Jason Knight
Well-Known Member
- Region
- USA
- City
- Keene, NH
I wanted to switch to some lighter weight whitewalls on my Aventure. Easy enough a task when I have a rack I can mount the bike upside-down on in my garage. But after I was done I found the front brake barely engaged, and the rear just up and did nothing.
EXACTLY how the bike behaved when I got it from Aventon.
So I grabbed my bleed kit, did the front first and got a LOT of air out of it, which is odd as I had checked it previously and it passes a pressure check... and it was working fine before I flipped it over. Got it back to being filled with fluid instead of air, and move on to the rear.
Opening the fill I was welcomed by the overwhelming odor of death. The stench of cadaverine, a smell I regretfully am all too familiar with.
I put the bleed kit on and black-green foam was foaming up as the oil went in!!! I immediately wheeled the bike outside and using a small hand-pump ran a hot water wash through the hose. The line was filled with a green slime that smelled horrible.
I'm a computer guy. I've seen this behavior before in liquid cooling loops. Bacteria was growing in my brake lines! I know how to handle that, it's just very odd to have to do it to a bicycle.
After a good power wash, pressure flush, and ajax soap in the sink, I did a long deep soak in my sonar cleaner drowning everything in IPA, All the parts checked out so I re-assembled and filled with clean oil, brakes good to go.
But it leaves me with nagging questions -- and even more distrust for this fiddly finicky hydraulic brake stuff. The liquid is supposed to mostly be just mineral oil, what was in there from Aventon and/or the brake maker that would allow growth like that? Did someone fill it along the way with water instead of oil? Did some sort of water left over from parts cleaning remain in the system from the factory? Brake oil should not be a growth-friendly environment.
The front had no such issues with growth, but both stopped working when the bike was flipped over. Could that be where/why so many people have problems with the brakes on the Aventure? Could it be as simple as "if the bike is flipped upside down in shipping, this design of brake needs to be bled and refilled?" Is that actually a thing with hydraulic bicycle brakes?
It's a very odd situation all-around.
It looks nice though now that it's complete and working. It also feels like it rides better which is funny since these are cheap Zinghang or whatever "wanda" / WD $80 a pop tires. Which apparently $80 each is cheap for fatties. A quick measure shows I'm at 68 pounds for the bike total, so that's 3.1 pounds less from my starting point. Pretty good since that's 4 pounds below the factory weight without rear rack and panniers. But again I took a lot of weight off when I swapped from the cast iron pretending to be "forged" cranks and pig iron chainring off.
It's funny, but the white-walls make the bike look less... I dunno... absurdly oversized. It changes the lines of it. Running the various cables and hoses through some cheap plastic conduit cleans up things nice as well.
Suspension post, comfortable seat instead of unrideable butt-floss, headlight that's not a pathetic weak joke, Whole different beastie now.
Next up to get a longer fork since it feels to me like the bike doesn't have enough "rake" and like everyone else I'm bottoming out these cheapo's. Also want to find a longer front fender because the existing one does nothing to stop your shins-down from getting covered in gunk... or the down-tube for that matter which I hadn't noticed had gotten so grotty until I flipped it over.
EXACTLY how the bike behaved when I got it from Aventon.
So I grabbed my bleed kit, did the front first and got a LOT of air out of it, which is odd as I had checked it previously and it passes a pressure check... and it was working fine before I flipped it over. Got it back to being filled with fluid instead of air, and move on to the rear.
Opening the fill I was welcomed by the overwhelming odor of death. The stench of cadaverine, a smell I regretfully am all too familiar with.
I put the bleed kit on and black-green foam was foaming up as the oil went in!!! I immediately wheeled the bike outside and using a small hand-pump ran a hot water wash through the hose. The line was filled with a green slime that smelled horrible.
I'm a computer guy. I've seen this behavior before in liquid cooling loops. Bacteria was growing in my brake lines! I know how to handle that, it's just very odd to have to do it to a bicycle.
After a good power wash, pressure flush, and ajax soap in the sink, I did a long deep soak in my sonar cleaner drowning everything in IPA, All the parts checked out so I re-assembled and filled with clean oil, brakes good to go.
But it leaves me with nagging questions -- and even more distrust for this fiddly finicky hydraulic brake stuff. The liquid is supposed to mostly be just mineral oil, what was in there from Aventon and/or the brake maker that would allow growth like that? Did someone fill it along the way with water instead of oil? Did some sort of water left over from parts cleaning remain in the system from the factory? Brake oil should not be a growth-friendly environment.
The front had no such issues with growth, but both stopped working when the bike was flipped over. Could that be where/why so many people have problems with the brakes on the Aventure? Could it be as simple as "if the bike is flipped upside down in shipping, this design of brake needs to be bled and refilled?" Is that actually a thing with hydraulic bicycle brakes?
It's a very odd situation all-around.
It looks nice though now that it's complete and working. It also feels like it rides better which is funny since these are cheap Zinghang or whatever "wanda" / WD $80 a pop tires. Which apparently $80 each is cheap for fatties. A quick measure shows I'm at 68 pounds for the bike total, so that's 3.1 pounds less from my starting point. Pretty good since that's 4 pounds below the factory weight without rear rack and panniers. But again I took a lot of weight off when I swapped from the cast iron pretending to be "forged" cranks and pig iron chainring off.
It's funny, but the white-walls make the bike look less... I dunno... absurdly oversized. It changes the lines of it. Running the various cables and hoses through some cheap plastic conduit cleans up things nice as well.
Suspension post, comfortable seat instead of unrideable butt-floss, headlight that's not a pathetic weak joke, Whole different beastie now.
Next up to get a longer fork since it feels to me like the bike doesn't have enough "rake" and like everyone else I'm bottoming out these cheapo's. Also want to find a longer front fender because the existing one does nothing to stop your shins-down from getting covered in gunk... or the down-tube for that matter which I hadn't noticed had gotten so grotty until I flipped it over.
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