KDXRIDER.NET

Hi Guys,
I'm STILL in the middle of rebuilding a 2002 KDX220R. I started the project a year ago but due to all the stuff going on I never finished it...YET. During the disassembly I weighed each part on a shipping scale which is accurate to 1/2 pound. I thought you guys that are doing any work on a KDX might find this information very helpful as it will allow you to KNOW and not guess what the weights are of the stock components of the KDX.

One note here is that I purchased 2009 KX450 Kayaba fork and it's 4.8 pounds lighter than the stock fork. Both weighed with triple clamps, hardware and oil.
Sorry, the first photo of the rear fender assembly is not readable. If anyone needs this figure I could re-weigh it.

Can only submit 5 photos at a time so I'll add a new message with attachments until they are all uploaded

more

last of what I have weights for

soup-n-sandwich wrote: 08:34 am Jul 21 2024
During the disassembly I weighed each part on a shipping scale which is accurate to 1/2 pound.

One note here is that I purchased 2009 KX450 Kayaba fork and it's 4.8 pounds lighter than the stock fork. Both weighed with triple clamps, hardware and oil.

Wow, 43mm old school 1980's 1st gen design cartridge forks + triples (yes I'm referring to the 1995-2006 forks) weigh 4.8lbs MORE than a taller and much larger diameter tube size modern 48mm closed chamber fork?!?!?
That's AWESOME! THANKS FOR THE COMPARISON!!!
Heck, I might be able to get my KDX to be closer to 17lbs lighter than stock with that info, and I hadn't even considered putting the original forks on the scale. I'd been telling people I was trying to drop 15lbs off my bike to lighten it up and help to compensate for ADDING WEIGHT with skid plate, pipe guard, and a larger diameter taller modern fork swap!
I'd noted that the aluminum VStrom steering stem (same as the RM125 but taller like the KDX's) swapped into the RM125 triples was aluminum and likely quite a bit lighter than the steel KDX stock steering stem...

Out of the Showa Twin Chamber 96-98 RM125 49mm right side up forks, I'd read in reviews that the '98 was lightened up vs the 96-97, so I picked up several pairs of these very desirable woods rider forks, so I'm excited to see the difference. I'll hopefully be stripping down my '99 220 in August for a major rebuild and finally fitting the '98 RM125 forks and modern Showa shocks to it, although I think I may put all the titanium parts I've been acquiring, + some aluminum parts, onto my '97 220 that I've been riding for 4 seasons since retiring the '99 temporarily.



So the stock forks + triples with oil weigh 27.9lbs - 28.0lbs? I see both those weights in two different pictures.

THANK YOU for showing us the weights. That is great.

I guessed horribly on all but the forks. I got them perfect. :-) I must have remembered from 19 years ago when I was shipping them back to people. :-)

Thanks again for showing all that. I was quite surprised on most of them.

That frame is a tank compared to a MX bike.

Hey guys,
Sorry for the long delay getting back on here. I guess my notifications aren't set correctly. You are very welcome. I thought "I can't be the only person that is surprised by the weights of the KDX components" The fork shocked the hell out of me too! The 48mm inverted fork from the 2009 KX250F is soooo much more beefier than the stock KDX fork but weighs almost five pounds difference!!

Guys I'm having a lot of trouble finding a machinist to do the stem mod for the fork conversion for this bike. Do you guys know of anyone to do this since Ron from RB-Designs has retired? I tried contacting Ron by email but the email server is no longer working for his website.

Any thoughts on this problem?
Chris

Chuck78 wrote: 01:22 pm Jul 21 2024

soup-n-sandwich wrote: 08:34 am Jul 21 2024
During the disassembly I weighed each part on a shipping scale which is accurate to 1/2 pound.

One note here is that I purchased 2009 KX450 Kayaba fork and it's 4.8 pounds lighter than the stock fork. Both weighed with triple clamps, hardware and oil.

Wow, 43mm old school 1980's 1st gen design cartridge forks + triples (yes I'm referring to the 1995-2006 forks) weigh 4.8lbs MORE than a taller and much larger diameter tube size modern 48mm closed chamber fork?!?!?
That's AWESOME! THANKS FOR THE COMPARISON!!!

Yeah that I was said to myself! I was very surprised and very happy about that. That's a big deal when trying to loose some weight on the KDX. Swapping out other steel parts like the kickstarter, brake lever and shift lever are all steel too. So you could save some weight there. Bars are steel (stock ones). I looked into a frame swap but wow is that going to be a big ordeal. The frame on the KDX is 30 pounds. Some of the alum. frames on the MX bikes are almost 10 pounds different. I think if you had the tools and time to do a fame swap with the Kayaba 48mm fork from the 2009 KX450 that would be all you need to do to make the KDX MUCH lighter than stock.

