SS109 wrote: ↑09:52 pm Oct 09 2023
I know it's a bit more work but don't forget about the '04-'05 Kawazuki KX250F/RM250F chassis'. They handle great, are steel framed, etc. These bikes were great other than the Suzuki designed engine they came with.
I really don't care for the stylings of those, & those are beyond the Revolution 2 vintage/post-vintage race classes, so no go for vintage events.
I don't even care for the '03-'05 stylings honestly, and each year 03-05 uses different swingarm and linkage parts, but 04-05 may be interchangeable - same design but slightly altered.
There seems to be a ton of parts support for the '99-'02 era, based on looking at the IMS website, Devol Racing, and Clarke Mfg.
https://imsproducts.com/pages/product-r ... 25~yr_2000
But really I'm now seeing the mass centralization design fully when browsing photos of the 95-98 vs 99-02 & 03-05. The KX's handle and feel better than the KDX because they not only have a 2.17-2.2 gallon fuel tank vs 2.9+ on a KDX, BUT you're basically
SITTING ON TOP of a larger majority of the fuel tank on the '99-'08 KX125/250, moreso than this same positioning on the '95-'98 even. This also makes the bikes taller, and also on the 99-08, makes the seats very thin on padding... The 95-98 era have the thickest seat, which would be more comfortable for trail riding. BUT that also probably screws up the clearance to fit a SmartCarb SC2 36 in there.
95-98 has the least options and least desirable looking options for oversized fuel tanks. The custom order 3.1 gallon requires cutting the upper fuel filler cap area of the shrouds off, and IMS doesn't even have a photo of it.
The '99-'02 3.1 gallon IMS tank is he best looking, but another big concern is that the oversized tanks will have interference issues on a hybrid with the engine, petcock, spark plug, etc, and the 3.1 gallon hangs extra low at least on the pipe side. They offer a 3.2 gallon as well,which doesn't sit so tight to the pipe and carb/head which may be the better choice for a 200/220 hybrid as the 125 engine's cylinder jug is absolutely tipped forward more vs the 200/220. I'll have to read into this a bit more to figure out exactly where the clearance issues lie, but I only recall the build thread reference stating "desert tank" clearance issues requiring heating up the tank and forming some clearance into the plastic.
IMS 3.1 gallon '99-'02:
IMS 3.2 gallon '99-'02:
I think if I ran a 95-98 125, I'd absolutely have to keep stock 220 port height (which is always the preferred route if you wish to preserve the best traits of the 220) and run a Lectron Billetron Pro Series carb, both done in order to get better fuel efficiency. On long hauls, I could always attach a small auxillary fuel tank behind the left rear side plate, which would also keep with the theme of lower center of gravity and mass centralization... Keeping the factory 2.2 gallon tank on the '96-era.
The 99-02 still have excellent geometry for tight woods riding and hard enduro, so some aesthetic alterations may be in order here.
I browsed for a cheap basket case 95-05 KX125 last night, but nothing much available. A guy parting out a roller with no engine in Kentucky, 2001, that was it... I'll be watching this winter for one!
If 03-08, I'd go 03 for the shorter swingarm. The 27° rake is a bit more high speed friendly than I'd care for, but forks could be dropped lower to get 26.5° or 26.25° and also lower the ride height slightly. The wheelbase will still be a noticeable bit longer than a KDX200/220 and 94-02 KX125. I'm aiming for a lighter weight lower center of gravity nimble agile & highly flickable hard enduro weapon here... And the 220 engine with a modded head and supporting pipe, carb, & ignition mods I've already determined is an absolutely awesome engine for this type of riding... Noticeably more suited to this type of terrain and riding than a KDX200 or KTM 200. The 220 chassis with suspension mods does pretty darn well, but it's just that high center of gravity top heavy feel that bothers me a bit (and also makes it a bit harder to pick up in very compromising steep gnarly hillside flops, which is why I was even considering a 144cc, 151cc, or 167cc big bore or big bore/stroker engine).
I still have a lot of titanium to swap out onto my 97 or 99 220 to drop the weight down, but the weight is significantly more noticeable up high than it is down low, so the fuel tank positioning/shape issue is a hard issue to work around, and really the only reason that I would consider building a hybrid over a modified H series chassis. The slimmer seat on the '99+ and an aluminum subframe will also drop a little bit of top heavy weight on a hybrid, I should add.