Vintage BMW Motorcycle Owners

Hi there, been tinkering with this R69S since it arrived in my possession this past winter. Finally got it fully operational over the summer and have been slowly getting it to where I want it.

It came with a set of aftermarket pipes that are... well, loud. Not exactly my style. However, the bike also came with another muffler set that I was told was the factory pipes. So, last night I went to swap those back on and quickly realized they don't come close to fitting. Will include some images here of those mufflers, but they're far too short to meet the headers and instead of having extended tabs to mount to the frame, they have a recessed threaded fitting. I feel like I maybe could fab some sort of bracket to make them attach, but they'd still be too short.

Also, in the midst of all this, I noticed that a previous owner appears to have cut out the crossover pipe off the headers!

So... questions...

- How much power am I giving up without the crossover pipe? The bike feels awfully low on torque, but this is the first R69S I've had the pleasure of riding, so I don't have much to compare it to. I ask because it looks like a new set of headers is far from cheap.
- Is Keihan the best choice for a replacement set of OEM-like mufflers? Anything else I should consider?
- Any suggestions on what this mystery set of mufflers might actually fit? Hoping I could at least sell them and recoup some of the cost of buying a new set of mufflers for this bike.

Thanks!

This is the current exhaust on the bike: Here's where the cross pipe should be. And this is what my random other exhaust is. Great condition! Wrong fitment...

The muffler in your pics is for a 53-54 (and '55 R67/3) plunger twin. It will not fit a "/2" style swingarm frame (as you found out). I'll leave it others to comment on aftermarket mufflers/exhaust systems.

Hope that helps.
Chuck S.

The probable reason the header pipe has no cross over is that the pipes rotted away and the bad was cut out.
That happened to mine. I bought some cheaper after market silencers that could be moved forward.
With the advent of the internet I was able to purchase a complete exhaust. I did go with keihan.
When shopping you might want to check out purchasing directly from the UK.
The Keihan has held up well, except a big dent in the back that I inflicted on a mishandled twisty.

If I were replace the exhaust now, I would seriously consider a chromed set. Few abuse these motorcycles with weather and mileage to need stainless. Chrome colors correctly to blue, Stainless yellows.

Oh, and not having a crossover made absolutely no noticeable power difference.

Don

Edit, R69s came with 100mm silencers, earlier R69 with 90mm. Either size will fit on both models.

If/when I consider getting new mufflers for my R69S, I think I'm going to strongly consider the versions that Mark Huggett offers on his site. I think they were built to the original specs...probably will cost it as well!

As for the cross over, they have these things on the 1970-on Airheads...I think my /7 has them. My understanding is that they help with midrange torque and/or power. Maybe not noticeable, but I don't think BMW would have done it without some reason...or perceived reason.

sherman980 wrote: ↑

Wed Oct 13, 2021 11:20 am

The muffler in your pics is for a 53-54 (and '55 R67/3) plunger twin. It will not fit a "/2" style swingarm frame (as you found out). I'll leave it others to comment on aftermarket mufflers/exhaust systems.

Hope that helps.
Chuck S.

Hugely appreciate this, Chuck. Will see if I can't find a good home for them.

And thanks all for the other suggestions and advice! I guess I'll keep an eye out for an affordable set of headers with the crossover, but won't sweat its absence too much.

TimStevens wrote: ↑

Wed Oct 13, 2021 1:58 pm

sherman980 wrote: ↑

Wed Oct 13, 2021 11:20 am

The muffler in your pics is for a 53-54 (and '55 R67/3) plunger twin. It will not fit a "/2" style swingarm frame (as you found out). I'll leave it others to comment on aftermarket mufflers/exhaust systems.

Hope that helps.
Chuck S.

Hugely appreciate this, Chuck. Will see if I can't find a good home for them.

Tim, put them on the for sale area of the forum. I am sure they will find a good home.

On my R 75/5 I replaced the crossover pipe with generic 1.25" O.D. exhaust pipe. It just balances the back pressure and makes the engine run a tiny bit smoother.

Craig

schrader7032 wrote: ↑

Wed Oct 13, 2021 12:40 pm

If/when I consider getting new mufflers for my R69S, I think I'm going to strongly consider the versions that Mark Huggett offers on his site. I think they were built to the original specs...probably will cost it as well!

As for the cross over, they have these things on the 1970-on Airheads...I think my /7 has them. My understanding is that they help with midrange torque and/or power. Maybe not noticeable, but I don't think BMW would have done it without some reason...or perceived reason.

I use the parts from Salis for all my exhaust components and they are made very well. I would suggest any exhaust components from Salis.

cbclemmens wrote: ↑

Wed Oct 13, 2021 2:19 pm

On my R 75/5 I replaced the crossover pipe with generic 1.25" O.D. exhaust pipe. It just balances the back pressure and makes the engine run a tiny bit smoother.

Craig

I used one of these, fit snug with no need for a clamp. I cut off the threaded part. Still shiny after 10 years.
1-1/4 in. x 12 in. Chrome-Plated Brass Double Threaded-Joint Sink Drain Tailpiece Extension Tube
https://www.homedepot.com/p/Everbilt-1- ... /205153650

sherman980 wrote: ↑

Wed Oct 13, 2021 11:20 am

The muffler in your pics is for a 53-54 (and '55 R67/3) plunger twin. It will not fit a "/2" style swingarm frame (as you found out). I'll leave it others to comment on aftermarket mufflers/exhaust systems.

Hope that helps.
Chuck S.

Same on my 1954 R51/3
#8
https://www.bmwclassicmotorcycles.com/p ... rt-one-22/
right__ double click on picture to enlarge
https://bmwclassicmotorcycles.com/index ... -5472.html
left__double click on picture to enlarge
https://bmwclassicmotorcycles.com/index ... -5474.html