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1955 R50 Question

cwroady

New member
New owner of a 1955 R50. I am sure I will have plenty of requests for help ... starting now :). The oil pan has a good sized dent in the back. I thought I would attempt to heat it up and remove the dent. Doable? Part 2 of my question is which pans are interchangeable and are they available? I see deep pans in google searches, but would prefer a stock size. Appreciate input and thank you in advance.
 
Looking forward to your questions. As for reshaping the oil pan, I don't see why you couldn't do that. You might create a hairline crack but that shouldn't be a problem...there are JB Weld products that you could use on the inside of the pan to cover any cracks...it's not under any real pressure and it should be able to withstand the temperature. The biggest issue would be that the mating surface of the pan is flat so it doesn't leak where it mates to the engine. Pounding out the dent could warp the pan a bit. So if the pan seals well now, it might be worth leaving for the time being.

As for interchangeability, RealOEM has this page showing the part number and the other models it was used on:

https://www.realoem.com/bmw/enUS/pa...-R50&mg=11&sg=11&diagId=11_2616&q=11130007029

So any twin cylinder bike in the '50s and '60s has the same pan. I tend to get my parts from Vech at Bench Mark Works in Mississippi:

http://www.benchmarkworks.com/

Give them a call to see what they have. I bought a deep oil pan for my R25/2 from him. You might want to consider adding some rare earth magnets in the pan to help capture some of the metal debris that's floating around...that helps keep it out of the slingers. Ahhh...slingers, another whole topic!!

Have you had a chance to determine when your bike was built? I've captured information on VINs over the years and have posted that in this thread. There's also an email that you can use to send back BMW Classics to get the build date for your bike. That can be compared to what's in the lists here.

https://forums.bmwmoa.org/showthread.php?50039-2-VIN-Numbers-Model-Years-and-Build-Dates
 
Excellent, thank you for the real OEM link, that will help a lot. I have only done a little 20 mile ride so far and had leaks from the pan and?? I cleaned everything up and will hopefully gets better idea where it is leaking soon. This is my first bike older than my /5. I have reasonable confidence I can replace parts on the 5, but need to gain some knowledge about parts availability for a 1955. I wasn’t going to try and straighten the pan if finding a replacement would be a pipe dream. I didn’t get any manuals, so ordered the Barrington book which is supposed to arrive tomorrow. That will give me a little more confidence to dig in more also.

I have written a request for the build date info and will PM you that along with the VIN once received. I attempted to insert a few photos of the bike and the oil pan, but kept getting upload errors. Sincere thanks for the help.



Chris
 
Chris -

The upload errors are probably due to the large size of the picture. Try reducing the size to something on the order of 1Mb or 1024x768 pixels. Windows has a paint program which lets you resample images in this way.
 
oil pan integrity

The biggest thing I've noticed is that people tend to over tighten the pan bolts so that the sealing surface is warped around the bolt holes. The only gaskets that I have found are made of cork and compress easily. My cure has been to use a piece of 1/2 inch or so plate that is about an inch long. I put it in a vise and use a hammer to flatten out the lip on the pan where the bolt holes are found. It doesn't take a lot of torque to tighten these bolts, so I use a sealant (let's not get onto that thread) and blue Loc-Tite on the bolts to get the pan situated so that it doesn't leak.
 
My '55, Lets see yours

I wouldn't even try to straighten out the oil pan unless it was a minor dent. You can find one easy enough on fleabay or maybe even Vech has a used one collecting dust. I found the best thing for a leak free seal on the oil pan is to first make sure you flatten out the mating surface (where the gasket goes) and then give the new cork (only use the cork) gasket a good coating of bearing grease, both sides and edges. The bolts should be cleaned thoroughly and apply a little bit of grey Permatex gasket sealer to the threads.

I've tried the gasket sealer on the oil pan gasket with no success and a headache to clean up.
 

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Thanks for that input. I actually found several loose bolts and after snugging them up it seems to have stopped leaking (from the pan anyway). I do want to pull the pan and take a look, so will follow your advice when I reinstall it. Missing the vented bolt that holds the speedo cable into the trans so that is on order and will eliminate another dribble. Also the seal need replacement in the clutch actuating arm at the trans .. my biggest offender left. Tray remains dry surprisingly, so maybe the rear seal is ok ...

I would appreciate some suggestions on bars? Yours look like they would resolve an obvious issue with mine. I have the sport tank and the bars have actually damaged the paint on the top of the tank from the controls hitting it. I assume they are the Euro bars, but seem VERY small and low profile, so maybe not. Either way, they gotta go. The gentleman I purchased from also gave me a set of bar end indicators which I would like to install, so notched bars would be nice (the current ones are notched.) From what I have gathered so far, bar end indicators are not period correct for a '55, but I can live with that. There are already a few items that have been replaced with '57 and/or /2 parts along the way that keep it from being 100% period correct. The front wheel has the shallower indents, the PO said the controls were /2 also and the air filter is rounded vs squared off at the top. I expect I will identify other thangs as I go, but I think that is about it at this point.

