Showing posts with label Tech-Tip. Show all posts
Showing posts with label Tech-Tip. Show all posts

Saturday, 27 June 2015

The MERCENARY Guide to Repacking Your Exhaust Can

The exhaust noise from the stubby Laser can on the ironically named Stealth KLR is obnoxious. Personally, I don't like loud exhausts. I think they make a bike very tiring to ride. Also, I have already accumulated some hearing loss from motorcycling and I don't want any more.

It's not that I think bikes should be really quiet. The exhaust tone contributes to the sensual experience of motorcycling and I love the sound from the Laser can on my Africa Twin and the Yoshimura on the Buell. I doubt either are legal with regard to noise, but they're not obnoxious - They're just sort of horny!

The KLR is too noisy. Driving it attracts too much attention, which I don't want, particularly as I drive it off road which isn't really legal in Ireland...

So I fabricated a baffle for it a while back (you can read about that, here) and although it did have some effect, it wasn't nearly enough!

So this evening I repacked the silencer with fiberglass wool...

Did it work? I dunno yet...

Anyway, the process isn't particularly difficult but there are a couple of things that can be a challenge, Firstly, it can be tricky to get the end-caps off and secondly it can be frustrating to get all the rivet holes to line up afterwards.

The MERCENARY Guide to Repacking Your Exhaust Can
Remove the silencer from the bike. Make a note of what's front and back and what's left and right. Use a marker if you want to. Consider that the inside is filthy so you may not want to do this in the kitchen!

The MERCENARY Guide to Repacking Your Exhaust Can
Drill out all the rivets with an appropriately sized drill-bit. These are 5 mm rivets and that's a 5 mm drill bit. Drill slowly for best results. Try not to put the hand holding the silencer in harms way.

The MERCENARY Guide to Repacking Your Exhaust Can
Right! This is the first hard part. Make sure all the rivets are drilled out and use a soft mallet to tap out the end-caps. Don't put it on a bench and whale on it! And don't try to lever it apart with screwdrivers. Hold it with one hand in free space and tap the end-caps from side to side and they'll gradually drift out. If it's not working at first, tap a bit harder.

The MERCENARY Guide to Repacking Your Exhaust Can
The remains of the old wadding.

The MERCENARY Guide to Repacking Your Exhaust Can
Cut your new fiberglass wadding to size with a strong scissors. This is a stubby silencer so the length needed to be trimmed. The width was fine.

The MERCENARY Guide to Repacking Your Exhaust Can
Wrap the wadding around the core of the silencer, tucking it into the rim of the end can.

The MERCENARY Guide to Repacking Your Exhaust Can
Secure the wadding with some stainless safety wire. The wire is snug rather than tight. I used a twisty safety wire pliers for this 'cos I have one but a regular pliers will work too.

The MERCENARY Guide to Repacking Your Exhaust Can
Right! The other hard part. Replace the end caps, tapping them home with the soft mallet and making sure the core lines up. The rivet holes should all more-or-less line up. If they don't something may be upside-down or back-to-front. Use a small Philips screwdriver (about 4 mm in diameter) to get the first rivet to line up. Sort of wiggle it around till the holes line up and insert the rivet (but don't set it). Go to the hole on the opposite side of the silencer and repeat. After you've done the first couple of rivets you should find that the rest of the holes line up automatically.

The MERCENARY Guide to Repacking Your Exhaust Can
When all the rivets are in place in both ends, check again that the core is lined up and set the rivets with your pop riveter.

The MERCENARY Guide to Repacking Your Exhaust Can
Job done! This took about 30 minutes but it's not a race, so take your time and be methodical and careful.

The MERCENARY Guide to Repacking Your Exhaust Can
Tools for the job - Drill gun with 5 mm bit, soft mallet, strong scissors, safety-wire pliers, Philips screwdriver, pop-riveter. You will also need some pop rivets, some stainless safety wire and some fiberglass wadding.


#MercenaryGuide #Mercenary #MercenaryGarage

Tuesday, 3 June 2014

Motorcycle Tyre Mount

I've never tried this but I have used a slightly more complicated technique using luggage straps to keep the bead down inside the middle of the rim. This guy's method looks much easier...

Motorcycle Tyre Mount

#Workshop #TyreChange #Mercenary #MercenaryGarage

Thursday, 1 May 2014


I fucking hate Torx.

They're fine on a washing machine or a toaster but they shouldn't be used on fucking motorcycles!

Mercenary Garage - Torx
This used to be a Unior T40 Torx key. It was a quality bit of kit that I bought in an engineer's suppliers about 8 years ago. It's the main reason this post is so sweary... Note that the bolt in the image isn't the one that broke the tool. The one that broke the tool was totally fucked too.

Hex nuts and bolts are great. if you have an M8 bolt the widest diameter of the threaded part is 8mm. The hex head is generally 13mm across the flats and its about 15mm across the corners. The salient point of this is that when you apply force to the head of the bolt with a wrench, neither the tool nor the head of the bolt have a particularly stressful time because they're big and they have a mechanical advantage over the 8mm threaded part of the bolt. And so long as you use a wrench of reasonable quality and the correct size, everybody is happy.

Socket (Allen Key) bolts are great too. Your M8 Allen bolt uses a 6mm across the flats Allen key that's a little under 8mm across the corners. There is a slight mechanical disadvantage but both the head and the tool are pretty robust so provided you use a reasonably good quality tool, generally there's no problem. In addition to being reliable, Socket heads look really nice and can be used in areas where a hex head won't fit. Also, they can be sunk flush to the surface and this looks even nicer. I fucking love Allen bolts - especially stainless steel Allen bolts. Each and every one is little sparkly, magical unicorn-poop-diamond to me.

But fucking Torx!! I fucking hate Torx! A Torx tool is essentially similar to an Allen key except that a fair proportion of material has been removed from the tip of the tool making it substantially weaker. The bolt head has a corresponding amount of metal added to it which perversely makes it weaker too! This might seem counter intuitive but what happens is that all the force acts on the weakest part of the tool and the weakest part of the head and they just break each other to bits. It's a fucking stupid idea for high torque applications so if you happen to know the person who first thought of fitting one to a motorcycle, I'd appreciate if you punched him on the nose. Thanks.

So why all the ranting?

Well, I'm still working on my fucking Buell. It normally takes me between a half a day and a day to strip a motorcycle (even old, rusty abused motorcycles from the '70s), but every single bolt on this fucking bike is seized. Today's all-day twenty-minute job was stripping the hardware off the wheels so I can send them for powder coating. 

I can't bring myself to write about the details, but everything was difficult and everything took a lot of time and a series of escalating techniques. I've picked up a couple of small injuries and broken several tools not to mention some small collateral damage to stuff in the workshop.

The most annoying part was removing the Loc-Tited Torx bolts holding the brake rotors. In the end, I welded on lengths of 8mm steel rod to the heads of the bolts in lieu of breaking more tools. The combination of heat and leverage worked a treat.

Anyway, I prevailed and I'm off to the powder-coaters in the morning.

Mercenary Garage - Torx
Welding on a lever has two advantages. Firstly, you can be reasonably sure its not going to slip off and secondly, the heat from the welding process cause bolt and the wheel hub expand and loosen their grip on one another. The bolt comes out with very little effort and a smooth buttery feel.

Mercenary Garage - Torx
That's a lot of Loc-Tite. A brake rotor is a fucking service item - it should be removable without all this trauma!

Mercenary Garage - Torx
This is a really useful technique. Obviously the bolts aren't in any condition to be reused, but everything else survived. The post-battle StarWars aesthetic will polish out with Scotchbrite.

Mercenary Garage - Torx

 *Apologies for all the swearing!

#Buell #Torx #MotorcycleWorkshop #Mercenary #MercenaryGarage

Thursday, 9 January 2014

Shorty Brake & Clutch Levers

I often wonder how things work, whether they do actually work, and if they can be improved upon. I was like this as a child - it's just the way I am.

Mercenary Garage - Shorty Brake & Clutch Levers
Cut-down brake lever on my CBR1000F.

So I've often wondered why clutch and brake levers are so long. Most bikes have levers long enough to be operated by all four fingers with room to spare. On the face of it, that seems legit - you've got four fingers so you might as well use 'em all. But the reality is, most people don't use all four fingers. I use three fingers, I know other riders who use only two. So why the long levers?

Mercenary Garage - Shorty Brake & Clutch Levers
Kawasaki Z1 brake lever - long enough for two hands!

I have a theory about this. In the late '60s and early '70s with the advent of the multi-cylinder Honda CB750 and the Kawasaki Z1, bikes suddenly got simultaneously much heavier and much faster. Braking technology attempted to keep up with this giant leap but didn't quite get there. The nascent hydraulic brakes with a single, solidly mounted front disk and a single-piston caliper could handle speed or weight, but not both. Motorcycles of this era had super long brake levers installed to allow the terrified pillion passenger to get in on the action. It also allowed a solo rider to use both hands if things got really desperate.*

(*This is just a theory. Like Evolution. Or Gravity. It may not be entirely and fully resolved...)

It wasn't until the latter half of the '80s that brakes became something that could be taken for granted and four-piston calipers acting on large twin, floating disks were adopted as a general standard for fast bikes. So by the '90s, two-finger braking was a reality but nobody ever thought to reconsider the length of the brake and clutch levers. 


So what? Well there are a couple of issues with long levers. The first is one of robustness. 
Mercenary Garage - Shorty Brake & Clutch Levers
Courier CX500 - Note the cut down levers.

When I was a courier I learned very quickly that long levers were very vulnerable to breaking if a bike falls over. Sometimes, the lever would just bend and sometimes the end would snap off leaving the lever still useable. But more often than not, the lever would break near the root, putting the lever beyond use. On a number of occasions I came out of a drop-off to find my bike mysteriously lying on it's side in the street with one or other lever snapped off. 

This is problematic if you're depending on the bike for your living. Obviously, it's possible to drive without a front brake lever, but it's not a good idea. Driving without a clutch lever is also possible, but it's not an easy thing to do in traffic. In either case, I would have to stop what I was doing and go and drive to a motorcycle shop and replace the broken lever. Sometimes, this meant giving away urgent work to another courier and a consequent drop in earnings. All in all, it was a pain in the hoop!

So after this happened a couple of times I declared war on clutch and brake levers (and motorcycle robustness in general). I started to carry spare clutch and brake levers in my tool kit. This helped somewhat, in that I no longer needed to drive anywhere before executing a repair, but it didn't actually solve the problem of the breaking levers. 

So my next step was to use a hacksaw to partially cut through the lever to create a weak spot an inch or so from the end to encourage the lever to break there, rather than near the pivot. This proved to be only partially successful, so the next step was to just cut the ends off the levers and file them smooth. (I found that if the lever wasn't filed smooth it would wear a hole in my glove fairly quickly.)

This has generally worked pretty well. I can't remember ever breaking a cut-down lever.


There are another couple of issues with long levers concerning health and safety. Because the levers are apparently designed to be used by all four fingers, and because most people only use three fingers, the little-finger is vulnerable to being trapped between the lever and the handlebar in a crash. This is a very common occurrence in motorcycle racing and quite a number of racers have missing little-fingers as a result! Mick Doohan and Joey Dunlop spring to mind but there are many, many more.

Mercenary Garage - Shorty Brake & Clutch Levers
Titax folding brake lever. Tasty, but a bit spendy...

There are folding brake levers available on the after-market to prevent this from happening. They're also supposed to fold up rather than break if the bike falls over so in theory they should solve the problem of the snapping levers too. They're a bit expensive though. I've never used them so I can't say with any authority, but I can imagine a situation where they could still tear off a little finger (if the bike slides in such a way that the lever is pushed directly back towards the bar with no upward force to fold the lever up and away). And I can also imagine a situation where a force is applied directly up the length of the lever causing it to snap at the folding pivot rather than fold. 

Like I say, I've never used these levers so I may be wrong. But in any case, cutting down the standard levers so they're just long enough to accommodate three fingers mitigates against both of these risks and it's not very costly. I like solutions like that.

There is however, a second risk associated with clutch and brake levers that should be considered. Have you ever wondered why your clutch and brake levers have a ball at the end? 

That ball is there to help stop you being stabbed by the lever. I used to think that was a pretty remote risk until one evening I high-sided and got hit by my own motorcycle. I didn't get stabbed and I wasn't really injured but as I slid down the road on my ass with the bike tumbling behind me, it did give me cause to think about all the pointy bits on a motorcycle. It's a real risk. There was a motorcycle racer killed recently after being stabbed in the spleen by a lever...

Mercenary Garage - Shorty Brake & Clutch Levers
In light of the above, you might reconsider fitting levers like these to your streetfighter...

I only mention this as a consideration. I still choose to cut down my levers to protect my little-fingers and to prevent the levers from snapping if the bike falls over, but I finish the ends of the levers in such a way that the remain fairly blunt (see top pic).

On a courier bike, a touring bike and particularly on a desert bike, breaking a lever during a trip is very inconvenient. And on a stunt bike or a dirt bike, falling over isn't so much a risk as a certainty. So it just makes sense to me to cut-down the levers. 

I don't really understand why they don't come like this from the factory...

#ShortBrakeLevers #Mercenary #MercenaryGarage

Thursday, 5 December 2013

How to Make a Longer Throttle Cable

When I fitted the new handlebars to Big Honda a couple of weeks back, the riding position was radically altered and the original throttle cable would no longer fit. Below is the process of modifying the throttle cable to fit.

I used stainless steel gear-cable from a bicycle. The nipple on the cable is different to the one on the standard Honda throttle cable but it doesn't matter - it works fine. 

Gear-cable is much finer than brake-cable and is better suited to use as a throttle cable. If you need to make a new clutch cable, the process is the same, just use a brake cable and an appropriately sized nipple.

The other thing you need is a solderless nipple. If you still have a local motorcycle store, you'll get one there. Otherwise, you can buy them on ebay.

How to Make a Longer Throttle Cable
STEP 1: Remove the cable from the bike and tighten down all the adjusters on the outer cable so it's as short as it can be. Pull the inner cable to one end and measure the free length - The CBR1000F cable above has a free length of 100mm (4").

How to Make a Longer Throttle Cable
STEP 2: Cut and discard the old inner cable. Remove the adjusters from either end of the outer cable - You're going to reuse these in the new cable.

How to Make a Longer Throttle Cable
STEP 3: Get some bicycle gear/brake outer cable and cut it to the required lenth - In this case the new cable is longer by 125mm (5"). In the picture above picture, you can see all the ingredients needed to make the new cable - the two adjusters from the old outer cable, the new length of bicycle outer cable, the solderless nipple (5.5mm diameter, 7mm long), and a length of stainless steel bicycle gear cable. 

How to Make a Longer Throttle Cable
STEP 4: Fit the re-used adjusters onto the new length of outer cable. Pass the stainless steel inner cable through the outer making sure the permanent nipple is at the throttle end of the outer cable. Make sure everything is tight and pull the inner cable through. Cut the cable to match your original free length (in this case, 100mm). 

How to Make a Longer Throttle Cable
STEP 5: Place the solderless nipple on the end of the cable and screw it down. The cable is now ready for installation.

For the earlier parts of this story, see...


#LongerThrottleCable #Mercenary #MercenaryGarage

Wednesday, 27 November 2013

Mercenary Throttle-Cable Tool

If you've ever struggled to fit a throttle cable into your carburetors while they're still sitting between the motor and the airbox, you might consider making one of these...

Mercenary Throttle-Cable Tool
The Mercenary Throttle-Cable Tool.

It only takes a minute to make. You need about 20cm of 5mm aluminium tubing and  a length of old throttle cable. It works just like those things snake wranglers use.

The job will now only take a couple of minutes, not the rest of your life...

#ThrottleCableTool #ToolTip #Mercenary #MercenaryGarage

Monday, 15 July 2013

Broken Throttle Cable

Broken Throttle Cable

This is the sort of creative bodge that Dublin couriers used to regularly commit in the name of commerce. Back in the day, the courier in question would probably drive around like this for weeks until...

1. He had enough spare cash to buy another throttle cable

2. Could borrow a Vice Grips
3. Had some time over his busy weekend schedule to fit the cable
4. Got stopped by a copper and was given a producer

In most cases, all four conditions would have to apply before the repair would be carried out.

Another slightly easier, but no less dodgy solution to a broken throttle cable, is to adjust the engine idle as high as it will go and just sort of cruise around with your motor at a constant 2500/3000 rpm.

If you're the more future oriented type, you might consider taping spare throttle and clutch cables alongside the existing cables. So if a cable breaks, it's a relatively simple 5 or 10 minute, permanent repair.

Other courier breakdown essentials were...

  • A spare sparkplug (2-Strokes only) but not necessarily the plug spanner required to remove a spark plug.
  • An aerosol tyre repairer (This is a bit like the Lourdes medal your mother made you put on your keyring, it makes you feel invincible but doesn't actually have a practical application)
  • Truncated clutch and brake levers (So they don't break when the bike falls over. Sometimes this was done with foresight, but in most cases the bike just fell over and the tops of the levers broke off and were never repaired)
  • A rusty, off-brand Vice Grips and a bent screwdriver (because proper tools are effete)
  • A spare chain link (Another article of faith. This is essentially a relic of the Patron Saint of Motorcycle Chains. If your chain actually does break, in most cases a spare link is fuck-all use)
  • WD40 (More religious ephemera - Use it like holy water to bless electrical problems in the hope of some divine intervention)
  • John Player Blue (To give you something to do while you wait the five minutes for another courier to come and take all your work. Unfortunately, your JP Blue will have run out long before a van shows up to bring you and your bike home)

#KevinBrennan #GurriersNovel #DublinCouriers #Mercenary #MercenaryGarage