1977 BMW R100RS Restore Project

brook.reams · Apr 15, 2016

Standoffs for Mirrors

robsryder said:
After I got my R100RS redone and back on the road I quickly realized that the rear-view mirrors were only useful for monitoring the gradual build-up of bugs on my shoulders. But I'd rather have a view of the traffic behind me. Nick Greear, the Colorado Airmarshal, made some stand-offs that allowed the RS mirrors to be extended to allow a better view of the road. I understand that Nick doesn't have any more of these stand-offs, but I've found some other threads and photos of alternate mirror extenders. I like the ones shown in the following link; other links to threads also follow -

http://forums.bmwmoa.org/showthread...mirror-extensions&highlight=mirror extensions

http://forums.bmwmoa.org/showthread.php?57819-Mirror-Extensions
http://advrider.com/index.php?threads/r100rs-mirror-extensions.648011/
http://forum.boxerworks.com/viewtopic.php?f=1&t=1238
http://www.wunderlichamerica.com/motorcycle/8160447.html

Rob,
Thank you for posting these. I have been knoodling something similar to fix the same issue with my RS's.

Best.
Brook Reams.

markaz · Apr 15, 2016

I had a set of the extenders shown in the first link on my (now departed) RS. They worked even better with the larger RT mirrors on them. I don't think the guy makes them any more, tho.

Rinty · Apr 16, 2016

brook.reams said:
I've also learned that machining the heads to accept 40 mm valves is an option. Hmmm ... stuff to consider....

I used to have one of the most highly modified RS's in the MOA, but I think if I had another, I'd just give it a full service, and leave it alone. JMO

barryg · Apr 16, 2016

I've got a buddy Leo Goff who owns a '77R100RS. He bought it new back in the day. He's also a BMW motorcycle engine specialist. His has the large valve heads from the factory. Just between you and me; He said his stock RS would outrun a stock R90S. Just sayin. :dance

radar41 · Apr 16, 2016

RS Mirrors

markaz said:
I had a set of the extenders shown in the first link on my (now departed) RS. They worked even better with the larger RT mirrors on them. I don't think the guy makes them any more, tho.

I know the "purest" will be upset, but I needed to see behind me. These are from a Suzuki SV1000S, work great!!

brook.reams · Apr 17, 2016

RS Mirrors

Radar41 said:
I know the "purest" will be upset, but I needed to see behind me. These are from a Suzuki SV1000S, work great!!

Radar,

Those look nice and if they aren't blocked by your shoulders, they should work for me. Thanks for sharing.

Best.
Brook Reams.

brook.reams · Apr 17, 2016

2017 R100RS Anniversary Rally

AlanColes said:
Nice bike Rob.

I've just updated my BMWONS post if you'd like details on registering for the Rally and Todd's contact email to complete the process:
http://bmwons.forumpro.fr/t1635-2017-r100rs-40th-anniversary-rally

Alan,

Thanks for providing information about this upcoming celebration rally. I'm now on Todd's list to attend. SOOOOOOO .... that sort of pushes the 1977 RS ahead of the 1983 RS for rebuild-restoration. But, first I need to get the '75 R75/6"S" done and back on the road.

But, now's the time to collect costs, and ideas for the project, so I'm looking at those with RS bikes they've updated for information about parts that you think improved the machine. I know one item on the list is rear mirrors that let me see something besides my arm pits

Best.
Brook Reams.

radar41 · Apr 17, 2016

Mirrors

brook.reams said:
Radar,

Those look nice and if they aren't blocked by your shoulders, they should work for me. Thanks for sharing.

Best.
Brook Reams.

Brook,

Nope! They are out far enough that they work GREAT!!

You can take it for a test ride to try them out.

dw

robsryder · Apr 17, 2016

brook.reams said:
...I'm looking at those with RS bikes they've updated for information about parts that you think improved the machine...

