Zbroz 36" a-arms and rear skid geometry?
- Thread starter AaronBND
- Start date
I've got the same arms but stuck some 2019 850 takeoff ski shocks on them. They're actually a little shorter than what zbroz recommends.
Maybe that's the secret. I did stick some 16.2 shocks on there like I guess everyone else has. I do admit, it seemed tall.
Maybe that's the secret. I did stick some 16.2 shocks on there like I guess everyone else has. I do admit, it seemed tall.
They're right around 16" or slightly shorter.
I had similar concerns and was considering moving to lower hole and adding anti-stabs but then I rode it..
Awesome !
I didn't have the [cool] race car scale system you showed. But thanks to Amazon, my scales arrive today - and like you said, it should actually be kind of fun to see just how the sled all balances out. Not to mention better understand the dynamics involved.
On a related note - Z-Broz came back to me yesterday [after I asked about my plan to balance things out on scales] and said "put two turns of preload on the springs and RIDE IT".
I didn't have the [cool] race car scale system you showed. But thanks to Amazon, my scales arrive today - and like you said, it should actually be kind of fun to see just how the sled all balances out. Not to mention better understand the dynamics involved.
On a related note - Z-Broz came back to me yesterday [after I asked about my plan to balance things out on scales] and said "put two turns of preload on the springs and RIDE IT".
I'm about 195-200 with gear on and that's exactly what I ended up doing with there dual rate springs and it was perfect. I was originally thinking this was way to little and that's why started this thread. I had them cranked down tighter and the front end was so high making the skid look weird. I want to say I have like 4 threads showing on top of the collar and that's it. Do yourself a favor though and send your shocks to Andy at gasshockrepair.com and have them shortened to 16.250. It's literally like $60 to do and he will turn them that day or the next. He's awesome! My setup is 4 threads on the fronts (Zbroz dual rate), 8-5/16" on the center and 10-5/8" on the rear (stock springs).
Started the process last night. Didn't have much time, but couldn't wait to see. What a RODEO !! As mentioned above, I can't hardly wiggle a toe with out the weights going all over the place. Even to hold my arm out far enough to take a pic of the readouts next to the sled. But also sort cool to see how quickly things change with minimal movement.
With my existing set up, 2 full turns of preload on the fronts, not sitting on sled -
FL - 145, FR - 139, FTS - 5.6, RTS - 198
Sitting on sled
FL - 172, FR - 161, FTS - 160, RTS - 190
Needs more preload on the FTS.... if I stayed with orig length shocks.
Thanks for the recommendation on shock length update. I have a local place (I'm in MNPLS) that can do it on a one day turn around. So heading there tomorrow. Then start over. More details to come.
With my existing set up, 2 full turns of preload on the fronts, not sitting on sled -
FL - 145, FR - 139, FTS - 5.6, RTS - 198
Sitting on sled
FL - 172, FR - 161, FTS - 160, RTS - 190
Needs more preload on the FTS.... if I stayed with orig length shocks.
Thanks for the recommendation on shock length update. I have a local place (I'm in MNPLS) that can do it on a one day turn around. So heading there tomorrow. Then start over. More details to come.
S
Spaarky
Well-known member
Get on the sled, carefully jump around. Wiggle sled around to settle shocks in, then stand still. Make sure your tank is reasonably full. Makes a big difference.
Before preloading the FTS, try to lengthen your limiter strap. You may need to build one. To much preload will make the sled evil.
Before preloading the FTS, try to lengthen your limiter strap. You may need to build one. To much preload will make the sled evil.
Back at it - front shocks shortened to 16.25" center to center like those on a 19 Axys. (Orig length with 39" stance is 16.75 FWIW)
Sled alone:
LF - 140, RF - 144, FTS - 16, RTS - 185
Rider on sled:
LF - 149, RF- 151, FTS - 176, RTS - 189
Add tunnel bag, with small tool bag and 2 bottles water:
LF - 153, RF- 151, FTS - 185, RTS - 197
After adding 5/8 turn of increased preload on FTS:
LF - 147, RF - 150, FTS 198, RTS 192 Balances out at 44% on the front and 56% on the rear.
Exposed threads on shock body (end of threads to spring collar) front shocks 2 3/8", FTS 9/16", RTS 2 9/16"
Interesting adventure. Amazing how little a movement changes things. Plus the change from shortening shocks by 1/2". Time to ride ! Can't wait !
[For reference, this is a '18 Axys Pro RMK LE 155. 2.6" lug w/E Start. 4 gal of gas in the tank, oil tank 90% full, orig exhaust can replaced by an SLP can (11# loss), Z Broz 36" front end incl billet spindles, factory shocks shortened to 16.25" (2 full turns of preload) and Z-Bros 2 stage springs, and a Burant tunnel Bag w/basic tools on the back].
