Author Topic: cb125 cafe/race build  (Read 8279 times)

0 Members and 1 Guest are viewing this topic.

Offline jaguar

  • Old Timer
  • ******
  • Posts: 2,763
cb125 cafe/race build
« on: May 04, 2008, 01:50:16 PM »
i read once that the land speed record at the maxton mile for the 4 stroke 125cc class was in the mid 60s.  i thought that it would be fun to build a cafe CB125 and see what i could get out of it.   as most projects go this one is taking much more time money and work then i thought

first mock up


frame painted with brightside boat paint.(very strong stuff)


rebuildable shocks with stiff springs.  harely light

my super cool speedo. 

all together.  waiting to finish the wireing and some little stuff before she gets riden for the first time.  the pipe is also not finished


Offline crazypj

  • I'm brill, me
  • Old Timer
  • ******
  • Posts: 4,467
  • first 100,000 miles. 1977 CB550F
Re: cb125 cafe/race build
« Reply #1 on: May 04, 2008, 03:25:00 PM »
Do you have stock carb on it?
 We used to fit left side carb from early Suzuki GT 250 (it has 'choke' lever-enricher on it) re-jetted with decent pipe it will rev out in top gear.  You could probably pick up carb for YPVS and re-jet it to work easier though (26mm I believe)
You can fit XR cam for a bit more top end, although the early (one piece) head has different bearings  compared to the later two piece from what I remember of them.
PJ
I fake being smart pretty good
'you can take my word for it or argue until you find out I'm right'

Offline jaguar

  • Old Timer
  • ******
  • Posts: 2,763
Re: cb125 cafe/race build
« Reply #2 on: May 04, 2008, 03:30:29 PM »
i have a 28mm carb for it.  the motor in the pics is just a stock 100cc.  the 125 is still being built. 
big valves
xr cam
high comp piston.
port and polish
light/balc crank
i want to rev to the moon and gear to make 100 mph.  some people have said that i can get to the ton others think im nuts.  only time will tell. 

what other expireance do you have with hopping up these little mini motos?

Offline crazypj

  • I'm brill, me
  • Old Timer
  • ******
  • Posts: 4,467
  • first 100,000 miles. 1977 CB550F
Re: cb125 cafe/race build
« Reply #3 on: May 04, 2008, 03:44:38 PM »
I was working in a Suzuki /Yamaha dealer when the 12bhp/125cc law was in force in Britain.
 Had a bit of practice 'bending' the rules  ;D
 Don't remember who made what good parts now,  probably most either don't do anything for old bikes (Piper for cams and exhausts for example) or are just out of business.
 The CB/XL  125 motors like a long intake tract, 7"~9" or so, and, lighten the piston as much as possible so the big end stays in one piece at 12,500 rpm
PJ
I fake being smart pretty good
'you can take my word for it or argue until you find out I'm right'

Offline jaguar

  • Old Timer
  • ******
  • Posts: 2,763
Re: cb125 cafe/race build
« Reply #4 on: November 30, 2008, 04:08:37 PM »
bike is almost ready to ride. 
stock 100cc motor still in it well time and money are bing looked for to finish the race 125

anyone have a fairing that would fit this bike?

Offline 333

  • Time for change
  • Really Old Timer ...
  • *******
  • Posts: 7,557
  • Mail List Member #162 - Call me Stan
Re: cb125 cafe/race build
« Reply #5 on: November 30, 2008, 04:18:27 PM »
That record can't be right.  I had a bone stock '80 CB125S, and it would do close to 70 out on the highway.
Go metric, every inch of the way!

CB350F0  "Scrouching Tiger"
CT70K0    "Sneezing Poodle"

www.alexandriaseaport.org

Offline jaguar

  • Old Timer
  • ******
  • Posts: 2,763
Re: cb125 cafe/race build
« Reply #6 on: November 30, 2008, 09:30:43 PM »
http://www.ecta-lsr.com/RecordsMoto3.php

but you do only have a mile to get to the top speed.

Offline syth82

  • Hot Shot
  • ***
  • Posts: 401
  • 1976 cb550f project
Re: cb125 cafe/race build
« Reply #7 on: January 18, 2009, 07:06:34 PM »
bike is almost ready to ride. 
stock 100cc motor still in it well time and money are bing looked for to finish the race 125

anyone have a fairing that would fit this bike?


http://www.airtech-streamlining.com/hondaz/MT1251975-77.htm
Not really sure if this one would work, but Airtech has quite a selection, so maybe if you search around you might find something.
-Luke


By trying to make yourself sound intelligent you appear to be #$%*in stupid......

