Drop and Roll.....

[Pappillion]

Ive heard a couple of you guys talking about a Drop and Roll mod. I've never heard this before. Could someone please enlighten me. THX

 

[green momba]

drop and roll is were you drop your jack shaft down and roll your chain case and driver shaft back. changes your attack angle of your track.

 

[Pappillion]

drop and roll is were you drop your jack shaft down and roll your chain case and driver shaft back. changes your attack angle of your track.

Does anyone have any pics or instructions on how to do this. Thanks in advance.

 

[Modman]

What sled is it for? Depending on that, you can get a kit from Fabcraft or other manufacturer depending on make and model you have. They make the templates and all you have to do is rivet them in and drill the new holes through the bulkhead. If there is no kit, then you have to measure and drill. It is a challenging task, not one for those less mechanically inclined. I have done several of them, it still takes me about 20 hours from start to finish. I'm pretty fussy though, others could probably do it in less time. You need to have perfect alignment on the shafts, so drilling and cutting holes and placement of the shafts is critical.

A D&R will also give you increased tunnel clearance at the bulkhead so that you can clear a taller track. mod T-cats back in the mid 90's, that was the main reason for doing it, we ran 2 1/2" plastic paddles on a "long track" 136", no drivers were made small enough, so you had to roll the case for clearance.

There are companies like Timbersled? (I know someone is making them, don't quote me on Timbersled though) or some others that are making extended chaincases so that you don't have to re-drill the jackshaft hole, it can stay inside the engine compartment. This is a more expensive option though (typically they are machined from one piece of billet aluminum which ain't cheap - looks amazing though). Another option is to have your existing chaincase cut in two and a piece welded into the middle to make it longer, I have seen some real nice ones like this, I have also seen some total butcher jobs. You will have to get the cover machined to match too and a longer o-ring. In our racers, we used to just use a lexan cover over the chaincase instead of machining the chaincase cover as well, we didn't run any oil in the chaincase since it only had to go 2000 vertical feet at a time. Some motorcycle lube on the chain and sealed bearings was all that was required. The lexan was only there to keep the parts contained in the event of catastrophic failure.

Hope that helps. If you get a kit, it will have instructions with it. I do have pics of mine, not on this computer though and they aren't very comprehensive, more like before and after shots. I can send you them once I am back at my other computer in a few weeks. PM with your email if you like.

 

[steve8]

If You Look On The Summer Projects Fourm, I Have Some Pics Of A Drop And Roll I Did On My Rev. Picked Up The Kit From Specialty. Got 1.5 Or So Inches Of Clearance From The Tip Of My Track To The Cooler.

 

[slednecks11]

does any one have pictures for an xp?

 

[Maverick800XRS]

I just completed a specialty Drop and Roll in my 2007 Rev XRS, if you need more info like what sorts of tools you will need and how much you need to strip down the sled to get it done i can help ya out.

D&R helps clear snow out of the tunnel quicker with the added clearance and it doesn't build up as much so your freeing up horsepower. The lighter attack angle will help you stay on top the snow and trench less. More room in the tunnel means bigger paddles, a 2.5" challenger extreme fits under my rev with room to spare, i could easily go to the 3" if i wanted to.

This mod is not for the faint of heart!!! Modman makes a good post

Once i get a few more pics i will be posting my summer project XRS and maybe ill post a D&R forum for anyone who is looking for info or pics on D&R's on rev's

Cheers

 

[maxwell]

yes sometimes its a bit scary cutting into a brand new sled or tunnel lol. measure 5x cut once.


its the best way to run a 2.5 to 3" track also. alot of guys are cramming the new 3" into there machine with less than a 1/4" of clearance..........not getting the full potential there.

 

[Baja]

Hey Maverick since you just installed one maybe you can answer me a question. I'm installing one right now and not sure how the chaincase cup is fitted, does it go under or on top of the exsisting sled and does the back piece of the cup get installed on the inside ,outside or trimmed. Also any other tips would would be great. Anyone else that may have some tips and hits about the install to make it go smoothly would be appreciated.

 

[KORE]

Baja, is this a rev D&R? And the cup is a universal thing. You could if you wanted to put it on the top in front and under at the back. The footrest is removed and the tabs are bent down and forward. The reinforcement (black) can get in the way depending on the cut you made you could tuck the bucket tab in between. It would generaly go on the outside of the stock alumininum, underneath and/or behind. Do not trim the bucket tabs. You will use them.

