Tange ln 3922 bb
 

Hi,

I have the Tange ln 3922 bb in my Kilo tt, and have some bearing drag in it. No idea how many miles are on it. I've done maybe 700, and then there are the miles the previous owner had on it. Is there a way to service it?

Dave

How much drag? If you twist the axle by hand, you'll feel a little smooth drag in a healthy BB -- that's the seals keeping water and crap out of the bearings. It's not actually enough to slow you down.

The bearings are cartridge units. If they feel rough or make noise, they're shot. Unfortunately, that means buying a whole new BB. I have an LN-7922 that I might try to rebuild, but there's no guarantee of success with that mission. ;)

I'll have to take the crank arms off and check the drag. Noticed a sluggish feeling this weekend after riding a friend's fixed gear. He had 79 gi, and I have 74 gi. My bike was much harder to pedal.

If I do need to replace it, are there higher end JIS square taper brackets that would work? Maybe something a lot lighter? These are boat anchors at 300g.

Dsve

Have you tried taking off the chain and spinning the cranks first? How do the wheel bearings feel?

The Tange LN-7922 is a bit lighter than the LN-3922 thanks to a hollow spindle, mine is a 118mm but only 247g. :thumb:

I took the chain off, and spun the crankset. It spins very freely, and there is no noticable drag whatsoever. The bb bearings feel very smooth, and there was no play.

Maybe what I'm seeing is the difference between a mid-range bottom bracket, and my friend's Dura Ace bb and crankset? If so, the difference is HUGE!

Dave

If your friend's DA is loose-ball, it probably will spin a little freer. The flip-side to that is you would need to clean, re-grease, and adjust it on a regular basis to keep it from wearing out.

But if your crank also spins freely with no play, that makes me think something else on your bike is slowing you down.

This. Check your chain tension. Likely too tight.

as far as I can tell, the chain is ok. Got about 1/2" of chain deflection when I push down on it.

That sluggish feeling is likely due to any number of other things.

I concur.

Try the Metamucil Two-Week Challenge.

lol. Maybe the crappy Sugino vp130 crankset?

Wheels are pretty nice, H plus son archetypes with Gran compe hubs. Those are pretty new, doubt they're the problem.