Unlike most riders, I am curious to know what my bikes actually weigh – especially before and after a makeover. For years I’ve used the bathroom scales trick; balancing the bike with the scales under one wheel, then the other then add the two figures.
You will find this old thread on Advrider with the usual mix of sneering, humour, muddled thinking and bare-faced logic. Read to the end and you’ll see the single bathroom scales technique has been proved to vary at just 1% over other methods like recycling weigh stations or hanging scales. Also, the over-thought need to horizontally level one wheel to match the height of the other resting on the scales has proved not to be significant. But the ground surface must be horizontal and the actuating feet under the scales must all be in contact with the ground (or stick the scales on a board).
I went to a car park with lots of space and excellent horizontality. It can take a few goes to get consistency; eventually for my GS500R I got a reading: Rear: 104kg Front: 86kg Total 190kg with half a tank of fuel, or about the same as a BMW Sertao.
That is about what I expected: a few kilos added over the 186kg claimed stock weigh following the addition of a DR650 fork, crash bars, the pipe rack, SV shock, screen, bigger bars and a handful of other bits. Don’t know how the 19-inch SM Pro wheels with Tubliss compare to stock GS500 casts. You’d hope a small weight saving but cast wheels have a habit of being lighter
Since then I got some Salter Razor (right), now only 14 quid off amazon. Who knows about actual accuracy but this one is much more consistent than the round one above and much easier to use.
BMW X Country ABS, full tank, plastic handguards Front wheel 73kg Rear wheel 90kg Total 163kg – a very good weight for a pokey 650, if I may say so myself.
“It all started back in the beginning of the nineties,when we wanted to create a bike, which would be ultimate fun on bumpy small roads…” [Link]
I was recently reading an article by Brett Smith about a documentary on American dirt legend John Penton which included the line: ‘… studying his life will offer one key lesson: make your bike into what you need it to be…’
With something like that in mind, a couple of months ago I got myself a cheap TDM900 with a view to adapting it into a gravel and travel bike with my usual low-tech and inexpensive tricks. The word out there was that TDMs were a much under-rated road bikes, one of the many ‘sleepers’ which meet with high approval from actual owners but slip under the radar with most of the conservative buying public and performance-obsessed mags. ‘Only 86.2hp @ 7500rpm’ they scoff. Clearly not worth getting out of bed for then.
Mine came with hand guards, hot grips plus a tall screen (√, √ and √) but also an ugly Givi clip-on top box and an annoying Datatool alarm which was as old as the bike and playing up. It cost me sixty quid to get it professionally extracted. DIY is not so easy but I made some back selling the reprogrammable key fobs.
Action with the project was initially slow, partly because with 50k on the clock, I wanted to ride it around a bit first to make sure everything went up and down and round and round like it should. I don’t recall ever owning a bike with such a high mileage but the word was that, especially with the low-stressed 900 motor and providing it had been looked after, there were at least as many miles and another decade left in it.
Another cause for hesitation was that in establishing the Yam was in surprisingly great shape, I discovered it was actually a very nice handling road bike of the kind I don’t recall ever owning. Is it the ‘small’ wide wheels; low-profile rubber; relative lowness; a Fibonacci-like trail/rake/fork angle combo? Who knows, but for a heavy bike it dropped into bends with no bar input required. Throttle and clutch were light and the gearbox was snickety-snick. Only the suspension felt a bit harsh on the knackered suburban roads round here, but had plenty of settings to meddle with.
Looking on the web it’s no surprise to find I’m not the first person to want to adapt their TDM into more of an all-roader (see gallery bottom of the page). After all, Yamaha’s TDM evolved from the original late 1980s, 21/17 wheeled 750 Super Tenere (left) which at 200-kilos and with a 26-litre tank was inspired by the Sonauto YZE 750T Paris-Dakar bikes (below).
Peterhansel in the ’89 Dak and quite possibly in the Tenere desert. Who wouldn’t want something like that in the garage?
In the early 90s the 750 Super Tenere was transformed into the TDM 850 (below left, in red), taking a regrettably big step away from the 75o’s desert racing aspirations towards what I suppose what they call sports tourers. It’s said the 850 was a solid hit in Europe and Australia, but a flop in the US where the 850 was dropped within a couple of years (quite possibly to the regret of this guy).
