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/2 BMW motorcycle mufflers |
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Click here for /5 muffler informationBMW only offered new production with one muffler at a time. That means that BMW didn't offer a sport or after market muffler for motorcycles. BMW dealers offered the Hoske muffler (megaphone) but they were imported by Butler and Smith, not exported by the BMW factory. This was often the cause of confusion regarding accessories. Some after market firms offered mufflers and I will include info about them as I get pictures and information about them. The Earles fork BMW motorcycle muffler
This factory photo shows the first muffler. Note the shape and slightly smaller size.
This is Tom Bridgers' R69 restoration with the proper "salami," or "cigar" muffler. Thanks Tom The first BMW muffler of the Earles fork models, in late 55, was a small one that was salami shaped. That muffler was used on the R50 up to VIN 555205 and on R69 machines up to VIN 652304. All three twins used the same salami muffler.
After the short run of the cigar muffler, they changed to the second muffler which is the shape that we see today. The R69 had a muffler identical in shape to the R50 - R60. These were replaced in late 1960 with the 100mm silencers from the R69S. The R69 was unique in that it also used a third muffler in the crossover between the exhaust pipes. Read more about it here. The singles used the same basic muffler, but the mounting was different. In about 1963, BMW stopped having the contractor grind off the welds. We called those early mufflers "seamless" but it was only because we couldn't "see" the seams. After that, all mufflers had visible seams. I would love to get some anecdotal evidence of exactly when the seams appeared. This second muffler was continued all through the /2 production and used on the R50/2, R50US, R60/2, R60US and the R27. In 1961, BMW introduced the series that they called the /2 series. Some confusion exists because the /2 designation has been extended backwards to include all models with Earles forks and the last two years (68-69) of the series with telescopic forks. The actual /2 series offered a new model, the sport 500 cc model called the R50S. The 600 cc model R69 had the "S" added as a suffix. It became the R69S. These two models got a slightly different muffler. It was best recognized by the larger outlet. It was slightly louder with a throatier sound.
The outlet of the (left) sport models is larger than the (right) touring models Both /2 BMW motorcycle mufflers are interchangeable. Each can be installed on any model of /2 BMW motorcycle from late 55 thru 1969. Sometimes the fatter muffler will be in the way of the center stand in the up position. Usually it is a deformed center stand that should be reworked. The muffler can just be pulled out a bit and it will clear. If it is allowed to rub, soon a hole will be worn through your very expensive silencer.
Measurements of the two types of muffler. The sport muffler is NOS from 1973 for my R50S restoration. The R50/R60/R69 muffler is an old used one of an unknown source. Both are the later types with the weld showing. I am not saying that these dimensions are the ones used forever. BMW could have used different contract companies to make them over the years. That may explain some differences that you may find.
This is the underneath view showing the cutouts (really they are just pressed in sheet metal) for the center stand. The lower muffler shows the place for the tang to clear the muffler. The upper one shows where the foot of the right side clears. The two are different distances from the front because the tang and foot are not the same distance. The mounting tangs have changed a few times over the years. From time to time we could get a bike in the shop with a partially rusted away muffler. I had a chance to view the baffles. They seemed to be about the same over the years. I never measured them, so can't be sure. They tended to rust just in front of the baffle plate. We often drilled a 1/8" hole at the bottom at the point that would "bulge out" from rust. The water that condensed would be forced out the small hole and not encourage rust. We noticed no extra noise or early rust from this mod. They seemed to last longer for the owner that only rode a few miles per day to and from work. Aftermarket mufflers for the slash 2I will post information and photos of the aftermarket mufflers as I get them. I would like photos of the Hoske, Dixie, Bates and any others that were in general use.
This is a pair of MCM used mufflers found on eBay.
They are used and very pitted. OverlanderI've heard a lot of complaints about Overlander stuff. The Overlander R27 header I tried this past year was so off it interfered with the frame. At least if you live in Australia you can return stuff relatively cheaply. I lost over $100 in postage returning ill fitting parts. I would not recommend Overlander parts. ---Steve EpcoI have tried three systems: Overlander stainless, EPCO stainless and Mobile Tradition chrome. The Overlander headers fit poorly, the EPCO mufflers were too loud after I added a fairing, and the Mobile Tradition chrome system fit well. I have owned chrome mufflers for as long as five years on various vintage BMWs and have not had rust. Maybe that is because the bikes are garaged, not ridden very short distances and not ridden in rain. Hava (Swiss I think) also made sport mufflers, I may have one laying around here somewhere. Also Swirin, I think they were made in New Jersey. Hoske made more than one style of sport muffler. Bruce /3 muffler informationThe Swallow tail silencers and straight exhaust pipes were series right through till September 1953 (Introduction of 1954 models). As of R51/3 no. 526210 in 1952, fitted with the wider centre stand, thus requiring a cut-out or dent in the silencers for the centre stand to clear. This cut-out was no longer necessary in the torpedo type silencers of the 1954 models, as they were mounted further apart anyway. Mark Huggett There are birdtail and fishtail mufflers that will fit S bend pipes. They are notched out like the torpedo mufflers. Of course they are not correct on any bike. On another note, the straight pipes take longer pipe hangers. No Idea who has them long enough for straight pipes, I had to make them. Vech might have that answer. Tim Stafford TJ Scoots The symetrically cut mufflers are "swallow tail" mufflers and are appropriate for the early 50s bikes. The mufflers with the pointed "ankle biter" on the bottom are "fish tail" mufflers, and are appropriate for the late 30s bikes. Darryl Richman Information on the exhaust system. |
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This page was last edited:
09/04/2007 - copyright
Duane Ausherman |