Now you've got me wondering how much a KX 125 frame weighs!
I know the stated difference between a KDX H-series and a KX125/KDX200 hybrid is only about 5 lb difference, but the fuel tank is smaller and fuel weight sits lower, as well as having a thinner seat and an aluminum seat subframe, and seat subframe rails which don't stick back nearly as far as the kdx, so I figured over half of the 5 lb weight difference was probably all just in the seat foam and seat subframe area. Now I'm wondering if most of that was actually in the fork with only maybe a pound or two in the seat foam and subframe and the dished out race spec fasteners used on the KX versus the full head fasteners mostly found on the KDX.

I've been talking about making a post on here comparing all of the weights of each component on the bike, as I went on a real deep dive last fall buying parts for my next 220 rebuild after I rebuilt the suspension linkage and felt how heavy the linkage bolts and swingarm pivot bolt were. Then I ended up buying almost an entire bike worth of fasteners short of a few internal engine bolts and a few small screws here and there, and the KDX specific rear axle which is only similar to a DRZ400 axle, and not available in titanium aftermarket since pre-covid.
Parts like exhaust swapping, KX250 or 125 kick start lever, KX shifter and brake pedals in aluminum to save an extra 1 lb, KLX 650R or KLX300R aluminum suspension link pull rods / dogbones vs KDX steel, etc... Those dog bones are effectively lowering links for a KDX,but I needed that due to swapping a longer rear shock onto my KDX.

Has anyone weighed a KX125 frame (with seat subframe) to compare to the KDX200H frame weight???

soup-n-sandwich wrote: 08:34 am Jul 21 2024
One note here is that I purchased 2009 KX450 Kayaba fork and it's 4.8 pounds lighter than the stock fork. Both weighed with triple clamps, hardware and oil.

This was really exciting to hear... I honestly figured initially that I needed to go to drastic measures to drop weight elsewhere "TO MAKE UP FOR THE ADDED WEIGHT" of larger diameter & longer forks!

I had my hopes up pretty highly... I weighed my '97 KX500 forks (a bit low on oil, leaking seals) with the added & required inverted fork brake line clamps (I MUST use my purple '96 fork guards with these & not switch to different guards & "CR brake hose routing"), as well as 1 of my pairs of '98 RM125 forks (actually the only '98 RM250 forks I have out of the lot of '98 RM Showas), & both were nearly identical at 27lbs 4oz - 27.25lbs, which isn't as drastic of weight savings @ 0.75lbs less than stock KDX as the '09 KX450F KYB's @ 23.2lbs / 4.8lbs savings...but still shaving 3/4 lbs off surprisingly!





This really makes me want to look into a pair of 2009+ KX250F Showa Twin Chamber forks in the future, knowing the more recent forks have shaved an additional 4lbs of weight vs the best of the late '90's...

'09-'10 are twin spring Showa 47mm Twin Chambers
'11-'12 are 47mm Showa SFF Type I forks with damping in one side and a single coil spring in the other. Same triples. '09-'12 triples are all compatible.
'13+ KX250F are 48mm coil spring Showa SFF Type II.

In my opinion the SFF coil spring Showas are the absolute best fork technology out there, excluding the TAC versions which are air spring ("race-only"/high maintenance in my eyes, but can be converted to coil spring to end up with a very nice fork). Less friction and stiction in the SFF design due to not having duplicates of every moving part and moving part interface... I'D REALLY LIKE TO KNOW WHAT THE '11+ KX250F/RMZ250 SHOWA SFF WEIGH IN AT!!!!!





I'm looking at building a woods/torque ported overbored "KDX134R" ultralight woods bike out of a 95-98 KX125 (or 99-02, all those years are viable and have sharp steering and very high ground clearance), and dropping 4lbs additional off of an already featherweight full size 191lbs bike would be amazing.

Here's some $$$$ eye candy, almost a whole KDX's worth of mostly titanium hardware, a few aluminum nuts/bolts, and aluminum KX shifter and brake pedal. Old used RCS (Renton Coil Spring) Titanium shock spring for 50mm Showas. Eventually I'll make a very detailed post, probably this winter, of detailed weight savings of the titanium & other parts, MX fork conversions, etc, vs what was stock that I'll be pulling off of the KDX, including some KLX300 invetted forks I'll have for sale soon!
Teaser - the steel KDX shifter and brake pedal alone weigh a full 1lb more than the aluminum KX versions... KX500 brake pedal is a direct fit to the KDX, as well as '93 & older KX125/250/500 shifters (same as a KX100 shifter basically).
96 grams for the '93 KX shifter
-vs-
292 grams for the KDX shifter, wow!

