|12-18-2012, 08:31 AM||#1|
Joined: Dec 2011
Location: San Francisco
Have Enduro bikes evolved in the past 20-years?
I recently asked a local Husqvarna dealer: Which of his bikes he felt provided the most bang for the buck in the dirt? He responded that, if he was down to one bike for personal use, it would probably be the Husqvarna WR125.
As I looked at the spec sheet between the Husqvarna WR125 and CR125; I noticed that both have the same gearbox ratios; so a WR125 is essentially a CR125 with the additional weight of a lighting kit, an 18" rear wheel, and a kickstand. It's a marketing strategy by Husqvarna that reduces cost by using the same product (CR125) to target the Enduro market (WR125). This aligns with Husqvarna off-road contingency support.
The U.S. 2-stroke Enduro market is currently dominated by European manufacturers: KTM/Husaberg, Husqvarna, GasGas, TM, Beta. With only the KTM 150XC, and the Husqvarna WR125 catering to the U.S. small-bore 2-stroke Enduro market.
With the exception of the 2013 Yamaha YZ125, and the minis (KX100, RM85, YZ85); the Japanese manufacturers have given up on 2-strokes for the US Market; and have not produced a 2-stroke Enduro bike since the '06 KDX200, '98RMX250, and '97WR250.
Bump on any debate on 4-strokes vs. 2-strokes... or the KTM200EXC vs. a YZ144... or if a 144cc overbore is worth gaining 2HP
The KTM 150XC and the WR125 (comes w/ 144cc kit) engines are derived from the 125cc engine. Both use a single-backbone CrMo steel frame. A fuel-tank that saddles the single-tube backbone often provides a lower center-of gravity than a perimeter style frame.
I did a bit of research to find a Japanese dirt bike that was similar to the current Husqvarna WR125 design: CrMo Single-tube backbone (similar dimensions and steering geometry); 2-stroke motor ('square' bore x stroke) with reed valve intake, mechanical exhaust power valve; open-cartridge USD forks.
The 1997 Honda CR125R was the last year of the CrMo frame and arguably had the most powerful CR125 engine ever made. Honda ceased making 2-stroke dirt bikes in 2007. Yamaha still imports the YZ125. Although still available outside the USA; by 2007 Kawasaki and Suzuki stopped importing the KX and RM model.
Yamaha YZ125 '96 to '01 steel frame (Green Sticker) and '05 to current '13 aluminum frame (Red Sticker) are the most popular 125cc for Enduro conversion. Many say the YZ motor is the 'most-tractable' or 'least peaky', but in the 125cc context that observation may be relative. Common mods are a Steahly flywheel weight, and Athena 144cc big-bore kit. '02-'04 YZ125 had a 5-speed transmission. Punt on debate on 5-speed vs. 6-speed. The YZ PSS suspension is considered much more 'sophisticated' than the KTM or Husqvarna components. 'Sophisticated' may be in the MX context and not the off-road/trail environment.
The KX125 were imported until '07, RM125 were imported to the US until '08. Both the KX125 and RM125 had steel frames. Regarding weight difference: AMA rules is the primary driver. KTM linkage-less PDS suspension and steel frame design produced lighter bikes. As far as motors: the Hybrid sub-culture of KX engines in CR frames may be a indicator of best of breed.
A 125cc 2-stroke Enduro hasn't evolved much in the past 20-years. Explanations: Manufacturer R&D investment in 2-stroke technology; limitations in weight, suspension, and chassis design for the off-road environment: ability to effectively put HP/Torque to the ground in a wide range of traction conditions.
So what's all this chatter on the dirt-bike forums about 2-strokes making a come-back? ( do you follow Superhunky? ) KTM/Husaberg leads in 2-stroke R&D investment. Yamaha seems to still be committed as they were in the 70's vs. Honda 4-stroke bias; but the YZ line changes at a glacial pace relative to KTM. Husqvarna simply has less R&D funds, so they reuse technology from their emission compliant models: as a result some of the Husqvarna technology is criticized as a little long in the tooth. Comparing the differences between a 20-year old 2-stroke 125cc motocrosser and a current Husqvarna WR125 seems to be appropriate.
