20x0.15
16x0.15
14x0.15
12x0.15
10x0.3 (2) spacer
13x3.1 collar

The rebound pistons also have two bleed holes (1.5mm)

Midvalve
25.00x0.2 (3)

Rebound from the piston towards the nut
24x0.10
22x0.15
10x0.15 crossover
18x0.15
14x0.15
12x0.15
8.95x0.3 spacer
13x3.1 collar

110mm seems high for the oil level - I think the spec is out to 140mm - but you can decide based on bottoming performance. The stock oil wasn't horrible, but I typically use KYB 01M in all of the bikes I service.

Please share your valve stacks, and welcome again.

[HuskyDude]

CC = CrossCountry = XC

[twowheels]

Originally Posted by HuskyDude

CC = CrossCountry = XC

Sorta/kinda/maybe. US 2010 XCs were rest-of-world ECs without blinkers etc. I'm not 100% sure that they are equivalent to CCs (which I think was an official designation).

[hallam76]

Thanks for the input guys, i will check the deatil closely and report back, just one more question I know getting the centre cartridge apart is usually tight but these seem extremely tight I have tried a bit of heat but no look I thought I would check they are lefthand thread or anthing odd, any tips?

Also here in the UK a CC model is the same as a EC but without a back light speedo or flashers.

[twowheels]

Originally Posted by hallam76

Thanks for the input guys, i will check the deatil closely and report back, just one more question I know getting the centre cartridge apart is usually tight but these seem extremely tight I have tried a bit of heat but no look I thought I would check they are lefthand thread or anthing odd, any tips?

Also here in the UK a CC model is the same as a EC but without a back light speedo or flashers.

Heat, heat, and more heat! And the correct tools. Once you've got it good and hot - but don't melt the little seal inside. Then, holding the cartridge tightly, rap the tool to break the cap free and you're in.

Took an updated/2011 compression tap apart last night - shorter tap due to shorter piston. Bleed holes are gone, replaced by a bleed shim and significantly different valving.

[hallam76]

Thanks will give it another go, what is the compression stack like compared to 2010's could you post a pic of the new midvalve/rebound piston setup. Here in uk we are not getting Sach on the 2011's they coming fitted with marazocci's so would be interested to know what the differences are in the Sach 2011's

[hallam76]

I have checked the setup of the shim stacks and it seems that they are std, I am not unhappy with the performance so I have left them std with some fresh oil for now. While they were down I fitted some air bleeders, I have now realised just how much air pressure they build up, They build up more pressure just bouncing them up and down in the garage than my showas used to after a full days riding, is this normal???

[TNT Cycle]

Forks seals could be going? Mine never built up much pressure until they had some hours on them. Iam at 65 hours and they will build up quickly now as the seals allow air to bypass as they move.

I did some revalving with my 2010 sachs and love the results. I took the 12mm shim from the base of the base valving and added it to the crossover. I took the midvalve apart and removed one check plate shim and reassembled. Oil level is set at 100mm. The results are brillant for my 155pound self. I did moto and trail riding to test it out and couldnt believe the difference.

cheers,

Rick

[hallam76]

After the rebuild things have started to dry up where i go riding and thus the suspension is starting to feel a little harsh. I am going to make some small mods but was looking for some feedback on my thoughts. I think the forks are riding too low in the stroke and it seems i am using neary all the travel quite easy, i have noticed that there is very little preload on the fork springs so have decided to add a 5mm spacer to try and add a bit of preload to the spring, I have also decided to try running the air gap at 100mm instead of 120mm. I have also added a 12mm to the compression stack cross over. My theroy is to try and keep the forks up the stoke a little but give it a bit of plusher feel. Am i going in the right direction????