If I really enjoyed the woods converted big bore/ported KX125 engine enough, I'd look into another batch of $700-$1300 worth of titanium hardware for the entire bike, but that really only saves 5.5lbs-7.5lbs, and the KX already has the lighter shorter length seat subframe and thinner lighter seat, aluminum shifter and brake pedals, etc, so there's not as many areas (vs a KDX) to shave much more weight except some Silicon Chrome steel lightweight fork and shock springs from Diverse Spring...
Worst case if I'm not fully happy with the 134cc or 139cc woods converted engine nearly well enough vs the 12.5lbs heavier & very torquey 220 engines, it'll get my spare KDX220 engine transplanted!

Stock KDX kickstand with mounting bolts:
2lbs 9.2oz (picture on scale iswithout the two large mounting bolts)


Trail Tech billet aluminum kickstand and bracket:
1lbs 4 oz*



*(Trail Tech bracket with integrated footpeg mount for aluminum frame YZ250/YZ250F etc. = 1lbs 9.7oz minus the right side YZ bolt-on footpeg bracket 6.6oz = 1lbs 3.1oz estimated for a steel framed YZ125 2004 & older version Trail Tech bracket)


So the Trail Tech billet kickstand conversion will drop yet another 1lbs 5.2oz off the KDX200/200, while being a MASSIVE upgrade in functionality and liability reduction, as the stocker is NOT an enduro bike kickstand whatsoever, and can snag roots and brush when on it's side sliding down a gnarly steep hillside, making it a BEAR to retrieve one's bike after a get-off...

I may convert my KDX frame to have welded in sleeves to mount Yamaha aluminum frame YZ footpeg mounts, in which case they make Titanium versions of these to shed more weight... Although the Trail Tech YZ aluminum frame footpeg + kickstand mount combination bracket would make things incredibly easy! I may just use that YZ A.F. bracket and chop it up and weld it to the KDX frame like the stock factory KDX220R kickstand mounts on, a design the off-road models would have been significantly better off with...


The fork weight reductions really surprised me on the mid-2000's and up modern 47mm-48mm-49mm forks weighing the same as the KLX300 inverted 43mm forks and presumably about the same as the '91-'95 KX125/250 43mm forks... I may now keep my hoards of 49mm Showa Twin Chamber right side up '98 RM125 forks just for one of my two KDX220's and run a 2008+ CRF250X or 2006+ YZ250 2-stroke triple clamp set and some 2009-2010 KX250F Showa 47mm Twin Chamber forks or 2008+ CRF250X 47mm Showa Twin Chamber forks on the bike that ends up with the extensive amount of titanium hardware on it... I'm fairly certain that this iteration of my KDX will really feel close in perceived weight to the modern center spine frame woods bikes... while retaining the awesome woods bike geometry of the KDX's (& the '94-'02 KX125 which is very similar with 0.5 degree steeper steering 26 vs 26.5* and more ground clearance on the KX125, with only a hair longer swingarm '97-'02 KX125 which is perfect if you do steeper technical slow hill climbs).

soup, very interesting to learn about parts weights. You inspired Chuck, too!

What is the status of your KDX rebuild?

billie_morini wrote: 12:46 pm Feb 23 2025 soup, very interesting to learn about parts weights. You inspired Chuck, too!

What is the status of your KDX rebuild?

I've been inspired for about 15 months or even longer, ever since doing a linkage rebuild on my KDX and feeling just how massively heavy the linkage bolts and swingarm pivot bolt were! I quickly realized the KX500 shares the same part # swingarm pivot bolt with the '89-'06 KDX200/220, and same with 1 of 3 linkage bolts (the frame end rocker bolt), and figured that I could adapt the pull rod link dog bone bolts from the KX500 to the KDX with using the thicker aluminum 117mm KLX300 (or thanks to Chopperpilot, the KLX650R 115mm) links that I realized I'd already want due to the longer shock I'm installing and needing to tame the increased ride height...

