Introducing myself and my dual suspension BMX build!

Discussion in 'Introduce Yourself' started by HotRodRob, Jun 4, 2014.

  1. curtisfox

    curtisfox Active Member

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    Map bike I have some old mini bike wheels if your intressted? Am cleaning and a lot of stuff to go.............Curt
     
  2. mapbike

    mapbike Active Member

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    The Yellow bike in this video is identical to what mine is and was, only thing missing is mine came with rat trap peddles and this bike in video doesn't has the plastic square plate the was attached to front of bike across the front shocks that said Yamaha in those 70's psychedelic looking letters.

    http://youtu.be/wj2Q3jNEo6A

    the second video shows what the front plate looked like.

    http://youtu.be/ao1e7-BrPTo

    Another look at the old bike

    http://youtu.be/UwB0BRzbX0g
     
  3. mapbike

    mapbike Active Member

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    ooops.......a mess up here and cant delete it..LOL
     
  4. HotRodRob

    HotRodRob New Member

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    Map,
    Yep the Yamaha moto-bikes where mainly sold at the Yamaha dealerships. They could have very easily been NOS. I could imagine they would be quite pricey back then. If you still had all the parts it would be worth a pretty penny now. I'm sure the frame is probably pretty valuable too. The 74 model (or model A) came with raw front shocks. Then in 75-76(model B and C) they where painted the same color as the frame(yellow or orange). Do you still have the chain guard? That would be the easiest way to identify the year. Each year had a different chain guard. Yeah post that pic if you get a chance. I'd like to see what you have. I love old bikes! Especially vintage bmx bikes.

    Did your bike have the front yamaha number plate? I've only seen a few that do. Thanks for sharing those vids. Those are some really cool bikes. I really like the banana seat that some of them had. Funny thing is at first I planned to use a banana seat and had an idea of how I would mount it. Well as I was looking at banana seats I stumbled across the Yamaha Moto-bike and the way they mounted the banana seat in 75 is exactly how I planned to mount my seat.

    I'm about to go finish up adjusting my derailleur and rear brakes. Once I do that I'll mix some gas and see what she will do. Wish me luck! I'll be back on later to let you all know what happened and I'll try to have some pics.
     
  5. mapbike

    mapbike Active Member

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    Mine had the raw non painted front shocks and yes it had the number plate, I still have the frame with rear shocks, the cranks and the handlebars and the original front wheel, everything else got stolen.

    I'll post a pic tomorrow of the frame and yes the bikes were expensive back then compared to aother popular bike like the old Huffy Bandit bikes and such, I never seen another of the Yamaha Moto bikes in my town, everyone I knew back then were crazy about mine and my brothers Yamaha bikes, I did some jumps on mine that makes me still cringe today when I think about it, I took full advantage of that suspension many times...LOL!

    map
     
  6. HotRodRob

    HotRodRob New Member

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    Map,
    Ok your bike must have been a 1974 model A. I had never seen one before in my town either. My dad who was a teen in that mid 70s time period had never seen one either. He had a cool Schwinn lemon peel back then. Sounds like you have the most important parts. Some of those parts are easy and cheap to replace. Unless you want the original parts which will probably be up there in price. Do you still have the triple trees? I would like to see a pic of your bike when you get a chance. How was the suspension on the Moto-bike? I only weigh 125lbs and my rear suspension seems pretty firm but soaks up the big bumps and the triple trees suspension is a little softer and gobbles the little bumps. Haven't came close to bottoming either out yet.

    On to the DS-20. So, I got all the tweaks done last night and went for a ride. WOW!!! The motor fired right up first couple of kicks. This is my third china girl and best one yet. I noticed when I got my motor the jug and head had been decked/machined at the factory. The new head has a squish band on the outer edge and looks more like a performance head than the older stock CG heads I've seen. Which is good because I have no room for an aftermarket performance head.

    I have a billet intake, rt carb, performance plug wire, ngk plug(indexed and gaped at .28) and my SBP expansion chamber. I also ramped my piston at the exhaust and smaller ramps on the intake transfer port sides, as well as trimmed the intake side of the piston skirt. I also decked the head and cylinder a little more than factory and used a thinner head gasket to bump the compression up a tiny bit but not so much its really hard to start.

    The SBP exhaust is a lot quieter than my old banana pipe I used on my last build. It's also pointing more to the back and puts the sound behind me. It sounds really good. I have the sound deadening material in my side covers and they have made my motor super quiet. I can mainly only hear the intake and exhaust.

