Grinder And Grinding

[3dd]

Hello everyone. I have got a grinder at work which I use to grind my rim. Although I keep failing to get harsh grind, every time it seems very light. I tried grinding and cutting disc and no effect. Although it is 115mm 11000 rpm one. I have seen few that have bigger disc and lower RPM and even adjustable ones. Does it mean if rotation speed is lower it will give you sharper, deeper grind? These are the following I was thinking to purchase:

1 - small, but the speed is variable

2 - bigger diameter disc and adjustable RPM, although the handle seems a bit uncomfortable to grind rims? Am I wrong?

I also watched tarty rim grind guide, and they are using bosch one with 115mm disc but I seems a bit slower than normal grinders. I got a ground rim from them once and it had a nice sharp grind.

Any opinions?

Edited December 10, 2009 by 3dd

[DannyBazz (:]

It's all about technique.

If you hold the grinder at a shallow angle, and don't apply much force against the rim, it's gonna be a light grind. For a harsh grind, you gotta hold it at a steep angle, and push into the rim as well as going round, if you get me?

If you can get hold of some old rims/wheels, practice on there first

EDIT: Remember, new cutting discs are always better. And a thinner cutting disc is generally better, but a thicker grinding disc is better for harsh grinds. Only when new, though as after a while they go blunt.

Edited December 10, 2009 by DannyBazz (:

[Canardweb]

Hi:

I have been trying an awful lot of grinding of method on 6 different bike (all the people of my local club's bikes). Now the best one after 6 months of experimenting:

-Make sure you have a good clean rim (Also some rims hold the grind much better than others: for example DX32 hold the grind very well). If your rim is dirty, clean it with aceton. This is because my method does not remove material but just conditions the rim!

-Then, always leave the tyre on the wheel, never take it away from the wheel or it will put some rubber from the tyre on your rim, this will result on a contaminated grind.

-Start grinding, if you run an HS33, grind the rim the opposite way from when the wheel turns,

if you run Vees, grind the rim the same way the wheel turns.

I don't know why but both these type of brakes perform better depending on the direction you grind your rims...

-Always use a brand new Metal cutting disc, about 2 or 3 mm wide.

-When you grind, never push on the grinder, just let it touch your rim and move your arm around.

-Choose your own angle depending on the depth of the grind you want. As you use a metal cutting disc, be careful not to put it under 30 degrees, or the disc will potentially break (and it's not funny, believe me!).

-Grind all the Rim surface, otherwise, if your wheel is untrue, the pads will touch a part of the rim that is not grinded --> BRAKE FAIL!

-Sand your pads afterwards to remove all the previous stuff that could be on the rims before the grind.

-Take your time when griding, you don't want to damage your rim, and you'll get faster after many griding.

[3dd]

Thanks man that did help a bit.

[JT!]

Watch the vid about grinding on tartybikes.

[Leistonbmx]

I also watched tarty rim grind guide, and they are using bosch one with 115mm disc but I seems a bit slower than normal grinders. I got a ground rim from them once and it had a nice sharp grind.

Watch the vid about grinding on tartybikes.