CB900 Scrambler / Racer

Discussion in 'Some Assembly Required' started by Entrepre-neer, May 13, 2013.

  1. dakman74

    dakman74 moto-butcher expert

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    Ahh ok...haven't found a set of those in a 120/80/18 and 100/90/19 or close to those sizes. :-S

    Am thinking I might pop for the Heidenau K60's like on the LHC CB750, if I can find a set in the sizes I want.
    #41
  2. Pezz_gs

    Pezz_gs Cant ride for crap

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    Dont know the final weight for sure but will go and buy some scales and give it a weigh tomorrow.

    I could lose a fair bit of weight going to XR600 rear mudguard and lights. But I like the styling at present :1drink

    Tail light assembly is pretty heavy as is the steel rear mudguard and rack.

    let you know what it comes in @
    #42
  3. Highside>Lowside

    Highside>Lowside Hairier Than Thou

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    Coming along nicely! Can't wait to hear details! :ear
    #43
  4. Entrepre-neer

    Entrepre-neer Ultimate Tight A$$

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    You couldcheck out the Kenda Big Block I think they have a 19 front. I almost went with Dunlop 606 but chickened out...:rofl
    #44
  5. dakman74

    dakman74 moto-butcher expert

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    Yeah, but there's not a 120/18 rear. The IRC Volcanduro that I have looks like it would fit in the 110/100/18 size but I don't think I could run THAT gnarly a knobby on the street, especially on a heavy bike.

    I'm guessing you're running tubes on the 244s. Looks like they have them in the right size, but only "tubed" style. :-S
    #45
  6. Entrepre-neer

    Entrepre-neer Ultimate Tight A$$

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    I'm running a 130/??-18 on the rear. Its not as wide as the 120 street tire that was on it.

    Yep. I'm running tubes.

    Check out the BMW tire topics. They have lots of discussion over trail-capable radials.

    Can you run a tube with the cast rims? Seems harmless. Bias ply tires are usually cheaper right?

    Sent from my EVO using Tapatalk 2
    #46
  7. dakman74

    dakman74 moto-butcher expert

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    Sometimes it's possible to run tubes in cast wheels, but I'd rather not. Easier to carry a plug and CO2 kit than spare tubes...especially since it's a bitch to break a tubed-tire bead on a tubeless rim, from what I have read. I've read about a couple guys running the 244 tubeless...not sure I'm willing to experiment to THAT level though!

    I might settle for the Kenda K761s...mixed reviews but for me the wet traction isn't really an issue, and likewise mud is rare. Wish for more sand traction, however. Either those or the Vee Rubber VRM-163...the more I read about them the more I'm leaning towards them, actually....if I can find them close to the same price as the Kendas.
    #47
  8. Entrepre-neer

    Entrepre-neer Ultimate Tight A$$

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    This thing is sweet!

    [​IMG]

    I tried to finish her up Friday night but it seemed like everything fought me. The exhaust didn't want to go back on so I wrestled it for over an hour. I put the wiring harness on and hit the starter button...nothing. The relay was bad so I had to replace it with a different one I had that required me to rig a fuse on it. Once that was straight I mounted the carbs and put fuel to them only to have them pour gas all over the motor. FUUUUUU@%!!! The rubber on the float needles had dried out a bit while sitting on the bench the past few weeks. It was about 2:45am by this point. I went to bed rather than throwing tools and shouting.

    Saturday morning it was all much smoother. Turned the gas back on and no leaks. Hit the starter and she fired up. Synced the carbs and she purred. Made a wiring harness for the rear signal/brake. Bled the front brake. Grabbed the tank to pull the masking tape and paper off from adding the satin black trim paint. FUBAR. Whatever little bit of fuel that was in the tank gave off enough vapor to melt the paper into the red paint so I have to re-do the top of the tank...whatever...it still looks tough for now.

    [​IMG]

    I put almost a hundred miles on it Saturday. I stayed close to home. The headlight mount bolts loosened up on my first short run so I went home and dug up some nylock nuts.

    My idle was set to run well cold but once I really got her warmed up the idle was too high so the CV carbs wanted to take off and idle to the moon when I'd stop. I stopped and adjusted it down to a controlled level and I'm set! ended up with the rear springs one notch down from the highest pre-load. I may go one softer.

    When I got home I noticed one of the front engine mount bolts was gone where the cash bars attach. It should be easy to replace. (and Loctite)

    Pulls strong all the way up as far as I can tell. Plenty of brakes to lock up the front and the rear. With such a low CG it corners really nice even with the 50/50 knobby tires. :clap

    I'm calling this Phase I complete! I couldn't be happier with this so far considering this is my first bike build and I've only had her for about 6 weeks!

    My wife took some video of the maiden voyage out of the driveway. I'll post that and some dirt footage later this week.

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    #48
  9. hardwaregrrl

    hardwaregrrl ignore list

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    Just inhaled this over coffee.....lookin' good Braden!!! Maybe I'll volunteer just to see this beast!!!!
    #49
  10. Entrepre-neer

    Entrepre-neer Ultimate Tight A$$

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    Thanks Jenna! My mom is planning the trip out there already and she said you can stay with us if you don't have other plans!
    #50
  11. Pezz_gs

    Pezz_gs Cant ride for crap

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    Entrepre-neer

    I went out and bought a set of $8.00 bathroom scales from K-Mart.

    Front axle is 82kg and rear is 94kg making total mass of 176kg (388lbs)

    I reckon I could lose a few kilograms with lighter rear guard, tail light and rack.

