R11 brake plate breaking

Bruce Frey · Post by **Bruce Frey** » Wed Apr 05, 2006 2:25 am

to hook up both carbs to the single cable, bmw offered a 1 into 2 splitter, but i've never seen one for sale. the closest alternative is to use their /5 version..it looks almost identical.

Philip Dreher offers the "one into two" splitter used on the twin carb R12.

Best regards,

Bruce

Darryl.Richman · Post by **Darryl.Richman** » Wed Apr 05, 2006 9:14 am

to hook up both carbs to the single cable, bmw offered a 1 into 2 splitter, but i've never seen one for sale. the closest alternative is to use their /5 version..it looks almost identical.
Philip Dreher offers the "one into two" splitter used on the twin carb R12.I'm confused (not an unusual situation!) -- At least on the R12/R17, I thought that the twin carb setup used two cables. My R12 came with twin carbs of unknown provenance. The twist grip has a hole for each of two cables, and the traveller inside is set up to capture two cable ends.

olebmw · Post by **olebmw** » Wed Apr 05, 2006 10:58 am

My R11 has some kind of aftermarket carburetor and I want to replace it with an original single carb and I think that would be a two slide type. I don't want to replace it with twin carburetors. I didn't realize that a side slide carb was an option. That sounds like the best set up for my single cable Amol twist grip. Does the side slide carb intake tube make a u-turn and pick the dirty air off of the cluth/flywheel area like the original two slide carb?
My rear fender flap has two bolts that attach it to the fender in about the 11:00 and 1:00 position and it sure looks original. ??

Barry Robin · Post by **Barry Robin** » Wed Apr 05, 2006 11:09 am

naw, you're not confused there, darryl. as far as i know, all the rules change on the R12/R17.

the twin carb set up did use a dual cable twist grip-you're not going crazy...at least, not because of the thread posting.
the sum, being a single carb, has a matching single traveller twist grip; this was for the milatary model.

the twin carb was civilian and usually came with the matching throttle;for those who wished to upgrade an older bike, bmw offered the splitter so the throttle didn't have to be replaced too...

Barry Robin · Post by **Barry Robin** » Wed Apr 05, 2006 11:47 am

weclome back, dan-i was starting to wonder what happened to you there...!

o.k., lets see...

"Does the side slide carb intake tube make a u-turn and pick the dirty air off of the cluth/flywheel area like the original two slide carb?"

-yes and no. bmw pulled their usual change the parts game the year of your bike, so either carb will fit nicely.
they discontinued the flywheel air tube the same year (because the sum has it's own external air filter); most R11s came with a blanked off flywheel cover and no tube into a slightly modified manifold , but some came with only the carb changed...go figure.

so don't change anything-just bolt on the sum carb.

on the rear fender bolts: your two bolts appear to be done in a postwar style that i'm unaware ever came on the original fender-but dont worry yet!
first make sure that the fender is correct:
all R11/16 fenders will have a single bolt holding the main and rear sections; there should be a stamped-in collar showing.
(by the way: please tell me that your fender has no hinge...; a hinged fender would indicate that the fender is from a later bike).

now, you may be looking at something i've seen before: people have modified the two small holes below meant for the taillight and moved the entire assemblly up the fender to be used to bolt both parts together. if i had a picture i could tell you instantly...
-b

Bruce Frey · Post by **Bruce Frey** » Wed Apr 05, 2006 12:19 pm

naw, you're not confused there, darryl. as far as i know, all the rules change on the R12/R17.........the twin carb was civilian and usually came with the matching throttle;for those who wished to upgrade an older bike, bmw offered the splitter so the throttle didn't have to be replaced too...

I think that may be true for the later versions when the controls were changed to the "R5" type (retard lever and two cable throttle).

Mine is an September 1935 twin carb (with orig 20hp builders plate that matches the enine and frame numbers) with the one into two cable set up and twist grip retard. Everything else, including the scroll speedometer, seems original, so I assume the carb cabling is, too.

The Ersatzteilliste gives a multitude of different control combinations.

Best regards,

Bruce

Barry Robin · Post by **Barry Robin** » Wed Apr 05, 2006 1:55 pm

i do think you're right there, bruce; i've only seen pictures and the parts book photos, so my knowlege of the R5 setup is sketchy at best.

isn't it funny that most of us have had to become crash-course experts in all these bike details-but usually only for the bikes we've owned or had to rebuild.

-barry

olebmw · Post by **olebmw** » Wed Apr 05, 2006 2:35 pm

Barry, I'll try to send you some pictures of the rear fender,the fork pin striping and the center stand. It may take a few days. Thanks for all the information,I appreciate it, Dan

Barry Robin · Post by **Barry Robin** » Fri Apr 07, 2006 7:14 am

dan-
i know this isn't quite the direction you were going in, but here's a correct series 1/series 2 carb for your R11 on german ebay:

http://cgi.ebay.de/BMW-R42-47-BMW-R11-1 ... dZViewItem

-barry

Bruce Frey · Post by **Bruce Frey** » Tue May 02, 2006 4:15 pm

Sorry Barry, but the only R11 brake plate I saw was already attached to another bike.

Best regards,

Bruce

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