TRX850 Adventure bike build

Discussion in 'Some Assembly Required' started by Homerb, Aug 7, 2011.

  1. itsatdm

    itsatdm Long timer

    Joined:
    Jun 19, 2004
    Oddometer:
    5,029
    Location:
    Nor Ca.

    The carbs and their inability to deal with all the altitudes was always a problem. An airbox is a good idea to make CV carbs work. They are susceptible to float height problems.

    They do not deal well bouncing around in high altitude either. I do not know the cure to that. Left me flooded at about 13,000ft.

    I also had periodic problems with hard starting and flame outs. It would just run out of gas in windy conditions. My fuel pump would run the battery down trying to get the vacuum pump to fill the bowls.

    A common fix was a low pressure electric pump off a early 90's carburated R6. You need a relay.
    #61
  2. Homerb

    Homerb Been here awhile

    Joined:
    Jun 24, 2011
    Oddometer:
    473
    Location:
    Toukley NSW Australia
    I actually fitted a Facet 1-4psi pump last week trying to solve the fuel starvation problem. Didn't use a relay though.

    Took the bike for its first long ride today. 350kms (220 miles) on dirt roads, back roads,main roads and freeway riding. Carby definitely sorted. Definitely need more padding in the seat, my arse is sore.:cry
    #62
  3. Homerb

    Homerb Been here awhile

    Joined:
    Jun 24, 2011
    Oddometer:
    473
    Location:
    Toukley NSW Australia
    Well after some months and a lot of miles on the beast ive had my first get off. A concrete causeway and some soft sand was my undoing. I also answered the question of whether I had enough engine protection, after I punched a hole in the alternator cover.
    A few days on the welder and Ive got some custom made engine bars. Also replaced the rear disc caliper with a unit from a zzr250 Kawasaki, and while its early days yet, there seems to be a definite improvement. Also had to beef up the sidestand mounting bracket.
    Bought some heated grips which Ive still got to fit before an overnight trip next weekend.
    #63
  4. Homerb

    Homerb Been here awhile

    Joined:
    Jun 24, 2011
    Oddometer:
    473
    Location:
    Toukley NSW Australia
    Well after nearly a year on the road and plenty of miles, the Beast is still a work in progress.
    Major problem has been the rear shock and linkage. The guy who built the frame builds roadrace bikes and sidecars for a living, and apparently applied the same principles to this adventure bike build. Problem is, he used a very nice roadbike shock absorber with about 45mm travel and built a custom linkage to achieve 200mm rear wheel travel. This resulted in a leverage ratio of approx 5:1. Ideal is 1.8:1 to 2.2:1. This meant I needed to run a 1200lb Eibach spring to get effective suspension with no bottoming out. The super stiff spring cooked the oil in the shock in a couple of months. It looks like the oil was overheated while trying to stop the shock snapping open due to the stiff spring.
    So I completely redesigned and rebuilt the suspension linkage. Then I refitted the original shock, minus the spring, and I've only got 100mm wheel travel. Clearly I need a new shock. A dirt-bike shock with at least 80mm of travel should do nicely. A quick visit to my local bike wrecker turns up a completely shagged 1981 Honda CR125R shock and spring. The shock has 85mm of travel, and the mounts and dimensions are almost identical to the original Technoflex unit. The shaft needs re-chroming and the rest of the shock needs rebuilding, but when fitted to the bike without the spring, I had 200mm of wheel travel! I'm hoping the rebuilt shock will arrive today so I can go for a ride this arvo!!
    #64
  5. bigalsmith101

    bigalsmith101 Been here awhile

    Joined:
    Sep 21, 2009
    Oddometer:
    933
    Location:
    Lake Stevens, WA
    We need a comparison photo of the roadbike shock versus the new shock that you plan to put in the bike.

    And a photo of your newly redesigned rear shock linkage.

    And a photo of the bike from the front.

    And, and, and! MORE!!!

    --Alex
    #65
  6. Homerb

    Homerb Been here awhile

    Joined:
    Jun 24, 2011
    Oddometer:
    473
    Location:
    Toukley NSW Australia
    Will do Al, damn shock didn't arrive today as hoped. As soon as it turns up I'll take some photos for you. Ps. Followed your ride around south america....loved it.:clap:clap:clap
    #66
  7. mudanddust

    mudanddust n00b

    Joined:
    Nov 27, 2011
    Oddometer:
    5
    this bike is awesome!
    #67
  8. Harvey Krumpet

    Harvey Krumpet Been here awhile

    Joined:
    Dec 26, 2011
    Oddometer:
    973
    Location:
    The Shaky Isles
    Why do I have a sudden urge to bastardise my TDM? :freaky
    #68
  9. SlipChip

    SlipChip Adventure Commuter

    Joined:
    Nov 28, 2006
    Oddometer:
    3,532
    Location:
    East of CleveOh
    Cant believe it has taken me this long to run across this build. Any updates?:deal
    #69
  10. Straightedge

    Straightedge Skin Donor

    Joined:
    Aug 24, 2010
    Oddometer:
    37
    Location:
    Bluegrass, near Louisville
    ^^ What Chip said.
    #70
  11. Homerb

    Homerb Been here awhile

    Joined:
    Jun 24, 2011
    Oddometer:
    473
    Location:
    Toukley NSW Australia
    Sorry guys, no updates. I sold the bike a year or so ago. I needed a new project. Had a couple since then.
    #71