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I will look, but if all I can get is the 17x26mm O.D. bushing, than Bamm, still in business. As you said just have the outside turned down to fit what I need.
So if I want 1/8inch thick bushing, than I should do a 13/16 inch hole, might have to do 7/8" because of what drill bit is available to me, but I got your point Larry.
Any ideas about drilling the hole, do you really need to slowly increase the drill bit size until you get to the size you want ?
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Step drilling helps. Step up however whatever drills you have.
But the last step before finish should be barely less than finish size.
The lighter the cut and the sharper the finish drill is, the more accurate the final size.
So....twist drills typically are only good to +.005 tolerance.
In a machine shop you would step drill it up to .015 under size and then put a reamer through it.
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I was never told about it that way. If I get the larger tolerance in bushing size than a 3/4 hole will be undersized a little.
The brake support bracket is the hard one, not lot of room and all the bushings have large OD to them, so I will just get the bushing turned down to press fit into the bracket.
Enough work for the day.
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The bushing that is located in the caliper support bracket which rides on the 17mm axle.
Now I had planed on just drilling a 3/4" hole like on the rockers, but I see the rockers will need to be larger at 7/8" dia for the axle hole so I can use that larger bushings so I can ream it out a bit for the 17mm internal dia.
*** the question is how much bushing is truly needed on the support bracket ?
the 3/4" OD x 5/8 ID bushing will give me 2mm of thickness of material after I ream inside to 17mm dia.
This is close to 3 / 32 of inch thick bushing, shouldn't this be enough for the support bracket to roll on the axle ???
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If I am understanding correctly...your axle will be fixed, the only rotation will be the caliper mount itself, and it will be only a few degrees when the brakes are applied. A bushing wall of 3/32 would be fine , The main reason for the bushing is to avoid the undesirable situation of having steel on steel. Hoping I'm on the right track here?
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2 Attachment(s)
Going back and looking at the numbers......it look like my bushings are .125 wall
The main reason is that they are off the shelf items from any industrial hardware supplier. MSC, Granger, McMaster carr, ect.
[ATTACH=CONFIG]62334[/ATTACH]
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1 Attachment(s)
Also.....you keep saying "on the axle".
I am not sure what you mean there.
The axle for the wheel itself will not have any bushings on it.
The brake stay will be on a bushing that rides on the axle spacer.
I suppose you could make up the bushing as a replacement for spacer length. That way the stay would rotate on a fixed bushing. But I would not want brass as a spacer. Would prefer the axle be more solid tight.
Attempt a pic. But it is hard to tell the stay is on the od of axle spacer.
[ATTACH=CONFIG]62302[/ATTACH]
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I barely can see it, but I do see what you are talking about. I got it wrong from the start than as I thought it just road on the axle and that is why it needed a bushing in it, so the bushing wore not the axle or bracket.
This rim, rotor, and factory spacer out of the hub allows the support bracket to mount flush up against the hub spacer, this is in alignment with the rotor for caliper mounting.
I take it a thin friction shim should be between the hub spacer and the bracket, spacer is aluminum and bracket is 304SS.
I see if one long spacer was used, to cover distance between rocker and factory hub spacer, and if is press fit onto the spacer at the end, that would work, but my mind says I still should use a friction shim between things.
Oh, my mind is gone, a 3/4 OD and 5/8 ID, does not mean a 1/8 inch thick bushing, it is only 1/16th of inch thick on each side, duh...…………
So is that right size to use on the 5/8" shoulder bolts on the rocker arms ? or do we want the bushing to be 1/8th inch thick wall ??
If I got this wrong I have to change things up and go to 7/8" OD on the hole with the 5/8" ID, guess would not be bad as I have to do that up front for the axle hole, go 7/8" OD and have the inner reamed out to 17mm, that is if we want the thicker walled bushings.
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got it!....no part of the axle bolt 17mm diameter is exposed. Just axle spacers....true you must pivot the caliper mount on one of the spacers. I've got a drum up front, so reaction link to the bail, which I have since learned should be to the fork tube. maybe this winter...
Getting back to Andys mounting plate
are there any provisions needed to prevent side to side movement on the caliper mount?:confused:
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Let's get it started correctly.
The axle is 17mm dia. and is a fixed axle, meaning the rocker arm will have a set screw in it to hold the axle in a fixed position.
Rockers can collapse inward if spacers are not used, I will need spacers to keep the wheel hub centered on the axle.
side to side movement, well if brake stay was pressed on a bushing and that slides onto the axle and than the final spacer, the brake stay would be kept in it's location by the two spacers, and of course we have the reaction arm that will hold the brake stay from rotating to far.
So we use a press fit bushing on the spacer. The spacer will roll on the axle, if not, than the brake stay rolls on the bushing that is pressed to the spacer ? Or is it do to the fact that the spacers all push up against each other and this pressure keeps them from rolling around the axle ? so for this reason the brake stay must roll around freely on the press fit bushing on the spacer ?
If you press fit the bushing into the brake stay, than as the brake stay rotates a little the bushing rolls on the axle, not the steel brake stay...….that is what my mind has always seen, spacers on each side keep all in position and centered.
I say the question is which method gives the most free movement, eliminates the chance of binding...….and I think my idea or way, well is seems it could have more pinch or binding because more parts are involved.
but if you tighten up the axle bolt to much than spacers bind up on each other and my way is not freely moving.
I see if brake stay was riding the bushing on the spacer, well brake stay will still rotate on the bushing that is fixed to the spacer.
So if this is the case, I will need to drill a much larger hole for the large bushing.
17mm dia. axle, 19mm = 3/4", so that is a 1mm wall thick bushing.
So a 1" OD bushing with a 3/4 ID pressed onto a spacer that is 3/4" OD with a 17mm ID, but the spacer has to be fixed so that the movement of parts are on the bushing and not spacer to axle area ?