Yamaha Neos 50cc build

Discussion in 'Scooter Projects' started by BunnyMum, Jan 23, 2017.

  1. BunnyMum

    BunnyMum Active Member

    Messages:
    191
    right, so the re-tapping the air-shock seems to have worked, it now accepts 1/8" BSP fittings nicely, and no swarf in the cylinder. win!

    The plastic case for the air pump arrived and in test-fitting I broke a little fitting off the air pump (where the old pressure gauge went), but it left a teeny hole which needed filling, so I'm waiting for araldite to set on that. Fortunately it wasn't vital and I've already got another pressure gauge in the setup which should give me the current tank pressure, which is what I'm most interested in.

    20170722_185342_www.jpg

    Hopefully though, that means the air system *should* now be complete "end-to-end" which means once I get the pump mounted in its case I should be able to pressurise the prototype of the setup and see whether the air part of it might actually work. If it holds air I can build the electrics side of it.

    and here's the 3rd part of the catchup video...

     
  2. BunnyMum

    BunnyMum Active Member

    Messages:
    191
    some more thread cutting bits arrived and it looks like with those I've been able to consolidate all the threads in the air system to use bsp rather than a mix of bsp/npt and [unknown]. The pump also looks good so I think once I've gone through and sealed all the pipe joins I can actually pressurise the system and see whether it might work, hold air etc etc \o/

    Also the bends and straight pipe arrived to hopefully let me finish up the fairing bars and the main structure of the bike. Lots to do over the next few sessions :cool:
     
  3. BunnyMum

    BunnyMum Active Member

    Messages:
    191
    just sealed and connected up the air system in my test configuration to see whether it holds air and whether the pneumatic ram is anywhere near suitable/strong enough to suspend the bike etc. The compressor I'm using on the bike doesn't have a box yet so I'm just powering the system from a small spray gun compressor.

    The good news is that it does actually work, exactly as hoped, perhaps even better than...when does that ever happen?

    The system holds air, and the one way input valve works to the extent that you can disconnect the supply hose and the system stays pressurised. I'm doing a leakdown test at the moment since I guess the air will seep out eventually, but that needs to be a matter of hours not minutes.

    [edit] Leakdown test shows loss of ~10psi over 1 hour for the overall system, which is way better than expected. Just the part with the ram may leak more quickly, especially given there will be movement of the ram and inevitable losses from that, but that will get automatically topped up from the system/reservoir.

    The air cylinder's (pneumatic ram) movement is very strong, tbh it's probably a little too violent currently so will need to add a restrictor so that airing up and down is a bit more gradual rather than just throwing the bike into the air or dropping it on the deck instantly. If I try and push the ram back in (e.g. push it onto the floor) when pressurised I can barely make it deflect, and that's at ~50psi, not the planned 100.

    I reckon the actual "height adjustment" will be a pressure regulator like from an air compressor so you can set a target psi for the ram to maintain, and it just tops up seamlessly from the reservoir as it needs it (as you ride). When the reservoir pressure drops the pump kicks in and tops it up.

    Currently the only issue I have is that I'm testing it on 50 psi which seems like more than enough pressure, but the pressure switch which is supposed to turn the compressor off only kicks in at about 100psi. it's looking like 100psi is way overkill so I'll probably need to source a replacement pressure switch which cuts off lower, or ideally is adjustable. I'm going to see how it is on the bike first though since adding the weight of the bike into the mix may mean 100psi is actually where we need to be.

    On the upside, if the system works well on a lower-than-spec system pressure, that's a really good thing since it means the electric compressor wouldn't have to work as hard to power the system, and that was something I was concerned about since it uses electricity and is potentially quite noisy too (not that you'd hear it over the engine but still).

    Next I need to build the compressor which is going on the bike (a former portable tyre compressor) into a box to protect it from the elements and reduce the noise. I also need to re-tap the threads on the actual ram I'm using on the bike too so that it can use the fittings i have. I re-tapped a smaller (cheaper) one of similar design in case it didn't work..but it does. I need to make a little bit of wiring too but then we should be able to actually test it on the bike.

    system as it stands. used a compressor to pressurise it here
    20170730_154900_www.jpg

    holding at 50psi :)
    20170730_154927_www.jpg

    if this works I'm so going to have to test it on a car project too ;)
     
    Last edited: Jul 30, 2017
  4. BunnyMum

    BunnyMum Active Member

    Messages:
    191
    next build video - stretching the frame. it's playing catchup to this thread but that's the last one, future videos are up to date.

     
  5. BunnyMum

    BunnyMum Active Member

    Messages:
    191
    Testing the air suspension...

     
  6. waynesworld

    waynesworld Member

    Messages:
    120
    Looking good can't wait to see it done
     
    BunnyMum likes this.
  7. BunnyMum

    BunnyMum Active Member

    Messages:
    191
    Been waiting on a 1-way valve for *weeks* now...normally this stuff arrives a lot quicker but this one is taking forever. I liked the one I already have though so re-ordered from the same place but for some reason it didn't work out this time. Just gave up today and ordered an alternative/replacement from the UK so can hopefully get back on with this project.

    I also managed to injure my hand (4 separate injuries on 3 fingers) which meant I couldn't do anything physical for a few weeks...has been doing my head in, esp as it meant I couldn't type (which I have to do for work). I spent a week or two ignoring the injuries but that only made them worse to the point where I thought it may become a serious problem. Then I got pissed off and fashioned a sort of "finger armour" out of some ali pipe which helped massively and allowed recovery. Fingers are mostly healed now so as soon as the new valve turns up I should be able to get back to the important things in life!

