What size?
 

About every 3rd or 4th tooth on my chain rings is about half the height of the others, and appears to just have been worn down. However the chain and rear procket (nexus internal 7 speed) looks new. Is this normal? I thought maybe they needed to be replaced, but the LBS says as long as the chain is not slipping why bother. Of course they are a MTB store and I have a recumbent. They also said the chin rings are Welded and the whole crank would need to be replaced, but they don't want to do it. The chain rings also "sway" like they might be skightly bent causing the chin in the biggest gear to hit the derailuer and make noise. So if I wanted to replace the chain rings, I guess I would need to get a new crank. How do I tell what I have so I know what to replace it with? :confused:

Now I am a newbie as well. The information I have could be wrong and I hope that our fellow members will correct me.

I have been told that the half-height teeth are made that way to ease shifting. On my bike, the teeth on the rear sprocket are also curved a little. My LBS told me that the curve also helps to ease shifting.

The wobbling in the front chain ring in my experience was a loose crank that progressed into blown bearings. Once I got a new sealed bearing unit for my crank, the wobbling was gone and the pedaling was really smooth.

True, the bike this happened to is a normal mountain bike and not one of those nifty recumbants, but I would think that the technology would be still be similiar.

Yes, uneven teeth are as they should be-some even splay a bit left to right. The ring runout is probably caused by either a bent BB spindle, or, more likely, by a bent ring. You can very easily bend a ring by hitting a step, or by dropping a bike sideways.

Well the SWAY just seems to be in the largest gear, and it does not seem to effect the pedals (Cranks?). The funny looking nut around the cranks that looks like it keeps everything in the bottom bracket (hope I am using th eright terms), was loose, I had the LBS adjust and tighten stuff after I put it together (shipped apart). But out of curiosity, if I needed to or wanted to replace the cranks, bottom bracket (the bracket or just the bearings?) how would I know what size (or what ever) I would need to to do it? :confused:
Thanks, fofa

Umm...let me get this straight:
Did you assemble this bike? If so, did you have the correct tools? And lastly, just what brand/model of bike is this?
It sounds as if the outer chainring is bent.
A welded chainring is, by any definition, a piece of junk. I'm assuming that this is one of those internet-purchase recumbents? I've seen ads for them, and they look just awful. Chances are, it uses a lot of those non-standard components used in el-cheapo department store bikes, too. Most LBS'es won't work on such models, anyway.
Was it inexpensive? Well, you got what you paid for.

Your local bike shop (LBS) would be happy to work on your bike regardless of where you bought it. Its foolish to turn down busness because of snobbery. Its also good busness to get someone just starting out hooked on their service so when (if) you ever want to move up to that $1000 bike you know where to buy it ;)

You wont need to replace a nexus-7 rear cog anywhere near as often as an exposed deraileur setup. They will not wear as quickly because the gear does not suffer the stresses of shifting, it all happens inside the hub.

The front chainrings are indeed shaped strangely to facilitate shifting. They should not be bent.

Sounds like your bottom bracket was never adjusted (or assembled?) correctly. If it was loose, you would have easily ruined the bearings riding on it. I prefer the ball bearing and spindle arrangement, but for low maintenance, you made the right call to go with a sealed bearing setup.


What size tool, or what size replacement part? I'll help if I can...

Parts, if I wanted to replace the parts, how would I know what size to get?
It is a Lightfoot Cycles Explorer, probably about 4 years old.
I bought while out of town, and had it shipped to me, and to ship it the gut had to take off the wheels and seat and handlebar along with all the associated garbage hooked to those. The BB must have been loose when since that was assembled. besides the "sway" in the large ring, I would also like to increase the middle ring by 1 tooth, and the large by 1 or 2 teeth. It appears the chain will handle at least one, but I figured if I am going to do that I should replace the whole she-bang up front, just don't know what size to look for.
Thanks