125cc 2-strokes are arguably much less expensive to rebuild than their 4-stroke brethren. 125cc 2-strokes are easy to find since most riders are trading-up to 250cc 4-strokes. In California: Green-sticker 2-strokes are the most desirable. I hit CraigsList and discovered that a pre-aluminum perimeter frame Honda CR125 can be found for under $1000.
Is a Japanese 125cc 2-stroke viable for Enduros (F.I.M. E1 class)? For the 'Hobby class' in Europe a used 125cc MX bike modified (lighting kit, protection) for Enduros are very common, and may provide an inexpensive alternative. Note: Although proven on the 250cc engines, the debate continues on the advantage of flywheel weight on the 125cc engines. For similar reasons, a gutless bottom-end that is difficult to improve, FMF doesn't market a Gnarly pipe for the 1/8 liter bikes. Just fan the clutch and keep the revs in the powerband!
The similarities between a 2013 Husqvarna WR125 and a 1992-1997 Honda CR125R are quite revealing:
The steering geometry specifications, weight, and dimensions imply that the 1997 CR125 was more nimble than the current 2013 WR125. The transmission gear ratios reveal the CR125 had a wider gear ratio range compared to the WR125. I'm not convinced that the 30 lbs. difference in dry weight can be accounted for in the WR125 lighting equipment and kickstand.
Clarke and IMS make larger fuel tanks for both models; the pre '95 Honda CR125 is equipped with a 100/100-18 rear wheel which is a direct swap for the '96+ 19" MX rim; and Enduro equipment (Skid plate, pipe guard, hand guards) are readily available from the after-market. Suspension tuning will get the cartridge forks and rear shock sorted for off-road riding.
To add to the argument in the CA OHV context: The 1997 Honda CR125 is eligible for Green Sticker; and the Husqvarna WR125 is a Red Sticker bike.
When was the last time you rode a sub-200 lbs. bike that revs to the moon; and cost less than a grand? It's just too much fun!
The objective of this effort is to get the 'best bang for the buck': Can you get a great Enduro ride without breaking the bank?: A budget of $2000 or less or do you have to fork out $6000+ for current 4-stroke (or a KTM or Husqvarna 2-stroke).
So this kicks off the 1997 CR125 Project... yes, we've got one! and already have it converted to Enduro spec just in time for the January 20th, 2013 Prairie City Grand Prix.
1998 Husqvarna WR125 received the Marzocchi 45mm USD Cartridge Forks.
1998-2010 CR125/SM/WR/WRE125 share same Wossner piston and Top-end rebuild kits;
1998-2012 CR125/WR125 use the same conrod
Same bore x stroke: but cylinders have different part numbers through the years.
38mm Mikuni TMX. 1999-2012 use same intake manifold.
ProCircuit makes the same pipe for 1999-2004. FMF designed the same Fatty Pipe for 2000-2002 models; 2003-2006
All had 6-speed transmissions. 2000-2011 Clutch is same as 1986-1999 Honda CR125
Brake caliper pad are same rear 1998-2009; Same front 1998-2004 then 2005-2009.
I'll have to leave it to y'all to figure out the significant changes from 1998 to 2013. Here's a link to the evolution of Husqvarna 125cc bikes: http://www.motodacross.com/husqvarna/cr125.htm?a
$7096 Eye candy: 2012 HM Moto CRE 125R
Utilizes 2007 Honda CR125 frame, porting, NiCaSil cylinder, and transmission with compression ratio bumped up to 12.5:1. Dell'Orto VHST 28 carburetor (same as Aprilia RS125), ignition map selector switch, Acerbis plastics, Blackbird graphics, Vertex pistons, Maestroni expansion chamber, LeoVince silencer, Domino controls, SuperSprox sprockets. Options for Paoili 41mm or Kayaba 46mm USD fork; 'wave' brake rotors, and electric start.
HM Moto choked down the carburetor from a 38mm Mikuni TMX down to a 28mm Dell'Orto VHST to meet Euro 3 emission standards and be street legal. Note the e-start displaced left side kick start and right side chain.
There is no hunting like the hunting of man, and those who have hunted armed men long enough and liked it, never care for anything else thereafter. -Ernest Hemingway
Seavoyage screwed with this post 02-24-2013 at 03:15 PM
|Thread Tools||Search this Thread|