As a matter of taste, I used the accordion fork gaiters ( pn# 31 42 1 234 908, RUBBER BOOT, $20.45 ea, 2 needed; 07 12 9 952 121, HOSE CLAMP - L=47-54MM, $3.68 ea, 4 needed). MaxBMW Fiche -
http://www.maxbmwmotorcycles.com/fiche/DiagramsMain.aspx?vid=51647&rnd=07012015

I used NGK resistor spark plug caps rather than the stock metal topped caps. I had the metal caps short out once in a rain storm. Motorrad Elektrik has other good stuff -
http://www.motoelekt.com/ignition.htm

The mechanical advance unit was broken on my RS. I replaced the points and mechanical advance with a Boyer Electronic Ignition unit, purchased from Rocky Point Cycle. Easy to install and works well.
http://www.rockypointcycle.com/p-bmw8_electrics-9606.html
More comments on the Boyer for airheads on ADV -
http://advrider.com/index.php?threads/boyer-ignition.834732/

At the time I was re-doing my 77RS (2004 time frame) EPCO was doing a pretty good job making stainless exhaust headers and mufflers. Also their shop was pretty close by and I just drove over and picked up the stuff. I've heard less good things about EPCO in recent years. I know that they had a fire a few years back and the owner was pretty near the retirement point, so perhaps he is effectively retired now. I do like the stainless exhaust system though.
http://www.epcostainless.com/mufflers.htm

My center stand pivots need some attention. A feller on ADV made some stainless threaded bushings which were said to be a better replacement. Alas, this guy passed away a couple of years ago. Following is a link to a discussion on ADV -
http://advrider.com/index.php?threads/center-stand-repair-revisited-1970-80.397246/
I saw a mention that BoxerMetal is now making the stainless bushings for repair of the center stand pivot -
http://boxermetal.com/bmw_motorcycle_parts-2/
http://boxermetal.com/bmw_motorcycle_parts-2/#!/Centerstand-Repair-Kit/p/32521363/category=11634050

I obtained one of the early upper fork braces from Toaster Tan, but found that it would not allow my speedo/tach bracket to be attached without additional machine work. It sits in a box awaiting some future modification. Some folks like the brace for the upper triple clamp. I obtained a simpler, more robust upper clamp from a feller (can't recall name at present) at a rally. Info on the Toaster Tan upper fork brace -
http://forums.bmwmoa.org/showthread.php?14683-upper-billet-or-fork-brace
http://www.pbase.com/toastertan/standard_top_brace
http://forum.boxerworks.com/viewtopic.php?f=1&t=10
http://www.gunsmoke.com/motorcycling/r100rt/topBrace/index.html

I replaced the dash clock and voltmeter (originally from motometer) with VDO marine units. I can't recall the reseller, but it was a marine supply place in Florida. As I recall the price for both was around $130 in the 2004 time frame. The clock now keeps good time and the volt meter is accurate. I did have to carefully clean all electrical contacts. If the female spade connector was corroded, it was replaced. I use a dab of dielectric grease at all electrical connections.

My transmission needed some work when I got the bike. Upon initially draining the transmission oil I found a fingernail sized piece of metal. This piece was one of the teeth from the engaging dogs on the intermediate shaft. Fortunately I was able to find a good used intermediate shaft from Re-Psycle BMW. I also installed new shift pawl springs and the shift upgrade kit, all from Re-Psycle BMW (along with some assembly instructions). The shift kit was to help avoid false neutrals sometimes encountered. In addition to help from Re-Psycle, I obtained and watched numerous times the Cycle Works transmission video.
http://www.cycleworks.net/index.php?main_page=product_info&cPath=29_35&products_id=243
Snowbum discusses the issue with the pawl spring and the shift kit in his lengthy article on airhead transmissions - look for section 9A
http://bmwmotorcycletech.info/transmission.htm

Good source for used parts -
http://www.re-psycle.com/

I mentioned earlier my migration to LED headlight and running lights. I already have the LED taillight from MotorRad Elektrik (recommended) -
http://www.motoelekt.com/lighting.htm

Personal preference - corbin seat and hagon rear shocks
http://corbin.com/bmw/7484canyon.shtml
https://www.davequinnmotorcycles.com/cgi-bin/webc.cgi/HAGON_TWIN_SHOCKS.html
http://www.hagonshocksusa.com/

jad01 · Apr 17, 2016

brook.reams said:
Radar,

Those look nice and if they aren't blocked by your shoulders, they should work for me. Thanks for sharing.