Offline crazypj

  • I'm brill, me
  • Old Timer
  • ******
  • Posts: 4,467
  • first 100,000 miles. 1977 CB550F
Re: cb125 cafe/race build
« Reply #8 on: January 18, 2009, 10:19:54 PM »
I've got an Aprillia RS50 (I think) fairing I was going to fit to CB360 but it looks 'too new and angular'
 
PJ
I fake being smart pretty good
'you can take my word for it or argue until you find out I'm right'

Offline many408

  • Full Member
  • *
  • Posts: 58
Re: cb125 cafe/race build
« Reply #9 on: January 20, 2009, 11:35:51 AM »
What are you going to do for footpegs?

Offline jaguar

  • Old Timer
  • ******
  • Posts: 2,763
Re: cb125 cafe/race build
« Reply #10 on: May 19, 2010, 06:45:51 PM »
been riding the wheels off this little thing.
turns heads....lol   its loud and so people look, but then they dont know what to think when they see such a small bike

been working with powroll for a stroker/big bore motor.
trying to work something that will keep me legal in class.
guys over at oldrice.com have been a ton of help too

school and work got in the way of running the bike so far but i hope to run this summer.

rearsets will be tarozzi universals on a custom bracket.


hondaman helped me out and made one of his ignitions that will work on my single


right now the rear shocks are too firm and need to have the springs changed
looking for a set of excel wheels to relace to the stock brakes

going to get more pics so this thread can get moving again

Offline Sam Green Racing

  • Really Old Timer ...
  • *******
  • Posts: 16,068
  • I REALLY? hate black rims.
Re: cb125 cafe/race build
« Reply #11 on: May 26, 2010, 12:38:45 AM »
Jag, is it a 125 yet and which class are you running it in?

Sam. :)
C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline jaguar

  • Old Timer
  • ******
  • Posts: 2,763
Re: cb125 cafe/race build
« Reply #12 on: May 26, 2010, 05:43:46 AM »
so far school and the CB/CR750 have taken most of my time
the 125 is back home.

been collecting some parts like pistons, springs and stuff
there is a maxton 124 four stroke class and thats were i would like to start running.  the record is still in the mod 60mph range.  i think someone is running like a rebel 125 or something like that.  i assume is someone that saw a hole in the record books and filled it.

i just ordered rule books from scta and ecta.  ill read over them and see what makes the most sences.

goal is still to run at the end of the season.  even if its not will the fully built motor and just using a mild one. 
dream is to someday build a streamliner like buddfab


Offline Sam Green Racing

  • Really Old Timer ...
  • *******
  • Posts: 16,068
  • I REALLY? hate black rims.
Re: cb125 cafe/race build
« Reply #13 on: May 26, 2010, 07:28:49 AM »
I guess you'll be chasing the Williams/Lone Eagle Racings records, all in the low 60mph bracket.
You wont be running in the group you posted back in reply 6( http://www.ecta-lsr.com/RecordsMoto3.php ) that class if for bikes with altered chasis or factory made race frames.
This is the class you'll be in, ( http://www.ecta-lsr.com/RecordsMoto2.php ) It's the modified production class.
M= modified.
G= gas.
F= fuel.
PS= partial streamlined.
B= blown (super or turbo charged).
If you have enough money, you can lay claim to all the records that are above your lowest spec ie MG/125 4 providing you can better them.
The bike looks like it can loose a lot more weight yet. loose the big gas tank and rear shocks, fit struts in place that will lower the rear end. Drop the front forks through the Tees leaving about 2" of travel and get rid of the big wide bars. Clip ons that go across the front of the forks allow you to get your leavers inboard of the fork legs for a slimmer profile.
Remove the lighting and charging system as you bike is no longer stock, just run battery points and coil.

Good luck Sam. :)
C95 sprint bike.
CB95 hybrid race bike
CB95 race bike
CB92
RS 175. sprint/land speed bike
JMR Racing CB750A street ET drag bike

Offline jaguar

  • Old Timer
  • ******
  • Posts: 2,763
Re: cb125 cafe/race build
« Reply #14 on: May 26, 2010, 11:44:10 AM »
all  very good points. 
the pics are mostly form when she still was on the street.  hell its still on the road now, but am going to start getting more focused on race trim.

struts you say?  i would have thought that i would want some rear suspenssion.?

i plan to keep it in gas so yeah if i do get a record i would be able to run in many more classes.

from what it looks like im best to get the motor built to about 175cc seems like that slots me in a good class both at maxton and the salts if i can ever get there.

im looking around for a pair or excel rims or something else light.  i dont really need something crazy strong but weight savings would be nice.
also would like to run a fiberglass tank.   i really like to cr110ish tanks
 as for the bars yes the wide clubmans need to go.
im waiting on the rule book to see about rider posioion.
can i once im in top gear pull my legs back and put my feet on pegs mounted by the rear shock/swingarm point?
ive rode like that and it seems to work well.  heavy on the wrist but not too bad