Sled alone:
LF - 140, RF - 144, FTS - 16, RTS - 185
Rider on sled:
LF - 149, RF- 151, FTS - 176, RTS - 189
Add tunnel bag, with small tool bag and 2 bottles water:
LF - 153, RF- 151, FTS - 185, RTS - 197
After adding 5/8 turn of increased preload on FTS:
LF - 147, RF - 150, FTS 198, RTS 192 Balances out at 44% on the front and 56% on the rear.
Exposed threads on shock body (end of threads to spring collar) front shocks 2 3/8", FTS 9/16", RTS 2 9/16"
Interesting adventure. Amazing how little a movement changes things. Plus the change from shortening shocks by 1/2". Time to ride ! Can't wait !
[For reference, this is a '18 Axys Pro RMK LE 155. 2.6" lug w/E Start. 4 gal of gas in the tank, oil tank 90% full, orig exhaust can replaced by an SLP can (11# loss), Z Broz 36" front end incl billet spindles, factory shocks shortened to 16.25" (2 full turns of preload) and Z-Bros 2 stage springs, and a Burant tunnel Bag w/basic tools on the back].
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Trenchers are great I had z Bronx with shortened shocks before. They really screwed up geometry the trenchers do not!
Thanks for the findings. Fun to look at. What made you decide to do the 5/8 turn on the FTS? This would make the front skis lighter correct? Maybe I should play with that one. Why is that one the only one with a locking ring I wonder? Also noticed your front right side is heavier than left. This must be from the starter and battery.
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Somewhere along the way (perhaps the Skinz YouTube video) I thought I saw a recommendation to balance out the weights in the rear between the FTS and RTS. Granted, this will change based on fuel level. So I did this with just under a half tank.
On the left/right question, the weights were so sensitive, the even holding my arm out to the side to take a pic of the scale readouts (all lined up beside the sled) while sitting on the seat changed things drastically. Otherwise, on that right side, the exhaust canister change out prob washes out adding a battery. But then to add a little for the starter motor ?
Real test will be on the snow just after the 1st.
I cant find those scales on amazon? You have a link?Will soon find outI have scales with remote readouts on the way (found on Amazon for $30 ea). [Didn't want to buy 4 scales but riding time is short and valuable, so I'm trying to be as prepared (in advance) as possible].
Going to be measuring and balancing out the weights with spring preloads based on the guidelines in the SPG video suggested above. Objective is roughly 150# on each ski, and the rest balanced 50/50 between front and rear track shocks of the rear skid. Adjustments will be based on rider on sled.
Rear springs are stock..... Z Broz is selling stiffer springs for the front shock of the rear skid on the grounds that the orig is too soft. Any one have this experience ?
Have to search parcel or postage scale.
https://www.amazon.com/Smart-Weigh-...534&sr=8-1-spons&keywords=postage+scale&psc=1
J
JJ_0909
ACCOUNT CLOSED
Seeing some good numbers here!
I agree with Sparky, using too much preload on your FTS is a bad idea. You are much better off trying to keep that as soft as you can and letting out the limiter. What this does is allow the front end of the skid to "collapse" and jump ontop of the snow, all the while keeping the front end weighted appropriately (150lbs per ski)
When I valve my suspension I go very soft on the FTS, and I want to keep this shock as linear as I can (if I have an air shock - I don't this year).
This allows you to open your limiter and still maintain a good angle of attack to jump on top of the snow. How can you have both? Again, its valving. Front arm collaspes, angle of attack is improved, sled jumps on top of the snow, then you'll have more track on the snow (with the limiter out).
Use your rear track shock to keep skis down.
K-Mod does this better than anything I've used (on a Polaris). Toms is a cheaper solution on the Ski-Doo side.
YMMV.
I agree with Sparky, using too much preload on your FTS is a bad idea. You are much better off trying to keep that as soft as you can and letting out the limiter. What this does is allow the front end of the skid to "collapse" and jump ontop of the snow, all the while keeping the front end weighted appropriately (150lbs per ski)
When I valve my suspension I go very soft on the FTS, and I want to keep this shock as linear as I can (if I have an air shock - I don't this year).
This allows you to open your limiter and still maintain a good angle of attack to jump on top of the snow. How can you have both? Again, its valving. Front arm collaspes, angle of attack is improved, sled jumps on top of the snow, then you'll have more track on the snow (with the limiter out).
Use your rear track shock to keep skis down.
K-Mod does this better than anything I've used (on a Polaris). Toms is a cheaper solution on the Ski-Doo side.
YMMV.
Are you drilling new holes to do this and do you need anti-stab wheels?
J
JJ_0909
ACCOUNT CLOSED
On a stock skid, yes. I'm not talking a massive amount. Maybe 3/4".
As far as the K-Mod. Woh. Its incredibly good. Its so dynamic. When in position 1 I can pick the skis up at will. Position 2 reminds me of a stock skid that gets up on the snow faster. Position 3-4 - those are for business time.
As far as the Raptors go, good shocks. But there is a change brewing
I don't want to spill the beans for Kevin though!Similar threads