Best.
Brook Reams.

I did a similar thing... this has to be one of the most useful modifications one could make to the RS. It yields a completely unobstructed view of what's behind me. I'm fairly impressed that they don't vibrate any more than the factory mirrors- they stay pretty clear through the rev range. I appreciate this modification every single time I ride the bike. My thread: http://forums.bmwmoa.org/showthread.php?70807-RS-mirror-extensions

:beer

8ninety8 · Apr 17, 2016

IMHO an RS pushes too much air to to out run a slightly tweaked 90S.

brook.reams · Apr 17, 2016

robsryder said:
As a matter of taste, I used the accordion fork gaiters ( pn# 31 42 1 234 908, RUBBER BOOT, $20.45 ea, 2 needed; 07 12 9 952 121, HOSE CLAMP - L=47-54MM, $3.68 ea, 4 needed). MaxBMW Fiche -
http://www.maxbmwmotorcycles.com/fiche/DiagramsMain.aspx?vid=51647&rnd=07012015

I used NGK resistor spark plug caps rather than the stock metal topped caps. I had the metal caps short out once in a rain storm. Motorrad Elektrik has other good stuff -
http://www.motoelekt.com/ignition.htm

The mechanical advance unit was broken on my RS. I replaced the points and mechanical advance with a Boyer Electronic Ignition unit, purchased from Rocky Point Cycle. Easy to install and works well.
http://www.rockypointcycle.com/p-bmw8_electrics-9606.html
More comments on the Boyer for airheads on ADV -
http://advrider.com/index.php?threads/boyer-ignition.834732/

At the time I was re-doing my 77RS (2004 time frame) EPCO was doing a pretty good job making stainless exhaust headers and mufflers. Also their shop was pretty close by and I just drove over and picked up the stuff. I've heard less good things about EPCO in recent years. I know that they had a fire a few years back and the owner was pretty near the retirement point, so perhaps he is effectively retired now. I do like the stainless exhaust system though.
http://www.epcostainless.com/mufflers.htm

My center stand pivots need some attention. A feller on ADV made some stainless threaded bushings which were said to be a better replacement. Alas, this guy passed away a couple of years ago. Following is a link to a discussion on ADV -
http://advrider.com/index.php?threads/center-stand-repair-revisited-1970-80.397246/
I saw a mention that BoxerMetal is now making the stainless bushings for repair of the center stand pivot -
http://boxermetal.com/bmw_motorcycle_parts-2/
http://boxermetal.com/bmw_motorcycle_parts-2/#!/Centerstand-Repair-Kit/p/32521363/category=11634050

I obtained one of the early upper fork braces from Toaster Tan, but found that it would not allow my speedo/tach bracket to be attached without additional machine work. It sits in a box awaiting some future modification. Some folks like the brace for the upper triple clamp. I obtained a simpler, more robust upper clamp from a feller (can't recall name at present) at a rally. Info on the Toaster Tan upper fork brace -
http://forums.bmwmoa.org/showthread.php?14683-upper-billet-or-fork-brace
http://www.pbase.com/toastertan/standard_top_brace
http://forum.boxerworks.com/viewtopic.php?f=1&t=10
http://www.gunsmoke.com/motorcycling/r100rt/topBrace/index.html

I replaced the dash clock and voltmeter (originally from motometer) with VDO marine units. I can't recall the reseller, but it was a marine supply place in Florida. As I recall the price for both was around $130 in the 2004 time frame. The clock now keeps good time and the volt meter is accurate. I did have to carefully clean all electrical contacts. If the female spade connector was corroded, it was replaced. I use a dab of dielectric grease at all electrical connections.

