Rim Grinding

[12ozrebel]

Hey All,
This is a total beginner question and I didnt feel like asking in that forum.
A had a comp yesterday "Sunday" and it RAINED all day, but I put what I thought was a nice grind on my rim. The next morning warming up for the comp I slowly started to lose braking and I looked down at my rim and my rim was smooth like I didnt grind it at all.So, what gives? Is it the type of metal the rim is made from? Is there a certain disc for the grinder to keep a grind for more than 15 minutes? Trying to convince my ol lady that dics is they way to go considering how much they are is going to take some time. Any help or guidance would be great.
Thanks,12oz:blah:

[johnglazer]

Make sure that it is a new grinding disc, otherwise the grind will not last.
Some people prefer to use a cut-off disc or a masonry disc.
Watch the instructional video that is in the video section to make sure you are grinding at the right speed/angle. (i'd post a link but for some reason it won't let me access the video section)

I grind my rim maybe once a month, probably closer to every other month or so. I'd probably grind more often if I didn't have coust pads...

[rush]

Definitely a new disc. Ive used ceramic cutting discs, metal cutting discs, and normal grinding discs. It really only takes maybe 4 grinds until the disc is too worn to put a good grind on.

[aki]

What type of rim & brake pads do you have? Echo/DX32 will last longer for grind than Try-All/BT though they do weigh more. Aside from having a new disc to grind, it depends on the type of grind you're putting on.

Also each brake pads are designed specifically for certain type of rim surface. You can't throw a sharp grind on Rock green's and expect to work better than Rock blue's. It almost sounds like you either have a harder compound brake pads and/or threw a fairly light grind on it.

[music_maj_34]

Does it look anything like this? Your grind should last a lot longer than 15 minutes. Maybe your just being to cautious and your grind is not heavy enough?

http://biketrials.com/iB_html/uploads/post-1-46424-Picture_040.jpg
__________________

[tubender]

I experienced exactly the same thing, with a whole different set of mistakes.
(1) got MOE pads, liked them fine but always used a pretty light grind.
(2) riding buddy got yellow pads, used a deep grind and destroyed them in 10 mins.
(3) I used the same (yellow) pads with no grind (great) then with tar (awesome)
(4) it rained, I went back to MOE, but skimped and didn't change the grinding wheel and the grind really never "took" to working good.
(5) killer grind yesterday, back to great.

I brought a grinder with me to the comp but didn't identify the issue till it was too late.

[caleb1978]

Did you use a cut off wheel to grind that rim? That looks very harsh to me. Is that what you would call that, or is that the normal grind you run?

[music_maj_34]

Did you use a cut off wheel to grind that rim? That looks very harsh to me. Is that what you would call that, or is that the normal grind you run?

Not sure what you mean by a cut off wheel? It's actually not my wheel, but I found a pic of a rim that looked very close to how I run my rims. I don't believe that it is too harsh at all. In my opinion it's a perfect grind. I think the close up picture just makes it look that way.

And believe it or not I don't go through brake pads fast at all. I use the yellow plasmatic brake pads that have lasted all season so far.

[BootsRiley]

If you dont have access to a grinder are there any other methods to grind a rim?

[full_clipp]

ohhhhhhhhhhhhhh yessssssssssss theeeeeeeerrree arrrrrreee,

pm user Kimosabi (http://www.observedtrials.net/vb/member.php?u=6306) for more details

[FDS2223]

If you dont have access to a grinder are there any other methods to grind a rim?

You can get one at walmart for like $30.

And does anyone have a working link to AndyTs video? When I clicked on it in the video section it said it was no longer available.

[jak442]

Not sure what you mean by a cut off wheel?
A cut-off wheel is the skinny kind, made for cutting things off using the edge of the wheel. As opposed to a thicker(about 1/4"+) grinding wheel, which is made for grinding things down with it's flat side.

I have been curious about this too and info seems hard to find. Cut-off wheels would be swell since they're cheap and the fine edge makes more sense for getting sharp edges to your grind.

Of course..... I don't see why you couldn't get a similar result with some 40-60 grit and a sanding block. A short stroke in one direction should do the job nicely. Could be wrong though.... think I'll give it a shot.

And here:http://www.youtube.com/watch?v=iAtdLzUZyT0 by the way.

[music_maj_34]

A cut-off wheel is the skinny kind, made for cutting things off using the edge of the wheel. As opposed to a thicker(about 1/4"+) grinding wheel, which is made for grinding things down with it's flat side.

