BONNIE MOD #6
TEC 2-1 Exhaust

PREFACE: I’ve been running on these pipes for a week before publishing this post and I must say, I LOVE THEM!

Oh, before we start, check with your state’s emissions policy. Here in New York, motorcycles must pass a safety inspection each year in order to get registered. HOWEVER, motorcycles are EXEMPT from emissions standards – in New York. So, we subjects of the Empire can do things like remove catalytic converters and air injection systems from our motorcycles. Places like California can’t, so check with your DMV before modding something that you may need to later unmod in order to pass inspection. You’ve been warned.

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Swapping out the stock Bonneville “peashooter” pipes was a must, at least for me. (secret confession – nothing beats the Ducati sound and I miss that!)  The Bonneville stock pipes are well made and look nice, and I know that there are purists who would cringe at the thought of swapping them out, but they severly hamper performance and they sound, well… like a bundle of ping pong balls rattling about in the clothes dryer (p-twin, after all). Hmmmm, what to do…?

After many nights with The Google, I purchased a set of 2-1 pipes from TEC Bike Parts, USA. Watching Del (of Delboy’s Garage, pronounced properly, ger-rige) on the YouTube convinced me to go this route.

This was actually my second proposed mod but I finally got around to installing them two weekends ago. I wanted to wait for my 500 mile checkup before mucking around with something a bit more critical to performance – I wanted to make sure that the bike was on track in all its stock glory. I also wanted to install the Dime City rear seat to see if it would play well with the stock pipes – all the gory details here.

A big shout out to Del of DelBoy’s Garage – he’s a big proponent of TEC. Watching his install video (several times mind you) of he putting these pipe(s) on Penny’s bike, I became convinced to try them on for size. What Arrow was charging $1200USD for, TEC was only charging $400USD. I’m always leery of a “sounds too good to be true” story but listening to Del convinced me otherwise in this case.

It took close to a fortnight (due, in part, to missed UPS deliveries – thanks to Judy for trying to resolve the situation) but the box finally arrived. I must say, very well packed and completely protected.

All the pipes were wrapped tight with bubble wrap and saran wrap and smothered in a bed of polystyrene peanuts (unsalted).

I think that the hardest part of this whole mod was removing the damn saran wrap. These were VERY well protected.

Not a lot of parts going on here. You’ll notice in the above picture:
– 1 Silencer
– 2 Header Pipes
– 1 Intermediate (aka, Intermediary) Pipe
– 2 Crush Washers/Rings & Sensor Port “Plugs” (not used for EFI, only carb models)
– 2 Springs to keep the Intermediate Pipe “kissed” to the Header Pipes
– (not shown is an included, well thought-out four page How-To document)

Okay, now I’m going to be a little critical but I want to remind you… these pipes ONLY cost $400USD. That is incredible! No one else offers pipes like these at such a low price.

I found some of the machining and welding to be a bit rough, albeit not terrible by any means and NOT inherently weak, just rough. Then I reminded myself. Yeah, sure, $1200USD Arrow pipes would probably look perfect but that’s $800USD more. That’s crazy. I decided that $400USD was worth the craftsman home shop look.

The silencer reads (and I’ll spare you the caps), “This exhaust system meets European Union noise regulations when fitted to the Triumph Bonneville and to the Triumph Thruxt on [sic, I sense a t-shirt – Thruxt On, Baby!]. Fitment may affect compliance to the emissions regulations.” I need to find where these are manufactured but obviously for the EU market and then imported to the States. Hopefully in the UK, thus “keeping it real”.

And I didn’t think about it at the time, but as I was unpacking them, they weren’t heavy at all. I’ll refer back to this later in the post.

Remember that song, “Working for the Weekend” by Lover Boy. (I’m dating myself.) Well, that’s what this week was like. I was dying for Saturday to come so that I could install.

YES!!! It’s Saturday. Let’s get to installing…

Overall, it’s fairly simple to remove the existing peashooters. For carbureted bikes, they are attached at five points:
1. at the buddy pegs.
2. a clamp securing the silencer to the header pipe.
3. underneath the outriggers.
4. at a front junction bracket clamping the two header pipes together.
5. at the cylinder heads.

For fuel injected bikes, there is an additional #6:
6. O2 sensor ports on the header pipes.

My recommendation is to start at #1 and work your way to #5/6, and alternate between sides. The silencers are super heavy and I felt it best to take those off first so that their weight wouldn’t twist the header pipes while I kept the header pipes bolted in tight.