My transmission needed some work when I got the bike. Upon initially draining the transmission oil I found a fingernail sized piece of metal. This piece was one of the teeth from the engaging dogs on the intermediate shaft. Fortunately I was able to find a good used intermediate shaft from Re-Psycle BMW. I also installed new shift pawl springs and the shift upgrade kit, all from Re-Psycle BMW (along with some assembly instructions). The shift kit was to help avoid false neutrals sometimes encountered. In addition to help from Re-Psycle, I obtained and watched numerous times the Cycle Works transmission video.
http://www.cycleworks.net/index.php?main_page=product_info&cPath=29_35&products_id=243
Snowbum discusses the issue with the pawl spring and the shift kit in his lengthy article on airhead transmissions - look for section 9A
http://bmwmotorcycletech.info/transmission.htm

Good source for used parts -
http://www.re-psycle.com/

I mentioned earlier my migration to LED headlight and running lights. I already have the LED taillight from MotorRad Elektrik (recommended) -
http://www.motoelekt.com/lighting.htm

Personal preference - corbin seat and hagon rear shocks
http://corbin.com/bmw/7484canyon.shtml
https://www.davequinnmotorcycles.com/cgi-bin/webc.cgi/HAGON_TWIN_SHOCKS.html
http://www.hagonshocksusa.com/

Rob,

All very useful things for me to consider. Thank you kindly for sharing this. The bike has dual plug heads with Dyna III ignition module and a Telefix fork brace. The front end feels excellent based on 75 miles of riding, so that brace doesn't feel like it's tweaked

And, the brakes actually do what you ask when you ask them, unlike the single ATE disk on the R75/6 whose behavior I can sum up as "Make a reservation when you want to stop and the brakes will get back to you when they have the time."

Best.
Brook Reams.

PAS · Apr 17, 2016

I have to ask, in the first pictures it looked like the valve covers were on the wrong sides. Was that an illusion or....are they.

barryg · Apr 17, 2016

Good eye PAS.

brook.reams · Apr 18, 2016

Valve Cover Orientation

PAS said:
I have to ask, in the first pictures it looked like the valve covers were on the wrong sides. Was that an illusion or....are they.

PAS,

Yeah, that's true. I took these pictures just after I got it home from buying it, so all the warts are fully displayed.

Best.
Brook Reams.

toooldtocare · Apr 20, 2016

8ninety8 said:
IMHO an RS pushes too much air to to out run a slightly tweaked 90S.

Hijack on,

Two bikes, my old R90S (1974), totally rebuilt by certified BMW mechanic about 15 thousand miles ago. Also, my now sold Motorsport (1978), with about 16K miles on it. Both bikes modified, the R90S has dual plugs, partial San Jose handling kit, Dyna III ignition. The Motorsport has the kitchen sink thrown at it. Shift kit, lightened flywheel, San Jose handling kit, dual plugs, hardened valve seats, 40mm exhaust, hotter cam, Dyna III, lightened wrist pins, semi-floating brake rotors, ceramic brakes, SS brake lines.

The riders: the R90S owner is a close friend, and also an ex-road racer from the 70's. If you are interested there is an article on California racing in the 70's in May's edition of Motorcyclist magazine. He is mentioned and there are two photos of him. He is an excellent rider, the best I have ever ridden with; me, I have 50 years of experience, but I am not in his class. I do not mind going fast straight, but I hate pushing it too much in the curves, I've scared myself from time to time.

The course, back roads around St. Louis, usually Hwy 94 west of town towards Herman.

