What is ment by "dropped and rolled" as a mod

[FNG]

Ok so I definatley don't know s**t about sleds but I'm tryin...

I see "dropped and rolled" as a mentioned suspension mod for many older sleds (mine is an 01 Summit 700 144 track Zx chassis). What is "dropped and rolled" and how would it improve my sled's handling or ride.

I did search for this but came up with no explanation btw...

Any pics of "dropped and rolled" vs non would also be helpful.

Thanks, I'm just lookng for some summer/fall upgrades that may be doable for me and improve my sled.

 

[Snorider]

A d&r is when you move your drive shaft down and back from stock location.

It does several things, decreases attack angle, which is the angle your tracks hits the snow. 2nd it creates more clearance from the top of your tunnel and the front of your cooler or bulkhead allowing to to run bigger drivers/taller lugs.

Another thing it does is when your track turns it will build up snow and air pressure. with more room to let it pass a d&r will reduce drag. if there's not enough clearance to get everything through the top of the tunnel/back of the bulkhead it takes power to push it through.

 

[PJ-Hunter]

It means that the chaincase/jackshaft and driveshaft has been lowered and slanted (rolled) with the driver moving farther back. It is not an easy mod to do. I believe that peeps do it to change to larger drivers and to also modify their approach angle to the snow surface. I have never done this so please correct me if I am wrong. I do not have any pics.

 

[Snorider]

Not always does it mean the jackshaft moves, I have only done a couple where we moved the jack shaft. Since the guys I was doing it for didn't want to spend the money to have theirs extended or buy a extended one already.

It makes life a lot easier if you are able to leave the jackshaft in the stock location.

 

[NoSecondChances]

Not always does it mean the jackshaft moves, I have only done a couple where we moved the jack shaft. Since the guys I was doing it for didn't want to spend the money to have theirs extended or buy a extended one already.

It makes life a lot easier if you are able to leave the jackshaft in the stock location.

Jackshaft has too move unless you run a longer chaincase. Yes, life is a lot easier if you mod the chaincase and leave jackshaft in stock location.

I will post pics tomorrow of a bulkhead sitting in my garage with the stock driveshaft location and the now D&R'd location.

Its probably one of the hardest mods to do to a sled.

NSC

 

[puckered]

Not to jack, but how does the D&R affect handling? I mentioned it to a bud that wrenches on sleds, he said it messed up the handling but wasn't specific. Any thots?

 

[Adrenaline Revolution]

Not to jack, but how does the D&R affect handling? I mentioned it to a bud that wrenches on sleds, he said it messed up the handling but wasn't specific. Any thots?

When you D&R the drivers you must also drop the rear axle attatch points accordingly or you will lose a ton of ski pressure which makes railing into the corners pretty hairy!

No big deal though, Drop brackets solve this.
Generally speaking, if you drop the front by an inch you'll have to drop the back by around 2 inches for a 144" track and about 3" for a 151".

Most sleds after 2001 or '02 already solved the "angle of attack" problem that was prevalent on the earlier sleds though.

As long as we're talking old solutions on the old iron...Anyone remember "Tunneling" your sled?
Ah yes... The good old days!

BTW, if you don't want the hassle of the whole drop and roll but still want to decrease the angle of attack (lessen the angle) just re-drill the front axle holes about 1 1/2" inches back from the stock position and move the rear axle location back the same.
It decreases the angle a little.

 

[Skadi]

Its probably one of the hardest mods to do to a sled.

NSC

Agree, this is a NASTY mod!! Even WITh a template to help you know that you're drilling your holes in the right spots!! I did it to my sled last summer and it was by far the most involved thing I have ever done! However I can now run a 2.5" Challenger Extreme with 8T 3.0 Avid drivers!

Pics:
You pretty much have to strip the sled down so it's easy to work with:

Final chain case location:
If you're looking at doing one on a Rev I have a lot of lessons learned for ya!

No big deal though, Drop brackets solve this.
Generally speaking, if you drop the front by an inch you'll have to drop the back by around 2 inches for a 144" track and about 3" for a 151".

Why would you drop the back MORE, aren't you taking AWAY your attack angle gained?