Let’s begin…

Remove the buddy pegs which serve to attach the rear of the silencers to the frame. There is a nut on the backside of the buddy peg. You’ll need to loosen it – you can use a 12mm socket or a crescent wrench. Once the nut is loose and you can pull the peg out enough to clear the pinholes, you can remove the buddy peg by twirling it off while holding the back nut in place.

Now that the buddy pegs are removed, we need to loosen the clamp that secures each silencer to the header pipes.

With the clamp undone, now comes time for a little shimmy and shake. If you look at the above picture, you’ll see patches of orange where the silencer meets the header. That is silicon helping to keep the silencer butted firmly to the header pipe. First making sure that you pull the silencer hanger out of its receptacle where it was being held in by the buddy peg, you’ll need to do a bit of wo/man-handling here and twist and turn the silencer while at the same time pulling it back. It takes effort but you can pull the silencer off in 30 seconds or less – just rock it, twist it back and forth, doing all kinds of x-y-z axis motion. Not too crazy though, don’t go all Chubby Checker.

Make sure to hold on to the bushings from the stock silencers – you will need them for the TEC silencer.

Now you need to remove the bolt holding the back end of the header pipe to the frame – this is below the outrigger and sprocket cover, one on each side.

Now let’s move to the junction clamp that is hidden. It is holding the two header pipes together, unbeknownest to me at the time. You’ll need to get on your back and loosen this in order to be able to separate the header pipes from one another.

Get in there with an allen socket wrench with a 3″ extender to loosen it. This will allow you to pull the two header pipes apart when the time comes.

By the way, at this point, if you’re running a fuel injected Bonneville, you will have probably noticed some hosing/wiring running into the header pipes. These are the O2 sensors which I’ll get to in a few. Just make sure that you’re aware of them – I don’t want you yanking the pipes off without realizing that they’re there.

Okay, the final attachment point – the headers bolted onto the cylinder heads.

You’ll need a 12mm socket to release the header pipes from the cylinders. It’s a bit of a cramp and I found a flex joint to be quite helpful.

Remove those nuts but now, before attempting to remove the pipes, take a close look at the O2 sensors. Note that if you are modding a carbureted bike, you won’t have these and you can take a smoke break.

I’m sure that more experienced mechanics are going to have a better method and probably scoff at this, but what I did was to unscrew the sensors in position. This led to a bit of twisting of the wires, so you have to be EXTREMELY careful that you don’t shear the wires as you unscrew the sensors out of their ports.

Once they’re out, go ahead and remove both header pipes. Take your time and go slow. You don’t want to damage the cylinder head bolts.

Alright! The ping pong ball peashooters have been removed. Put them someplace safe or sell them on eBay (Anyone want to buy a used set? Mine only have 800 miles on them and were driven by a lovely Gram).

Now for a bit of a sticky wicket. Let me give you a bit of foreknowledge that will save a bit of frustration as this is something that I had to figure out. The right O2 sensor will fit into the new TEC pipe no problem but the left side is a different story – you will need to do a bit of rerouting in order to get it over to the right side of the bike. So, you might as well get it out of the way and save yourself a bit of headache. You’ll need to loosen the oil cooler and move the harness clip below the horn in order to route the left sensor over to the right side.

Once that is done, leave it for now. It will be ready to reroute once you have the TEC headers in. One caveat… because I left the other ends attached, I knew which was the left and the right sensor. If you decide to remove the sensors at both ends, it is IMPERATIVE that you label them. The left sensor MUST remain the left sensor, and the right the right. You cannot switch them – you’ll muck up your performance. You’ve been warned.

Okay, now that the stock exhaust system has been removed, let’s put in the bitchin’ TEC 2-1 system, shall we?

First, we need to pull out the old crush washers from the cylinder head. After all, they’ve done been crushed. We’re going to replace them with new uncrushed crush washers thoughtfully supplied in the TEC kit.

Dab a little black silicone on the new ones – this is only to help keep them in place while you perform the mod, so don’t fret about a “proper way” – you’re just dabbing them.

You’ll notice a HUGE difference between the old crush washers and the new ones. You’ll immediately realize, “Crush. I get it.”

Plop in the new TEC-supplied crush washers, one into each cylinder head port.

Next step is to join the header pipes to the cylinder heads. Start with the left pipe as I found this to be easier due to the way the two TEC header pipes intermingle. Refer to the photos below to help determine which is which. Hint – the left one is way more kinky.

Go ahead and put the nuts back on to the cylinder head bolts. Don’t tighten them, though. It’s best to get the entire exhaust system into place first, and then we’ll go through and tighten everything down.

