Trek 4300 Bent Bottom Bracket

[Aditya Yadav]

Hi,

My Trek 4300 (2012 from BOTS) has a bent Bottom Bracket, when pushed hard it makes a pretty bad sound.
Karan figured I need to replace it asap as it'll only get worse and may damage the frame.
BOTS doesnt have this in stock and it sounds like this part is hard to get.

The bike is just 4 months old. I have done about 3-4k on it, alot of which is to-fro office. (30km per day)

The specs are (directly from the sticker on the BB):
BC-73
BC 1.37x24T
VP Components
L <-- 124.5mm --> R
I cant find 124.5 anywhere on chaireaction, evans, jenson etc.
Anywhere else I can get this from?

Thanks,
Aditya

[Arvind Ganesh]

Shouldn't it be covered by the warranty?

See if this helps http://bicycles.stackexchange.com/questions/3874/clicking-sound-coming-from-pedals-pedal-spindle-crank

Otherwise, from what I can gather it appears that a 73 x 122 BB will fit - there are plenty on ebay. Ask BOTS before you order.

-Arvind

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[Sreepathi Pai]

Decathlon had a stock of BBs from VP Components.

124.5 is not a hard requirement -- you can use a shorter one provided
you still clear the chainstays.

--
Sreepathi Pai

[Aditya Yadav]

Arvind- I am hoping it is covered in the warranty, I'll confirm that with Rohan again but I guess he would have proposed that as the first solution!

Sreepathi, Arvind- Rohan said nothing smaller than 124 would do. Not sure if 126 would be fine.

Sreepathi- I just called up decathlon and they say, they have no Bottom Brackets.

How does the warranty exactly work in these scenarios? You let the LBS (BOTS in this case) handle it or you have to fight it out with Trek yourself?
Is their a chance my warranty goes void if I get a part myself and get it replaced? That would happen if I replaced the thermal paste on my processor and heatsink.

Thanks,
Aditya

On Tuesday, July 17, 2012 3:35:14 PM UTC+5:30, Sree wrote:

Decathlon had a stock of BBs from VP Components.

124.5 is not a hard requirement -- you can use a shorter one provided
you still clear the chainstays.

[Aditya Yadav]

Arvind- http://bicycles.stackexchange.com/questions/3874/clicking-sound-coming-from-pedals-pedal-spindle-crank
This is the exact same issue I have. It runs out it was the BB.
--
Aditya

[Vasu]

This is a good excuse to get hollowtech BB (bottom bracket) and cranks... make your bike lighter too. I 'think' it will fit.

V

[Aditya Yadav]

Does the "Bottom Bracket" comes in the "components", or VP components is supposed to take care of this?

http://www.trekbikes.com/us/en/support/warranty

"

2 years

• Session (carbon) model frames and swing arms
• RIDE+ motor, controller, & battery pack (or 600 charges, whichever comes first)
• All original Bontrager forks, parts and components (except consumables such as tires and tubes)

This warranty applies to 2011 and newer model bicycles and covers only Trek and Bontrager branded products. Any other original part or component shall be covered by the stated warranty of the original manufacturer. Any products not specifically included above are hereby omitted.

   "

Vasu- Nah not yet. I dont think I need an upgrade yet! May think about it if there is no other option!

--

Aditya

On Tuesday, July 17, 2012 4:20:19 PM UTC+5:30, Vasu wrote:

This is a good excuse to get hollowtech BB (bottom bracket) and cranks... make your bike lighter too. I 'think' it will fit.

V

[Aditya Yadav]

I am not sure how important the spindle length 124.5 is.
The two BBs I found which match in all aspects (i.e. shell width, tapered sqaure and threading) but not Spindle Length are:
Shimano UN26 http://www.jensonusa.com/Bottom-Brackets/Shimano-UN-26-Bottom-Bracket
Shimano UN53 http://www.jensonusa.com/Bottom-Brackets/Shimano-UN53-Square-Taper-BB
Shimano UN55 http://www.chainreactioncycles.com/Models.aspx?ModelID=71369
These are 122.5 and I guess are my best bet.
I have no idea whats the difference between the 3, but I guess I'll get the cheapest one.

