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Suspension questions

Thread: Suspension questions

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  1. Alexd's Avatar

    Alexd said:

    Suspension questions

    Hi All. Finally put the bike together. Took few rides, rear shocks leaking, found a post about replacement but front end is little bouncy, I had forks apart, cleaned everything put new seals and 15 wt fork oil using manual for capacity. Could it be too heavy oil? I’m not a little guy around 240 lbs, so figured heavy oil should be better.
    1978 CB 400 T2 Hawk
     
  2. longdistancerider's Avatar

    longdistancerider said:
    15w fork oil is about as high as you want to go. I'd replace the rear shocks before doing anything else.
    https://www.tecbikepartsusa.com/TEC_...20-hcb400t.htm
    Jim O'Brien
    1979 CM400T "road bike" modified for travelling
    1978 CB400T1 restored
    1972 CL350 survivor restoration


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  3. Alexd's Avatar

    Alexd said:
    Thank you. That is what I figured to start with. Ordered new shocks from davidsilver
    1978 CB 400 T2 Hawk
     
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  5. Alexd's Avatar

    Alexd said:
    Got new shocks, rear feels better but front end still bouncy almost like a pogo stick feeling. Not sure what is causing this. New neck tapered bearings, no play in them, new tires with new tubes and balance beads in the tubes.
    1978 CB 400 T2 Hawk
     
  6. longdistancerider's Avatar

    longdistancerider said:
    Is the pogo effect speed related? I had a pair of tires that were causing this effect at 20-40 mph, after fighting thru everything on the suspension over 10K miles I finally tossed the almost new tires. No one could find any defects visually in the tires
    Jim O'Brien
    1979 CM400T "road bike" modified for travelling
    1978 CB400T1 restored
    1972 CL350 survivor restoration


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  7. 66Sprint's Avatar

    66Sprint said:
    Time for your "slightly off-center sprocket" story Jim.......
    Last edited by 66Sprint; 06-13-2019 at 12:00 PM.
    "I have a mind like a steel trap.....Old and rusty, of antiquated design, and hard to get stuff back out of...."
    Contact info: E-mail; [email protected] Phone; 540-525-5199
     
  8. ancientdad's Avatar

    ancientdad said:
    I'd like to hear it, for sure
    Tom

    Ride along at the drag strip - https://www.youtube.com/watch?v=20jFPazXlvU



    running points... because I'm too old for mysteries that begin with pushing
     
  9. Rscottp's Avatar

    Rscottp said:
    Did you measure to fork springs to see that they are still in spec?
    1981 Honda CX500D
    1974 Honda CB450
    1986 Yamaha Radian 600

    Martha's Vineyard Ma
     
  10. Alexd's Avatar

    Alexd said:
    No I will have to look into how to do that
    1978 CB 400 T2 Hawk
     
  11. longdistancerider's Avatar

    longdistancerider said:
    Quote Originally Posted by 66Sprint View Post
    Time for your "slightly off-center sprocket" story Jim.......
    My $1000 front sprocket??? Moral of the story. Never buy that "good deal" of unknown manufacturer. In this case a front sprocket a local shop had laying around.
    In 2014 I had gone thru the road bike completely prepping it for another cross country tour hitting the remaining lower 48 states I missed in 2011. Bearing, brakes, chain, sprockets, tires, Ignitech ignition, carbs, suspension, etc. Everything new or rebuilt. Shortly after taking off I encounter a pogo effect in the front end at 20-40 mph. Did a number of changes with fork oil, air pressures, shock settings, head bearings, etc on the road over the next couple of months trying to cure it. Even had a Metzler tire rep inspect the tires, had new ME888's on it. Probably had 30 different people look at it and offer suggestions. Then I hit Tail of the Dragon again and got bitten one more time. I suddenly got a snapping banging feel from the rear and stopped, only to find that the rear sprocket had come loose from the wheel. Actually the hub was worn away so the giant circlip came off.
    Suspension questions-10460725_10202421801281432_1601429618875553063_n.jpg
    Suspension questions-201_6474-001.jpg
    So my best friend that lives in WV dispatched his son to pick me and the bike up in Ashville NC and get me north to his home/shop in Martinsburg. Fedex'd a spare wheel, axle, axle adjusters, brake plate from home, Redding CA. Son in law works for Fedex so cheap shipping. Local ordered new rear sprocket and chain, front looked good. Figured that was the cause of the pogo but no, it remained. Took off headed north and east, turned around in St. Johns, New Brunswick, Canada heading west. Made it to New Hampshire when I discovered the sprocket coming loose again. Rental truck used all the way back to Martinsburg WV, most of that $1000. Saved the wheel this time. Another rear sprocket and chain. Focused on why this was happening and started paying real close attention to the front sprocket. That's when I found the center was not centered, running elliptical and that the tooth section was mis-machined as well. Thick on one side causing the chain to tighten and thin on the other relaxing the chain.
    Suspension questions-201_6699-1-001.jpg
    Now it should be noted that I religiously lube my chain every 300 miles of 2 tanks of fuel and adjust as needed. lube was typically done with the side cases on so the rear sprocket was barely visible.
    Even the front sprocket didn't fix my pogo effect. Eventually while riding in Michigan I decided to toss the almost new Metzlers. Found a shop in Illinois that had a set of Michelin Commanders and instantly the pogo was gone.
    Now for those that ask "Didn't you hear anything weird before the 1st failure?" I've been mostly deaf since 2004 until last year. So no I didn't hear anything. Now with the 2nd Cochlear Implant done 3 weeks ago I'm hearing all kinds of things.
    Jim O'Brien
    1979 CM400T "road bike" modified for travelling
    1978 CB400T1 restored
    1972 CL350 survivor restoration


    https://www.hondatwins.net/forums/22...d-attempt.html and https://www.hondatwins.net/forums/1-...r-attempt.html
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