Let’s now get to those pesky EFI O2 sensors. Again, carbureted bikers can take another smoke break, even grab some coffee.

First, route the left sensor over to the right side. We already prepped for it, so it should be easy peasy at this point.

Route it down to its new home, making sure to keep it away from any surfaces that get hot during the bike’s operation.

Now, to screw the sensors in to their respective ports (Keep left, left. Keep right, right.), I did something that would surely be frowned upon. I twisted the wire counter-clockwise before screwing in the sensor. That way, the wires would be back to straight once the sensors were fully in. I’m sure that I’m fatiguing the wires, but since I’m only doing this once, I think I’ll be okay.

Note: if you are modding a carbureted bike, you will not have these sensors. You will plug the sensor ports on the new TEC header pipes with the sump bolts and crush washers thoughtfully provided by TEC in their infinite wisdom.

Take a look at the photo right above. You’ll see a humongous banjo bolt, Deliverance-style. It interferes with the right header pipe. I found that rotating it counter-clockwise about 1/4″ – 1/2″ at most solved the problem.

Now on to the intermediate pipe. Remember when we pulled off the stock silencers and there was that layer of orange silicon? Well, we’re going to take the same route. Go ahead and dab in some black silicon and spread it around to achieve a nice 2″ layer round the inside of both sides.

This next step takes a bit of dexterity but should pose no problem. Making sure that the spring loop is facing downwards, snug the intermediary pipe onto the two header pipes and butt everything together.

Now take the two springs that TEC, again, so thoughtfully provided, and use them to bridge the pieces together. If you have a special grappling hook, great, but I didn’t and used a pair of pliers. Be careful that you have a tight grip or your pliers will slip off and you’ll have a spring fly across the garage (as I did, twice).

Finally, on to the silencer. The finish line is coming into view.

As we did with the intermediate pipe, coat the inside 2″ with a layer of black silicon and snuggle the stock bushings (which you kept, right?) into the two hanging collars.

Place in the stock bolt and bushings at the front of the silencer. Now snug fit the silencer onto the intermediary pipe and fit the rear hanger into the buddy peg bracket, making sure that you fit it in from behind. The TEC hanger will fit in perfectly, I found. Put in the buddy peg, only finger tightening the nut…

…and then screw in the bolt underneath the sprocket cover, again only loosely.

Wow! This is the home stretch – all the pieces in place. Wait though… before you start tightening everything down, get up and stretch your legs. Maybe touch your toes a few times to unkink the back, and then take a good long look at your new set up. Make sure everything is in its proper place, make sure that you’ve got the O2 sensors in their proper respective ports, and make sure no wiring is resting on any hot bits. Once you’re satisfied, go ahead and start torquing everything down. TEC was very helpful in supplying all the proper torque settings in their instructions. The most important is the torque setting for the header pipes onto the cylinder head – 20lbs, I believe. Enough to crush the washers and provide a good seal but not enough to damage the head – just right.

And there you have it, a right proper 2-1 new exhaust system for your Bonnie. I didn’t weigh the kits but I imagine this shaved at least 20 lbs off the bike – the stock pipes are HEAVY!!! The stock silencers are ridiculously heavy.

I’ve been running on these pipes for a week now and I noticed a significant performance advantage. The bike has a LOT more pep (and it sounds way better). However, you will notice a hit to gas efficiency, and I now get some backfiring due to the unspent fuel (so, I’ll be removing the air injection this weekend). In terms of miles per gallon, I was getting around 96 miles per 2.5 gallons (averaged over six weeks, very consistently). I need to average these new pipes over six weeks, but this first week, I believe I got 80 miles per the same 2.5 gallons. That’s a bit of a hit, but with all due respect, I’m not modding this bike to be a tree hugger (oh geesh, I just alienated all my Green Party friends). I’ll provide new stats as I get them.

Whew, this was a long, involved post. Let me close out with a few After photos. I think that you’ll agree that these new pipes make the bike look WAY cooler! (you’ll note that the air injection is now gone – post to come.)

Cheers.

 

Oh, sheesh! I almost forgot… make sure to reinstall the left buddy peg. Your friends won’t be very comfortable riding on back with just one foot peg.

Supplements:
TEC’s Official How-To PDF

Audio file of a TEC 2-1 exhaust system starting up on a Triumph Bonneville T100.

Tools Required:
12mm Socket
Others. Where’s my damn list!?!?
Sharpie

Company URL:
TEC Bike Parts, USA