Bending your own exhaust pipes.
Page 1 of 2 1 2 LastLast
Results 1 to 10 of 15
Like Tree4Likes

Thread: Bending your own exhaust pipes.

  1. #1
    Senior Member Richard_Pitman's Avatar
    Join Date
    Sep 2014
    Location
    Worcester, England
    Posts
    2,543

    Bending your own exhaust pipes.

    Does anyone think that this is a viable option, or better yet, already done this ?

    Using one of those '12 ton' hydraulic pipe benders from Ebay, Machine Mart, Harbour Freight et al ?

    Mild steel tube, packed with sand to reduce creasing.
    1970 Honda CB175K4
    1972 Honda CL175K7
    1999 Honda CB600 Hornet
    1970 - 1972 Random heap of CB/CL/SL 175 parts, slowly being reassembled ..

  2. #2
    Senior Member Alan F.'s Avatar
    Join Date
    Aug 2009
    Location
    Boston
    Posts
    1,763
    There are tons of videos about pipe benders vs tubing benders, tubing rollers are another option. My thoughts gravitate toward the Japanese fabricators that bend free hand with just a torch and a radius gauge.

    I recommend the videos as research before deciding on your method of bending. Your material of choice will also help dictate your method, as not all methods will produce the same results with the same materials.

    Someday I'll give this a shot myself, subscribed!
    CB250 Nighthawk projects 92,93,92.
    81 CM400C Sold
    93 CB750 Nighthawk Sold
    73 CB750K3 Long term project stuck in the 'parts collecting stage.'
    Fork Swap info: http://sites.google.com/site/alansdocuments/

  3. #3
    Senior Member Richard_Pitman's Avatar
    Join Date
    Sep 2014
    Location
    Worcester, England
    Posts
    2,543
    Ah, that was my fevered imagination working last night. In the cold light of day, I think some pre bent mandrel bends will be my best bet, stick them together with the mig welder. Cluttering up my shed with a pipe bender that might get used a couple of times only doesn't seem such a good idea on reflection.

    I've just managed to find a rusty set of down pipes on Ebay, like hens teeth for some reason, that'll sort out the difficult top part of the pipe work.

    And a can of PJ1 black exhaust paint …..
    oupa likes this.
    1970 Honda CB175K4
    1972 Honda CL175K7
    1999 Honda CB600 Hornet
    1970 - 1972 Random heap of CB/CL/SL 175 parts, slowly being reassembled ..

  4. Remove Advertisements
    HondaTwins.net
    Advertisements
     

  5. #4
    Senior Member Brent's Avatar
    Join Date
    Feb 2016
    Location
    Bancroft, Ontario,Canada
    Posts
    581
    Go to a good muffler shop and they will be able to bend it to any specs, they should be able to do header pipes as well.

  6. #5
    Senior Member Alan F.'s Avatar
    Join Date
    Aug 2009
    Location
    Boston
    Posts
    1,763
    I think one hurdle is finding the right material to begin with, Shops may not have suitably narrow tubing for smaller displacement motorcycles. I remember I did a search a year or two back and my most local and inexpensive choice was zinc plated steel fencepost tubing with a 1.15" ID for my 250 Nighthawks (if memory serves)
    The zinc plating can be removed easily with a soak in plain white vinegar, then I could bend the tubing with whatever means I wanted to experiment with.
    Or I could leave the zinc on just to experiment with bending without wasting lots of money on materials.

    I'm not certain how well it would bend but for less than a dollar a foot retail it seemed worth experimenting on.

