Woosh Big Bear Bottom bracket

[Benjahmin]

The bottom bracket on my wife's 2014 Big Bear LS is making cracking sounds. I'm guessing it needs replacing. The spec tells me it's a cartridge type.
I've never done a bottom bracket before so any help/info would be much appreciated.

 

[Woosh]

it's easy to replace the bottom bracket. The replacement should be a 68x122 bottom bracket.
I usually replace the old one with 68x127 cartridge type so I can replace the old pedal sensor with a left side pedal sensor at the same time.

 

[sjpt]

Probably best to search online for YouTube or non-video instructions that suit you best.

One important thing: when you use the crank puller make sure (1) you have removed the crank bolt, and (2) the inner part of the puller is fully unwound, and the puller is fully screwed into the crank. Then screw the inner part of the puller forward to push the crank off. If you omit (1) or (2) you will strip the thread on the crank.

 

[Benjahmin]

Thanks Both.
Looking at 68x122 brackets, some are labelled british thread, like this one

Shimano BB-UN300 Tapered Bottom Bracket British Thread | Tredz Bikes

Save up to 38% - Shimano BB-UN300 Tapered Bottom Bracket British Thread from £14.99 or available with 0% APR finance on baskets over £99. All Square Taper are delivered free to the UK mainland*, 365 day returns & Price Match. Buy Now.

www.tredz.co.uk

others don't specify. Any clues?
Tony, what tool will I need for removal?
As the pas is working ok, am I liable to break it on dis-assembly so needing replacement?

 

[Woosh]

Looking at 68x122 brackets, some are labelled british thread, like this one

others don't specify. Any clues?
Tony, what tool will I need for removal?
As the pas is working ok, am I liable to break it on dis-assembly so needing replacement?

If everything is still working, may be a little sand has got inside the ballbearings on the left and right cups. Did you try to grease it?
Thread: BSA BC 1.37x24.
don't use the Shimanos. They are good quality but the diameter of their spindles is a tad too big. In case you want to replace the pedal sensor with a left side one. Buy a cheap Chinese NECO BB on ebay. We do have replacement parts but the post charges so much that you would get it cheaper on the net.

Tony, what tool will I need for removal?

Ask Andy@wooshbikes.co.uk for recommendations. I just use whatever I have at hand.

Pardon our interruption...

As the pas is working ok, am I liable to break it on dis-assembly so needing replacement?

it's unlikely. Just hold the PAS sensor head while you undo the chainside cup. Note that the thread on the chainside cup is left hand. If in doubt, remember this: turn the cup in the same direction as you pedal.

 

[Benjahmin]

Thanks.
Turns out I have a tool, must have bought it yonks ago, perhaps to change the chainguard.
Neco BB ordered from bankrupt bike parts - now to find the anti seize compound !

 

[guerney]

now to find the anti seize compound !

My BB was seized, had to position the other side over a vertical metal spike and hammer on the frame around the BB. Galvanic corrosion is a bitch.

 

[saneagle]

The bottom bracket on my wife's 2014 Big Bear LS is making cracking sounds. I'm guessing it needs replacing. The spec tells me it's a cartridge type.
I've never done a bottom bracket before so any help/info would be much appreciated.

Are you sure the noise isn't coming from the square taper? Try tightening it first. Also, check the pedal bearings. They normally wear before the BB.

Another knocking sound you can get is when there's side to side movement in the BB, which is pretty harmless. You adjust that with the left side retainer.

To loosen the retainers, you bash the arm downwards when it's pointing forwards. That's the same on both sides because the right side has a left-handed thread. It helps a lot to use the crank bolt and a washer to hold the BB tool in the BB while you bash it, otherwise it jumps out and damages the splines. That only works with the ones that have flats for a large adjustable spanner or whatever.

 

[saneagle]

My BB was seized, had to position the other side over a vertical metal spike and hammer on the frame around the BB. Galvanic corrosion is a bitch.

Next time, try heat. It always works for me.

 

[Benjahmin]

Are you sure the noise isn't coming from the square taper? Try tightening it first. Also, check the pedal bearings. They normally wear before the BB.

That's certainly a possibility, the crank bolts and the bottom bearing nuts were too easy to remove. They've now been put back on tighter while I'm waiting for the new BB.

 

[Benjahmin]

Just spent a week camping and cycling the Somerset levels - flat but some very bumpy little lanes.
Bottom bracket behaved perfectly but wife reported intermittant power delivery. Having eliminated brake switches I took the crank off to find the pas disc in about 6 pieces. One magnet had fallen out but stuck to the chain guard bracket, lucky me. I put it back together with a combination of superglue and some sticky backed velcro found in the bottom of my tool bag. Took a bit of fettling but it lasted the rest of the week without a hitch.
Try that with a 4K Bosch bike !
Anyway, the existing disc is a 6 magnet. will strip it out in the morning to find the diameter and get one ordered.
The Big Bear trundles on.
A one piece would be nice but I'm not sure what plugs are on the sensor. Also bit wary of hitting compatability problems with a Lishui controller.

 

[Woosh]

Do you need a new sensor? Email Andy if you do. He has magnet disc and sensor.

 

[Benjahmin]

Thanks Tony, will do.

 

[saneagle]

Just spent a week camping and cycling the Somerset levels - flat but some very bumpy little lanes.
Bottom bracket behaved perfectly but wife reported intermittant power delivery. Having eliminated brake switches I took the crank off to find the pas disc in about 6 pieces. One magnet had fallen out but stuck to the chain guard bracket, lucky me. I put it back together with a combination of superglue and some sticky backed velcro found in the bottom of my tool bag. Took a bit of fettling but it lasted the rest of the week without a hitch.
Try that with a 4K Bosch bike !
Anyway, the existing disc is a 6 magnet. will strip it out in the morning to find the diameter and get one ordered.
The Big Bear trundles on.
A one piece would be nice but I'm not sure what plugs are on the sensor. Also bit wary of hitting compatability problems with a Lishui controller.

Well done for fixing it. One time, I was out riding and a magnet fell out of my 10 magnet disc. The KT controller is so responsive that every time the missing magnet passed the sensor, it cut the power until the next magnet passed. The bike was almost unrideable because of the power jerking on and off all the time, but I managed to complete the 5 miles home. