From B4rkWiki

Contents 1 NX650 1.1 In a nutshell 1.2 Engine 1.3 Tuning 1.3.1 Plan Change 1.4 Suspension 1.5 Tyres and wheels 1.5.1 Update 1.6 Tank and Storage 1.7 Bashplates and Bolt Ons 1.8 Drive Train 1.8.1 Update 1.9 Fairing and Pretty 1.10 Instruments and Controls 1.11 In Progress

NX650

Most recent update: As of 15th of May, the NX is back on the road!

Project now at 60%, as there's lots still to do, but it's on the road, so now I can ride it and test improvements as I ride it.

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This page is about the bike, the mods, the dreams, the aspirations etc etc as I get it ready for the trip to the Tip of Oz (and many more trips after that one :))

I'll try to keep this up to date as we get ready for the trip to the tip. I figured I'd spin off to another page to not swamp the main page with bike related trivia...

What it should look like: Image to follow later

What it Did look like:

What I want it to look like: Image to follow later

What it Currently looks like: Image to follow later

In a nutshell

The NX650 is a single cylinder 650CC dirt/road hybrid that was, if you believe the ravings of the many rabid fanatics, an ideal mix of traits that were required for both on and offroad adventuring, so much so that the bike stayed in production with very few changes for about 15 years.

Those who would disagree tend to claim its too heavy, geared incorrectly (take your pick of high or low depending on your riding background), too wussy suspension, and too much fragile plastic. Additionally, there's not enough fairing and the seats ghastly.

For my own appraisal, I haven't got enough dirt experience to talk for the soft suspension, but I would've liked to go another couple of teeth on the rear sprocket from what I've tried it for so far, but otherwise I think it hits the mark of an all-rounder damn well.

I've ridden it on a 3000km ride from Bris to Cairns and it was an enjoyable ride, with the wind buffet being a change from a road bike, but not unbearable. I've since removed the extended screen it had installed as I found it was better to be more 'evenly tired' - it might sound silly, but with the screen, my helmet caught the turbulence thrown up by the screen, and I had to work to keep my head from kicking back, but with the screen gone, the wind hits mid-chest, giving my neck a more even load and tiring out more muscles than just my neck, so I end up taking breaks and seeing the sights more, rather than pushing on and getting a sore neck.

In terms of ride performance, I have found that the stock cross-over rear tyre starts to let go if you're chasing a CBR up a mountain range, which is to be expected, and the suspension is bloody horrid once the dampening goes (see info about shock rebuild below). I used the NX650 as a commuter for a year or so and enjoyed it thoroughly, but in that time I never really got it offroad to a point of being able to test it. I changed to a set of Pirelli knobbies with the intention of using my road bike for the road (better bitumen braking, etc), and the NX650 for some fun weekends... I can tell you Pirelli tyres last really well on the road :p I've clocked several thousand kms on them, and they're still in good nick.

Bits that I have found to be annoying are the speedo (worm drive at the wheel keeps breaking), lights (always need brighter lights),

Engine

The engine is a 644cc single, which is air-cooled, so it doesn't rev particularly high. For my money, the damn thing is bomb-proof, so there's no point in modding this bit at all.

On the wish-list, however, is a new splined shaft for the gearshift, as the PO had incorrectly installed the gear lever, stripping the lever clamp and rounding the splines on the shaft somewhat. I've made do with a (brake) lever from an old Yammy, mounted upside down it gives just enough clearance around the case. You don't want to see this, and I have since replaced it with an aftermarket spare.

The other thing on the wishlist is to replace the timing chain. There's a rattle in the engine that I had a mechanic check out before I bought the bike, and he swore the noise was nothing more serious than play in the starter counterweights, but I would feel better with new chain.

Tuning

I've done Daves Carby Mods, to increase the snap response of the throttle. I didnt chnge the jetting though, as I've been told in no uncertain terms that the fuel and heat up here mean we should generally run leaner than other parts of the country/world. I'll give it a go like this, and then maybe rejet it in a few months and see if there's any worth to it.

