Dilemma

[jas]

I have been having the itch to venture further and further off road and am trying to decide if it is time for the Rockster to go to a new home and be replaced with a 955i Tiger or work on creating a more trail worthy Roc.

So the question is, is there a supplier for spoke wheels at a decent price for 17” rims, front and back, that will bolt on. Or are there other suggestions out there. I cannot afford to sell and buy a GS or KTM.

Most of the riding will be cross desert and mild single track.

[hank]

Don't see why this can't be done, but would make an interesting project. Fit your Rockster with GS front forks, trailing arm, wheel and spring / shock unit. At the rear end fit the GS wheel, tourque arm and spring / shock unit. You could also fit the GS side, centre stand, footpeg hangers and add some alloy panniers to the mix. This would give you an R1150 RoGSter.

Avon tyres used to supply Distanzia's for 17 inch front and rear wheels, I seem to remember someone on here fitted them for a trip up the Dalton Highway in Alaska.

Hank.

[sweatmark]

Fit your Rockster with GS front forks, trailing arm, wheel and spring / shock unit....

This is a great idea. Since the R1150R shares so many fundamental parts with its GS cousin, the conversion of suspension and wheelset should be straightforward. And since the Rockster's drivetrain is same as that found in the R1150GS Adventure, it seems only fitting that RoGSter should get same dark rims on spoked wheels, blue anodized fork tubes, serious knobbies. note that the GS Adventure shares the Rockster's blueish painted valve covers.

Some Adventure pics: http://micapeak.com/bmw/gs/gs_adv.htm

Considering the passage of time and now-mature R1200GS model line, there might be some R1150GS Adventure parts both available and affordable.

[Roxster]

Woo Hoo. This will be fun to watch. I agree most, if not all, of the parts should transfer over. Before you get overwhelmed, make a list of your priorities for the bike. Such as ground clearence, wheel travel, appearence, terrain, etc... Using that list, find out which parts will give you more bang for the buck. If your just doing light off-road/fire road type driving, you might be able to keep the rims you have. If not, look for someone who might want to trade. The grass is always greener on the other side and there are guys trying to make their GS into a road carver and they might want to swap. That's why we see the R12GS available with spoked or cast rims. Big question is do you have ABS? The GS could switch theirs on and off depend on the road surface. Second, I think the ABS rings changed in 02 so watch what you pick up.

[jas]

So the project shall begin. I do have ABS which is the biggest challange maybe sweatmark needs an all expense paid trip to Eagle / Boise to help sort that end out. Time to start talking to the local indy shop and the boneyard. As for wheels, I too want the best of both worlds so I'll have a couple options when the project is complete.

Time to start making a list of parts. God forbid the cost drives me out of the house!

[riceburner]

About the only thing I'd bother to change is that mudguard - it catches mud like a bastard and the front wheel gets clamped up.

Other than that the Rockster's not bad off-road

[jas]

Riceburner - I've been waiting for a responce from you! I agree it is a capable bike, problem is that I live in the desert and the off tarmac riding would be in the scabrock for the most part. I guess the the cheapest way to do business would be to find a set of laced wheels for the front and back that allow for a more deverse selection of tires and the abs ring along with removing the carbon front guard to prevent it from getting trashed. Maybe new wheels, bashplate and engine guards should be my starting point.

Maybe I start by having you sending me those Stanton guards

[riceburner]

Riceburner - I've been waiting for a responce from you! I agree it is a capable bike, problem is that I live in the desert and the off tarmac riding would be in the scabrock for the most part. I guess the the cheapest way to do business would be to find a set of laced wheels for the front and back that allow for a more deverse selection of tires and the abs ring along with removing the carbon front guard to prevent it from getting trashed. Maybe new wheels, bashplate and engine guards should be my starting point.

Maybe I start by having you sending me those Stanton guards

Those Stantons have saved both of my high mileage bikes... you're not getting your hands on em!! (but - go look on UKGser - Steptoe is occasionally (I believe) making a batch of similar guards).

Is it worth looking at R1150GS wheels?? the mountings etc will be identical, (bushes might be a touch off, but nothing that 5 mins on a lathe wouldn't fix one way or another)

the fork bridge on the Rockster is actually quite a distance off the tyre's outer diameter - I've not measured it, but you MIGHT get a larger wheel in there??

[riceburner]

Actually - thinking about it.... a larger, 19" or 21" inch wheel will give you benefits on the rough stuff, so I'd suggest it's a VERY good idea to go for the long forks and big front wheel as suggested above.

That's the way I'd do it I think.

I also have a vague idea that the telelever arm should be roughly the same dimensions so it would be a case of just swapping out the fork legs and the wheel. And mounting a beak - which should be doable..

