696 Headstock Bearings

Discussion in 'Monster' started by FatAlan, Oct 11, 2019.

  1. Hi all. Im just changing my headstock bearings on a monster 696. Getting the lower bearing race off was unpleasant but now done.

    When it comes to installing they seem super tight on the bottom race. Is there any recommended way to get these to fit square on the shaft? I dont fancy beating some bearings on only to find they have to be removed again.

    Thanks,

    Alan
     
  2. Never done it but I would try freezing the bearing to make it as small as possible - then heating the head-stock to make it expand. I expect that you can't use a blowtorch because of the proximity of wiring and possible paint damage so a hair dryer if you don't tell your lady... Or hot towels!
     
    • Like Like x 1
  3. Agree with PerryL.

    I've done a few now and I put the new bearings in a plastic bag in the freezer overnight (inside their packet to reduce condensation - not sure if this makes any difference whatsoever, but it makes me feel better :)).

    Make sure the headstock is clean and grit free. Now you have to work fair quickly, a smear of grease/oil to the inside of the headstock to help matters along. Pack the bearings with grease and another smear on the outer faces.

    Next I use a heatgun directed evenly over the inside of the headstock and get it really hot, then using the old bearing as a drift or a flat, chunky piece of timber, knock the bearing home with a hide or dead-blow hammer.

    It's very important to keep the bearing square to the bore, if it twists it can jam and your in trouble. A couple of light taps to start till it 'grips' and then it's preferable to strike it firmly a few times rather than lots of little taps.

    Always ensure that your old socket or whatever your using, puts the force on the outer edge of the new bearings, not the centre. Of course, if your using the old bearing or a lump of wood, the the force should be distributed evenly in anycase, just make sure it doesn't slip sideways.

    Sounds a lot more difficult than it is, just approach it with confidence and have everything readily to hand before you start.
     
    • Like Like x 1
  4. If you are trying to get a bearing on the steering stem then you need the stem cold and the bearing warm so that there is the maximum differential in temperature between the two, stem in the freezer and bearing in the oven at 100 degrees C for half an hour. You will have less than 2 minutes work time and as soon as they are in contact with each other the temperature differential changes quickly so all tools ready to start as soon as they come out of freezer /oven.
     
    • Like Like x 1
    • Agree Agree x 1
  5. In my experience they almost fall on using this method with just a little persuasion to seat the bottom race home fully. Worth also just checking that there are no scores/scrapes on the stem from removing the old bearing, remove any such with emery /wet and dry.
     
    • Like Like x 1
  6. Looks like I have tomorrow planned then :). Hopefully its a straight forward operation. I have done these before (on a GSXR) but the removal and replacement were pretty straight forward and less hammering was involved.
    Will update you all tomorrow.

    Thank you!
     
  7. Put the yokes in the freezer.
    Bearing races in the oven.
    You will still likely need to tap them on square.
     
    • Like Like x 1
  8. And don't forget about the washer/spacer under the bearing if it has one there! DAMHIK!
     
    • Face Palm Face Palm x 1
    • Useful Useful x 1
  9. Well.. I have a confession to make. After damaging one set of bearings and having to buy another set where I then installed the race upside down (yep, I did that.. the shame..) I decided to hand it to somebody else. Gunster Racing in Grimsby did the honours.

    I probably shouldn't admit to doing something so stupid publicly but I wanted to put a warning for anybody else doing this. In addition to Laavas warning of ensuring the spacer is there always make sure you fit the race the right way round.

    Thanks everybody. So, to conclude - freeze the stem, heat the bearings and they go on with relative ease. They are a nightmare to get off - Cutting them off was the route I used but this was quite destructive.If you are rushing things will go wrong. Arm yourself with good tools.

    I'll go to the corner and hang my head in shame.
     
    • Like Like x 1
  10. Don't worry about it Alan, we have all done some stupid things to our bikes in the past.
     
    • Like Like x 1
    • Agree Agree x 1
  11. Apologies all, just re-read the OPs post and realised that he was talking about the bearing on the steering step itself. I locked on to the races part and went on to describe how to fit races IN TO and similarly bearings IN TO a recess. In these cases, freezing the races/bearing and hearing the housings to obtain maximum clearance is correct.

    However, as several others have correctly pointed out, if you ar fitting bearings ON TO a stem, then the reverse applies to obtain maximum clearance.

    Don't worry about admitting stupid mistakes publically, I've just done it too, sorry all :blush:
     
    • Like Like x 1