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Replacing Schwinn Tourist bottom bracket
#1
hello all,

I bought a Schwinn Tourist at Target a few months back and want to replace the bottom bracket. It is the cup/cone/bearing type. In short, can I use a sealed bottom bracket or must I stay with the cup/cone and bearing type? It is 68 X 127. I'm fairly certain (but not sure) that the TPI is 24. The spindle is square taper. I researched the spindle on the Sheldon Brown site (it is 3S) and it is actually 125 mm wide, but the "symmetrical equivalent" per his charts is 127.

I was looking at the shimano BB-UN55 and figured that one would fit based on my best evaluations. I'm also kind of leery of the plastic end on the shimano part. I've already learned my expensive lesson of buying a bike from target.

Any ideas?

On the other hand, if I should stick with the cup/bearing type, would there be a reasonably priced upgrade?

Any thoughts are appreciated! Thanks!
  Reply
#2
(10-19-2011, 10:54 PM)mizzoudoc89 Wrote:  hello all,

I bought a Schwinn Tourist at Target a few months back and want to replace the bottom bracket. It is the cup/cone/bearing type. In short, can I use a sealed bottom bracket or must I stay with the cup/cone and bearing type? It is 68 X 127. I'm fairly certain (but not sure) that the TPI is 24. The spindle is square taper. I researched the spindle on the Sheldon Brown site (it is 3S) and it is actually 125 mm wide, but the "symmetrical equivalent" per his charts is 127.

I was looking at the shimano BB-UN55 and figured that one would fit based on my best evaluations. I'm also kind of leery of the plastic end on the shimano part. I've already learned my expensive lesson of buying a bike from target.

Any ideas?

On the other hand, if I should stick with the cup/bearing type, would there be a reasonably priced upgrade?

Any thoughts are appreciated! Thanks!

You can replace with a sealed bearing type - basically a throw away part, not serviceable, or keep the serviceable cup/bearing type. Do you mean UN54? http://www.amazon.com/Shimano-BB-UN54-Bottom-Bracket-127mm/dp/B0011ZCEHK/

The plastic end actually works better than metal in this application because the rigid bearing assembly needs some give in the part to prevent binding.

My preference is cups and seperate loose bearings (not caged); because it serviceable, stronger and stiffer than the alternatives. I use grease intended for boat trailer wheel bearings, due to low cost, very water resistant and works well.

I replace the balls whenever I service the BB. Proper tightening is critical.
Nigel
  Reply
#3
(10-19-2011, 11:12 PM)nfmisso Wrote:  
(10-19-2011, 10:54 PM)mizzoudoc89 Wrote:  hello all,

I bought a Schwinn Tourist at Target a few months back and want to replace the bottom bracket. It is the cup/cone/bearing type. In short, can I use a sealed bottom bracket or must I stay with the cup/cone and bearing type? It is 68 X 127. I'm fairly certain (but not sure) that the TPI is 24. The spindle is square taper. I researched the spindle on the Sheldon Brown site (it is 3S) and it is actually 125 mm wide, but the "symmetrical equivalent" per his charts is 127.

I was looking at the shimano BB-UN55 and figured that one would fit based on my best evaluations. I'm also kind of leery of the plastic end on the shimano part. I've already learned my expensive lesson of buying a bike from target.

Any ideas?

On the other hand, if I should stick with the cup/bearing type, would there be a reasonably priced upgrade?

Any thoughts are appreciated! Thanks!

You can replace with a sealed bearing type - basically a throw away part, not serviceable, or keep the serviceable cup/bearing type. Do you mean UN54? http://www.amazon.com/Shimano-BB-UN54-Bottom-Bracket-127mm/dp/B0011ZCEHK/

The plastic end actually works better than metal in this application because the rigid bearing assembly needs some give in the part to prevent binding.

My preference is cups and seperate loose bearings (not caged); because it serviceable, stronger and stiffer than the alternatives. I use grease intended for boat trailer wheel bearings, due to low cost, very water resistant and works well.

I replace the balls whenever I service the BB. Proper tightening is critical.

Yes, that is the one I was looking at. Thanks for the correction. As well, I appreciate your insight. I suppose the reason I wanted to change/upgrade was because I had read (and have seemingly found) that the parts they use on that bike are bottom of the barrel. Moreover, I read somewhere on the net that the bearings that come on my bike wear out fast.

Perhaps the easiest thing to do would be just to replace the bearings....it would likely be cheaper too in the long run. Thanks for your tip on the grease too!
  Reply


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