By the mid-90s we got the MkII 850 with a few improvements, most of which I forget but which included a less lent-forward engine (reducing carb needle wear) and best of all, the crank offset by 90° to give the motor an uneven ‘Ducati’ beat and crossplane power characteristics. This pulse and sound remain one of the TDM’s main attractions, especially once you fit some fruity, free-breathing slip-ons.
In Europe alone over 60,000 850s were sold in the decade before the lighter, alloy-framed and fuel-injected 900 came on the scene in 2002 [good article]. And by all the accounts I scoured (and not least to due to the 850s’ age these days), the 900 seems to be the one to get. It’s still in Yamaha’s line-up today, at least in Australia. In Europe it looks like the 900 may have been quietly dropped.
What would a TDM need to make it into more of an XTZ750? Would it be worthwhile simply extending the suspension, slapping on a bashplate and fitting some knobbly rubber before shoving it out the hatch over gnarly territory?
Wheels are 17 and 18-inchers but tall-sidewall tyres are an easy way to an inch or so of clearance. Some 4.10 x 18 or 120/90/18 tyres would actually be taller than a 19er and theoretically provide lots of dirt cushioning for the rims while probably giving less secure roadholding on fast bumpy bends. The two Aussie bikes above left are running high-wall fronts.
A more lateral solution to increase clearance was to reroute the under-engine pipes (left). But a quick look proved there was no easy way of bend them round the sump and centre-stand. The whole TDM motor is packed in tight with a 5-litre oil tank jammed between the gearbox and EFI.
Off-the-shelf crash bars do exist (right) and making a home-made bashplate wouldn’t be too hard. My 900 came with a kerb-mashed belly pan which I soon ditched but left the brackets in place for later. As it is, you can ding an exhaust without the sky falling in (plenty of used ones on ebay), but it only takes one rock with a mission to hole the cases, so it does need something down there which takes back the inch of clearance you gain from the high-wall tyres.
‘Better five inches of good, progressive suspension than eight inches of ill-sprung, underdamped movement’ you hear said, but I looked into lengthening it anyway. The back is easily done of course: find a used shock that’s a tad longer than the R1-type unit, buy an over-length aftermarket unit, or meddle with the dog bones.
On the front I had the idea of ‘fork extenders‘ before I realised they actually existed. Seems they’re a bodger’s hangover from the twilight years of the 70s chopper craze. You get either slip-on sleeves (far left) or screw-ins (left) to give your USU fork a few extra inches. You then either fill out the slack spring with spacers (chopped off ‘bar ends between coins we used to use) or splash out on longer progressives. Some claim these extenders were outlawed years ago or that they’re dangerous, and even I have to admit that on a hefty gravel roader like a TDM, creaking, wearing slip-ons might eventually strain the lower triple clamps under repeated hard braking. Screw-ons in a modest ≤ two-inches seemed a better solution. This guy on xrv.org got some made for ATs and a mate offered to lathe me a set. One problem with the TDM forks was it wasn’t simply a matter of packing out or slipping in longer springs – the fork damper adjustment rods running down from the fork caps (top left) would need extending too.
Thant’s not too hard but it was all getting a little more complicated and pricey for my low-tech, low-budget resolve. The next step was to track down a longer used forks off something else. The TDM runs 43-mm tubes and the slider tubes are 621mm long. First I wondered about simply buying a same-diameter but slightly longer set of replacement fork tubes off tube makers Tarozzi, but wasn’t sure if the milled fork tube ends differed from bike to bike. Probably, so then with the help of this handy Tarozzi fork tube length / diametre webpage I found that thetwin-disc forks off an XT660Z Tenere came closest with an additional 90mm (3.5″) of exposed slider compared to the TDM. Like I said I wouldn’t want anything more than a two-inch rise which would leave 1.4 inches sticking out on top so it might have needed bar risers. I soon found a near-new pair of used 660 Paiolis.
