TWO-STROKE TEST: 2012 TM MX144 IS THE ITALIAN ANSWER TO THE AUSTRIAN KTM 150SX

February 23, 2012
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Q: WHERE HAS TM BEEN?
 
A: TM’s niche in motocross is as an exotic, expensive, boutique brand mixed in among the mega manufacturers. They are like the exotic Italian sports cars of the motocross world. When Americansstarted cinching their purse strings a few years ago, luxury items like TMs, Lambos and Ferraris were no longer on the grocery list. Plus, adding to TM’s woes in the USA was a revolving door of importers that made publicity, products and parts hard to come by.

Q: WHAT HAS RECENTLY CHANGED IN THE TM PICTURE?

A: Late last year, original TM importer Pete Vetrano of Motoman Distributing decided to take the Italian motocross brand back on. Vetrano is a savvy businessman and a hardcore motocross racer. Even though he hadn’t imported TMs for over six years, he thinks that the economy is improving enough to bring the hand-built Italian bikes back on line.

Q: WHERE DOES THE TM MX144 FIT IN THE ITALIAN BRAND’S LINEUP?

A: TM offers 85cc, 125cc, 144cc, 250cc and 300cc two-strokes, and 250cc, 450cc and 530cc four-strokes (although not every model or engine size will come to the USA). In the last few months, the MXA wrecking crew has tested the 300cc two-stroke, 250cc four-stroke and 450cc four-stroke. We’ve been impressed by how TM has stepped up their game since our last go-around, which was back in 2005.


2011-2012 TM 144: The TM brand can be distinguished by the powder blue color and TM logo (Thomas and Mirko were the founders’ two sons). Up close, TM is distinguished by the materials and craftmanship of their components.  

Q: IS THE TM MX144 JUST A BORED-OUT TM 125?

A: No, it has been specifically designed as a 144. Back in 2007, when it looked like 144s would become the new 125s, TM began R&D on their own 144. They started with a bored-out 125, but they quickly realized that to get the reliability and performance they demanded, they would have to redesign the engine. Since TM has an engine division devoted to making two-stroke kart engines for the World Karting Championships, they quickly had new crankcases, a crankshaft, rod, cylinder, piston and head ready to go. The prototypes performed well in testing, and production was started for the 2008 season.
 
Q: HOW NEW IS THE 2011-2012 TM MX144?

A: Since the original TM MX144 engine was finished in 2008, only minor modifications have been made to the powerplant since. The connecting-rod needle-bearing assembly tolerances were improved to fix some seizure issues. The cylinder head porting/timing was changed for more power. Most of TM’s effort has gone into developing the aluminum perimeter frames and their own running gear.



Swedish gold: Ohlins’ goal, like TM, is to offer products that need little or no modification at the professional racing level.

  Lean me out: TM’s jetting specs for the 38mm Keihin PWK were in the ballpark, but our 144 was very rich. A leaner mainjet brought out the natural responsiveness of the engine.


Real deal: This isn’t a bored-out 125. The 144 has dedicated crankcases, crankshaft, rod, cylinder, piston and cylinder head.


Power up: The 270mm Braking rotor, Brembo caliper and Nissin master cylinder brought the TM 144 to a screeching halt.

Q: HOW DOES THE TM MX144 FIT OUR TEST RIDERS?

A: If you switched back and forth between Japanese bikes and European bike in the 1990s, you would think that they were made for two different species of humans. The ergonomics of European bikes in general were very quirky compared to the Japanese-built bikes that American racers cut their teeth on.

Fast-forward to 2012; that Euro stigma has been greatly diminished. Most of the MXA test riders felt pretty comfortable on the MX144. The pocket of the seat was a little far back, and some riders felt like the handlebars sat too far forward. The solid bar mount/top clamp offered no adjustment.

Q: IS IT REALLY A 144?

A: Sometimes model designations can be far from actual displacements. This isn’t the case with the TM MX144. It has a bore and stoke of 56mm by 58.2mm for a displacement of 143.35cc.

Q: HOW POWERFUL IS THE TM MX144?

A: As a general rule, we expect a 144cc two-stroke to be on par with 250Fs in peak performance, but due to the natural characteristic of a two-stroke engine, the smokers produce that power over a much narrower range. On the dyno, this held to be true.