    Wow though the ride last night was awesome. It was dark so I couldn't take any pics. Its raining today so I'll snap some tomorrow. This motor has some serious power! Not a vibe to be felt. Super smooth motor.

    I only used up to half throttle last night and with the gearing this thing feels like a stump puller! When I would roll the throttle back she would pull forward hard. Hard enough to feel it pulling you to the rear a lot more than any of my other motors. I never did much internal mods on my last motors nor had the rt carb or sbp exhaust, but this new motor feels like night and day to even my best running CG.

    I have a "vintage style" cable speedo. I have one on my 26" Schwinn Searcher and it was kinda close to accurate. Well, this new one said it was for 20" bikes and was the only one I could find for 20" bikes. Anyways, I don't think its actually for 20" bikes. The only thing different was the cable is shorter and the new one didn't have a dial to reset your odometer. The new speedo seems way off though. I was probably going ~15-20 mph and it was reading close to 30 mph. I'll have to get a gps to see how much its actually off but it seems like a lot.

    As far as the gearing it's perfect just like Theon and I had thought. Feels a lot better and more peppy than my 44t sprocket on 26" wheels. I had talked to Jim at Sick bike parts and he also had the same conclusion about the gearing.

    I will have some pics tomorrow if its nice out. So check back in and let me know what you think. All I have left to do is install my battery, mini-gen and charger for my lights. As well as my chrome fenders and tail light. Then I will paint the tank, fairing and some other parts VHT fire metallic red. Some other parts like my chain guard and fender mounts will be flat black to match my frame. I think when I get closer to paint I will do a more detailed build thread and let you guys know the link.

    Again, thanks for looking and check back in soon for more pics and updates. I'll have pics of my exhaust installed tomorrow.
     
  7. mapbike

    mapbike Active Member

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    Here are the pix of the Yamaha Moto frame, I do not have the triple tree, it got stolen, I thought I still had the front wheel but I cant find it now but I found a rear wheel that I think may be for the old Moto bike, I have the Handlebars and the cranks and that is all I have for it, sure wish I would have been able to put this old bike back together some day but just not enough parts to put it back original.

    [​IMG]
    [​IMG]
    [​IMG]

    This last pic here shows how mine looked when it was new, I'm not sure the cranks on this bike are correct though, the chain ring isn't like mine, but maybe there was more than one that they could have had.

    [​IMG]

    Map
     
    #47 mapbike, Jun 26, 2014
    Last edited: Jun 26, 2014
  8. worksmanFL

    worksmanFL New Member

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  9. mapbike

    mapbike Active Member

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  10. HotRodRob

    HotRodRob New Member

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    Cool bike map and nice pics thanks. You are lucky to have that bike. You could always buy a ds-20 and use parts off it. It would probably be cheaper than finding the original parts. That last bike maybe a non-correct restoration. I'm not 100% sure but like I said earlier the 74 had metal colored front forks and no banana seat. Then in 75 they had the option of a banana seat but frame colored forks where standard. Also if I'm not mistaken the chain ring and guard look from a 76. I believe the 75 had a metal chain guard then in 76 it was black plastic like the one on the last bike pic. The wheels and reflectors as well as the other parts are period/make correct but could be from different model years.

    After it stopped raining and dried up a bit this evening I went on my second ride on the ds-20. WOW!!! Is all I can say. I never thought I would say this but this CG is almost scary fast and its not broke in or tuned yet! When she gets on the pipe and hits the power band its like a rocket! The power band is in the mid to upper rpm. The higher the rpm the harder she pulls. I've only held it full throttle one time and for only a few seconds. My (very inaccurate) speedo was pegged at 50 very easily and she wanted to keep going. I was probably going more like 35-40 mph. Even with the oil rich gas mix and not being broke in yet, she has tons of power. I don't need or care to have anything faster than this. It's all I need plus a lot more. I usually cruise at 15-25 mph anyways.

    When I first got my SBP shift kit and put it on my 26" Schwinn it was a huge improvement over my stock single speed 44t. Well, now with the new gearing and better motor and parts its leaps and bounds better than my last setup. I'm already having so much fun with this bike it might be a while til I paint it and do the finishing touches.

