ChrisTrials2012 Posted August 14, 2012 Report Share Posted August 14, 2012 I have to grind my rim, cause I'm from Ireland it rains every other day, and also cause I want to get the most out of my TNNs. But my dad won't let me because he believes that it will destroy the rim, even though I plan on grinding once every month/month and a half. So can grinding, if done correctly, ruin a rim completely after one go, or will it weaken it significantly. Quote Link to comment Share on other sites More sharing options...
AndrewEH1 Posted August 14, 2012 Report Share Posted August 14, 2012 What rim are you using? Depending on the rim you'll be able to grind it quite a few times. I understand where your dad is coming from but if done right a rim grind won't 'destroy' your rim. Quote Link to comment Share on other sites More sharing options...
isitafox Posted August 14, 2012 Report Share Posted August 14, 2012 You won't need to grind it once a month, a decent grind will last you a few months if done properly. Would your dad rather let your brake risk slipping and cause you an injury? I cannot be 100% certain but I'd stick my neck out and say that trials rims are designed with grinds in mind nowadays. Your rim should still last at least a year when ground unless your super rough! Quote Link to comment Share on other sites More sharing options...
Aii_Aitch Posted August 14, 2012 Report Share Posted August 14, 2012 I've heard of people grinding their rims 6 or 7 times before replacing them. I've ground my rear with sharp, deep grinds twice since getting it and i'll probably do it at least a few more times before replacing it. You can cut straight through a rim if you don't do it right, but it still takes some doing because trials rims are designed to take a good beating. Almost everyone who has a rim brake in trials has a grind on it, it just gives you better bite and hold... A new rim is only £30 or £40. if you buy from the forums, you can get them for as little as £10, so it's not like if you mess up it'll cost the world. Not that it's easy to mess up. Just remember to grind one way and only one way. Quote Link to comment Share on other sites More sharing options...
rocky111 Posted August 14, 2012 Report Share Posted August 14, 2012 no if you just do light/medium grinds with a new thin diamond/tile cutting disc your rim should last years. Quote Link to comment Share on other sites More sharing options...
N.Wood Posted August 14, 2012 Report Share Posted August 14, 2012 Out of the ~10 rims i've owned in my trials lifetime, only about 3 have failed through over grinding. The sidewalls get thin and dent easily. These lastest about a year and a half though. The rest cracked / went out of true too badly and had to be replaced. This is nothing to do with grinds. Quote Link to comment Share on other sites More sharing options...
williams Posted August 14, 2012 Report Share Posted August 14, 2012 My dad where quite skeptical about grinding it first, but then I showed him the tarty video and he said fine. And you can grind your rim bloody more than 6 times, I think i've ground mine 10-15 times could probably do 5-10 more. Bare in mind that I rather have a awesome brake, replace the rim more often, do a harsh grind, than be careful and not have the same powerful brake. So yeah. GRIND IT! 1 Quote Link to comment Share on other sites More sharing options...
ChrisTrials2012 Posted August 14, 2012 Author Report Share Posted August 14, 2012 you it's a DOB Mag rim, and I'll show my dad a few grinding videos(no pun intended). Quote Link to comment Share on other sites More sharing options...
Blake Posted August 14, 2012 Report Share Posted August 14, 2012 I don't get the pun. Quote Link to comment Share on other sites More sharing options...
ChrisTrials2012 Posted August 14, 2012 Author Report Share Posted August 14, 2012 I don't get the pun. Look it up, can't be saying. Quote Link to comment Share on other sites More sharing options...
isitafox Posted August 14, 2012 Report Share Posted August 14, 2012 Ooh, chances are it won't last as long as an aluminium rim I'm afraid. When you kill it get an echo tr, they hold grinds brilliantly and should last. Quote Link to comment Share on other sites More sharing options...
Jake. Posted August 14, 2012 Report Share Posted August 14, 2012 What TNN's are they? My beleays work surprisingly well with a dab of tar. Quote Link to comment Share on other sites More sharing options...
ChrisTrials2012 Posted August 14, 2012 Author Report Share Posted August 14, 2012 TNN Be-Greens, and I don't like the idea of tar, as I'd f**k it up. They just don't have enough hold at the moment, because I'm fairly heavy (200 pounds) and progressing to the point where I would require extra hold and bite. Also, I need advice on my Louise disc brake, which has lost its hold and a lot of its bite, plus while the TPA still works, the lever almost pulls to the bar. Quote Link to comment Share on other sites More sharing options...