The TM was competitive until 10,000 rpm, where its power was a match for the KTM 150SX, and three horsepower above that of the Yamaha YZ125. Just above 10 grand, the TM peaked at 34.84 horsepower. That is not an impressive peak number, although the low-to-mid horsepower figures were very substantial. After 10 grand, the TM 144 flattened out and dropped off. Surprisingly, the smaller YZ125 engine continued to climb the rpm scale?and while it didn’t beat the TM MX144 in peak horsepower, it got within 0.8 of peak horsepower. On the other hand, the KTM 150SX power continued to rocket up into the stratosphere to a 250F-romping 40.28 horsepower.

Q: HOW DOES THE TM MX144 RUN IN REAL-WORLD CONDITIONS?

A: The dynamometer is a great tool, but the track is where winners are made. The TM MX144 proved to have potency, but didn’t make it easy for riders to utilize it. On two-stoke powerbands, flattening out always feels like dropping off entirely. Even though the TM 144’s dyno curve hung around its peak output for 1500 rpm on the chart, the powerband wasn’t very usable. Keeping the little two-smoke pulling hard in the sweet spot was like walking on a tightrope; it needed a lot of little corrections to stay on center, and there was a big penalty for falling off the pipe. That said, after a couple of practice sessions, all of our two-stroke-experienced testers figured out just how to keep the TM percolating. With some hard work, we could stay on the back of 250Fs coming on to a straightaway, then look to pass them under braking. We had to work harder than they did, but it could be done (it would have been easier on the KTM 150SX).
 
Q: COULD THE TM MX144 BE FASTER?

A: A rearward view of the TM 144 silencer reveals what appears to be a pretty long, small-diameter core. Aftermarket silencers, while keeping the stock expansion chamber, tend to help the two-stroke’s top end and over-rev?and that’s exactly what the TM needed. The problem for Americans is that few?if any?aftermarket companies make exhaust systems for TMs.

Q: HOW WAS THE JETTING?

A: In a word: rich. We went to a leaner mainjet on the Keihin 38mm PWK and were rewarded with marked improvement. We raced it on a hot day and felt that we could still go leaner. Perhaps on a cold day the stock jetting would be okay (stock settings are in parentheses):
   Mainjet:
178 (188)
   Pilot:
50
   Needle:
NOZE
   Air screw:
2 turns out (1-1/2 turns out)
   Clip:
3rd from the top
   Notes
: Amazingly enough, when we looked at the TM MX144 spec sheet, it claimed that the bike came stock with a leaner mainjet than we had to put in to get the bike to run right. There is obviously a communications gap between the engineering department and technical writing crew.

Q: HOW WAS THE HYDRAULIC CLUTCH?

A: Most MXA testers absolutely loved the easy pull and self-adjusting nature of the hydraulic clutch. This was important because the 144 had to be clutched often.

Q: HOW DOES THE TM 144 HANDLE?

A: Italian bikes of years past have all too often had bipolar handling personalities; one moment everything would be fine, and the next moment they would try to kill us. TM’s current chassis geometry is in the ballpark. The lightweight (204-pound) factor could make up for any shortcomings, but luckily it doesn’t have to. We feel confident in saying that after testing both the TM MX300 and MX144, the 144 does have its own personality. It hesitates slightly to lean the first 15 degrees, but once you initiate the turn, it rolls into a full berm-blasting lean angle. Overall, it turns well, remains stable on straightaways and can be ridden with the aggression that all small two-strokes require.
 
Q: HOW WELL DOES IT STOP?

A: TM uses high-quality brake components. The front disc is an oversize Braking 270mm cauliflower design with a Nissin master cylinder and a Brembo caliper. The rear is a 245mm unit, also Braking with Nissin/Brembo components. Both the front and rear offer great feel and modulation?power definitely exceeds what a lightweight two-stroke requires. The catch is with the rear brake pedal?which itself is a beautifully crafted piece of billet aluminum?but cannot be adjusted low enough, or even level, with the footpeg.

Q: HOW WAS THE SUSPENSION?

A: The bike’s stiffness and spring rates were appropriate for a 125/144. Big kids and smaller adults will feel right at home.
 
Q: HOW WERE THE FORKS?

A: Over the last decade, Marzocchi suspension has been a bit of a noodle scratcher?sometimes they’ve been good, and sometimes they are wet noodles (more accurately spaghetti). Often, they seem to have capable components that are hampered by quirks like improper assembly or poorly chosen specifications. Thankfully, TM has their Marzocchi stuff figured out for 2011. The 144’s Marzocchi USD forks worked fluidly through their stroke and handled big and little bumps equally well.
 