After that, I went off the deep end on titanium fastener sourcing and KX aluminum parts swapping vs the KDX's steel shifter and brake pedal etc, aluminum rim lock nuts, aluminum M12 kickstarter nut, titanium engine mount bolts throughout, all the big fasteners then onto the M8 fasteners in the triple clamps, spark arrestor mount, subframe stay mounting bolts, YZ titanium footpegs, etc etc etc... Then on to find the KDX forks are the heaviest possible forks we could run, despite being "small diameter and very flex-prone" vs the modern forks of larger diameter, with the KLX and KX 43mm forks and 2000's KYB Open Chamber 46mm and 48mm forks being 4 lbs to 4.5lbs lighter than stock and better in most ways! The Closed Chamber / Twin Chamber forks found on all high end modern bikes are about a 2lbs weight savings due to the added internals to carry the damping oil up high in the forks vs the lubrication oil down low, but for many will be worth the weight tradeoff - that's also why a lot of bikes in the 2010's went to air spring forks, to eliminate the weight of the coils springs to lighten up the forks and still run a closed chamber setup, but air forks are not really that popular, only a racer weight savings thing, but they still make great forks with the coil spring conversion kits.



My project bike is a little further along, but it's still in the suspension swap R&D stage really, needing to pull the engine and split the cases to send the cylinder and crank out.
I'm very eager to hear how Chopper's Millennium 223cc big bore porting/head work comes out, as well as these suspension ventures he and I are working on separately but simultaneously...

I haven't seen SoupNSandwich on here for a short while, I hope his build is making progress!

Best of luck guys, wishing you all the best in your endeavors getting ready for the riding season! Well, Billie, you're in California, so winter probably IS the riding season vs summer heat! or year round North of SF Bay area...dreamy!

Chuck78 wrote: 08:31 pm Aug 07 2024

soup-n-sandwich wrote: 08:34 am Jul 21 2024
One note here is that I purchased 2009 KX450 Kayaba fork and it's 4.8 pounds lighter than the stock fork. Both weighed with triple clamps, hardware and oil.

This was really exciting to hear... I honestly figured initially that I needed to go to drastic measures to drop weight elsewhere "TO MAKE UP FOR THE ADDED WEIGHT" of larger diameter & longer forks!

I had my hopes up pretty highly... I weighed my '97 KX500 forks (a bit low on oil, leaking seals) with the added & required inverted fork brake line clamps (I MUST use my purple '96 fork guards with these & not switch to different guards & "CR brake hose routing"), as well as 1 of my pairs of '98 RM125 forks (actually the only '98 RM250 forks I have out of the lot of '98 RM Showas), & both were nearly identical at 27lbs 4oz - 27.25lbs with triples/hardware and USD fork guards, which isn't as drastic of weight savings @ 0.75lbs less than stock KDX as the '09 KX450F KYB's @ 23.2lbs / 4.8lbs savings...but still shaving 3/4 lbs off surprisingly!


This really makes me want to look into a pair of 2009+ KX250F Showa Twin Chamber forks in the future, knowing the more recent forks have shaved an additional 4lbs of weight vs the best of the late '90's...

'09-'10 are twin spring Showa 47mm Twin Chambers
'11-'12 are 47mm Showa SFF Type I forks with damping in one side and a single coil spring in the other. Same triples. '09-'12 triples are all compatible.
'13+ KX250F are 48mm coil spring Showa SFF Type II.

Teaser - the steel KDX shifter and brake pedal alone weigh a full 1lb more than the aluminum KX versions... KX500 brake pedal is a direct fit to the KDX, as well as '93 & older KX125/250/500 shifters (same as a KX100 shifter basically).
96 grams for the '93 KX shifter
-vs-
292 grams for the KDX shifter, wow!

Screenshot_20240807-220048.png

So I quickly weighed my stock '95-'06 KDX forks WITHOUT the triples, vs a current Showa 49mm Twin Chamber fork 2017+ model, this version being the 2021+ KX450X / 2026+ KDX300R Showa 49mm Twin Chamber forks...

KDX forks have unknown oil level (seals were leaking slightly) & stock .35kg springs for a 130lb rider...
2024 KX450X forks are brand new factory take offs from Babbitt's Race Team's spare race parts inventory from Lyndon Snodgrass and his teammate's extensive stable which is cleared out for new annually, running .48kg fork springs and more oil than I'll run. Superlight fork springs are in the mail to drop more weight.