[Roxster]

Guess I am a little slow, but I was thinking about your project and the placement of the oil coolers on the GS versus the R. You drop the bike on it's side and it could be the end of your trip. There is an awesome thread in the R1100 section of a blue R1100R that looks fantastic. He relocated his oil cooler without getting the GS beak. On a plus side, you could use the old oil cooler mount points to mount your PIAA lights.

[sweatmark]

If this modification is truly new ground, we should be able to think it through collectively.

While the GS fork tubes are different, I'm betting that the Telelever trailing A-arm from Roadster/Rockster can be utilized. My bet's based on pics comparing R1100R Telelever with that of R1150GS, and Oliver's confirmation (via his beautiful R1100R project posted here) that R1100R A-arm is same geometry as the R1150R's piece.





We already know that the use of the GS Paralever strut on R1150R has worked on board member bikes for many years without issue, so the rear end of RoGSter requires only that simple change... assuming the GS spoke rear wheel hub has the rear brake disk mounting bosses.

ABS can be managed. Not sure there's an easy means of deactivating the ABS as per GS fitment, while retaining the servo power braking operation; I've yet to find any documentation on iABS controller.

The kinship between R1150R and R1150GS really could be exploited! I'm fond of the Adventure, including the OE engine guards:

[jas]

Super-single from ADV is going to send some pictures of his rebuild, and I may be able to pick up a rear wheel and torque arm from him.
Here is his Rockster:http://www.advrider.com/forums/showthread.php?t=44075

[boxermania]

Based on your intended use and the minimum amount of investment may I suggest the following approach:

Buy the GS FD locator bar which is 20mm shorter than the one you have (365mm vs 385mm), this will straighten the FD and raise the back end of the bike about 1/2". The gain is clearance and quicker steering.

Keep the mag wheels and shod them with the right tires for your use.

Fit a GS engine brush plate or make one up.

Last but not least, assuming hotter ambient temperatures and increased engine load, I would use synthetic oil.

Good luck

[jas]

Keep the mag wheels and shod them with the right tires for your use.

This would be the best bet, but I have two concerns, the 180 is mighty wide and the only tires I have found that would be an improvement in the dirt would be the Dunlop 616, Pirelli Scorpian Sync, or cross my fingers and hope the Scorpian Trails are available in the 180. The other concern is how well the cast wheels will hold up in scab rock, BLM roads. That being said, the 1200GS comes standard with cast wheels and they do appear to do the job.

Unless there is someone on the site that would like to trade the rockster wheels for the standard R1150R wheels!

[boxermania]

Other than the width of the rear wheel, 5.5" for the Rockster and 5" for the R1150R there is no difference in the material or manufacture.

You can mount a 170 size on your wheel if they are easier to source, or get an R wheel and mount a 170 or a 160 tire.

[sweatmark]

Super-single from ADV is going to send some pictures of his rebuild, and I may be able to pick up a rear wheel and torque arm from him.
Here is his Rockster:http://www.advrider.com/forums/showthread.php?t=44075

So it's already been done! Based on the ADV thread comments, you can keep the OE Rockster forks or move to full-length GS variety. Depends on how much suspension travel you need, and your budget for GS-type transformation.

Does the ADV bike have ABS? Looks like a front wheel ABS timing ring in the left side pic, but not great image quality (much like my BlackBerry camera photos).

Good luck with your project.

[riceburner]

Not a lot of detail on that ADV thread....

Are those standard GS wheels?? even the front??

[DrAlf]

I’m currently running a Rockster\GS hybrid. I bought the bike as an ongoing project and have modified it further. R11XXGS wheels will fit the Rockster but the front wheel will only just clear the mudguard with road tyres i.e. tourance. There is not enough clearance for a TKC80 tyre. The only way round this is to fit the telelever arm and possibly the front forks from a GS model – I believe that this requires replacing the front discs as the GS uses 300mm discs as opposed to the Rockster\S 320mm IIRC. In short converting a Rockster to true GS spec is going to be difficult and very expensive. Personally I’d sell the bike and buy an old R1100GS if offroad riding is your goal. Alternatively you could fit TKC80’s to the standard 17" cast wheels and remove the front mudguard but the cast wheels on the Rockster\S\RS\RT\R are incredibly soft and prone to bending – not ideal if you're riding through a desert.

Pics of my GSRR:

[boxermania]

DrAlf, your bike looks really nice....I was just picturing the removal of the black beak, but then I realized it is just a cover over the white portion. I visualized, how clean the front would look with out it.

Cheers

[riceburner]

nice skid mark there Alf.