And that’s about as far as I got with the TDM Super Tenere project. The acquisition of the longer forks required a call to action, including a suitable wheel; a spoked wheel on a Tenere hub would have been easy enough, though I’d rather stick with native tubeless. But the more I rode the TDM the more I thought this was not some worthless old hack like my GS500R. It seemed a real shame to quite probably snuff out TDMs exceptional road manners by converting it into a top-heavy dirt tank which, without the investment of high-end suspension, would lack any real-world off-road agility. One thing I learned with the GS500R (and the Benele from 1984 come to that, above left) was that it’s easy to make a bike taller to add ground clearance. It’s less easy or more costly to gain good-quality suspension.
TDM (yellow) overlaid on a XT660Z with key points marked to show just how much higher the red XT is.
On top of that I suspected the height difference between footrest and bars was too small for easy standing up (see animated gif left) and a stack of bar-risers to dodge that would create cable-length issues. Plus early on the scales had revealed a rather shocking 230kgs fully fuelled which I wasn’t sure equated with the claimed 190kgs dry (though the handbook claims 221kg wet). And they say the 900 was lighter than the 850.
I enjoyed tooling around on my mid-winter TDM, but great road bike though it was, I think I’ve become too conditioned to trail bikes: the stance and the impression of go-anywhere agility. I couldn’t see the TDM ever delivering that on jacked-up suspension. Despite its qualities it’s too heavy for my sort of riding which I’m reminded wants a bike that’s <200kg wet.
Below, a few examples pinched from the web of what could have been (mostly from this advrider TDM thread). Some are 850s and some are based on the same-engined, trellis-framed TRM 850 road bike or XTZ750s with TRM / TDM 850 motors.
Since I rode the GS up to Scotland in June it’s received a few mods and the 700 mile ride back south (right) was a chance to put them to the test. Among other things I’d fitted K60 tyres on Tubliss liners with a splash of Slime. I made the back brake work, nearly finished my piperack, fitted flat track bars and an LED riding lamp.
Setting off for the first 250-mile stage to a mate’s near Stirling west of Edinburgh was a sparkling day (left), but already there were warnings that an incoming storm would wipe any traces of late summer warmth off the face of Britain. Any chance of enjoying a slow ride home would be better compressed into the usual dash. A day after I got back it was another ‘month’s rain in a day’ story we’ve been hearing all summer. Roads I’d ridden hours earlier were closed by flooding or high winds, the trains stopped running to Edinburgh and a coastal town near Aberdeen got caked in wind-borne sea foam.
Backing up, the ride over the Cairngorms proved I really should have remembered my Aero Kanetsu electric vest. Running it off the GS’s battery was one reason for fitting the SR-M LED lamp (to reduce the alternator load). Even in the sun the Trail Tech Voyager (to be reviewed) barely reached 9°C, so a hot soup in Aviemore spread a bit of warmth back into the limbs.
Day two was going to have to be a 10-hour, 450-mile haul right through to London if I was to miss the much forecast gales. Even then, I could’t bare the thought of the dreary but functional M6 and M1 motorways, with the statutory pile-up/hold-up somewhere in the Northamptonshire area. Instead, a more interesting line jumped off the map: A7 from Edinburgh to Galashields, hop over to the A68 which led over the border to Darlington, and from there slot onto the A1 to London. The variety made covering the necessary distance satisfying and I knew the run through Northumberland and County Durham would be fun.
The miles piled on and the GS got notably smoother, as engies do. The lightly loaded Magadans sat behind me, tucked well in and attached or resting on the piperack, while the Voyager kept tabs on various aspects of my progress as I rode up some sweepers to the English border strung across the Cheviot Hills (right).
It was a sunny Sunday and there seemed as many road bikes out as cars, but it has to be said cars do get in the way of enjoying a smooth ride, even on a GS500. I must have been stuck behind one of these or eyeing up the Voyager when the A68 took an sneaky right just before Otterburn while I blundered on along the A689 towards Newcastle. Didn’t want to go there so I turned right onto single track farming roads which I knew would lead to the A68 somehow. Without maps or a satnav, the Voyager’s compass proved a handy aid to negotiating the angular byways until I popped out back on track near Corbridge where the weekend throng were enjoying pub lunches. A fill up saw the mpg improve to 62mpg after yesterday’s all time low of 57 (conversion table here).