    [​IMG]
    #51
  12. Entrepre-neer

    Entrepre-neer Ultimate Tight A$$

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    You nailed it with that bike mate. I've seen it in a few videos. Sounds amazing!!! At 388lbs it's lighter than a lot of the big adventure bikes on the market today. :clap

    From the look of these bikes you'd think the weight would be front biased but the early inline 4s were all rear biased on weight I think.

    I knew going into this project mine would never be light but if I can keep the suspension travel and spring rate close front and back I think it will still be a very stable and fun back roads bike.
    #52
  13. dakman74

    dakman74 moto-butcher expert

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    There's a "Steve McQueen Replica" on local craigslist right now from OCD Custom Cycles and Repair (my favorite name for a shop, by far)...CB500 twin, Shinkos like yours...I know these links die pretty quickly, but here it is:

    http://santafe.craigslist.org/mcy/3805870807.html

    Just noticed he's running the same bar-end mirror I am. I like that i can run it down low or up high, depending on my mood and style preference.
    #53
  14. Entrepre-neer

    Entrepre-neer Ultimate Tight A$$

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    That's a cool project!

    I'm going to put some bark busters on to protect levers and controls. I think I'll end up with the Highway Dirt Bike guards with integrated mirrors and signals. 2 less things to break off. They have some pretty trick switches and billet gauge mounts too.

    [​IMG]

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    #54
  15. Bambi

    Bambi Been here awhile

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    Hello all,
    there's one thing I'd like to point you to. As a scrambler you might use that bike (it's been called Bol d'or in Europe) at other steady revs than in it's formerly intended role as a naked, sports-derived bike.
    That bike developes some high-frequent vibrations in some parts of it's rev-range. On the bike of a friend those caused the original rivets, holding the front-mud-guard in place, to break. The mud-guard followed the turn of the wheel leaving my friend with something like a mono-ski. Even today he's not able to tell how he managed not to fall off and come to a safe halt. Only thing he says is that he immediately recognized the situation and thus used the rear-brake only ...
    I just tell the story to ask you to keep an eye on these vibrations. It's said, that you can barely feel them. And that they came in at something around usual touring speed (that's some 60 mph here in Europe).
    However, that's a nice bike. Go out and have fun with it!
    Kind regards, Bambi
    #55
  16. VxZeroKnots

    VxZeroKnots Long timer

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    Bad ass man! Love the style!

    Personally I'd keep the enduro seat gaurd for laughs but it's your bike.

    Carry on!
    #56
  17. Entrepre-neer

    Entrepre-neer Ultimate Tight A$$

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    Wow! :eek1I may go ahead and put some stainless bolts and nyloc nuts on just to prevent that. Especially if the fender makes the fork swap transition! This is why I love these threads. Life saving info from all over the world.

    It does have a resonant vibe at highway speed when on the throttle hard but I couldn't tell where it really comes from with my DS helmet. I'll have to test it out with a quieter street helmet on.
    #57
  18. Entrepre-neer

    Entrepre-neer Ultimate Tight A$$

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    Yeah the EE seat cover badge is something that only the dirt riding crowd is likely to understand. :wink: I think it has to stay even if I do make a leather cover.
    #58
  19. Entrepre-neer

    Entrepre-neer Ultimate Tight A$$

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    Here's some info that I posted to answer questions over on DTT.

    Budget...so I'm a cheap bastard so Phase 1 was to get the bike on the road for as little as possible. I borrowed tools and dug through scrap bins for metal and told all my riding buddies about the project and got plenty of support. It also helped that the bike came with four boxes of hardware, electrical harnesses and parts. (Including a spare oil cooler, set of motor covers, and full head and cams)
    Here are the numbers:
    Bike $350.00
    Registration, title, Ins $102.00
    Carb Boots $69.00
    Carb Kit $124.00
    Handle bars $35.00
    Tail Light/signals $42.00
    Fork Seals $35.00
    Rear Hoop $40.00
    Exhaust Wrap $51.00
    Tires and Tubes $133.00
    Gauges $140.00
    Paint $65.00
    Seat Foam $22.00
    Battery Donated
    Scarp metal Free

    Total $1,208.00


    What are the future build phases?

    Phase 2 involves suspension and wheels. I figure there's probably 10-15lbs of un-sprung weight to be shed by swapping to aluminum wheels and a rear disk. If I find the right donor rear end I'll probably swap to an aluminum swingarm to make for less fabrication. I have a few folks willing to donate some forks/trees to the cause from older honda 600R and 650Rs. Haven't decided on shocks but looking to raise the bike by about 2 inches overall and balance out the front and rear.

    Phase 3 - Might be a new set of carbs but it's running strong right now so I'm not sure if I'll need that. I want to build an airbox to see how it runs that way at least.

    Phase 4 - Maybe some updated controls, braided brake lines, and new wiring. I'd like to try a hydraulic clutch conversion. I have a spare clutch cover and the stock plug on the cover seem like a slave cylinder adapter could be machined in a pretty straight forward way.

    The biggest hurdle to progress is that I'm pretty satisfied with the bike as is (I still think I want some extra suspension) and I've got the itch to work over an old thumper. GN, SR, XR, XT.......?

    And this is waiting in the garage for some love...

    [​IMG]
    It's a basket case project I picked up about 6 months ago for almost free. FT500 motor in a modified CL175 frame, CB550 forks with dual disk setup, aluminum rear wheel, Clip-ons, rear sets, tiny little bike with a bigger thumper motor. No title but I think I can fix that.
    #59
  20. Jacl-Kampuchea

    Jacl-Kampuchea Booze Merchant

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    Nice build and a fantastic bottom line too:deal

    Do you think that you may want just a bit more seat going forward? What you have looks like it might not be fun on rough stuff.
    #60