Jake. Posted August 14, 2012 Report Share Posted August 14, 2012 How can you f**k tar up? If you put too much on just rub it down. Quote Link to comment Share on other sites More sharing options...
trialsiain Posted August 14, 2012 Report Share Posted August 14, 2012 does tar make brake stick on ? Quote Link to comment Share on other sites More sharing options...
aener Posted August 14, 2012 Report Share Posted August 14, 2012 Rim sidewalls are ~2mm thick. A grind will take off ~0.1-0.3mm, unless you're being seriously aggressive. A DOB mag' rim won't last as long as an alloy one because they're a super soft metal. That's just unfortunate. Point out to your Dad that pretty much 95% of rim-brake users grind their rims. Most of them don't buy a new rim very often, and when they do it's not usually because of too much material being removed from a grind. I can totally understand where he's coming from. I felt exactly the same when Ed Potts (a guy 'round here who was my gateway in to trials) suggested a grind - but he changed my mind saying "If, by some miracle, you do knacker the rim, it can be replaced for about £40. You can't replace your back. If you loop out in an unlucky place, you're screwed for life." He said this because I just looped out in front of him because my brake on a smooth rim was so bad. Just remember you only need to roughen the surface up. You don't actually need to "grind" deep, it's just thousands upon thousands of surface scratches. Also point out to him that you can pay for it to be done to a rim before you even get it posted, by the most influencial trials shop in the world (http://www.tartybikes.co.uk/workshop/tartybikes_rim_grind/c34p10160.html). They wouldn't be able to offer that if it posed serious problems. Don't go to tar, it's horrible. It's sticky and feels (and SOUNDS) absolutely rank. Also, when it's wet, it turns to oily sludge and makes the brake WAY worse. Tar is always a last resort 1 Quote Link to comment Share on other sites More sharing options...
Dan6061 Posted August 14, 2012 Report Share Posted August 14, 2012 I wouldn't grind a DOB mag' rim! They're weak enough as it is! Mine only lasted a few months. Quote Link to comment Share on other sites More sharing options...
ChrisTrials2012 Posted August 14, 2012 Author Report Share Posted August 14, 2012 Rim sidewalls are ~2mm thick. A grind will take off ~0.1-0.3mm, unless you're being seriously aggressive. A DOB mag' rim won't last as long as an alloy one because they're a super soft metal. That's just unfortunate. Point out to your Dad that pretty much 95% of rim-brake users grind their rims. Most of them don't buy a new rim very often, and when they do it's not usually because of too much material being removed from a grind. I can totally understand where he's coming from. I felt exactly the same when Ed Potts (a guy 'round here who was my gateway in to trials) suggested a grind - but he changed my mind saying "If, by some miracle, you do knacker the rim, it can be replaced for about £40. You can't replace your back. If you loop out in an unlucky place, you're screwed for life." He said this because I just looped out in front of him because my brake on a smooth rim was so bad. Just remember you only need to roughen the surface up. You don't actually need to "grind" deep, it's just thousands upon thousands of surface scratches. Also point out to him that you can pay for it to be done to a rim before you even get it posted, by the most influencial trials shop in the world (http://www.tartybike.../c34p10160.html). They wouldn't be able to offer that if it posed serious problems. Don't go to tar, it's horrible. It's sticky and feels (and SOUNDS) absolutely rank. Also, when it's wet, it turns to oily sludge and makes the brake WAY worse. Tar is always a last resort I've basically told him I'm intending to do it. And I told him I looped out on some particularly vicious rocks, and all he said was"wear your helmet". He's gonna be stuck like this for ages til I do it and he has to accept it. But I'll show him this topic anyway. Quote Link to comment Share on other sites More sharing options...
Blake Posted August 14, 2012 Report Share Posted August 14, 2012 TNN Be-Greens, and I don't like the idea of tar, as I'd f**k it up. They just don't have enough hold at the moment, because I'm fairly heavy (200 pounds) and progressing to the point where I would require extra hold and bite. Also, I need advice on my Louise disc brake, which has lost its hold and a lot of its bite, plus while the TPA still works, the lever almost pulls to the bar. If you can't put tar on I wouldn't grind your rim 1 Quote Link to comment Share on other sites More sharing options...
ChrisTrials2012 Posted August 15, 2012 Author Report Share Posted August 15, 2012 If you can't put tar on I wouldn't grind your rim Thou shalt not cast aspersions upon my grinding prowess.............But I have ground a rim before and it turned out well, but my dad reacted badly to it. Quote Link to comment Share on other sites More sharing options...
SamKidney Posted August 15, 2012 Report Share Posted August 15, 2012 My dad was the same, pretty much told him to do one and let me get on with it haha. Nothing wrong with it at all Quote Link to comment Share on other sites More sharing options...
ChrisTrials2012 Posted August 15, 2012 Author Report Share Posted August 15, 2012 My dad was the same, pretty much told him to do one and let me get on with it haha. Nothing wrong with it at all Shmart lad. Quote Link to comment Share on other sites More sharing options...
dezmtber Posted August 15, 2012 Report Share Posted August 15, 2012 hope trialzone ? Quote Link to comment Share on other sites More sharing options...
ChrisTrials2012 Posted August 15, 2012 Author Report Share Posted August 15, 2012 hope trialzone ? No.......................just no Quote Link to comment Share on other sites More sharing options...
dann2707 Posted August 15, 2012 Report Share Posted August 15, 2012 My dad was also the same when I first got a trials bike. I think everyones is if they don't really know about the sport / what it requires. Quote Link to comment Share on other sites More sharing options...
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