I was due for a feed myself but wanted to catch up on my error and find an ambient eatery for a quick and casual refill. That turned out to be a Sunday bakery in a place called Tow Law near Consett. Consett I’d heard of – your man Edmund Blackadder (right) was born there, and in 1980 its steel mill – one of the oldest in the country – was not so much closed down as eradicated. The inevitable social consequences became a byword for post-industrial collapse.
Sat at over 1000 feet in the east Pennines, nearby Tow Law was a smaller version of Consett, established after a Victorian era coal rush but now plateauing out following a steep decline at the end of the last century. But it had a Greggs (left) – the first I’d seen in months, so Tow Law is alright by me. Two hot pies, a cream cake and a coffee. I was primed for the next 6 hours.
Soon enough the A68 ran into the A1, the Great North Road built by the Romans. The better part of the day was over now, all that remained was to ride into the rain. That started somewhere in Lincolnshire, a light drizzle that the winds kicked up into a full-on lateral hosing. Like many bikers before and since, I sat on some Armco pulling my Rukka one-piece over my legs and wrapped the top half under the waxed Falstaff which was to be put to the test, along with the Magadans, the Rukka itself, the GS with it’s new K60 tyres and my X-Lite. I was also seeing how neoprene kayaking gloves worked as wet weather gloves (short answer: they don’t).
What rider isn’t familiar with that trance of concentration that envelopes you when riding a busy road in the wet. The bike is humming as you try to maintain momentum while knowing it takes just one slow- or too fast reaction by you or others to become the unwelcome filling in a pile-up sandwich. Meanwhile your gear slowly begins to succumb or resist the 70-mph onslaught. If I was looking at myself behind the cosy flip-flap, flip-flap of some wiper blades I’d be thinking ‘cripes, rather you than me, mate’. The temperature dropped to 6 degrees, not a long way from snow, and the rain washed off the bugs but started running down the inside of the X-Lite’s visor, further reducing visibility while I bored through the spray. It was the autumnal equinox and luckily some sort of daylight shone through the murk. The thin neoprene gloves were proving to be a fast track to rheumatism, but the PVC Rukka lowers and even my old Altberg boots stayed immune. So too were the Magadans it turned out later. The insides got damp (they don’t claim to be waterproof) but barely a drop licked the outside of the thick inner bags. And the K60 tyres never missed a beat on the motorway or while cutting across Sunday night traffic through the middle of London.
Using the Magadans Although it was only a short ride, I got a bit more of a feel for using the Magadans. The buckle idea I mentioned is definitely the way to go to replace the over-seat velcro. As the bags sag or lift with different payloads you want to make small adjustments and doing that accurately with the double-sided velcro is a pain. With a ‘friction-bar’ buckle (right) a quick tug or release and you’re done. Opening the bags for access is of course easy but the inner bags are rather stiff when cold and so difficult to roll up and clip while complying with the outer form. But it was a cold day and anyway, the are scores of roll-top dry bags available, either full-size singles, or smaller multiples to help compartmentalise. Though it’s much thinner coated taffeta nylon, Exped make a light blue XXL 40-litre rucksack liner dry bag (left) with taped seams and a white interior. As with the Kriega Overlanders, a white or light colour would make digging around to find stuff a little easier. I lashed on my sewn on D-rings to the rack rather crudely and with numb hands had to yank them off when I got home. Once I have the rack finished I’ll be able to make some permanent attachment points on it and figure out a quick clip-on system, probably a smaller, one-inch version of the black clips pictured right.
Not so amazing or surprising, was the Falstaff’s performance. After an hour I could feel the wet against my arms just as I’d done in Spain months earlier, but more so. It was only when I got home that I saw the entire lining bar a small patch on the back (right) was soaked. My wallet and phone in the inside pocket were on the way to saturation. What a shame. Design and construction wise it’s a great bit of kit, but it doesn’t do what it needs to so I won’t be wearing that again.
Still, now I know what works which so far still includes the Suzuki GS-R. I can’t say I notice any negative roadholding or handling issues from what might be seen as a thin rear tyre or indeed running identical tyres front and rear like an old Lambretta. Again I’m surprised how comfortable and endurable long days are on this bike, even in sub-optimal clothing. A big part of it must be the seat which engages well with the corresponding part of my anatomy, but I also wonder if it’s something to do with a modest engine and braking power which puts little stress on the body, while being enough not to feel vulnerable and under pressure in traffic. That was the reason for choosing and adapting an otherwise ordinary machine.