KDX '95-'06 43mm KYB Open Chamber fork legs = 21lbs 4oz
KX450X '21-'25+ Showa 49mm Twin Chamber legs = 19lbs 7oz (same forks that'll likely be on the new '26+ KX300X/ KDX300R

1lbs 13oz lighter for a far more advanced and rigid fork is a nice savings! And also, the springs I have in the mail will be significantly lighter than the stock springs, so that will drop a hair off the brand new 49mm Showas as well... Nick from ApplegateMX had a pair of those Diverse Springs Superlight low friction micropolished fork springs in hand, and thought they were titanium, and said they were the lightest springs he's ever felt! They had the Diverse Spring DS######## part number on them, which is how I instantly was able to identify them...

I'm very excited to have a pair of brand new Showa Twin Chamber 49mm current model off-road forks to swap onto my KDX along with this Showa rear suspension I've been tinkering on adapting a few evenings a month now for several months... I hope I can get the valving close for the first ride of the season April 4th on opening day at Perry State Forest! I still absolutely love the original versions of these, basically the 3rd gen Showa Twin Chamber, or rather the last year of the 2nd gen Showa Twin Chamber forks, 1998 RM125 right side ups, but I'll see if the extra 1lb off the front end especially up higher in the CoG will be noticeable between the two bikes, vs the nuisance of running inverted forks and dealing with mud packing into oil seal and causing leaks, as always inadvertently happens in most riding areas other than California and the Southwest...

Here's the comparison between the goofy awkward and very wear prone stock KDX Kickstarter lever, versus the popular KX 125 shorty kicker upgrade using the KX250 splined portion with the lever from the KX 125...
The KX125 lever/250 knuckle shorty combo is literally half the weight of the stock clunker.

Chuck78 wrote: 04:27 pm Aug 05 2024 Has anyone weighed a KX125 frame (with seat subframe) to compare to the KDX200H frame weight?

Anyone done this yet?

I still haven't cracked into a full rebuild & major upgrade of my '99 KDX220 yet, but I'm still slightly considering picking up a '96-'98 KX125 chassis for a hybrid build, IF it's noticeably lighter than a KDX200H/220R frame...


I've asked the only seller on all of eBay woth a KX125 frame AND seat subframe if he'd weighed them for shipping yet, and if that'd be a possibility.
It's in the year range I'd be looking for, so there could perhaps be an impulse buy going on here if it comes back a fair but lighter than the 30.3lbs that the original poster soup-n-sandwich here is showing... No swingarm or linkage or seat etc though, so it'd be a pieced together bike, meaning probably more of the full titanium hardware type custom builds for me - & with Showa Twin Chamber forks & Showa 50mm shock as well!

If it doesn't end up being any significant amount lighter (less than 3lbs difference), I'd still perhaps look for a complete '97-'98 KX125 needing full rebuild, to possibly build a '97 KX139X or '98 KX134X out of, as the engine is the heaviest difference between a KDX200/220 & KX125...





I do recall several people stating that the KDX200/220 hybrid builds only end up at around 5lbs lighter than the KDX. I don't know if that's a KDX with a fork swap, but there's an easy 6.5lbs to 9.5lbs weight savings to be had on a '95-'06 SOLELY by swapping on an aftermarket exhaust (-4.5lbs+) and doing a good 1999+ KX or other modern fork swap (1.1lbs - 2.3lbs on a closed chamber fork swap, 1lbs-4.5lbs savings on an open chamber KYB fork swap).

The aluminum KX brake pedal and shifter lever shave about 1.1lbs off vs stock KDX steel versions, the KX seat subframe doesn't extend out as far in the rear, the '99+ seat gian is classic modern seat that's not for full time sitting or all day riding comfort (half the thickness of fiam, saves up to 1lb,), & far more of the KX bolts have dished out race spec heads to shave probably 0.75kbs more off the bike... & the KX triples all have aluminum steering stems, so shave another 0.85 lbs off, as well as the 2.2 gallon fuel tank being slightly lighter and never allowing the KDX's 2.91 gallons (0.60 gallons extra fuel weight all up high)....
Also, the KX frames are missing the KDX's case saver frame hoops...
So those are things which total up to about a 5lbs difference there...which leaves me wondering if it's really worth it? Perhaps, the '96-'02 KX125 geometry has a much higher ground clearance at 15"+ vs the KDX & 2003+ KX @ 13.75" or so, & the steering angle is even steeper on the '02 & earlier KX125 ('90-'02? definitely '94-'02) @ 26° which makes for a very excellent fast sharp steering for tight woods riding. The '97-'98 swingarms are slightly longer by an extra chain link I believe, and taller. That'll help the short wheelbase and steeler steering angle on the steep hill climbs since that's the KDX200 & '94-'02 KX125's only weak point in the chassis geometry handling - steep hill climbs. Handling everywhere else in the woods is super crisp and responsive...