Bikeguide.org - Bike maintenance for BMX'ers
The Street => The Bike Shop => Topic started by: WoBBLE on July 09, 2015, 12:11:55 PM
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Hey,
I've had 2 7kas for years now. Back one is still awesome but the front one slips whenever I pull my front brake. I've adjusted the brake, tried new pads etc (clear ones), and ultimately it's still shit. Considering the age, does chrome just wear down? There is no flaking at all, and the rim is still structurally sound.
Anyone have any experience or knowledge about this? Ideas for quick fixes?
Some people are offering hazard lites as a replacement (I run 48 spokes); how do they compare to 7kas? Modern day alternative perhaps?
Thanks in advance, my front brake is in your hands...
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As long as the chrome isn't peeling then you shouldn't have a problem. I've been running the same chrome rim in the rear for probably close to 6 years and I've never noticed a change in braking power. With clear pads and a chrome rim you should be able to lock it up really easily. Biggest things I can think of to check is making sure the pads hit the rim at the same time, make sure both the rim and pads are clean, and either try getting a new cable or squirt some tri-flow down your existing cable to minimize friction.
In regards to the 7ka vs. haz lite, they've both been around forever. The 7ka is a couple mm's wider and made out of 7000 series aluminum while the haz lite is 6000 series I believe. They're both almost the same weight but the 7ka is going to hold up to more abuse.
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Try the basics before replacing the rim. I have had rims with the chrome worn off of the sidewalls completely from braking (down to the copper layer), and even that did not affect braking much.
-Clean the braking surface on the rim with alcohol.
-Sand the pads to remove any glazing.
There could be a glazed over layer on the rim as well from old pads, so a good cleaning with alcohol should help.
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Sorry to be dumb, but when you say alcohol, are we talking like whiskey or a specific cleaning chemical?
There could well be a build up on the rim (it's genuinely gutting as the rim is in SUCH good condition for 8 years old). I recently used a KFC lemon wet-wipe to clean it and it didn't make a difference :(
I just want my front brake to stop on a dime and sound like goose rape! Like the back one!
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Rubbing alcohol, like for cleaning cuts
What kind of pads & brake?
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Ideas for quick fixes?
Auto Belt Dressing. Spray a little on. Your brakes will lock up.
(http://i5.walmartimages.com/dfw/dce07b8c-11d2/k2-_1a5f30c0-70e3-4841-a24e-3620ffe0d06c.v1.jpg)
This is only a quick fix though. I personally would rather have well lubed new housing, quality lever, quality brake, quality pads etc.
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Simple Green is an excellent cleaner that will make your brakes rock.
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i remember when i first started riding, the letters page in ride uk each month would have like 2 letter minimum about people making their own braking mixtures to rub on their rims so their brakes would lock up better lol
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Simple Green is an excellent cleaner that will make your brakes rock.
For like 20 minutes.
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i wipe mine over every week with a bit of white spirit and a old cloth , then if you really want , add a small amount of coke (not the white gear!!) to the rim for maximum stick and scream sounding worse than a elephant raping a duck
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Simple Green is an excellent cleaner that will make your brakes rock.
For like 20 minutes.
Very true, but they still work great. I like to have some modulation in my brakes.
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I go over the rims with steel wool (0000) which is the least abrasive made, this brings the sidewall back to a brand new condition. I just put the bike upside down and spin the wheel while holding the wool to the sidewall, then clean the walls with isopropyl alcohol, doing both will remove any embedded dirt or brake pad material from the chrome. Last thing to do is wipe the pads down with the alcohol on a rag until they look fresh again, if they are in bad shape you can use sandpaper first to make them fresh then wipe down with alcohol to remove contamination.
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Thanks guys, I found some form of alcohol gel to use and played around with the brake pads, now the rim squeaks a lot (which is a good sign), just waiting for a session to properly see if it's made any difference at all!
I'm reluctant to buy a new rim, so if this doesn't work, looks like fizzy pop treatment for like. Ever.
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what about rechroming? might be expensive tho?
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. . . and either try getting a new cable or squirt some tri-flow down your existing cable to minimize friction.
. . .
Most people fail to do this. New housing without any kinks in it and FILLED with Tri-Flow is key (i actually use a light layer of white lithium grease on inner cable in addition to Tri-Flow). Kinks in the housing or the inner wire create friction in the pull and reduce braking power.
When you add a good lever to this, your brakes should work really well regardless of the cleanliness of the rims and pads. I'm not saying cleaning them doesn't help, I'm saying it's not the primary issue.
Short levers are not as good as long ones (basic physics: https://en.wikipedia.org/wiki/Lever (https://en.wikipedia.org/wiki/Lever) ). http://www.empirebmx.com/catalog/brake-stuff (http://www.empirebmx.com/catalog/brake-stuff) Those bent-out ones, like the DiaTech Gold Finger are a stupid work-around. It's better to get handlebars with a narrower bend-to-bend distance, then have a long grip and plenty of finger room. You can still do index finger braking by moving your hand to the outside of the long grip. Like this:
(http://i255.photobucket.com/albums/hh138/upsetbmx/frontbrakes_zpsjfxmlsis.jpg)
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you probably had some sort of oil on the rim.
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I still haven't had a chance to get out there to see how little difference my tinkering will have made, but I know the cable is a little... Dated. It's an old slic cable so could do with being replaced, and then lubed up.
For anyone wondering though, I'm pretty sure I have a decent enough set up to get solid braking power (evo 2, clear pads, OLD primo levers, and tiny tiny fit flow bars).
Will keep you guys updated!
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I managed to fix my brakes by toe-ing in the pads to account movement for the calipers on the brake mounts (they wiggle quite a bit), and mostly by putting Jello mix on the rims!!! I applied a thin layer just after dissolving some, now it has 'set' it seems to be working wonders!