    If its nice out tomorrow I will take some pics of the exhaust and other stuff. Thanks for looking and check back for updates and new pics. I will be adding my fenders and getting the lights/battery all hooked up soon.

    Rob
     
  11. HotRodRob

    HotRodRob New Member

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    It was nice today so I got a chance to get some pics. I still have several parts to put on but its too fun to stop riding long enough to do anything haha. I found out that I can rest my feet back on my pegs and the pedals stay wherever I put them.

    I was at a stop sign last night going to a friends house when a guy walking down the street says "That's bad*ss man!!" I love peoples reactions to my bikes. Last summer as I'm putting around the local park, I see a guy who has his head down really struggling on his bike. He looked very tired. Then he looked up and saw me and my bike. The look on his face was priceless! It was the look of "I'm over here about to have a heat stroke and this guy is effortlessly cruising around with the wind in his face!"

    Like I've said before I have been really lucky with this build so far. Before I got my SBP expansion chamber exhaust I found a "muffler tip" at the local auto parts store that I liked. When I got the pipe I slid it over the sbp muffler and it was a perfect fit. The muffler is 2" and the chrome tip is 2 1/8"! Also, its the perfect length to put the exhaust sound behind me and right behind and bellow the rear foot peg. Check it out!
     

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  12. HotRodRob

    HotRodRob New Member

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    What category would you say my bike fits in?
     
  13. worksmanFL

    worksmanFL New Member

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    Happy 4th Rob!

    Very nice build!

    Hows it going?

    New pics and videos maybe?

    :)
     
  14. HotRodRob

    HotRodRob New Member

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    For some reason I'm just seeing your comment. Thanks for the complement. The bmx is still in the same mock up stage as it is in my pics. I built another bike so I can have it to ride while I finish the bmx. I messed up the cdi on my new bike and had to use the one from the bmx. I'm gonna order a new one and a couple other things this friday.

    She will be back on the road again but I plan to get the last few things done on my other bike before I finish getting the rest of what I need to finish the bmx. Hopefully if everything goes as planned(they never do) then I will have both bikes done before summer. Waiting for good weather to paint as well.

    I will start new threads on each of my current builds once I get some things done and pics snapped. I will share the links to them here. Thanks for showing interest.

    The bmx was a gamble for me. Since I have never seen another one like it. I didn't know if the CG with SBP shift kit would fit in the frame. I didn't know if the moped seat would fit(it didn't without mods). I didn't know if I would be able to make the moped gas tank fit right(also took mods). I didn't know if the fairing I got would fit right.

    The bmx came as a single speed and in order to use a motor with the rear suspension(without some crazy chain tensioner) I needed to convert it to a multi-speed which I wanted to do anyways. In order to do that I needed some new wheels. After looking for wheels that would work, I found that it would be cheaper to just buy a donor bike with the wheels I needed. Plus I can use the other parts on other builds. For instance I used the triple tree from the donor bike as well as the original bmx wheels on my cruiser. The triple tree was a nice bonus. If I would have bought them separately it would have been almost double what I paid for the donor bike! The donor bike also has some nice handle bars as well as other parts from it and ones removed from the bmx and cruiser that will more than likely be use on other builds. Some of which I've already started planning in my head haha. This hobby is addicting.

    Being a single speed to multi-speed conversion, the axle spacing between the rear drop outs would need to be wider by about half an inch. I didn't know if I would be able to do that without messing it up. I didn't know if the tires and fenders I got would fit right. I didn't know if I could get my SBP expansion chamber exhaust to fit the way I had planned(position and exhaust tip). I didn't know if the folding rear foot pegs would fit without messing up my swing arm(chain stays) or interfering with anything. Another big thing I didn't know was if the smaller front driven sprocket on the shift kit(standard size was too big and would hit the motor) would work well for my needs.

    I still don't know if I can get my led moped tail light to fit on the fender i have. I don't know if I can get the battery and electrical components that I have will work either. All of that is part of the fun for me. I really got lucky on this build. Not as many headaches as I thought I would have. Some things almost fit together as if the where designed by the same manufacture. Things went together almost like a factory build. Basically if pretty much anything motor wise was a 1/8th inch bigger or if the frame was 1/8th inch smaller it wouldn't fit! Things had to go together a certain way or else it wouldn't go. A lot of parts on and off. It was a puzzle many times. So far the juice has been well worth the squeeze. Everything is turning out better than expected.

    More to come soon. Stay tuned.
     

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