 

[KORE]

here is a shot of the first D&R i did. I welded a bucket to fit the opening i had. The black reinforcment is off in the shot but later riveted to the underside of the bucket. Same idea tho. Also a specialty D&R

 

[j.c.higgins]

When i did my drop & roll i used a template from Van Amberg that dropped down 1 5/8" plus rolled back 2 5/8". This is on a 98 Gen II bulkhead where the template lined up using the steering post holes and a centering rivet. Then just drilled the pilot holes into the bulkhead. Then went thru with the proper holesaws for the bearings. Went with a CR u-cooler and removed the front cooler, which left me with 7" of clearance from the front of the track tips to the bulkhead and 2.5" down the tunnel. I still have the template if anyone is seriously interested in a copy but you will have to make your own support plates. Higgins.

 

[Baja]

Yes it is a Rev drop and roll and I was worried about the cup location because the bottom chaincase bolt attaches to the cup, so just wanted to make sure the bolt pattern would work out and also chaincase alignment. I was thinking also with the new plates on each side, the sides are spaced out a bit more and I want to make sure the bearings are sitting where they should be with the correct preload.

 

[KORE]

I dont think preload is an issue as they are seated and locked with a snap ring. There is room for adjustment at the other end of the jack shaft if needed. the float at your brake disc may be smaller if anything. Get some good rivets into the backside of the cup and you may find that the bolthole slop will be key to putting the chaincase back on. It helped to put the bolts in and the alluminum nuts on hand tight to get this movement and the precise location of the case. Also, the hole for the jackshaft may need some working. good luck

 

[Maverick800XRS]

The side lip should go on the inside of the tunnel and both ears go underneath the running boards and bulk head. I also bent the tabs a little to fit the runnings boards and bulkhead some, mine had to be bent up a little but then the fit was perfect, you may want to trim the ears back a little like i did, and maybe a little here and there that sticks into the tunnel and near the muffler, not an issue i just like things to be perfect.

Heres a pic of how it should look.

Don't mind the running boards, they are part of the project so your ears for the footrest thingy will be different, but you get the idea with the cup.

Any other questions feel free and ill try and help ya out.

Hey Maverick since you just installed one maybe you can answer me a question. I'm installing one right now and not sure how the chaincase cup is fitted, does it go under or on top of the exsisting sled and does the back piece of the cup get installed on the inside ,outside or trimmed. Also any other tips would would be great. Anyone else that may have some tips and hits about the install to make it go smoothly would be appreciated.

 

[Maverick800XRS]

O hey, i should mention, when you cut the tabs off to be able to mount the brake back onto the chain case make sure to grind them down flat to the tunnel. After i put mine all back together i noticed when i put the brake caliper back on, the outer pad corner was resting on the tunnel and this would cause an issue with the brake working properly, so instead of tear it all down again to grind some more, i ground off the corner of the pad a little and made sure i had some clearance. Just a heads up so you won't have everything together like i did and need to do some grinding!!!

And in case you don't have one, get yourself a C clamp vice grip, this was amazing to use to clap the cup and D&R plate tightly to the bulkhead for riveting, it would have been tough to do this without it, it also is really useful for riveting the cup to the running boards

And while im at it, these are some pictures that i got from specialty when i was asking questions from them...

*EDIT* OHHH !!!! i forgot to mention too, put the jack shaft in first and make sure it's all bolted up before putting the axle and track in, this will save you some circus poses trying to hold the nuts on the bolts and torquing them up... with mine the nut actually contacted the top of the tunnel and made the bolt sort of on an angle, i just torqued it up and called it good... i would have to make a slot in the tunnel for the bolt or shave one side of the nut right down to get it on there straight. Don't forget the brake rotor and the spacer that goes in between the chain case the bulkhead when putting the jack shaft in !

Happy modifying

 

[Baja]

Thanks Maverick that was the answers I was looking for this will help a bunch can't wait to give it a try

 

[vpfuelman]

good pictures guys they are better than the ones we have for the instructions ::: Welcome to Specialty Sleds :::

 

[maierch]

There are companies like Timbersled? (I know someone is making them, don't quote me on Timbersled though) or some others that are making extended chaincases so that you don't have to re-drill the jackshaft hole, it can stay inside the engine compartment. This is a more expensive option though (typically they are machined from one piece of billet aluminum which ain't cheap - looks amazing though).

I believe it is Avid who makes the extended chaincases, however there could be others.

 

[LBZ]

If You Look On The Summer Projects Fourm, I Have Some Pics Of A Drop And Roll I Did On My Rev. Picked Up The Kit From Specialty. Got 1.5 Or So Inches Of Clearance From The Tip Of My Track To The Cooler.

I know this is an old thread but it's too bad the pics got deleted from that thread. I would have liked to see them.