I've heard a few schools of thought here. One that you want to drop it as LITTLE as possible. You locate your front holes according to driver location -don't want any rub points when suspension is compressed (slightly oversimplified, I remember this being QUITE the process and the location given to me by the so called experts was NOT the right location, I had no adjustment left in my skid if I could STTTREEETCH it enough to get the skid in there, so, ya, I have the lovely swiss cheese effect!!) and then you do your rear the SAME as you dropped your front to NOT do a 'drop braket affect'.

This is what I did... I'm curious to hear some reasoning and thoughts behind the drop brackets and the drop and roll and how the two play together... or if they do... is it just a question of if you like the drop braket afect? does the drop and roll not really play into that? Nervous that it will turn into a drop bracket bashing (or a bashing of those who don't use drop brackets) thread!! I hope we can keep it civil and I can maybe learn a few things here!! I'm sure this has been discussed before but hey, while we're all here...

 

[Snorider]

I have never heard of having to use drop brackets with a drop and roll to maintain ski pressure.

I never have on all the ones I did, I would suspect limter straps being too loose.

As for the handling part I couldn't say better or worse, mine handles great, or so I think.

 

[wasatchrider]

i can see why people wouldnt want to drop and roll putting on the camo extreme. makes me want to keep my crappy 5.1 the camo looks to be the same lug layout only stiffer. i ran it on my m7 and liked it alot but i dont mind my polaris track it does suck climbing when it gets hard but there is usually plenty of snow when i ride.

 

[icr]

Drop and roll?

The second and third steps (respectively) to extinguish yourself if on fire.

 

[Skadi]

i can see why people wouldnt want to drop and roll putting on the camo extreme. makes me want to keep my crappy 5.1 the camo looks to be the same lug layout only stiffer. i ran it on my m7 and liked it alot but i dont mind my polaris track it does suck climbing when it gets hard but there is usually plenty of snow when i ride.

The track I had on there in the pic wasn't the camo extreme... it's the challenger light. Known to be pretty much ONLY a spring snow track... i hadn't gotten my hands on the camo extreme yet!!

 

[Adrenaline Revolution]

Why would you drop the back MORE, aren't you taking AWAY your attack angle gained?

....and then you do your rear the SAME as you dropped your front to NOT do a 'drop braket affect'.

Naw, you misunderstood what I was saying (because I didn't say it very well)

If you DON'T want to go through all the work of a drop and roll to reduce angle of attack you could do the re drill and set back like I was talking about.
It DOES reduce the angle but only very slightly.

As far as the rear end or drop brackets go...
'If you drop the front of your track but not the back you will lose ski pressure.
Think of lifting the sled by the real bumper and leaving the skis on the ground...
How much higher is the back of the track off the ground compared to the front?
you'll need to drop the back almost twice as much as the front to maintain geometry and the correct ski pressure.

Does that make sense?

BTW, drop brackets were designed to get the track farther down into the snow to help find harder pack and to relieve some clearance issues to the tunnel.
I hated them.
Wrecked the whole feel of the sled for me.

 

[longtrack156]

Drop, jackshaft;

Roll, note old chaincase location;

Tunnel;

 

[Adrenaline Revolution]

Nice looking tunnel job on that SS !!!

 

[yardsale_oem]

A d&r is when you move your drive shaft down and back from stock location.

It does several things, decreases attack angle, which is the angle your tracks hits the snow. 2nd it creates more clearance from the top of your tunnel and the front of your cooler or bulkhead allowing to to run bigger drivers/taller lugs.

Another thing it does is when your track turns it will build up snow and air pressure. with more room to let it pass a d&r will reduce drag. if there's not enough clearance to get everything through the top of the tunnel/back of the bulkhead it takes power to push it through.

yep!!!!!
i did it to my rev to accomodate a camoplast extreme.........had to get smaller drivers too.......makes a world of difference!!!

 

[FNG]

Wow!, hey, thanks for the replies, definaltely more work than I feel up to (or need) so I won't be doing this to my sled this fall but thanks for the info as I was having a hard time finding exactly what a drop and roll conversion was.

This forum is a great source of information!!!