On the curves he can blow the doors off me, but on the straights, both bikes are equal up to about 100, then the R90S pulls SLIGHTLY ahead. Guess that fairing does add a bit of drag, but not much. I doubt there is more than one or two miles per hour difference between the bikes. Both bikes seem to top out around 125 mph, although those speedometers are not the most accurate. That said, the R90S is only about one bike length in front of the Motorsport.

Was it fun, you can bet it was, we did this more times than I care to admit. My only regret, I SOLD both bikes. My favorite, the R90S, of course. Might buy it back someday. However, living in Florida now would not be the same, my buddy is still in St. Louis, and not in good health.

Hijack off,

Brook, will you ride the new bike to Sipapu this year. Be fun to see it, it is one beautiful bike.

Wayne

brook.reams · Apr 20, 2016

Sipapu Rally

Wayne,

Hmm ... it depends on how much progress I make on the rebuild/restore. I live in metro-Denver, so it's an easy ride from here. We shall have to see

Best.
Brook Reams.

toooldtocare · Apr 21, 2016

Brook,

We try to go to Sipapu every year, been going there since the mid 90s when we lived in Lubbock. Missed last year due to our move to Florida. Hope to see you there this year.

Wayne

Rinty · Apr 21, 2016

toooldtocare said:
Both bikes seem to top out around 125 mph, although those speedometers are not the most accurate....

I had an extensively modified '82 RS, and I've seen (from a GSX-R) it do 212 km/hr (132 mph) at 4,500' ASL. Calculating in a 10% speedometer error, this becomes 119 mph.

IMHO an RS pushes too much air to out run a slightly tweaked 90S...8ninety8

In his book on the RS, Bill Stermer has that fascinating graph on the drag characteristics and performance numbers of three different R100s. The drag co-efficients, top speeds and frontal areas are as follows:

R100RS Cd .571 / 117.3 mph / 8.7 sq.ft

R100S Cd .589 / 114.8 mph / 8.5 sq.ft

R100 Cd .627 / 112.4 mph / 8.5 sq.ft

The wind resistance tests were done in Volkswagon's wind tunnel in Wolfsburg by Motorrad magazine. IMHO opinion, the drag co-efficients of all the R100s are so high that engine mods wouldn't increase the top speeds by that much.

As for the hijack, I suggest that this is important RS performance data, and also, we need to keep bumping Brooks' thread.

brook.reams · Sep 15, 2016

1977 R100RS Project: Project Start

Folks,

I picked this bike up in April 2016. Finally, on September 1, I got started on it. I had to finish up work on the 1975 R75/6 "S" update and completed that in July.

I wrote up a project page and added my build plan. You can find these here:

1977 BMW R100RS Rebuild: Project Index

00 BMW 1977 R100RS Planning the Build

My goal is to complete this build by September 1, 2017 so I can ride the bike to the 40th anniversary get together in Pennsylvania later in September.

I have repaired the damage to the fairing panels and I'll be writing about how I did that soon.

I hope this material is helpful to those working on a first year R100RS. Here is what I started with and where I am so far.

<a title=""10 Foot" View" href="https://www.flickr.com/photos/brook-reams/26291559501/in/album-72157666863178492/"><img src="https://c6.staticflickr.com/2/1602/26291559501_cfc3fbac45_z.jpg" alt=""10 Foot" View" width="640" height="480" /></a>
"10 Foot" View

<a title="Body Work & Wheels Removed" href="https://www.flickr.com/photos/brook-reams/29644878925/in/album-72157672306851951/"><img src="https://c6.staticflickr.com/9/8321/29644878925_6152e9ea6b_z.jpg" alt="Body Work & Wheels Removed" width="640" height="426" /></a>
Body Work & Wheels Removed

Best
Brook Reams

1977 BMW R100RS Restore Project

B Reams

New member

New member

Active member

Beemerphan

B Reams

B Reams

Beemerphan

Motorcycleton

New member

New member

B Reams

New member

Active member

B Reams

Active member

Attachments

B Reams

Active member

New member

B Reams

Similar threads