joaovidal12 Posted April 20, 2016 Report Share Posted April 20, 2016 Greetings! I have a ground rim, read much about tar and violin rosin, couldnt get my hands on tar so I picked a violin rosin bar for 3€. I just want to improve the rear brake little more. My setup: Echo double wall rim (I guess it is) + TNN ADM pads + TNN clamps and integrated booster + 2004 Magura HS33 Race Line First impressions: - It is brittle AF ! If you drop it seems like it will shatter into a million pieces ... - It is not very sticky, gets into powder once rubbed in the rims. - After a few stops it gets embedded in the grooves of the rim, the rest disapears. - Performance in a garage run: Louder, more bite, a bit better hold. Quote Link to comment Share on other sites More sharing options...
isitafox Posted April 20, 2016 Report Share Posted April 20, 2016 I'm sure I read that you need to melt it and rub it on to the rim with a cloth? Quote Link to comment Share on other sites More sharing options...
joaovidal12 Posted April 20, 2016 Author Report Share Posted April 20, 2016 (edited) 7 minutes ago, isitafox said: I'm sure I read that you need to melt it and rub it on to the rim with a cloth? Read that too. I also read that you could get a bit of a chemistry into it and then apply as a liquid. On 13/09/2014 at 0:12 PM, Greetings said: Been using this for years. You can dissolve it in nitro thinner and carry a small bottle around with you. Better even if you find a small applicator like for eye drops but which the thinner will not dissolve. Few drops on the rim, ride around dragging brake - done. Could not understand what the nitro thinner was. Edited April 20, 2016 by joaovidal12 adding information Quote Link to comment Share on other sites More sharing options...
ooo Posted April 20, 2016 Report Share Posted April 20, 2016 47 minutes ago, joaovidal12 said: Could not understand what the nitro thinner was. Mostly acetone (organic name propanone) I think. Quote Link to comment Share on other sites More sharing options...
joaovidal12 Posted April 20, 2016 Author Report Share Posted April 20, 2016 Just now, ooo said: Mostly acetone (organic name propanone) I think. So, after dissolving with that, acetone will evaporate and leave the rosin in the rim? Quote Link to comment Share on other sites More sharing options...
ooo Posted April 20, 2016 Report Share Posted April 20, 2016 1 minute ago, joaovidal12 said: So, after dissolving with that, acetone will evaporate and leave the rosin in the rim? Yes it should do. But you need to check that your source is pretty pure, like old style nail varnish remover has acetone in it; but it may also have other compounds that don't evaporate. Quote Link to comment Share on other sites More sharing options...
joaovidal12 Posted April 20, 2016 Author Report Share Posted April 20, 2016 2 minutes ago, ooo said: Yes it should do. But you need to check that your source is pretty pure, like old style nail varnish remover has acetone in it; but it may also have other compounds that don't evaporate. I can get pure acetone in my lab. No big deal. I will try that in the second round. Quote Link to comment Share on other sites More sharing options...
bing Posted April 20, 2016 Report Share Posted April 20, 2016 You can buy pure acetone from boots, our lass uses it to take off her gel nails, it's only about £1.50 a bottle as well. You ask at the counter and they will sort you out Quote Link to comment Share on other sites More sharing options...
joaovidal12 Posted April 20, 2016 Author Report Share Posted April 20, 2016 The question that I have is: Applying it in the dissolved form will increase effectiveness ? Quote Link to comment Share on other sites More sharing options...
Tonan Posted April 21, 2016 Report Share Posted April 21, 2016 After you make a solution of rosin 10% rosin 90% solvent (acetone if thats your choice) put a little on a clean cloth wipe on rim braking area. It worked for me but went back to simple grind. Similar brake set up to yours and same pads, just switched to Echo SL clamps as my bike is not drilled accurately enough to run the Try-all clamps it came with brake power is where I like it now. Might tinker with some more rosin for when the grins is dulling though. Quote Link to comment Share on other sites More sharing options...
ogre Posted April 21, 2016 Report Share Posted April 21, 2016 i've just put it on like tar and it's seemed to improve bite for a while, does no one else find that putting stuff on your rim tends to affect the hold? Quote Link to comment Share on other sites More sharing options...
niconj Posted April 21, 2016 Report Share Posted April 21, 2016 With the above mentioned combination you shouldn't need neither tar nor violin rosin. Quote Link to comment Share on other sites More sharing options...
Greetings Posted April 22, 2016 Report Share Posted April 22, 2016 On 20.04.2016 at 11:52 PM, joaovidal12 said: The question that I have is: Applying it in the dissolved form will increase effectiveness ? It has to be applied with thinners because that will make it stick to the rim. Applying it like tar won't get good results as the rosin crumbles on contact with the rim and doesn't stick. If you can't get hold of some nitro, use acetone. Just as good. The bite on rosin is incredible and it retains a very responsive brake similar to that on a clean sharp grind. Quote Link to comment Share on other sites More sharing options...
joaovidal12 Posted April 22, 2016 Author Report Share Posted April 22, 2016 5 hours ago, Greetings said: It has to be applied with thinners because that will make it stick to the rim. Applying it like tar won't get good results as the rosin crumbles on contact with the rim and doesn't stick. If you can't get hold of some nitro, use acetone. Just as good. The bite on rosin is incredible and it retains a very responsive brake similar to that on a clean sharp grind. And alcohol vs acetone? They are two different functional groups (C-OH and C=O) so the results could be different from a chemistry point of view. Cetone will evaporate more quickly tough. Quote Link to comment Share on other sites More sharing options...
SamKidney Posted April 23, 2016 Report Share Posted April 23, 2016 I've just found that setting up your brake with a fresh grind and clean pads and leaving it untouched keeps performance consistent right down to a very dead grind. I've not bothered grinding the rims on my bike yet and managed to ride in the pouring rain up at Shipley glen without worrying about brake hold. A quick blast with a pressure washer when cleaning the bike in close to the rim removes any contaminants and good to go again. Used to love tar but the feel of the brake is so much nicer without. Hate that sticky feel. 1 Quote Link to comment Share on other sites More sharing options...
niconj Posted April 24, 2016 Report Share Posted April 24, 2016 18 hours ago, SamKidney said: Hate that sticky feel. And the sound. Quote Link to comment Share on other sites More sharing options...
joaovidal12 Posted April 24, 2016 Author Report Share Posted April 24, 2016 Unfortunately I haven't tried it yet in real riding. But there is no sticky feel with it, in the powder form. And a bit of extra noise, which I don't mind After the test, and the rosin effect disappear I will try the liquid form. Quote Link to comment Share on other sites More sharing options...
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