My 2004 GS runs a 2000 DR650 hub, rotor, calliper and just lately, a DR slave cylinder too, all fitted to a 19-inch Excel rim in the original swing arm. My non-bikey mechanic mate did the job, taking some suggestions from me.
The DR650 spindle is thicker than the GS so the swing arm slots and the spacers inside them were enlarged to take the DR size and a high tensile bolt was used. Can’t recall if this was because a used DR spindle was hard to find, a new one too expensive or the DR axle was just the wrong length so using a bolt was easier.
We considered lengthening the swing arm – apparently a DR650 will slot into the frame but is said to be rather long. Plus I thought the stresses on the already jacked up OE linkage with the SV650 shock might get too much and extending the GS5 swing arm a bit risky. But as it is, the bike handles normally within its limits. I can’t see myself skimming over the dune tops or powersliding like Gaston Rahier on his Marlboro BM.
As for spacers and alignment of chain and rotor, we focussed on getting the chain lined up first (the new rim was offset to fit, I recall) and sorted the rotor after. From the picture left, it looks like the OS DR spacers or a very similar tube spacer were used with just a couple of washers between the calliper and the swing arm to fill out, so it was a pretty close fit.
A custom sprocket was ordered to fit the DR’s sprocket carrier with a guesstimate that 42T (rather than OE 44) with the OE 16T would make the gearing near identical to the original GS500 but now with a 19-inch wheel; the guess proved spot on. The same chain is used with no length changes, but with a couple of extra links I could run the wheel at up to 1.5 inches further back to lengthen the wheelbase which is currently about 58” (as short as possible on the swing arm slots – original is 55.5″) and feels fine. There are no chain tensioners needed, but an idler might be an idea to stop the lower run rubbing on the pad which makes a bit of noise.
The OE GS slave cylinder didn’t work well with the DR rear calliper – mismatched hydraulic ratios meant weak braking, or so I thought. I eventually fitted a DR slave cylinder and rear braking improved to the point of being able to lock the wheel, but still requires a long throw of the pedal, even after replacing the linkage with a slightly longer item made from a bit of 3/4 inch tube (below right). I then found an image of a DR rear slave set up and the DR pedal pushes directly up on the vertical cylinder, not leaning over at 45° like mine which effectively lengthens from the throw. The GS brake pedal mounting splines are rather coarse so moving it around one notch didn’t work either. Alignment of the DR slave on the GS mounts is a bit tight anyway as it is now, but now I know the brake is working better than it was, an adaptor plate can be made to verticalise the slave cylinder so hopefully making a shorter throw and snappier brake.
I don’t think you could describe a GS500’s chassis (left) as something that Brunel would have tipped his hat to. Thin bits of box section glued together with spit and braced with stamped bits of plate. You get what you pay for and GS500s are not to be mistaken with the GSX-R pocket rockets.
Anything too clever or hefty would merely see the GS’s subframe wilt like the late summer corn. Up to a point a beam could be added from the pillion mounts down towards the footrests to help support the back end (right).
Trying to work out how to make the platform (or get it made), it occurred to me that a metal support tube as strong as any on the machine was staring me in the face: the silencer. By chance I’d had the pipe lowered to make room for my planned DIY panniers (which eventually became a set of Magadans) until a light bulb flickered momentarily: use the pipe.
All that had to be done was separate the pipe’s heat (not that much on the pre-catalyzed GS5) from the bag’s base and possibly add support at the back. A mention of Giant Loop’s good-but-too-short stainless pipe guard (above right; £15) gave me the idea to make my own from a bit of 2 by 4 ally off-cut.
On top of that screwed a layer of plywood on which rests the pannier. The good thing is that my Mags are throwovers so the full weight need not be taken on the platforms. But there’ll come a time when that needs to be done so I added a support from the silencer’s snout to the subframe using a 2 1/2 inch exhaust clamp (left).
Adventure Motorcycling Handbook 