Model 50 vs. ES2 exhaust pipes on Slimline bikes

HI Mike

AFAIK, you are correct, it is just the vertical height that differs, year by year the ES2 and M50 had the same pipe diameter, and the singles went to a smaller pipe size in 1958 or so, I think (someone will correct me if I'm wrong) just so that they could use the same silencers (mufflers) as the twins, which were massively outselling them by then, (although I have seen a 1 5/8ths pipe with a swaged-down end, but I don't know if it was an original one, or what it came off) but when the singles went into the featherbed frame slightly later, the smaller pipe provided more clearance to the frame downtube, so you probably need the smaller pipe. Norton Motors may have been planning ahead but I doubt it, I do know for certain that the pipes for the wideline singles have the same bend but are shorter on the horizontal section, so on a slimline the pipe won't reach the silencer if you use the downpipe off a wideline.

There were quite a few changes over the short life of the Featherbed ohv singles, and little information because at the time I don't think many people were interested in them, mostly they got what the twins got.

There is much talk about bend radii etc, but for my money if you can get someone to bend you one up that aligns with the port well enough to seal, doesn't foul the frame and then lines up with the silencer, then thats good enough.

Good luck,

cheers,

Niall

Previously wrote:

HI Mike

AFAIK, you are correct, it is just the vertical height that differs, year by year the ES2 and M50 had the same pipe diameter, and the singles went to a smaller pipe size in 1958 or so, I think (someone will correct me if I'm wrong) just so that they could use the same silencers (mufflers) as the twins, which were massively outselling them by then, (although I have seen a 1 5/8ths pipe with a swaged-down end, but I don't know if it was an original one, or what it came off) but when the singles went into the featherbed frame slightly later, the smaller pipe provided more clearance to the frame downtube, so you probably need the smaller pipe. Norton Motors may have been planning ahead but I doubt it, I do know for certain that the pipes for the wideline singles have the same bend but are shorter on the horizontal section, so on a slimline the pipe won't reach the silencer if you use the downpipe off a wideline.

There were quite a few changes over the short life of the Featherbed ohv singles, and little information because at the time I don't think many people were interested in them, mostly they got what the twins got.

There is much talk about bend radii etc, but for my money if you can get someone to bend you one up that aligns with the port well enough to seal, doesn't foul the frame and then lines up with the silencer, then thats good enough.

Good luck,

cheers,

Niall

Sorry Mike I meant to write that I have seen a 1 3/4" downpipe that reduced to 1 5/8" at the end, but as I say what it was, I don't know, could have been Inter for all I know.