BMW R1100 GS Based Rig Project

Posted by: @ned

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I installed some of those R1200-style fuel injectors in my R1100GS and Man-o-man did that engine roar!

. . . for three tankfuls.  😑  Then the Motronic scaled back the A/F ratio to the usual lean burn.

 

But still, it was an easy mod and maybe, just maybe, improved performance.  It did nothing for my looks but did provide a talking point if a BMW guy came over to ask about the rig.

Yeah, there has been a lot of mis-information about the "benefits" of this mod. 

The long term benefit to the upgraded four hole pintle is the ability for better atomization of fuel for a more even fuel oxidation.  In theory the bike should have a better cold start, slightly improved economy, and lower emissions per event.  Probably the most noticeable of the above is cold engine driveability.  If someone doesn't notice that, they won't notice any other benefit. 

Edit to add:  Low rpm could also be enhanced limiting complaints of "flame out", which is where a rider lets the rpm drop below idle when under load, causing the engine to suddenly die.

If you look at the metal cylinder portion of the spark plugs in the pictures above, you'll notice absolutely no black soot.  That is a great indicator of idle/cold engine efficiency. 👍 

Browsed through The Sidecar Technical Guide last night.  I think for someone who has never built anything, it is a reasonable starter guide.  I was expecting something more along the lines of Chassis Engineering by Herb Adams.  My bad for not doing a better job investigating the content.

While this book is way too basic for me, it has provided some insight as to why sidecar engineering hasn't really progressed since the '30s.  I mean Hedy Lamarr came into the world before that, and was a great example of something that doesn't need improvement. 

Picture from this  great article: https://www.smithsonianmag.com/innovation/hollywood-secret-weapon-180965209/

The "toupee"  came in today.  Very nice. A bit militant with the High&Tight, but since the sidecar is a Dnepr it sort of works. 

I ordered this size specifically for standing off road. Still have good grip with knees when standing. 

Comfortable to sit on, and doesn't move when I'm squirming around.  Elastic seems to be of good quality, as do the buckles.

Short 25 mile ride felt like I could do at least 25 more in comfort. 😉 

The wool is very thick and plush. In a couple of weeks I'll be doing a 350-ish mile day, so it will get a good test then. 

Hair Club For Men would be proud. 😎 

Hot day out with a very strong sun and no breeze.  Perfect day to do slow speed technical off road.  🤣  A better time would have been early morning.  Air was still and stifling with the slow pace.  Bike never went over 5 bars oil temp though. 

Wanted to get a reminder of how the rig behaves before changing the tires to something more off-road focused.  Won't be making a direct comparison of grip because that would be misleading and unfair.  The goal was a refresher in how the suspension and chassis behaves.  

Short 20-ish mile from the hobble is national forest with some great ATV trails.  The loop chosen is short and starts with about a quarter mile of beat up trail littered with big rocks half stuck in the ground.  Not a trail I'd want to do in a Camry.  An easy but bouncy long travel ATV type trail.  Leads to a steep drop off with rain ruts, and sections that have washed out from the summer storms.  That actually got a bit sketchy, because the whole rig was sliding to the left into the drop offs.  The only picture I was able to get was at the very top.  I think stuff like this is where the BMW front end shines.  It doesn't sink into the stroke under heavy front braking, but has plenty of travel to get over the bigger embedded rocks without the rocks impeding travel speed and pitching the rig askew.  Front was about 98% of the braking, because anything other than very light rear braking just caused the back end to slide towards the drop offs.  Sidecar braking would have helped, but the current tire is street oriented, so wouldn't have done much.

Top of hill.  Picture looks like a Miata could drive down it.  lol  I really suck at getting the "money shots".

At the bottom of this hill is a ravine, that goes off to the left through the trees.  Still had some muddy spots, some deep ruts, and some crazy off camber that had the left footpeg of the bike digging a trench.  That was a bit spooky because the sidecar is totally empty.   It would bounce over a half buried rock and provide a very closeup view of the fender.  lol  

Great opportunity for trail stripes.  Left hand guard did a great job of keeping the trees from applying the clutch.  😎 

One of the many things I appreciate about this rig is the sidecar shock.  It has a hand lever screwed into the preload adjuster, for super quick easy adjustments.  For this little adventure it was set to minimum preload.  Once back at the tarmac it was easy to just "twist it" back to max for straight travel.  It's a really cool feature.  No idea what it originally came from.