So far I am reading the Barrington book, developing a short term and long term to do list and have just started a "new to me bike" tune up, valve adj, fluids change, points, condenser, timing, carb sync on the list. Seems like the rocker covers have not been off in a long time ... so the adventure begins!
 
The handle bars are "plunger frame R 68" repops from vech

A friend of mine got the same bars for his '59 R 69 and cut 3/4" off each end and they look great. I have a set of the short (Europa bars) on my '65 R 69S and had the same control contact issue with the gas (Sport) tank, I did find a sweet spot that had no contact when turned side to side but it's a little tight for my comfort. Unless your in love with the "Sport" tank or plan on taking long trips with limited fuel stops I would find a good small tank for the bike, its a better and more correct option for it.

My 15 year stewardship of my R 50 has enlightened me to a few items unique to the early "swing arm" frame twins. If your looking for 100% correct you need to have good information, reliable source for parts, patience and a fat wallet. A nice running, decent example and fun to ride '55 R 50 can be a lot more enjoyable than a museum piece that you just look at and hope the header pipes don't blue out when you start it for an AMCA judging.

Early '55 R 50's as far as I know had a few distinct differences from later "swing arm" frame pre /2 BMW's
Different head light ears
Optional small coffee can tail light or Eber acorn light
Side car transmission standard
Rounded top front shock covers
Indented head light bucket
Black face speedometer
Solo seat coil spring
Oil filer cap
Straight chrome plated shift lever
Air filter housing similar to plunger frame bikes
Horn unit was similar to plunger frame bikes
Short rear brake arm
And to top it off there were a bunch of bolts and nuts on the early ones that defied logic but are correct for the early "swing arm" bikes

Bar end turn signals? Unless you need them (local DOT) or just like the look I would learn hand signals.

Its more the journey than the destination with the old bikes
 
Almost forgot

No metal brace on the front fender
Extra thick (sand cast) fins on valve covers
Non vented final drive with a specific ratio
Light weight crappy weak center stand brackets

I know there are more things unique to the early '55 "swing arm" twins but its late I'm tiered so I'm going to bed.
 
Called and spoke with Vech yesterday. What a cool guy with willingness to answer questions, offer advice and spend as much time as needed on every subject. Needless to say I placed an order (for some US bars and all cables along with other items like an oil pan, magnet, etc) and will do so again as I further evaluate the bike. Have done the simple things like changing fluids, adjusting the valves, replacing cracked rubber bits, etc. bike runs great, starts easily and I have got a couple of short rides on it. Today was my first freeway run as I was running a little late for my Clubs meeting. The Metzler tires gave me an uncomfortable squirmy ride on the ribbed concrete around 60, swung over into the smooth asphalt emergency lane and the feel returned to normal, so I assume it is the tires. I run the Pilot Actives on my /5 and like them a lot ... they may not look as correct, but since I plan to ride this bike, I will probably switch to them at some point.
 
How old are the tires? Can you find the DOT date code on them? I'm not sure the Pilot Activs will come in the right sizes for the /2 era bikes. I had been running IRC GS11 tires but seem to run into a bad one or two. I've since switched to the Metzler Block C tires...I run a 3.50x18 in front and a 4.00x18 in the rear. I suspect your bike will be 3.50x18 front and rear. Not sure if you realized it but it is possible to swap front and rear tires on these bikes.

Talk to Vech. He carries the Heidenau range of tires. They are vintage looking and probably something he would recommend.
 
They are Metzler 350 x 18’s 565 Block C5 tires with a 2018 DOT date and minimal wear that still have rubber **** on the sides ... I assumed they were a plus, but like I said earlier, they felt unsafe on the ribbed concrete at 60 MPH ... disappointing, but oh well. My first though at the wobble feel was it might be related to a front end service of bearings and suspension refresh (which I’m sure is needed and will get to) or worse, but when it smoothed out on the smoothly paved emergency lane it makes me think it is the tires ... make sense?

Edit to add I will talk to Vech.
 
Well, ribbed concrete is going to create some handling problems depending on the tire choice. No ribbed concrete around here so my Block C tires feel just fine. Might consider some Avon tires...maybe Road Riders?...they don't have the tread lines around the circumference. Not sure if they're available in the right sizes. I don't see the 3.50x18 offered at Revzilla. I'm personally not a fan of metric tires when there are good inch-sized options out there.
 