How can I find out if 122.5 will fit my bike?

126mm is not an options as it comes in octalink only.

Thanks,
Aditya

[berkeleydb]

check with RR Cycles, Madivala.  they said few weeks backs they have them in stock.  do make sure you double check the specs (dimensions etc.) for what they have.

-{db}.

[George Joseph]

I seriously doubt anyone could bend a bottom bracket. The spindle is
VERY thick - more than a cm of solid steel or Chro-Moly. If it is
cracked thats a manufacturing defect.

If it sound like grinding noise it could be that your BB needs to
tightened or the bearings are gone. Now depending on the type of BB
Trek installed you might have to toss the whole BB. Get the mechanic
to show you the spindle and bearing and look for a crack or a fracture
of some sort in the BB spindle.

Again as another poster said, it should be under warranty since its
less than a year old. Don't buy the argument that its "normal wear
and tear".

Good luck,

George Joseph
gjos...@gmail.com
IN cell: 91 94-83-501169
NA cell:1-847-859-9591

[Aditya Yadav]

Hi,

db- BOTS people are looking for the BB. If they cant find one, then I'll head to RR.

George- You cant see the bend in the BB, but if you hold it and spin it around, you can feel its not turning around its axis. It becomes visible when the chainring wobbles.
The plan is to replace the whole BB for now. Karan didnt open up the BB, but from the wobble it was clear something is faulty. It could be a bend/crack/fracture.
For now he has greased the BB. There wasnt any sound on my ride back from BOTS but the wobble is there.

I mailed Trek, Firefox bikes and VP components about this. No reply from any of them. I couldnt get a contact number for any of them. Just mailed everyone!
I am not sure if BOTS will consider it under warranty or not. For now I hope they find the right sized BB and I can start riding again!
The Trek website says they, cover only Trek and Bontrager parts. I dont know if they cover anything else including shimano stuff on the bike.

Thanks,
Aditya

[George Joseph]

Who makes your bb?  It's not a trek/bontrager part?

Worst case it won't cost that much to replace. 

George Joseph

IN Cell: 9483501169

NA Cell: 847-859-9591

-sent from my iPhone 4S

[Aditya Yadav]

From the sticker on the BB it looks like these guys make it.
http://www.vpcomponents.com/newen/product_detail.php?id=240

I am hoping it comes cheap, but the priority is to get the bike working without any noise!

--
Aditya

[George Joseph]

Vp sells there own stuff and makes parts for all sorts of bike companies. 

It should be affordable. :) 

George Joseph

IN Cell: 9483501169

NA Cell: 847-859-9591

-sent from my iPhone 4S

[berkeleydb]

aditya,

i had to replace the BB on my Trek4300D few months back.  couldn't get the same part back then, so the RR guy put in one of type 'open', not 'sealed' as a temp solution.  and then (as i mentioned in my last post) he showed me the 'sealed' one few weeks back.  so they (should) have it in stock.  i think what they have is Shimano, not sure.  the other brand they mentioned was Suntour.  (don't recall now which was the brand for the 'open' one that they have put in my bike; Suntour or something else.)

i'm still having some noise coming from the front assembly -- either it's still related to the BB, or maybe it's simply a pedal that needs to be replaced.  will be getting some investigation done during the next maintenance.  hoping it's not an issue with the bike frame.

best of luck with your issue!  hope it's resolved properly / quickly.

-{db}.

[Aditya Yadav]

Hi,

BOTS got a Shimano 73x123 BB and it fits pretty well on my 4300! The annoying noise stopped and the bike is super smooth again!
I hope it sticks around for years to come!

db- looks like 4300 BB has issues. The stores should start stocking spares.

Thanks for the help everyone. Looks like Sreepathi was right. The spindle length aint a hard requirement.
--
Aditya

[nilesh dhumal]

Nice the bike is in no pain now,  just love well maintained bikes