|   Paul crosstops v-brake | M
Sep 24, 2001 5:59 PM | | I have a set of old 1995 crosstops v-brakes, I can get the front brake to lock up with my weight(170) on it, but I cant get the back one to lock up. The problem is that the cable housing gets in the way, when the brake gets almost to full closure(almost lock), the cable housing pushes the right(drive side of the bike)brake arm away from the wheel. There seams to be not enoff travel space for the cable housing, between the cable stop and the back brake. The Directios say that you you need a smooth arc, that does not seam possible. I've changed the cable housing to different lenghts, but nothing works. I've had the brakes on two different bikes with the same problem, tryed boosters, I'm also using gore-tex cables. Anybody have any ideas.....M |
| re: Paul crosstops v-brake | uphiller
Sep 25, 2001 2:57 PM | | hey man
this question is right up my alley. i have the exact same brake myself, ad really have fetish for all those wacky mid-90s quasi-v-brakes. as i understand it, your problem lies in the big crossbar that connects the two halves of the brake running into the cable housing before the brake locks up. to wit, here are some tips for setup:
-before you do anything else, set the pads up with just a wee bit of toe in. but what's really most important is that the pads are set up such that both arms are about ten to fifteen degrees from vertical when the pads first hit the rim.
-another note about pad setup: if the brake just doesn't want to lock up the rim, then move the pads so that they're actually higher up on the rim. this will give you less leverage, but the pads will also hit the rim a lot sooner for the same reason. the brake has enough leverage to lock the rim almost without regard to how high the pads are. the real issue here is whether the linkage will move so far that the main linkage rod thingie hits the cable housing before you can lock the wheel.
-now set up your housing. you mentioned that the linkage actually pushes one of the arms away from the bike. this means more than likely that the rocker (the instructions call it a dealie, as i recall) is rotated way too far to the right as the picture shows it. the way to solve that is just shorten the length of the adjusting rod. also, your housing needs to be longer than it does on most v-brakes or the extra cable tension that comes with using a short housing will interfere with the linkage. make sure your housing is long enough!
-now, at your brake lever, make sure your barrel adjusters are all of the way inside the handle, don't have any threads exposed.
-now run the cable through the housing and into the brake. pull the cable as taut as it will go before you tighten the bolt down on it. at the same time, don't pull on the brake cable so hard that you make the rocker arm move. what you want here is to have rocker arm rotated all or most of the way clockwise so that it just rests on the left-hand caliper.
-now just lengthen or shorten the adjuster to your taste.
-don't fret when the short arm moves more than the long one. it's normal.
-if you can, try to score some old, cantilever xt slr plus levers, they start off with low leverage and then get higher, which means that you can set the pads far from the rim and still get great stopping power.
-use a booster. sometimes the leverage of the brake is so high, particularly on steel or ti frames, that the frame will flex like mad and waste all that leverage the brake has. in any case, if you do get a booster, put it on after you've set the rest of the brake up.
i hope this helps and that i've been clear. post back again and tell us what happens.
later
tim |
| re: Paul crosstops v-brake | M
Sep 25, 2001 10:00 PM | | I know it is in the housing lenght because of the front brake housing is about 16" long and there is enoff flexiblity for it to move out of the way of the cross bar, but in the back the cable housing is to short to be flexible. The rod is the shortest already, it could be shorter if I take out the nut. I allready have the pads toed-in. I was running Avid 2.0 levers at first then changed to Reals, no change in the power. I have a set of 93 XTR's levers with shifter nubs, but I dont want carve them up(these brakes are on my retro single speed). I will try some of the ideas and get back to you...M |
| re: Paul crosstops v-brake | jim catterson
Sep 26, 2001 4:23 AM | | i still have the crosstops as well but they are in the parts box! could never get them to lock the rear wheel either, which made my trips to mammoth and moab oh so interesting back in the day... |
| re: Paul crosstops v-brake | uphiller
Sep 26, 2001 1:14 PM | | hey there-
if the adjusting rod is already at its shortest position, then just adjust the pads so they're closer to the rim. don't do this w/ the barrel adjuster, just readjust the pads themselves. also, don't use v-brake levers. if you do, your lever won't move very far before the pads hit, and when the pads do hit the rim your lever will feel rock-solid and nasty, meaning that you've got no leverage. the crosstop is not a v-brake- it just kinda looks like one. take it from someone whose tried that brake with every lever under the sun.
oh- and if you really can't the brake to work, i'll be more than willing to buy it. email me!
post again if you still can't fix it.
tim |
| re: Paul crosstops v-brake | jim catterson
Sep 27, 2001 5:31 AM | | tim, if you want my crosstop [black w/ dual compound pads] let me know...i'll never use it and i am too lazy to put it on ebay. termite@rocketmail.com |
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