TRX850 Adventure bike build

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

  1. Homerb

    Homerb Been here awhile

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    Now this is a beast!!
    <!-- #dg-post-title --> <!-- message --> I've been watching and loving this thread for a while now, and finally decided to get off my backside and post some pics of my latest project. First some history. Some years ago I bought a Yamaha TRX850 road bike off a mate and absolutely loved the thing, especially the motor, except I'm a dirt biker at heart, and the riding position aggravated an old wrist injury, so I sold it to buy a dirt bike.
    Fast forward a few years, and this puppy comes up on ebay and I buy it for just over $1100. Ugly as a hatful of assholes, with 17 inch front and rear wheels, with a badly fitting seat and the tanks been reshaped by a blind man with a large hammer!
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    #1
  2. Homerb

    Homerb Been here awhile

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    It actually started out like this.
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  3. Homerb

    Homerb Been here awhile

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    So since I've had it I've replaced the wheel s with spoked 17" and 21" wheels off a KLR650 Kawasaki. Was given a KLR650 rolling chassis so fitted the KLR forks as it made it easier to fit the KLR wheel. Used the KLR calipers after rebuilding them, and fitted the KLR front master cylinder as well.
    Its looking a bit more like an adventure bike now. Next need to strip and paint the frame, fit the KLR headlight and rear guard. Hardest part is going to be finding a tank and seat to fit that doesn't look like a dogs breakfast.


    I'd appreciate any tips/suggestions the folk on here might have.
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    #3
  4. Homerb

    Homerb Been here awhile

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    Update on my TRX850 based adventure bike

    Decided to remove, check and clean the carby's. PO had removed the hot water pipes from the carbys, and disconnected the drain hoses. After putting it all back together, and hitting the starter button......nothing. Short circuited the relay to the battery and turns over fine, just no joy from the button. Suspect its the starting circuit cut off relay, but as the PO has removed the clutch switch, sidestand switch and neutral cut out switch I'm buggered if I know where to start. Ended up running a new wire from the starter switch block to the relay. Voila, success. Have to run it through the ignition switch when I fit it but should work OK. Put battery on charge overnight as I flattened it testing the starting circuit. Hook it up this morning and not enough grunt to turn the motor over. Bugger it, off to the bike shop for a new battery and $70.00 later she's purring like a kitten. Dying to take it for a spin, but its bloody raining again.

    Suppose I could go and fit the headlight, rear guard, taillight and indicators but its freezing in my garage and I'm nice and warm in front of the heater at the moment......theres always tomorrow.
    #4
  5. Homerb

    Homerb Been here awhile

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    Well the TRX build has being making slow but steady progress. I got to the stage where I had to sort out the tank/seat dilemma before I could move on. So, chucked the bike on the trailer, and drove1.5 hours to Metropolitan Motorcycle Wreckers in Silverwater, Sydney. The guys there were really helpful. Let me try a number of tanks on for fit, starting with a yamaha FZ6, looked OK but tank was too long, then a TDM850, no good, then a TRX850 again too long. Now I know why the builder shortened the original tank. Then one of the guys suggested trying a tank off an XJ6 Yamaha. Bingo! Looks great, fitted pretty well, and schmick paintwork and a nice red that I'd be happy to leave as the colour. Result. 17 litre capacity isn't too bad either. Tank didn't include the filler cap but whern I got home discovered the original TRX cap will bolt right in. I'll have to make a plate to bolt over the hole in the bottom where the fuel pump lived, but that's not a big hassle.

    Then to the seat. Tried a few different seats without success before trying the seat of the XJ6 were the tank came from.Looks pretty nice, if a bit thin, But most importantly, its a perfect fit up against the tank, and the length is good. If need be I can get the seat re-padded with more foam, or fit a sheepskin or an Airhawk for more comfort.

    Well anyway I'm really happy with the result. Now to repaint the frame silver, the swingarm black, and the headlight surround to match the tank, and fit black guards and I'm nearly done!!!

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  6. dolomoto

    dolomoto Destroyer of Motorcycles

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    I've got a few miles on a TRX850...great motor...same as the TDM, I think but with a different crank and firing order.

    That would be a beast off road! Well done!
    #6
  7. Homerb

    Homerb Been here awhile

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    Hi Dolomoto, yeah the TRX/TDM motors are the same. The earlier TDMs, pre 96 I think, had a 360 degree crankshaft. When the TRXs came out in 96 they had a 270 degree crankshaft to give it that V twin sound. I think the TDMs went to the same crankshaft about then too.
    #7
  8. Homerb

    Homerb Been here awhile

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    Well, picked up the frame today. Looks good. Have to finish painting a few engine bits and then to start reassembly.
    Let the fun begin.

    Attached Files:

    #8
  9. Qwik

    Qwik Adrenaline Addict

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    Great looking project. does the exhaust pass through the tube on the frame?
    #9
  10. Homerb

    Homerb Been here awhile

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    Yeah it does. Not really sure why it was designed that way.
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  11. Homerb

    Homerb Been here awhile

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    Engines in and its all going together slowly. Like the red and black colour scheme.

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  12. Bambi

    Bambi Been here awhile

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    Hello Homerb,
    could it be, that there's the fork of a Suzuki DR 750/800 in it? Not too bad, but if I'm right, it might be tricky to beaf up the front-brake for an engine with a power-output like your's ...
    Kind regards, Bambi
    #12
  13. Homerb

    Homerb Been here awhile

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    Well spotted Bambi, the forks are actually out of a 1991-1993 DR650. I'm hoping to use a four pot Brembo caliper and a 300mm disc on the front end. Hopefully this will offer enough braking, or else I may have to go to a twin disc front end.
    #13
  14. MODNROD

    MODNROD Decisions, decisions

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    Front brakes were the 1st thing I thought of too, I have to admit. Never had one personally, but have heard a lot of owners complaining about the brakes on that bike when standard, and your weapon is a fair bit heavier.

    Perhaps the DL650/1000 stuff will bolt in? A lot of that stuff interchanges. Don't they have twin 280/300mm discs and good Nissin 4-pots?
    #14
  15. elephant man

    elephant man Adventurer

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    nice build!
    why dont you try and fit a complete front end from a super tenere 750?
    twin discs, 43 mm and it will accept an fzr1000 front wheel...
    #15
  16. Homerb

    Homerb Been here awhile

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    I'd love to elephant man, but very few XTZ750s were sold in Australia, and used parts are even rarer. Theres a number of other twin disc 21inch front end I could use; Triumph tiger, yamaha xtz660, etc. Its just a matter of waiting for something decent to come up on ebay, or at auction etc.
    #16
  17. notaduc

    notaduc Adventurer

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    This is great!

    I just got a TDM 850 motor and am looking to build a frame similar what you have done with the TRX frame here. Ill be watching closely! Any photos you have will be great inspiration....

    Good work.
    #17
  18. notaduc

    notaduc Adventurer

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    Oh, what exhaust header is that? Is it the stock TRX?
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  19. Homerb

    Homerb Been here awhile

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    Hi Notaduc, no that exhaust isn't stock, it was built by the previous owner. The frame is heavily modified too. The stock trx frame looks a lot different.

    Attached Files:

    #19
  20. notaduc

    notaduc Adventurer

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    Yea, I have been studying what I can find on the TRX frame, I dont want to duplicate it, just make something actually more similar to what you have. That TRX project blog is amazing btw...
    #20