CRF150R Mods for Mini RR

Discussion in 'Mini Racing' started by JBinSD, May 28, 2019.

  1. JBinSD

    JBinSD Well-Known Member

    Just bought a stock 2008 CRF150R (small wheel), and will be converting to mini moto RR. Had a few Q's that may help others, so thought I'd start a thread:

    1. 450 Brake conversion: Seems like everyone agrees that the 2-pot CRF450r Brake conversion is the way to go, but which years are compatible? will an '08 450 fit an '08 150? Also will need a offset bracket to accomodate the larger rotor. Can buy an entire kit for under $400, but I've heard Flea Bay is a good cheap source for OEM front brakes. Feeback on that appreciated.

    2. 12" rims/tires: Moto Triad sells these mags for minis, so you don't have to deal with tubes/spokes

    3. Suspension: Haven't heard of many cheap-fixes for this, but recs for Racetech and Bobby Loo seem popular.

    Since I haven't done any of these mods yet, I'm soliciting input from anyone that has,

  2. JBinSD

    JBinSD Well-Known Member

    Just bought a CRF450 caliper and master on ebay ($100) and the bracket from CRF's only, will still need wheels and suspension. . .
    2wheeldev likes this.
  3. Toadmeister00

    Toadmeister00 Well-Known Member

    Wheel options are either the 12" cast wheels you mentioned or lacing 12" spoked wheels to o.e. (or aftermarket) hubs. I think both ways have some advantages and disadvantages.

    The cast wheels are less expensive but a little bit heavier and as you mentioned no tubes to deal with. 12" spoked wheels are a little lighter (and can be made tubeless to drop a little more weight) but are a little more expensive. The nice thing with building spoked wheels on o.e hubs is being able to easily source rotors, sprockets and bearings.

    You're on the right track with the brakes, the 250/450 calipers and masters work well. Add in a good brake line, a pair of Braking CM-46 pads and some RBF600 fluid and you'll be good to go.

    There are lots of options for suspension. Fast Bike Industries in NC has been doing CR85s and 150Rs for kart track use for many years, Thermosman, Race Tech, Traxxion Dynamics, Bobby Loo, Factory Connection, RG3, etc. all have good reputations.

    If you're trying to do it inexpensively to just get on the track, you could just put in some heavier fork/ shock springs and some heavier oil in the forks. It won't be ideal but it should be "good enough" to get you riding. BBR, Cannon Racecraft and K-Tech all have heavier springs available. Kevin Nolde of is also selling springs now (along with 12" spoked rims and Mitas tires).
    2wheeldev likes this.
  4. Toadmeister00

    Toadmeister00 Well-Known Member

    You can get aftermarket rebuild kits from Rocky Mountain ATV, Motosport and eBay but I trust the o.e. seals more for critical stuff like brakes.

    Rebuilding the master and caliper is pretty easy, there isn't much to them.
  5. JBinSD

    JBinSD Well-Known Member

    Thanks, just watched a 3 min video, looks pretty straight-forward.
  6. gt#179

    gt#179 Dirt Dork

    what's the opinion of 12" wheels vs 17" on the 150 and other mini motors. Most of the guys I know (mostly playing at a local spot vs actually racing them) are running 17" wheels instead of 12" wheels. Say it's better ground clearance and they like the handling but seems many run the 12" wheels.
  7. Toadmeister00

    Toadmeister00 Well-Known Member

    The general opinion is the 12s are better for tight, technical tracks where the 17s are better for tracks that are fast and flowing. It's also rider preference. I have a buddy that bought a 150R on 12s and hated it, ended up selling the wheels and went with 17s. I have another CR85 friend that ran 12s for years and decided to try 17s and hated them. Sold the 17s and went back to the 12s.

    The 12s should be more nimble but give up some stability to 17s. 17" wheels are a little more expensive and tires are about $100 more per pair but seem to last longer than the 12" race tires.
    noles19 and gt#179 like this.
  8. noles19

    noles19 Well-Known Member

    12s are twitchy compared to the 17s, is the consensus. But other than that it's rider preference. Out of the 15 people I know with 150rs it's split and people jumping back and forth.
  9. JBinSD

    JBinSD Well-Known Member

    Sent the bike for suspension with James Lin, a local guy in my area. Still need to source wheels/tires, I've heard bad things about the chinese mags, may have to bite the bullet on the spoked rims, though in the end they'll be several hundred more. . .
  10. Ethan Wakefield

    Ethan Wakefield Active Member

    Currently running Mitas tires and wheels from gator rimz. Let me know if you try a different tire out.
  11. JBinSD

    JBinSD Well-Known Member

    Anyone have a good source for chain adjuster sliders and handlebar sliders for the 1-fiddies? Also still shopping for tires/rims (12").
  12. Toadmeister00

    Toadmeister00 Well-Known Member

    Still trying to decide between spoked and cast wheels?
    JBinSD likes this.
  13. JBinSD

    JBinSD Well-Known Member

    Yep, but don't want the hassle of tubes, so will likely go with mags. . .

    Sent from my SM-G955U using Tapatalk
  14. JBinSD

    JBinSD Well-Known Member

    Axle sliders, swingarm sliders, bar sliders, handguards, all this $tuff adds up, I assume this stuff is worth it?
  15. Toadmeister00

    Toadmeister00 Well-Known Member

    Some tracks and orgs require sliders. Axle sliders definitely keep the forks, axles and swingarm from getting torn up. Handguards protect your hands and keep levers from breaking. I'd say they're worth it.

    You can do axle sliders for less, I've seen people use skateboard wheels or generic Delrin. You can use allthread on the front of your R, the rear is trickier.
  16. TurboBlew

    TurboBlew Registers Abusers

    make it out of PVC or delrin. Also a full sized adult running 12s on 150R? Id love to see
  17. JBinSD

    JBinSD Well-Known Member

    12's are the solid trend in SoCal, my buddies claim I can't pit with them unless I'm on 12's.

    Sent from my SM-G955U using Tapatalk
  18. TurboBlew

    TurboBlew Registers Abusers

    but are they fast?
  19. JBinSD

    JBinSD Well-Known Member

  20. Toadmeister00

    Toadmeister00 Well-Known Member

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