    I remember watching one video where the presenter was bending pipe or tubing (can't remember) with a hydraulic bender, he showed the huge difference that a slightly undersized bending die (smaller die than tubing) can make in the quality of bend produced. It was amazing and really stands out in my memory.
    I'll have to look for this video later when I have more time available.
    CB250 Nighthawk projects 92,93,92.
    81 CM400C Sold
    93 CB750 Nighthawk Sold
    73 CB750K3 Long term project stuck in the 'parts collecting stage.'
    Fork Swap info: http://sites.google.com/site/alansdocuments/

  7. #6
    Member Mike450's Avatar
    Join Date
    Feb 2011
    Location
    Pittsburgh, PA
    Posts
    45
    I had a company called J&D Tube Benders in Schofield, WI (J & D Tube Benders | Manufacturers of Hydraulic Tube Lines and Bending) mandrel bend some header pipes for me a couple of years ago for a CB450 cafe project I was working on with my brother. I just send them a drawing (PDF file in my case) with all the measurements and angles and once I had approved the quote they shipped them out a week or so later. Pics below. I tried using a bunch of pre-made mandrel bends from Columbia River but in the end the stuff from J&D was more cost effective and much cleaner because there weren't' a bunch of weld seems to contend with.

    If you're looking to replicate the stock profile I'm not sure this is an option as Honda tended to have quite a large radius curve on their header pipes.





  8. #7
    Senior Member Richard_Pitman's Avatar
    Join Date
    Sep 2014
    Location
    Worcester, England
    Posts
    2,543
    Thanks for the interesting replies.

    This is what I hope to achieve. I still have to sort out some suitable mufflers to go on the end of the pipes. Apologies for the accidental selfie.

    Bending your own exhaust pipes.-20190904_142147.jpg

    The double skinned original down pipes ( headers ) have a 35mm OD, as do the pattern ones in my photo. This means that 38mm tube, with a 1.5mm wall thickness, is a nice sliding fit, and could either be clamped or welded. There will in fact only be the one join in the pipes, and that will be tucked away down behind the footpegs.

    Interesting comment about Hondas large radius curves, it is quite noticeable that the pattern part shown here has much more acute bends. I wish to preserve these chrome pipes, so I've got some tatty rusty originals on the way, along with a pair of 45 degree mandrel bends in mild steel, rather then the stainless in my photo. Plan is to then paint these parts black, as SL175 pipes. I've requested that the new bends have longer lower legs than the short one shown here, to give me a bit more flexibility in final position.
    1970 Honda CB175K4
    1972 Honda CL175K7
    1999 Honda CB600 Hornet
    1970 - 1972 Random heap of CB/CL/SL 175 parts, slowly being reassembled ..

  9. #8
    Senior Member JamesPal's Avatar
    Join Date
    Sep 2009
    Location
    Bellevue, Washington
    Posts
    3,409
    Back when I was building the 450 I considered building my exhaust. Someone on this forum cited Cone Engineering as a source of very high quality exhaust components. f you like to weld, it would be a fun project. https://www.coneeng.com/motorcycle_components.html
    Jim Palmer
    '85 GL1200I (Garage Find)
    '81 GL1100 STD (Project)
    CB450 K5 Done
    https://www.hondatwins.net/forums/1-...s-cb450k5.html
    What I learned from Restoring a CB450 K5
    Watch Mike and Jim Take on Mt Erie Washington State
    "If everything seems under control you are not going fast enough" Mario Andretti...

  10. #9
    Senior Member oupa's Avatar
    Join Date
    Aug 2014
    Location
    Maryland, USA
    Posts
    627
    Cool idea Richard. Having experimented with welding pipes earlier this year (the experiment is not over yet!) I'd highly recommend some serious practice welding on like material before tackling your only pipes. Decent welds can be had with your mig welder but practice and get the settings right before giving in to temptation and going after the pipes you intend to use. I found that wire speed was critical to getting a good weld, which can be a bit tricky as you go around the pipe. If you can clamp it so the joint is pointing up, enabling you to stay level (think of the equator) as you go around the pipe instead of trying to weld with the pipes horizontal, where you're upside down half the time, you'll do a lot better... if that description makes any sense at all.
    "They're not like cars with a body that rusts out in a few years. Keep them tuned and overhauled and they'll last as long as you do. Probably longer." - Robert Pirsig

  11. #10
    Senior Member Brent's Avatar
    Join Date
    Feb 2016
    Location
    Bancroft, Ontario,Canada
    Posts
    581
    A good muffler shop or parts supply should be able to get any type of pipe needed. Personally, I would take the bike to the shop and have the pipe bent, fit and marked for alignment.

Page 1 of 2 1 2 LastLast

Sponsored Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •