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Newbie Bottom Bracket
#1
Hello Everyone,

My wife has a Giant Revive (comfort bike, way adjustable but heavy).

I had the crank and bottom bracket replaced when the bike was new due to the gear range being too high. Changed the front crank to a 36 tooth single (it has a rear hub so the front is a single speed). Also changed the rear cassette to a Megarange.

She is happy with the arrangement, however today had a mechanical problem. She hadn't reported any issues until the left crank arm fell off. Inconvenient but not Earth shattering since we where a half block from home when it came off. I looked to see if I could find the crank bolt but no luck. No biggie, new crank bolt coming up. Bolt in hand I was further surprised to find both bearing cups loose (finger tight) and the threaded insert in the center of the axle missing as well.

Is this repairable (threaded insert available) or am I up a creek?

Here is what I know, the crank is an FMF 160mm splined unit. The bottom bracket is splined axle, looks like 20 spline cups (internal) possible FSA unit?

Any help you could give me would be much appreciated.

Thanks in Advance,

Randy
  Reply
#2
Hi Randy;

Pictures needed of what you have.

There generally no threaded insert in the center of the axle...does the bike have a BB cartridge; or separate parts:
http://www.amazon.com/Pyramid-Bottom-Bracket-Axle-Type/dp/B000BMNQVW/
http://www.amazon.com/Wald-Bottom-Bracket-1990-24Tpi/dp/B003UPZLI8/
cartridge:
http://www.amazon.com/Origin8-Alloy-Cartridge-Bottom-Bracket/dp/B002I7MAME/


I am guessing you have something like this:
http://www.amazon.com/Truvativ-Power-Spline-Bottom-Bracket/dp/B002BBZOXY/
Nigel
  Reply
#3
(10-01-2011, 12:42 PM)nfmisso Wrote:  Hi Randy;

Pictures needed of what you have.

There generally no threaded insert in the center of the axle...does the bike have a BB cartridge; or separate parts:
http://www.amazon.com/Pyramid-Bottom-Bracket-Axle-Type/dp/B000BMNQVW/
http://www.amazon.com/Wald-Bottom-Bracket-1990-24Tpi/dp/B003UPZLI8/
cartridge:
http://www.amazon.com/Origin8-Alloy-Cartridge-Bottom-Bracket/dp/B002I7MAME/


I am guessing you have something like this:
http://www.amazon.com/Truvativ-Power-Spline-Bottom-Bracket/dp/B002BBZOXY/

NFMisso,

Thanks for the response,

Shame on me for not investigating further before posting.

I looked online and have determined the BB was replaced with an ISIS unit.

I had just went to bed when the thought occurred to me, I got up and took the crank bolt from the sprocket side of the crank and it fit perfectly.

I now need an ISIS crank bolt, I understand it comes in either 12 or 15mm.

I'm going to have to purchase a crank puller and a splined cup tool to tighten the cup to the BB as they were only finger tight.

I'm going to a local bike shop that is well equipped and should have what I need.

Question: How tight should I tighten the cups? Do they both bottom out of does one "center" the BB while the other butts against it or does it adjust laterally?

Thanks Again,

Randy
  Reply
#4
Hi Randy;

I strongly suggest that you watch Alex's videos on the subject above.

The text that you can see for free is enough if you are mechanically inclined.
Nigel
  Reply
#5
Excellent,

I'll do just that.

Thanks again,

Randy
  Reply
#6
Ye, 10-4 to what Nigel said.

See if the noise is there when you are not pedaling.

I had a noise like that on my bike and it turned out the frame mounted pump moved and the pedal was hitting it. Check crank rotation carefully.
Never Give Up!!!
  Reply


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