Plan Change

while Daves Carby Mods have made a bit of a difference, I have decided to add the Baja kit (Baja Designs Item Code: 151020) which is apparently a needle, spacer, jets, etc... even a drillbit for the carby slide.

jelf 22:25, 6 April 2009 (EST)

I also am looking to put a new exhaust on it. I was thinking of going a SuperTrapp, but having had the Oz dealer (a bloke called Michael) tell me that there's no such kit for my bike (which seems odd given the number of people around the world who have one), and the lack of reply from their regional agent I've decided to go a Staintune. The biggest factor for the exhaust isn't the performance gains, it's the weight loss and the 2-1 conversion which frees up a side for a PVC storage container in its place.

Suspension

As another wishlist item, I'd be happy to tweak this, but it isnt a big thing for me atm. I don't plan on doing big jumps, and as far as I can tell, the suspension is better off road than I am currently :p Seriously, Only about 2000km ago of road riding, I pulled the rear shock cos it was cactus and sent it down to some rebuild guys in Brissie. They cut it apart, replaced the internal components, and refilled it, then welded it back together and sent it back. It feels okay, but I can see what people mean when they talk about the front shocks diving and rocking and the rear being a bit soft...

Update on this: I went to a wreckers the other day, and lo and behold, it was my mate Brett behind the counter. He did me a good deal on an XL250X shock that has the same upper and lower fittings, but allows more travel and is stiffer than the original NX shock due to having a bunch more coils... Rhett has taken it away to press so we can compact it to fit in (too long under full extension)... At worst, it wont fit, and I'll go back to the NX unit with a stiffer spring. More to follow... jelf 11:01, 24 December 2008 (EST)

And indeed, more is following; the XL250L shock is able to be compressed into the bike, but I've decided to go the stiffer spring instead. Way I see it, if something breaks, I want to be able to take the thing off with minimal tools... rear shock compressor isnt minimal tooling. So, Cairns Performance Springs fabricated me up a new spring about 30% stiffer than the original. I'll post on performance as I find out. I still want to get progressive fork springs for the front... or switch them for XR650L forks and the larger disc that comes with it. jelf 22:25, 6 April 2009 (EST)

As a more long-term thing, these guys http://www.asr.com.au/index.php look to have some awesome shocks, but also with prices to match (over $1.5k) for the shock with the remote (641-027-00 Wilbers code). Apparently they config the shock based on rider weight, trail type, [urpose, etc, etc... If I ever find the cash to get one, I'll let you know.

Tyres and wheels

Bought a rim-lock (generic, slipstreamperformance.com.au) that I have yet to put on. Also got a set of tyre-irons I need to get conversant with using. In addition to that, I want to change the tubes for heavy-duty tubes (the rubber is about twice the thickness of the usual tubes) and also spray slime into the tyres (already got the slime).

Update

Installed the rimlock without a hitch. The tyre came off easily with the irons, but it was a bloody effort to put it back on after replacing the back tube with a new super-heavy-duty one. BOTH was the champion of the hour, after much swearing and kicking, he got it reinstalled and we pumped it up... will let you know if the tube's pinched soon :p jelf 22:25, 6 April 2009 (EST)

I really cant see the advantage (for me) of a front rim-lock atm, as for it to be of use, I'd need to be doing some heavy braking in soft sand, which is not part of my current to-do list. If I was trying to get into racing or something, I agree it would be essential, but it just doesnt seem like something I need. I'll probably revisit this point with egg on my face after a few months...

Tank and Storage

The NX comes with a fairly piss-weak 16 litre tank. This gets me half of bugger-all distance, and needs to be improved for the trip. I could get over 200km to a tank, depending on riding style, but thats not having a loaded bike and revving it riding through unfriendly terrain. As we want to get about 400km or thereabouts between tanks, I really would like another 10l stashed somewhere. I was looking at an Acerbis tank, as there is a guy in the States who got a limited run made to suit the NX, but the postage is the same price as the tank (260USD), which makes the whole thing a bit pricey. My new plan is to refurb the tank using this stuff [1] for all of about a hundred bucks, and then make the rest of the volume up with some aux tanks (there's an acerbis tank that fits the front triple clamps that holds about 4 litres for another $150ish, and a torpedo aluminium thing that can be bought for the rear, in various prices and sizes... or I can look at using the tank lining goo to seal a homemade contraption of PCV pipes... hmmm. OR, and here's my new plan for the additional fuel storage requirements made into reality by sensible pricing, available stock, and damn fine communication; I'm getting a Nomad rear tank (www.nomadtanks.com.au). about 8l and it bolts right onto my rear rack, and the kit comes with all the hoses and T pieces and valves etc... More info on build quality after I receive mine. jelf 22:25, 6 April 2009 (EST)