I have been curious about this too and info seems hard to find. Cut-off wheels would be swell since they're cheap and the fine edge makes more sense for getting sharp edges to your grind.

Of course..... I don't see why you couldn't get a similar result with some 40-60 grit and a sanding block. A short stroke in one direction should do the job nicely. Could be wrong though.... think I'll give it a shot.


Oh.. I thought he was talking about the wheel off my bike. Never mind.

The only problem I see with using a cut-off wheel is that the rim is only so thick, plus... if it is a cutting tool I'm assuming that it is going to cut clean and not leave a rough surface like you would get with a grind.

Even with a regular grind, you can only get so many grinds with your rim before if would start to weaken and need to be replaced. (or ride it till you destroy it)

You will definitely not get anywhere near what a grind will do for your rim using sandpaper. I used a dremel tool once before I got a grinder and it still was no where near how well a good grind works.

It only took me one good flip onto my back after my brakes failed to make me re-think how much I needed to grind my rim.

[johnglazer]

Oh.. I thought he was talking about the wheel off my bike. Never mind.

The only problem I see with using a cut-off wheel is that the rim is only so thick, plus... if it is a cutting tool I'm assuming that it is going to cut clean and not leave a rough surface like you would get with a grind.

A cut-off disc is exactly the same thing as a grinding disc, but thinner, so the only difference is that while it will wear down quicker, it will not get as rounded as a grinding disc, meaning that you can get more good grinds out of it.

Also, since you are moving it along the rim and not holding it in one spot, it's not going to cut through the rim any more than a grinding disc.

grinding wheel, which is made for grinding things down with it's flat side.

no, you still use the edge on grinding discs. The sanding flap-discs use the flat side though...

[stocktrials]

I use a an alloy cutting disc (made for cutting aluminium)
It's by Flexovit, pretty common. It's blue :)

[BootsRiley]

You can get one at walmart for like $30.






Thats a lot of money right now. Anyone grind their rims another way?

[FDS2223]

No other way. Its like trying to feed Randy without store bought cheeseburgers.

[jak442]

Thats a lot of money right now. Anyone grind their rims another way?
I have a grinder and a cut-off disc or 5.... and I live in Wedgewood. You're more than welcome to come over and use it, just pm me if yer interested.

I'd kinda like to see someone else do it before I get after one of my wheels :ugh:

[rush]

ohhhhhhhhhhhhhh yessssssssssss theeeeeeeerrree arrrrrreee,

pm user Kimosabi (http://www.observedtrials.net/vb/member.php?u=6306) for more details

:bowrofl:

[[BMF] Chris]

in a few weeks people will stop grinding thier rims, word on the street that is...... so save your pennies instead of buying a ginder

[rush]

Chris;507924']in a few weeks people will stop grinding thier rims, word on the street that is...... so save your pennies instead of buying a ginder

:werd:

It will be tar again. Or plaz coating.

[[BMF] Chris]

or better.........

[jak442]

no, you still use the edge on grinding discs. The sanding flap-discs use the flat side though...

Damn I hate that word.... (sorry to get off topic)

I know I've only been workin with steel for about 20 years and it's been at least a week since I welded anything, but I'm still gonna have to go ahead and ask you to shove that "no" back up your ass, if ya don't mind.:nuts:

Granted I tend to angle the disc at around 5-10deg from totaly flat, but that's still about 80deg from the edge.

[stocktrials]

http://www.mytoolstore.com/makita/9558nb.jpg

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http://www.tartybikes.co.uk/images/large_atomz26r2.jpg

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http://s3.amazonaws.com/picable/2007/04/01/23186_Happy-Face--Moon-Face_620.jpg

/thread.

[johnglazer]

Damn I hate that word.... (sorry to get off topic)

I know I've only been workin with steel for about 20 years and it's been at least a week since I welded anything, but I'm still gonna have to go ahead and ask you to shove that "no" back up your ass, if ya don't mind.:nuts:

Granted I tend to angle the disc at around 5-10deg from totaly flat, but that's still about 80deg from the edge.

I know, I thought about that when I was typing my post, but I was too lazy to go into more detail. My point was that the part of the disc that is doing the actual grinding is not the flat underside. It is the outside rim, or edge, or whatever you want to call it, that is doing the work, regardless of what angle you hold it.
If all he meant was that you don't hold it perpendicular (or close to it) to the work, then yes, he is right.

[toyota200x]

I used a file to ruff up the surface of my rear wheel on my mod. It worked but now that I know how to grind I would just use a angle grinder with a cutting disc. My hand/arm was pretty exhausted after using the file.