Road Cycling - BB Play?

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ridethecliche
05-17-07, 08:41 PM
I've put my bike through over 200 miles, which isn't a lot for a lot of guys on here but I just started riding and I can only go out twice a week because of classes and the like.
After reading all the threads on here about bb creaking being something bad, I decided to inspect mine. Nothing had ever creaked on it during rides and the truvativ cranks seemed fine.
I don't have a video of the movement, but this is what I found.
Stand with the side of crankset facing you. Now take the pedal and push it towards the bike body, aka apply a vector to make the plane of the pedal, which is parallel to the bike body, such that the pedal plane intersects the plane of the bike body. Of course you can't do this, but it's the direction of the force. I did this while looking at it and applying a little bit of pressure. and to my surprise; it moved! There was a little bit of 'play'. It was a bit of to and fro movement.
I got on the bike and rode it up and down my hallway (college dorm) and I noticed that there was a weird feeling/sound that hadn't ever happened before, but it only happened at a certain point of the pedal stroke.
It's a truvativ isoflow road crankset, and I'm not sure what the bottom bracket is. My MTB has the mtb version of the crankset and I tried the same with this and didn't find any play.
Thanks guys, I'm going to take it out for a 5 min spin tomorrow to see what's going on, but I'm a little frightened.
v1k1ng1001
05-17-07, 08:55 PM
yeah, don't ride that, go get it tightened up at the LBS if you don't know what is loose
ridethecliche
05-17-07, 08:57 PM
I don't have a torque wrench, but I have a wrench that fit and everything on there seemed pretty tight.
I've never noticed that before it was so strange.
Just curious, was my explanation of the problem/movement understandable?
Sirrobinofcoxly
05-17-07, 09:27 PM
Movement in a sealed BB is often an indication that it is worn out? How old is it? Is it 200M new? Have your LBS take a look. Better safe than sorry
v1k1ng1001
05-17-07, 09:39 PM
Yeah, what you said is understandable.
If it's not the crankarms that are loose, then it might just be the BB cups working themselves loose, although that would be extremely unusual too. Sounds like a misinstallation or warranty issue. Have your LBS fix it up for you.
ridethecliche
05-17-07, 09:54 PM
The bike is new. I've had it for less than two months. I'll get my LBS back home to take a look at it. I'm leaving college tomorrow. Ugh...
Is the non drive-side arm of the crank arm reverse threaded?
ridethecliche
05-17-07, 11:23 PM
I looked at it again when I went back to my room to make coffee (it's an all nighter kinda night).
The crank arms are nice and tight. There's a metal piece with a very interesting looking mouth of teeth in the cavity on the frame, aka the bottom bracket ;), which i can see move back and forth a little bit. I need to adjust my bb. I don't have a tool set, yet anyway, and it costs 10 bucks for the lbs to do it.
I'm guessing that I'm going to let them adjust it this time and watch, and buy a generic toolkit from pricepoint and do minor stuff myself from then on. My college has a bike co-op which has a lot of good tools, so I just need something for summer and winter when I'm probably not going to be home for more than a month at a time so I should be good with something basic and get more expensive tools for what I actually need.
v1k1ng1001
05-20-07, 12:11 AM
I looked at it again when I went back to my room to make coffee (it's an all nighter kinda night).
The crank arms are nice and tight. There's a metal piece with a very interesting looking mouth of teeth in the cavity on the frame, aka the bottom bracket ;), which i can see move back and forth a little bit. I need to adjust my bb. I don't have a tool set, yet anyway, and it costs 10 bucks for the lbs to do it.
I'm guessing that I'm going to let them adjust it this time and watch, and buy a generic toolkit from pricepoint and do minor stuff myself from then on. My college has a bike co-op which has a lot of good tools, so I just need something for summer and winter when I'm probably not going to be home for more than a month at a time so I should be good with something basic and get more expensive tools for what I actually need.
you shouldn't have to fuss with your BB very often, sounds like someone at the factory didn't install it correctly and then your LBS missed it on the out-the-door checkover
ridethecliche
05-20-07, 10:18 AM
Yeah, sounds like the BB is broken. A try to tighten it didn't work. I didn't buy it at an LBS (It's a BD bike, go figure).
*Hides*
Blah...
v1k1ng1001
05-20-07, 05:39 PM
well you should be able to get it repaired for a few bucks
ridethecliche
05-20-07, 05:48 PM
It's going to be 30 bucks for BB+ installation.
Oh well.
99m6z28
02-10-08, 08:45 PM
Just curious which of the BD bikes it is. I have the Motobecane Vent Noir that I got back in december and it also has some play in the BB. Mine is bad enough that when I put it in a heavy load it moves enough to allow the chain to touch my front derailler for just a second.
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