Bashplates and Bolt Ons

Drive Train

I've already bumped the rear sprocket up to a 47 (factory default of 45 on these things)and I'm also planning on getting a 14t for the front, down from the factory 15. That'll give it a gear ration of 3.36 apparently, which is .36 up on factory (wheelies!!!) I figure a JTF 308.14 from here [2]is going to give me all the low-down I should want. I've only just replaced the chain with another o Ring one, so it'll stay, but I am going to put on a scottoiller to keep it in good condition.

As a place for km/h info, here's a useful site http://www.gearingcommander.com/ that has preset gearing and stuiff to work out the NX and probably other bikes too... damn handy!!!

Update

Just to keep you informed, I now have 13/47, which will be changed back to something reasonable for the trip, but for now, I figure fun is fun, and a nose-light wheelie popping toy is fun :D slipstreamperformance.com.au had the vast range of sprockets for the NX, and were easy to buy from. The ScottOiller is a nice thing to drool over, but at the prices asked, I figure I might try my hand at fabricating something a touch more basic using some online plans. More to follow on this

Fairing and Pretty

Well, I really wasn't planning on doing pretty until I got it working the way I wanted, but I've just dropped the seat in to be reupholstered, as the vinyl was cracking pretty seriously due to the poor beast being left out in the elements for a little while (almost a year of being shunned in favour of the road bike). While it's in getting reskinned, the guy is also going to be replacing the foam with a 2-layer setup, keep the soft foam glued to the plastic form, but shave some of the top of it off and replace it with a couple of cm of some denser stuff... it feels nice to the fingers, but only time will tell what the stuff is like for a longer ride. He assures me the other bike guys he's done this for have been happy, so I'm looking forward to the result. jelf 16:56, 7 April 2009 (EST)

Other upgrades planned to improve rideability that don't really fit into any other heading would be the RocStompa pegs (http://www.rocstompa.com/) and ripping off the side-stand and replacing it with a portable race-triangle, as it seems to be the thing I catch the most when bumping over stuff.

Another mod to make is the replacement of the indicators with a more durable solution. The path I've decided to go down is to use LEDS on some border plastics, as it's the most visible, and extremely breakage-resistant. The idea is from the forums at http://www.4strokes.com and an example of what I mean can be seen here [3]

Instruments and Controls

The speedo has a bad habit of breaking after a short while every time the worm drive is replaced, which is apparently due to wear in the housing causing the thread to start to be able to move in an elliptical route. The extra play adds to the wear, which causes premature failure. The parts can all be replaced, but at Honda prices and with the knowledge that the same problem will reoccur in 50k or so more travelling, so I figured it was about due for a bit of modernization. Trailtech offers a range of bike computers, from the basic(Vapor) to the advanced (Vector), including one for the XR, which I figured would be close enough... turns out close enough isn't really what's needed, as there's some mods to be made to get it to work, and some unnecessary parts to work out how to integrate.

Turns out kit to mount the Vector on the 'XR650' computer is for the XR650R (rather than the XR650L), which has bigger brake calipers and discs so the magnetic pickup for the speedo doesn't bolt on where it should due to space limitations, and water cooling, which means the kit comes with a water temperature probe, which is molded into a connector pipe that should clearly go into your radiator hose line, and is somewhat redundant on an air-cooled bike. But, I'm nothing if not keen on hacking things up and making them work in some fashion, so mounting this toy is still a work in progress... I'll update as I get the thing working nicely.

I think I might need to explain the above line a little bit: The kit appears to be built in such a way as to allow the head unit to be mounted to anything. This unit then has a number of connectors that, I'm guessing here, have different bike-interfaces depending on the model bought. My XR650R kit, for example, includes a reed pickup for the speedo that mounts on the caliper, and a magnetic bolt to secure to the disc. This doesn't work on my bike because the caliper is about a half a cm closer to the fork, so the reed switch can't be mounted there, so the magnet cant, etc etc... to work around this, I currently have a ridiculously strong magnet ziptied to my spokes for the reed switch to pick up, with the reed switch mounted about an extra inch away from the wheel due to lack of free space to mount it closer... it works, but I doubt the rugged durability of the installation method.