Its not a Wet Head RS

Your riding an almost 65 year old motorcycle and even with new tires an shocks it is going to get a little shaky at speed. That's the beauty of the beast, you just have to understand and respect the quirks and limitations. One worn out shock or a head stock a little loose can make even a seasoned rider a little nervous, you just have to get a feel for the bike and make sure its safe and ride it within your and its limits.

Kurt I think JP cycles had the Metzler C block tire for a reasonable price and fast delivery
 
I clearly understand, and although I do have a modern RT, my daily rider is a 1973 75/5 and I have not been without a motorcycle for over 50 years. I know I have a lot to learn about this particular bike and appreciate the dialogue. Just wanted to give you a little of my background also to explain I’m not a rookie when it comes to knowing what is a bike limitation vs something not right.

Edit to update: Vech replied that the block C's and German Heidenau do in fact dance in rain grooves and even went on to say when he had ridden on them out of state, that it was scary (was my reaction as well) .. he mentioned Avons have a different type tread pattern but doesn't know first hand how they react to rain grooves. Bottom line for me is perhaps this simply supports your comment of knowing the limitations and factoring them into my ride. Glad to have some confidence it wasn't due to alignment, shot bearings, etc.
 
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Update ... I got a nice little 135+ mile loop in yesterday thru a couple of my local canyons called Silverado Canyon and Ortega Hwy and even a little rain grooved freeway that didn't produce as much negative reaction as I experienced on the stretch near my home.

Bike really ran nice and is surprisingly strong for a little, low HP 500. My "needing attention" list is growing though. I had eliminated the obvious oil leaks, but an extended ride identified a few more. Front crank seal is now on the list (maybe a silver lining indicating the slingers are doing their job?) as is the pinion gear seal.

I stopped at a local cafe called Hells Kitchen for a photo. There was only one other person there (closed) who walked up as soon as I dismounted and asked if I was interested in selling my bike hahaha ... man I just bought it ... no!

Since I still can't seem to get any pics posted, perhaps I can get around it with this link to my Instagram account with some pics I took yesterday?

https://www.instagram.com/p/B8N0zaTjbKvvhypFpK3ughcZqweV6f08BNrJvM0/
 
I had eliminated the obvious oil leaks, but an extended ride identified a few more. Front crank seal is now on the list (maybe a silver lining indicating the slingers are doing their job?) as is the pinion gear seal.

Not quite sure what you're referring to, but the slingers are positioned quite near the main big end bearings at the center of the engine. They separate out any particulates in the oil and then feed the main bearing surfaces. If there's leaking at the front crank, then it's an issue with the seal there. What pinion gear are you describing? Is that at the final drive?

Since I still can't seem to get any pics posted, perhaps I can get around it with this link to my Instagram account with some pics I took yesterday?

Instagram didn't work for me. Not sure why you're having troubles posting pictures. If you need to see some of the steps needed to upload pictures, I can show you that. Usually the problem is with pictures being too big in size. If they are more in the 1Mb range, uploading shouldn't be an issue.
 
Not quite sure what you're referring to, but the slingers are positioned quite near the main big end bearings at the center of the engine. They separate out any particulates in the oil and then feed the main bearing surfaces. If there's leaking at the front crank, then it's an issue with the seal there. .

Clearly neither do I 😂. I was just being hopeful that if oil was getting to a bad front crank seal (that I have ordered) that maybe that means the slingers were doing a good job of lubricating the internals. Having never been inside to see them, I guess it is just a case of my rookie-ness showing.
 
The oil leak and slingers and front seal leak are different issues

The Crank Shaft Oil Slingers do just that, they "sling" oil out and up to the bottom side of the piston and the small end of the connecting rod for cooling and lubrication. The "slingers" are simple pressed sheet metal disc's with a trough / channel that fills with oil while the motor is running and at some point over flows and slings oil out to the bottom side of the piston and the small end of the connecting rod. Over time and after many hours and miles of the motor running the trough / channels on the slingers get filled with "GUNK", "SOLID GUNK" and don't hold oil and even stop slinging oil up the the piston base and small end of the connecting rod. THE SLINGERS DO NOT FILTER THE OIL! THEY COOL AND LUBRICATE THE BOTTOM OF THE PISTON AND THE BRASS BUSHING ON THE SMALL END OF THE CONNECTING ROD.

Servicing (cleaning) the slingers requires some major surgery to the motorcycle but in the long run is well worth the time, money and education if you wish to preserve your investment in BMW history. You must remove the motor and disassemble it just to inspect the "oil slingers" to see if there is an issue with them. Plan on new gaskets and seals along with other shop supplies. Vech at Bench Mark Works has a pretty good explanation of how the slingers work and the importance of at least inspecting and cleaning as needed.

I was hesitant to tackle an inspection and cleaning out of the "oil slingers" on my '55 R 50 but I'm glad I got the tools and followed the directions.
 
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