I continue to be impressed with this rig. 😍  Looking forward to putting the new more off-road focused ADV tires on, and fabricating the sidecar brake brackets/lever to get that functional. 

Sounds like a fun sphincter-puckering ride. 

Perspective is weird.  I've taken photos of wicked steep inclines where you can't tell if I was standing on the top looking down or the bottom looking up.  Or flat.  All looks the same.

Posted by: @ned

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Sounds like a fun sphincter-puckering ride. 

Perspective is weird.  I've taken photos of wicked steep inclines where you can't tell if I was standing on the top looking down or the bottom looking up.  Or flat.  All looks the same.

Thankfully the new seat toupee is softer than Charmin.  😎 

Great photographers who are able to capture their intended context are amazing.  👍 

Changed out the transmission and final drive fluids today.  Original builder of this rig had purchased a '97-'98 transmission, rebuilt it, used Klotz gear lube and installed magnetic drain plugs in the transmission and final drive.  He used Mystik Precision Blue Marine Gear Oil (engineered for lower unit outboard drive duty) in the final drive. Roughly 12,000 miles on both since then.  There was no metallic substance on the drain plugs, and neither oil had that stench of used standard gear oil.  Pretty impressed with the quality of the used gear lube that drained out.  Sure didn't appear to be six years and 12k miles old.

Refilled with Liqui-Moly Synthetic 75W-90 Gear oil (included in the Box-O-Maintenance parts).  Hoping it will work as well for the next service period. Also interested to see how the gear noise compares to what I drained out.  Both transmission and final drive sound really good.  The Liqui-Moly liter bottle comes with a long flexible straw built into the neck.  So it was very easy to use.  While I'm not an oil snob, I appreciate the packaging. 😎 

Now the rig is ready to go for another Brozillian miles. 😉 

Mystik Precision Blue Marine Gear Lube: http://www.docs.citgo.com/msds_pi/591025.pdf

Klotz Synthetic Hypoid Gear Lube: https://klotzlube.com/shop/ols/products/xn-pure-estorlin-free-gear-qualifier-hypoid-synthetic-gear-lubricant-erck

Liqui-Moly Synthetic Hypiod Gear Lube: https://www.liqui-moly.com/en/fully-synthetic-gear-oil-sae-75w-90-p000232.html#1413

New Sidecar tire showed up today.  Took some time to mount and do a bit of measuring.  Will try to get out for a demo ride tomorrow.  Perfect excuse... err... important research project... to visit Cold Stone Creamery.  🤩 

Initial impressions:  When held square against the wall, the 100/90-19 AX41 is ~ 1/8" taller ground to top of knob than the Metzler Block-K 4.00-18 that was on the rig (26-5/16"). Probably they were the same height when the Metzler was new.  While the AX41 is wider across the treads, it is a pretty round tire, so not as much "rubber on the road." 

According to the electronic bathroom scale of lies meter, the two assemblies are the same weight (31.8 lbs).  Reality is probably within a few ounces of each other.  Repeated the process a few times, with different weights to ensure it wasn't a "memory" issue with the scale.  Kind of interesting.  The wheel that came on SYZ is an older 18" Ural wheel with standard spokes, and vented drum.  The Wheel with the AX41 is a later Ural 19", with a solid drum, and thick spokes (Woodie's Wheel Works calls it "Super Laced"). 

Static tire balance didn't require weights.  Will have a better idea on dynamic balance, when up to speed on tomorrow's ice cream run.  Grips the rocks in the driveway almost as tight as Rosie O'Donnell grips donuts.  So I'll need to be careful off road, if someone is following.  I didn't notice this issue with the 110/80-19 on the KTM.  Big spacing between the blocks on this size tire.  Should help in the soft stuff off road.

 Plenty of room to toss rocks:

Comparatively the Block K appeared to fill the fender well much better, due to the tall/square sidewall.

Block-K & AX41 side by side:

Edge on Comparison:

Mounted up:

Should be able to get an idea of road handling tomorrow, after scrubbing it in a bit off road.  Will wait to get some wear before reporting about off road prowess (or lack thereof).

Forgot to mention that mounting the tire to the rim was very easy due to the compliant (aka soft) sidewall.  Tire is rated tubeless.  On the sidewall it states to run a tube on tube type wheels.  Some Talc in the tire, and slathered on the 2mm tube helps with heat. 