I have a new disc and a set of pads coming, so when I rip it apart to install them I might have a little look at areas that could be shaved to make space for the pickup to allow it to be mounted in a more bomb-proof fashion.

The switches were a source of a bit of a worry too. I bought the housing kit for the Vector with the intention of replacing my cluster with the lighter, smaller digital unit. The housing is basically a plastic frame with 4 round holes and a gap in the middle for the Vapour. The housing kit comes with a bunch of rubber sleeves and caps for the round holes with basic icons (arrows for indicators, high/low, N, etc) and a series of 2core wires to run about a metre with small bulbs in them. The construction is simple: you select which 4 lights you want on your dash, clip in the rubber sleeve, cap it, and then feed the bulb in from the back until it doesnt go in any further. Hook the wire to whatever you capped it as. In my case, the cluster is fed by a 9-pin connector, so rather than cutting and stripping the wires individually, I'll be grabbing a new plug end from Honda and crimping the wires to make it a clean and durable fit. Photos to follow.

In Progress

This is from the other page... I'm in the process of merging the 2...

Just to tidy the page up a bit, I'm not going to fill it with stuff about the NX650. Instead, that'll be on a separate page here, and the hope is for each rider to similarly write up a bit about their bikes and mods and such, with this bit being a summary and a link.

This piece of class has had a bit of a rough life recently after being shoved out into the rain to make way for the Trumpy, so now I need to put a bit of effort into getting it back up to spec.

Things it needs include:

• Repair the fairing/Replace with aftermarket headlight and shroud (the front fairing is a bit shabby)
• Install an enduro tank (Found a guy in the States who has a couple left from a limited production run :) )
• Install a digital cluster [4]
• Repair the lights
• Replace the indicators with stubby flex-mount units
• Replace the seat cover (cracked from being in the weather)
• Mount driving lights
• Strip the brakes and install new pads/shoes
• Replace the brake levers with stubby units (link to follow)
• Replace the Clutch
• Repair the front chain shroud
• Replace all the oils and fluids
• Consider new tyres - not until closer to the date tho
• Mount BarkBusters
• Weld new luggage system to allow for fuel, water, etc, or get handlebar reserve tank and kit up the rear with panniers
• Install a rear rim lock. I probably dont need a front unit.
• Install Tyre Slime. I think I saw some at Supercheap
• Install a Scottoiler (or homemade equiv)
• Insure the bike [5] $110 for 3rd party :)
• Fabricate additional bashplates if required. Maybe not bashplates so much as rocker cage to shroud the exhaust a bit

Done

• Rejet/mod the carbie as per Daves Mods [6]
• Repair/replace the back tube
• Replace the chain
• Change oil and filters
• Inspect and oil cables
• Re-coil the rear shock
• Mount Bark-busters
• Mount Digital Speedo/Tacho/cluster
• Ordered 14t front sprocket
• Remove front fairing (running after-market headlights as not using OE cluster any more)
• Decided against the aftermarket tank as $$ arent sufficient :(

Just to keep on going with the bike thing...

I've ordered a set of front and rear wheel bearings, just cos, and found and paid for a 13t front and 48t rear, which should get me some wonderful tweakiness. I've also found some things I'm saving pennies for, namely a Nomad tank http://www.nomadtanks.com/ (probably the 7.5l one). I've also gone ahead with another headlight, just to ensure that I have one that'll pass RWC (hi/lo/park), and bought a new set of clutch plates. Also, I've found that there's a kit number 151020 at Baja Designs https://www.bajadesigns.com/NET/SearchByKeyword.aspx?word=151020 that supposedly does wonders for low end pull and stops stalling... supposed to be great on the early NXs in combo with Daves Mod. We'll see, as I've got one of them on the go... abt 60USD, but if it gives a stack more pull, it'll be worth it. Also gonna replace the fork oil, as I'd be confident it's been a while since that's been done.

Other than that, there's still the progressive front shock springs to get, or find some inverted ones (I read an article somewhere on the webs about some CRF shocks that bolted on nicely)... But they can wait until after I've got the RWC for the beast... same as checking the valve clearances,pulling apart and checking the kick-mechanism is in fine order, etc