    *frustrated* :(
     
    scubabiker likes this.
  8. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    6,635
    Uffda. I know how that is.
    Duct tape works great as splints.
     
    BunnyMum likes this.
  9. BunnyMum

    BunnyMum Active Member

    Messages:
    191
    ok so did some more testing with a different air pump - not sure exactly why but didn't seem to be able to hit the sort of pressures I'd need (with that arrangement), so for the moment I think I'm going to shelve the air-ride idea and just get the bike finished. I may revisit the air thing later with a combination of normal shock (to take the bulk of the load) plus air to adjust ride height...perhaps with soem sort of cantilever type thing. Or not.. dunno.

    At the moment though it's additional complexity and is holding things up. The shock is normally much more upright but with the stretch it's more like at 45deg so I don't think the oem one will be sufficient, but I think I've found a shock from a larger bike which should mean the flatter shock angle shouldn't be a problem. Waiting to hear back from the supplier but will post pics once it's figured out :)
     
  10. BunnyMum

    BunnyMum Active Member

    Messages:
    191


    So the air ride sorta worked but I wasn't happy with the reliability, and that's not something I'd want to fail at speed.It was holding up the rest of the project so I decided to go with a regular shock on the back for the time being and come back to the air later.

    As it turns out because of the shallower angle (due to the stretch) a stronger shock was needed, and I ended up doubling up with a longer shock from a Yamaha Vity 125 as well as the original NEOS shock. The first mount I made wasn't great and it rode too low under load so this video is about re-building the shock mount & rear suspension setup.
     
  11. BunnyMum

    BunnyMum Active Member

    Messages:
    191
    Now that the rear suspension is sorted I was able to figure out the positioning of the exhaust. Obviously with adding offset and the wider wheel the exhaust needed a little bit of "editing" to clear the wheel. Was a bit nervous about messing this up but it actually went ok.

    I'd wanted to tig weld it for maximum neatness but when it came down to it I couldn't be arsed to drag the welder, gas bottle etc out so just did it with the mig. Not as tidy but works just as well and took 10 mins instead of 10 mins plus 2 hrs setup/breakdown ;)

    I dare say extending the pipe will change the characteristics of the exhaust somewhat but I don't have a whole lot of choice in the matter since it wasn't gonna fit as it was.

    After doing the rear suspension last session I sorta didn't really have time to thoroughly test how it actually sits with rider weight on it and was a tad worried it was riding too high, but it's actually spot on. The rear arm sits pretty much bang on level with my weight on it, which I'm very pleased about.

    Now that the rear suspension and the exhaust are sorted I can mock up the rest of the pipework which will extend the fairing bars rearward and provide the rest of the foot platform/"floor", which will ultimately get checkerplated over and should visually tie the front and rear fo the bike together.

    With not having the air gubbins to house I've ended up with a bit of an empty space in front of the engine which i was trying to avoid, but as yet I haven't got anywhere to put the battery, so that might be a good home for it, perhaps with some sort of sheet-metal undertray if needed. It could be that the extended fairing-bars will eliminate that space but if not some sort of battery protection tray thing should do the job.

    Last pic, new cheeky addition to the collection ;) (just for riding, not taking apart!)

    20171104_152330_www.jpg 20171104_152314_www.jpg 20171104_134927_www.jpg 20171014_133337_1024_www.jpg
     
    Last edited: Nov 5, 2017
    scubabiker likes this.
  12. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    6,635
    Gpr50?
     
    BunnyMum likes this.
  13. BunnyMum

    BunnyMum Active Member

    Messages:
    191
    the other bike? yamaha r125 :)
     
  14. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    6,635
    Ah yeah I see it as that now.
     
    BunnyMum likes this.
  15. BunnyMum

    BunnyMum Active Member

    Messages:
    191
    had a couple of productive afternoons this weekend, made a little extension tube/inlet thingy for the carb so it doesn't foul the stretch frame anymore, had to extend a few of the hoses (meant taking the stator apart to get to the oil hose). Also fitted the longer throttle cable off some random quad (which is a bit long now, but works). Got her running though. Even managed to sort the pissing petrol everywhere issue - scubabiker called it, was a sticky float valve :cool:

    It seems to run fine on the extended exhaust and actually runs pretty well now.

    Hopefully the extended rear brake cable should be here in the next day or two and then we pretty much have full functionality which means I can finish up the fairing bars, add the battery box, and then we should be not far off paint and whatnot.

    20171126_144439_www.jpg
     
    scubabiker likes this.
  16. scubabiker

    scubabiker NITROJUNKIE

    Messages:
    6,635
    Its not about length but how you use it?
     
    BunnyMum likes this.
  17. BunnyMum

    BunnyMum Active Member

    Messages:
    191
    apparently so :p
     
  18. BunnyMum

    BunnyMum Active Member

    Messages:
    191
    we have rear brakes \o/

    I ordered an extended 84" brake cable for a gy6/ruckus from Drowsports in the usa, and apart from having to slightly reduce the diameter of the collars which fit in the brake lever case and the bit where the rear brake locks to the swingarm, it fits perfectly!

    now i just need a day when it's not chucking it down or snowing and I'm up early enough so that i can get into the fairing bars at long last.

    It's coming up to a year since i bought the bike too - been a bit of a learning curve, that's for sure. Fun tho! :cool:
     
  19. Werewolf197441

    Werewolf197441 New Member

    Messages:
    4
    What size square tubing did you use?
     
    BunnyMum likes this.
  20. Werewolf197441

    Werewolf197441 New Member

    Messages:
    4
    Also is that 18 inches from the front mounting holes to the engine mounting holes?
     
    Last edited: Jan 21, 2018
    BunnyMum likes this.

Share This Page