WD-40 on the bead, and the first side slid on by hand. Lined up the tire balance dot to schrader valve hole, and slipped tube into tire. Added just enough air for tube to get round inside tire, and spooned on second bead with WD-40. 

About 10 minutes of work.  No harder than any dirt bike tire I've done. 

Checked the toe setting this morning.  Turns out to be 1/2" +/- 1/8" toe-in (more likely on the plus, than minus side of that tolerance).  I was a bit concerned based on the feathered wear of the Block-K that it was more aggressive.  So good news there (no work needed).  Then found some close by dirt roads to scrub in the new tire.  Was fun to "wag the tail" of the rig around on the dirt/gravel surface.

Called up my buddy to see if he was free for lunch.  Picked him up without saying anything about the tire.  Figured I'd stop at the gas station down the road a bit to fill him in on his responsibilities for this ride.  lol  There is some really rough, and some nice smooth road between his place and the station.  Speed limits from 25mph to 60mph.

We get to the gas station, and before I could say anything he gives a questioning look and says; "What did you do to the sidecar?"  Fearing this was not going to be a good conversation I inquired as to the nature of his question.  He says; "It's like riding in a cloud.  I was bracing for the potholes and rough spots, but nothing materialized.  It's like you've smoothed out the suspension harshness."

Whew! I was $163 and change concerned.  lol  So I told him about the new tire, and asked him to focus on any balance vibrations through the different speeds we'd be traveling (up to 65 mph).  A few times during the ride I'd reach over and grab the hood rack.  I couldn't feel any vibrations.  Most importantly neither could Kris.  Said it was smooth at each speed, and during accel/decel.  That was just shear good fortune.  The same brand/model tire on the KTM required 1/2 oz to balance, and I've read some have taken as much as an ounce.  When he saw the aggressive knobbies he was surprised at the lack of noise (he wears ear plugs, and no helmet).  I also didn't notice any noise, but I wear a helmet with ear plugs, and the front tire growls pretty aggressively due to being cupped and worn out. 

I didn't notice a difference in the need to add steer input with Kris in the car, and the windshield on compared with the Block-K.  The rig also continues to track straight at constant speed when empty and the windshield folded down.  that means it must be getting some traction.

What happens in the future, only the future will tell.  With just 75 miles use compared to 12K miles (minimum) on the Block-K, it is very unfair to compare the two tires, but I don't have any other "baseline" to use here. 

I'm happy he noticed an improvement in comfort though.  The rest is yet to come.  🙂 

Well an enTIRE box of goodness was just delivered by FedEx.  🤩 

MotoZ Tractionator GPS 110/80B-19 for the front (looks very similar to the Shinko E705 which I'm very familiar with on this rig)

MotoZ Tractionator GPS Rear 150/70B-17.  It will get mounted in the "mostly off-road" direction (It's a "B-17" so it must be tough and functional)

More to come as I get Moto(Z Tractionator)-vated to do the install.

For those interested in knowing more about the tires, this guy does some great tire reviews.  https://youtu.be/9xEqFjJdiHM?si=64h6HQ84R1tqENjR

Front tire is mounted up. 😎

It would not be surprising to have people confuse it with the Shinko E-705.  Hopefully it handles better.  I was not impressed with E-705, and would not put it on the nice side of the "Naughty or Nice" list.  Time will tell how this new Motoz works out. 

Very easy to mount up the front tire.  A bit of WD-40, and the first bead slipped on.  Second bead with a bit of WD-40 went almost as easy.  For a tubeless tire it sure slipped on the rim easy.  Getting it to seat with the micro compressor didn't work.  Even though Motoz uses cardboard to keep the beads apart, it is a stiff sidewall.  Took a bit more compressor output.  Both sides seated well below 30 psi though. 

Balance wise, where the E-705 took 1-1/8 oz.s, the GPS took a bit more than 3/4 oz.  I ended up using 1 oz split into two 1/2 oz chunks so the weight is distributed over a wider area.  Circle is the light point, arrows point to the two 1/2 oz sticks.

Rim cleaned up very nice too.  No corrosion inside (that was a bit of a worry to me after reading some horror stories).  no signs of tire goop ever being used. 😎  Nor do I have plans to ever use that in these rims.

Compared to balance of Shinko E-705

If all goes well, tomorrow the rear tire will get mounted, and I'll get them scrubbed in.  👍