Britbike forum Forums British motorcycles in general British modified/specials High level exhaust pipe fabricator

I have a pair of high level exhaust pipes I need replicated.

They're fairly simple, with one pipe out each side, and being bent from 1-3/4", 18 gauge tubing. Bends are about a 4" center line radius.

Can anyone recommend a shop somewhere in North America that could do this >

Thanks,
..Gregg

Anyone? please ...

Thank you,
.. Gregg

Gregg,
Wish I could help you, but I've been looking for one for a number of years...

There is a shop north of me, claims to have a tubing bender, but needs to get it leveled.... Been asking them for 4 years now, if it's set-up yet...

There is a tubing shop on the opposite side of town, but he has had so many whiners, and returns constantly coming back for whatever, that he refuses any exhaust work now...

A friend of mine in Detroit says there is a tubing shop up his direction, but that is a 5 hour drive each way... I'm still working, so any weekday trip is out of the question...
Brett

Gregg-you might try looking over on the XS650 Forum. As I recall there is an individual that makes awesome high pipes for the Yamaha XS650's. I believe his name is Glenn Scott. Hope this helps.

Jerry

Brett,

I have to believe someone in North America should be able replicate my oriignal pipes, but like you I have been stumped.

Jerry,
I checked out the XS650 site, and it looks like Gordon Scott is the guy who makes the exhausts ... he fabs them by welding up pre-mandrel-bent sections. I've sent him an emai to see what he thinks.

Thank you both for your suggestions.

.. Gregg

OK then,
Several years ago at Mid-O, there was a fellow with a notrun I think?

He also was welding up sections of pre-bent tubing, to make up custom 'shaped' exhaust pipes...

He wasn't the fellow I ended up trying, but there is a shop in town, another one, whom I cannot recommend, who did just this, and, while they followed my request about the front of the pipe, after they got to the rear section, they did NOT do as they said they were going to do, and just took sections of tubing, welding them -near- what I was asking.

Then, without asking my permission, ground the chrome off the -supplied-by-me- muffler, to add additional muffler supports, attaching to points I wasn't wanting additional stress added to: mounting tabs for the tool box? The sheet metal tabs that are only 1/4 wrapped around the frame tube, and brazed on?

How often are these tabs broken off already, let alone adding additional stress to them???

Be careful who you do get any custom work done by!

Yep, makes me wonder what some of these guys are thinking ... maybe they're not (thinking).

Wonder what made him think that he could do his own thing rather than what you paid him to do?

. Gregg

Jerry,

Just got word back from Scott. He can not replicate the pipes I have by working from my originals. He says he needs the actual bike to work with.

The search goes on ...
... Gregg

Unless you can find a shop with a specialized pipe bender it will be difficult to find someone to bend pipes to match yours. I am making a set of pipes for a flat tracker using pre-bent sections and cutting them at the angles required to make the transitions. I made a special clamp to hold the sections together for welding. I think most spaghetti pipes are made this way.
I have a DiAcro pipe bender that uses a follower block to keep the pipe from squashing in the bend but it still does not replicate the continuous bends of the factory pipe. CNC benders have an internal mandrel that keeps the pipe round through the bends. If you are using 18ga steel rather than 0.035" stainless it is easier since there is more material for grinding and polishing.
Any particular reason for 1-3/4" pipes? Too large for good scavenging on most British bikes.

I've found various shops with a mandrel bender, but they concentrate on automotive applications consisting on pipes that are over 2" OD with a 16ga wall. Guess you can't blame them for going where the money is.

Fabspeed is possibly the best known of these shops, but they do not have dies for what they see as being fairly large radius bends (mine are 3 and 4" center line radius). The best they could do is a series of tighter bends.

Reason for the 1-3/4" tube is only to replicate the original system for my pre-war, 500cc 4-valve single. You're right about the cross-sectional area being too large, but I don't have a lot of choice but to reproduce the original pipes.

Thanks,
... Gregg

Thought it might be useful to post pics of the original pipes, which span about 29" O-all:



End View of Right Side Pipe:


End view of Both Pipes Together:


They're over 75 years old now, so let's hope someone can replicate them in our CNC world ...

Thanks to all,
.. Gregg

Those are a work of an artisan. They haven't made the CNC tube bender that will reproduce those bends! To produce bends like these, the tube often needs to be packed with a product like CerroBend:

http://www.hitechalloys.com/hitechalloys_005.htm

Unlike sand, lead, resin products Cerrobend is easy to use due to its low melting temperature and produces beautiful smooth bends because of the superior support offered due to its low coefficient of expansion.

By some pre-bent tubing, make up a couple of "U's" made up from 1/8" steel welding wire. Cut the tube removing the part of the bend you do not need, Place the bent loops of wire inside the tube facing in opposite directions (they need to be 10 to 12" long), weld the tube, and use another length of welding wire with a hook to fish out the two supporting wires.

Or insure the pipes for $500 and send them to a plater. Or if so inclined, wrap them up and send them to me for Christmas... Iv'e been good!

Those would not be too bad to replicate. WoolfACbenddie (woolfaircraft.com) has 4" centreline bends in 1-3/4" pipe (ranges from 1-3/4" to 12" in 1-3/4" pipe). You would need more than 180° for the first bend but to get the twist it has to be split and welded somewhere in the middle anyway. If the diameter at the head is larger than 1-3/4" then a sleeve can be added. I see the pipe being built from four pieces. You need a jig to split the pipe on the radial then another hold the pieces for welding. This is a TT pipe that I am making from stainless tube.

John, No question whatever that you are good! Santa came by this morning and dropped the pipes back off. He said the stockings you left on your fire place mantel were not large enough for him to leave the pipes in. Guess I'll have to follow the various (as usual) good suggestions you've made.

I've leaned toward fabbing them myself from mandrel pre-bends, but have been frustrated in finding a source of 1-3/4" 18 ga. tubing. Most seem to be made for automotive exhausts or intercooler applications.

Cerrobend looks interesting, but may be pricey for a one-off project. Having said that, I got a call from a friend in Montreal, regarding a shop in Montreal called "Turbotube". They have a (large) mandrel bender and specialize in custom exhausts. I'll be calling them on Tuesday when they get back from New Years ... they sound like my best shot so far.

Your suggestion about simply having my old ones re-plated has merit as well, but I'm concerned that they might be too thin in spots for proper surface prep. I understand also that they can't build up defects with copper, so I'd be pretty much stuck with a shiny surface on whatever defects exist. John, you know of a solution to that, by chance?

Thank you!
.. Gregg

Nice work! That alloy clamping jig is a good idea.

I checked the Woolf site, but their stock bends seem only to made from 16ga tube. I'll call first of the week to see what they can do about 18ga. Otherwise, using 16ga will mean swaging out the port end, or welding on a stub. I'll also check what they can do on the custom front.

Thank you,
.. Gregg

Here is the pipe mounted on the bike before the rear hangers:

To get all the mounting tabs right it has to be tacked on the bike then reassembled on the bench for welding.