125’s from different eras ridden

Very interesting, good watch. Brakes and suspension improvements proved valuable.

Bad choice of bikes except for the 70,s cr . There’s a lot of them raced in vintage yet. 90-97 is Hondas , not much for development on 2-st bikes after 04.  Speaking of 04,s after  landing a floater jump , just b4 I land I down shift to 3rd wo. A new yz250f was railing the outside rut . I braked hit 2nd gear & dove into a deep inside tacky clay rut. Into a steep hill with a ramp to jump the top of the hill. I easily passed him.  In tighter stuff a 125 has an advantage.  

Great stuff! 
Though in ‘81 the Honda was not great. I’m being kind… Basically all Suzukis and Yamahas on the line. 

I remember on my 82 cr125 getting smoked by some dude on an older down pipe cr125. Humiliating!

My ‘81

Most excellent! The bike and the gear! 

You still have that ‘81? I’ve always wanted to ride an ‘81 to feel how they compare to today’s bikes. 

Fix any holes in the powerband with a STIC Super X PWK 38 carb. Bout 7yrs using STIC on smaller bores and the power increase is significantly improved from low end to top. Broader peak HP and low end grunt that seems unstoppable. Greatly reduced clutching, roll-on is exceptional. Gives a full race tune, but with low end. vortex@sticfuel.us is the contact. 

Do you make one for the 28pwk yet? 

I had found a thread with talk about it being in the works, but then have never seen if it was made available.

I owned a 81 RM125. Almost no low end or mid-range. Bike came to life in the upper top end and pulled hard till it could pull no more. 

Brakes were shit. Ergonomics are alien to anything modern. 

The rear suspension was very, very good, the forks were okay. 

I passed a lot of kids on the new yz,s in the same section as the 250f.  That little blur bur that they hv is all it takes.  I,d like to build a 95-97 cr125 for vintage so bad. Or a 89 maybe a 01. Not healing very fast though 5 of 7 broken ribs r still gapped out . 3 rotator cuff tore & 1 strained was getting better . Then last 3 days it got worse . 

Back when I was on a ‘04 YZ125 a buddy came to the track with his ‘85 KX125 and we swapped bikes for several laps.  My YZ was better, but I was surprised by how good the motor and suspension were on the KX.  The brakes and cramped rider triangle were its most memorable flaws. 

For an accurate trip thru time this is a good lineup.  Development slowed considerably after 1987. HUGE leaps from 1974-1987.

1969 Penton 125
1974 Honda CR125
1977 Suzuki RM125
1981 Suzuki RM125
1987 Honda CR125
1995 Suzuki RM125
2006 Yamaha YZ125
2022 KTM 125SX

Huge leap from the original CR125 (‘74?) - short travel, air cooled, steel tank.

To

1981 RM125X (and the other Jap brands) Modern Travel suspension, single shock linkage rear, Watercooled, plastic tank.

7 years - a transformation.
These days some models get new graphics for 7 years.

I still have it - mainly sits in my Man Cave - I stare at it every day.
Unfortunately its not the actual one I owned in 1981 (pic below), and I’m not sure of the tune.
It has no bottom end or mid range - probably didn’t notice as a teenager coming off a YZ80!
I plan to try a tune it on my mates dyno - with EGT etc - see where we can get it to. Ride at the very occasional vintage day, and put it back knowing it is a bit “crisper”.

My 1972 Bultaco 125 Pursang in May of 1974 at Sunnyvale PAL.  It was hopelessly obsolete by now due to the Elsinore.  Things happened fast from 1972 to 1974: Pursang (okay on flat tracks), TM125, Elsinore, YZ Monoshock.  

The guy must have never wrung the 81 out too hard because we never saw the violent head shake that comes right after it tops out.

Mine was evil at times.

Best bike I ever owed

My Dream bike & 1st mx bike . Bought it on my birthday on 11-18-89 & picked it up with my brother in-laws elcamnio . I forgot tie downs of course.  It’s was a member on here’s cousin.  It had a NSR port job for hill climb competitions.  1,200 bucks & it was clean with. #18 on it.  The DG pipe I bought at Torque Center for 99 bucks . Great mid hit & long pull & screamed on top. I stacked 3 base gaskets I got more top that way. Drilled holes in sir box. And thought why is my bike slower.  Reeds had a bunch of plastic stuck in there. Lol. Quick , fast , handled awesome , futuristic everything on it.  This bihe gave you an advantage like no other bike ever made .  Way stronger  & faster than my new 92 RM125 with a PC pipe . That made it quicker & snappier.  90,91. KX was a great mid range bike , ovr rev was flat. Yet 125a riders kept it on the flat spot . Pass them easy a gear higher.  

I did the craziest shit on mine.  It’s was my 1st mx bike , see my other post.  I trespassed & made my own track on a ski hill.  The long distance ski ramp wood was gone. I jumped the ski flying ramp up , down & from the side then drop 800 feet, Huge Rush.  Deep wet & hilly sand track threw hills in the woods, 1 hill was a straight down on an off camber to straight up.  I beat 20 500,,s & some 250,s in open class.  And finished 2nd , I needed a 1/16 of a lap to get the leader ,. I didn’t stuff some of the 500,s quick enough . I pushed that bike to its limit & it was really Fuckin Good. That bikes  quick strong mid got me hooked on quick mid ripppers & hyper shifts.  Topend too 

I broke the shock in 4 foot whoops in 4th. I bought a WP shock , that shock was Awesone. Plush all the way through the stroke & great bottoming control.  Made that bike more amazing.  
Manual in sand rollers & square hole hard pack. That’s a good shock.

The 81 RM125X was like 2 development years ahead of the other 81’s…

And built by Dean at R&D was a rocket.

My RM465 blew a shock a few days before this race and a buddy shared his RM125X with me for the day.  I hadn't been on a 125 in about 7 years at that point.  Thing was awesome.

I know your love your 04 with the RC valves but IMO the 05 motor, which was a major change, was much better. It's a shame the twin chamber forks were canceled at the last minute on the 05. If you haven't, put the PWK with a STIC kit in yours.

Ok Thx , I,ll keep that carb in mind for next yr.  Not sure if it would change much . Stock to ported it has the same feeling below 7k . Like the cases belong on a 200 cc bike. I Love the way it runs though , u hv to hv momentum then the hit it shoots straight up to 18.8 ft lbs then builds ovr a hyper quick mid to aprox 10,500 & sounds nuts. 
It’s a blast to ride & hangs or pulls mod 25,s. Not on top though.  My carb has a different taper bore.  I need to get healed from 6-27 wreck & icu that hole in my lung created  pressure like a massive heart attack but not out side inside my chest for aprox 2 hrs.  It separated my ribs big time 5 of 7 r still separated. Since Sunday there knifing in , maybe from sneezing hard. 4-5 days of fall weather a lot of people got sick around here. 

I had 05 the 06 I installed a ikat, Rad Valve &03 hgs kx125 pipe with a reg pc silencer. Added low end to sharp hit , much longer mid & topend never stopped pulling . Stock cylinder & piston.  A 04 chassis is the best for rough 2nd motos.  It goes straight through deep square holes like no other . Much easier to hold a line .  06 is great but not as good.