Grinding Rims

[philking]

i think it actually can depend on your technique as well, as to which disc works best (Y)

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Good point,

and i was just wondering what people use technique wise... I mean i do strokes backward and fowards until the rim surface has been covered in that section. I think the sweeps i do are about 10cm and i try not to go over the same bit twice, and i have the grinder at about 45 degrees to the rim... Does all this sound ok cos i feel it is still hit and miss performance wise, as in sometimes the break is ace with a new grind and sometimes its poo!

Any other advise?

phil

[Janson]

Just give it some pasty.

Some pads don't work well on fresh grinds. Just keep riding and the brake WILL sort itself out.

[Mark W]

I just kinda push down pretty hard, and do single-directional sweeps over however long I think I need too. This grind was my first ever one, and it was with an old disk so it wasn't exactly harsh*. Managed to give a friend the good news in the eye with a tiny shard of metal too. "Not surprising" I hear you cry - however, he was about 8ft away taking the back wheel off my bike at the time.

I tried it with the metal grinding disk, and if you even thought about going over the same part it kinda smoothed it off for you. I'm gonna go for stone next.

*Unlike the pair of gouges I put in my practise wheel (an old Onza proto cassette hub laced onto DX-32) when I first did it. Brutal (Y)

[tank_rider]

i just literally brush over the rim surface with the grinder as close to 90 degrees as poss (in reality more like between 60 and 70). About 10 - 15cm strokes, and make sure all the rim has been got. Ive only done a couple but they have both turned out well.

As for holding the wheel, i put it on the floor, put one foot on the rim to steady it, then grind the opposite bit to where im standing.

[Wayne-king]

i just literally brush over the rim surface with the grinder as close to 90 degrees as poss (in reality more like between 60 and 70

As for holding the wheel, i put it on the floor, put one foot on the rim to steady it, then grind the opposite bit to where im standing.

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yeh, same as me (although i find grinding close to the 90 degree mark a bit sketchy! (Y) )

[Savage]

This has probally been said before, but -

I find it helps to lay your wheel flat on top of a small bucket. As you grind the the rim bounces on the spokes and gives a deep even pattern. I always try for 90 deg. to the rim.

Ben.

[Grant Peters]

Thinking about it the direction in which you grind the rim; if you grind at an angle less than 90 degrees might make a difference to the performance.

If you ground your rim at 45 degrees for arguments sake then would could you get a better bite form the brake if you ground the rim non drive side anti clockwise and the drive side clockwise?

To explain my thinking: the surface of the rim if ground like this could potentially leave more agressive edges for the pads to grip

ie. insert crap picture (pads)

If the rim was ground the other way round the surfaces that the pad would be able to grip on would therefore possibly not be as harsh?

Just a thought, and as you can tell form the diagram im just bored at work and wondered if it would make a difference?

90 degrees makes the most sense,

The rim in the crap picture is rotating to the left, therefore the pad would be the drive side

pads.bmp

[tank_rider]

grant, so long as you turn your wheel over and use the same technique on the other side you should have a great brake in both directions (Y)

[Will Arnold]

grant, your drawing is wrong (im prettey sure!) because surely 45 degrees to the rim would make it its sharpest. if you have it at 90 degrees to the rim then itll just be the top of the disk hitting it(which is flat, not pointy)

get me? or am i making no sence (Y)

Will

[Si-man]

I grind at a really shallow angle (<45deg) and it works well. 90 doesn't sound like it would make a harsh grind but different things work with different people

[Grant Peters]

WILL that "diagram" lol was of grinding at 45 degrees,

if "If the rim was ground the other way round the surfaces that the pad would be able to grip on would therefore possibly not be as harsh?" (from my other post)

then just take the pad as being the non drive side or left and the rim rotating to the right and you might get what i mean.

at 45 degrees the resultant edges left by the grinder should in theory make for a better grind, like shark skin smoothish one way but really rough the other...

[Will Arnold]

at 45 degrees the resultant edges left by the grinder should in theory make for a better grind, like shark skin smoothish one way but really rough the other...

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i think thats wrong, if its 45 + or 45- then itll make the 'snakeskin' effect but if its 45 degrees the itll be the same both ways(from the angle youve drawn your diagram

i think thats right, lolol.

Will