Q: WHAT ARE THE BEST FORK SETTINGS?

A: We slowed down the rebound to get the 144’s attitude to stay settled and to keep the front end down when entering turns.
For hardcore racing, we recommend this fork setup on the 2011 TM MX144-2T:
   Spring rate:
0.42 kg/mm
   Oil height:
300cc
   Compression:
20 clicks out
   Rebound:
19 clicks out
   Fork leg height:
level
   Fork leg height:
5mm up
   Notes:
There is a tiny air-bleed valve hidden underneath a rubber plug on the fork cap?just press and go. Additionally, fork preload can be adjusted by turning the inner portion of the fork cap.
 
Q: HOW WAS THE SHOCK?

A: If you were to buy the TM in Europe, you would get a Sachs shock (with the option of purchasing an Ohlins shock). American-bound TMs get the Ohlins as stock. An Ohlins user will have to tinke to learn how the shock responds to adjustments, and once he does, he can get a good setup. We softened the shock a bit from its recommended settings to help the rear end stay planted in transitions from smooth to rough ground. This is a very good shock.
 
Q: WHAT ARE THE BEST SHOCK SETTINGS?

A: Knowing that the Ohlins shock is sensitive to just a click or two, we went to work and found a good baseline setting for all our testers.
As a starting ground, we recommend these settings:
   Spring rate:
4.8 kg/mm
   Race sag:
100mm
   Hi-compression:
3/4 turn out
   Lo-compression:
16 clicks out (10 clicks stock)
   Rebound:
20 clicks out
   Notes:
The rebound adjuster doesn’t use a screwdriver and can be spun by hand.

Q: WHAT DID WE HATE?

A: The hate list:

(1) Pedal adjustment. Even when the rear brake pedal was adjusted as low as possible, it was above the footpeg. We had to dance the two-step.

(2) Light switch. This was a go or no-go powerband. It took some skill to keep it on the pipe.

(3) Price. If you can’t afford a Ferrari or Lamborghini, you can still look, but expect sticker shock. The same is true with the TM MX144-2T. The tag reads $7899.

(4) Triple clamps.
The CNC’d triple clamps don’t have rubber mounting for the handlebars Also, the handlebar mounts are not adjustable. You have to live with what TM offers.

(5) Bolts. Allen bolts fill with mud and have to be cleaned before they can be turned. The TM uses Allen bolts on the plastic parts, clutch cover, seat, engine cases and ignition cover.

(6) Rear sprocket bolts. There are nine bolts on the rear sprocket. That seems a little excessive.

(7) Shock preload ring. We hate KTM’s nylon preload-adjustment ring, so we weren’t thrilled to find it on the TM’s Ohlins shock.


Berm blaster: The TM MX144 rewarded trigger-happy clutch fingers with flying dirt; the hydraulic clutch had a smooth pull.

Q: WHAT DID WE LIKE?

A: The like list:

(1) Weight. At 204 pounds, the TM MX144 is acceptably light for a two-stroke. Weight is the only attribute of a bike that can be felt at any point in time around a track; you can’t escape gravity.

(2) Outsourcing.
We like the top-quality outsourced components from Moto Tassinari reeds to Ohlins shocks, to Brembo calipers, to Marzocchi forks. The fact that many are distinctly Euro adds to the flavor.

(3) Petrol capacity. With a large 2.3-gallon capacity, we could go two complete motos without refueling if we wanted to.

(4) Hydraulic clutch. Very sweet.

(5) Brakes. The 270mm Brembo front brake is the same one that comes on the TM MX450 four-stroke. It is powerful on the big thumper and uber-powerful on the lightweight tiddler.

Q: WHAT DO WE REALLY THINK?

A: The 2011-2012 TM MX144-2T rolls off the Pesaro, Italy, assembly line as though it is headed for the Concours d’Elegance. From its shiny aluminum to its billet parts, the TM is very much a works bike for the masses. It ooozes trickness that most production bikes can never dream of. Of course with trickery comes the occasional faux pas. If you are in the 150cc market, your only choices are European bikes or aftermarket big-bore kits. The TM is an alternative to the orange brigade, and it carries with it the status of being rare. If you want a TM, visit www.tmusa.homestead.com.

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