Production racer exhaust pipes

partno. 063893 (left hand) / 063897 (right hand)

I'm considering to buy a pair of those exhaust pipes as they should improve the ground clearance and have a nicer look. Is the difference with standard pipes considerable ? (especially on the left side)
As I want to keep the silencers, do the prody exhaust pipes have the same length as the standard ones ? (063375/6).
Norvil sell those but recommends to buy the -rather expensive- 069219A clips. Are those necessary ?

Thanks a lot for your help.

The original Production Racer pipes fron Norton were cut at the cylinder head end and welded on a slight angle to tuck them in closer to the frame rails. It looked like they started with the stock pipe bends, cut and welded them, and then had them plated. They definitely give you more ground clearance when leaned over. As I recall, they were the same length as the standard pipes. At least that's true for the ones that came with peashooter mufflers (Some of the earliest PRs came with Atlas mufflers, and I'm not sure what they did for pipes). They fit just fine with the original PR mounting brackets and mufflers, but I don't know if they would work with the standard Commando mounts. I don't know what the 069219A clip is. Norvil calls it a bracket, so maybe it's their version of the original PR silencer mounting bracket. I don't see that part number in the original PR parts catalog. All the aftermarket reprro "Production Racer" pipes I'Ve seen, including the Norvil ones, were not welded, but just had the tubes bent to bring them closer to the frame rails. BUB used to make pipes like that, but with the ends slightly bent to let them line up with the stock silencer mountings.

Do you have a copy of the "750 RACER and 750 FORMULA RACER CONVERSION KITS", Norton technical release N3/12? It has all the part numbers for the original PR parts, as well as F750 parts, and instructions for converting a stock Commando to either one, and is really handy if you're building a replica. I've posted a .pdf copy of it on the INOA site. If you don't have access to that, let me know, and I'll emal it to you.

Ken

I have what appear to be stock pipes. They took very little encouragement to fit the PR muffler mounts.

I have that conversion document, I can post it later this week.

Capt. Norton online version. This site is a gold mine of old gossip and wisdom.
750 Racer and 750 Formula Racer Conversion Kits and Components
http://home.clara.net/captain.norton/750_kits.html

hobot said:

Capt. Norton online version. This site is a gold mine of old gossip and wisdom.
750 Racer and 750 Formula Racer Conversion Kits and Components
http://home.clara.net/captain.norton/750_kits.html

Click to expand...

Good site, Steve, but that's an old scan, and the pictures of the parts are pretty bad. I scanned mine to a high res .pdf file, and the images are much clearer. I also scanned in .jpg, but the pics were much worse. Unfortunately, I don't think there's any way I can post .pdf files here.

Ken

Thanks a lot for your detailed answer, Ken.
I have a copy of the Technical Release N3/12 about 750 racer and 750 formula racer conversion kits. On the pictures below, the difference between the standard and Pr.Racer exhaust at the cilinder head is clearly visible:

standard exhaust pipe:



Production Racer exhaust pipe:



And the next photos show the difference between the standard pipe and the Norvil type that show that indeed the latter runs closer to the frame:

standard exhaust pipe:



Norvil type:



In the meantime, I've got a PM from a forum member who lives in Belgium as well. He has a pair of the Norvil style exhaust pipes and I hope to meet him soon to check if those fit my silencers. I'll report afterwards...

Thanks to all !

See em all tucked up ! . Was given a set of PR headers , and was to lilly livered to cut the side stand bracket off .

Wouldnt fit in under the primary with the 72 bracket . OUT with the Disc Grinder . You only live once . :roll: :wink:

Both pipes fit up and ' right in ' to the frame rails , so they dont act as skid rails like the Interstate headers .

Had Early type silicers too , the Atlas ish Glass pack , straight through suckers . :cry: Gave the headers to a 72 PR Owner .

The wisdom of hinsight . Wots a 55 T100 R . FUDGE . :shock: :?

atlas pipes will fit and have the correcct tucked in position , they are however of a bigger bore
we used that bore size on a 920 and later on a 850 outfit and they went well , but it was a 2 into 1 set - up , as copied from a factory sheet i got ,through 79x100 , from norman white

The early Proddy Racers had pipes similar to all early Commando ones, i.e. 1 3/8" at the front going to 1.5" where the pipe enters the silencer. No issue with side stand mounts because early frames used the forged bolt-on side stand mounting, which was simply left off. Early pipes on all models were pretty much pulled in towards the bottom frame rails anyway, with the pipes exiting the exhaust ports straight ahead rather than at the more logical outwards=pointing angle.

The obvious difference was that the pipes bent upwards at the end, so the Dommi type silencers were at an upward angle (as on Roadster systems), whilst all other bikes of the period- Fastback and "R" type- had the silencers parallel to the ground.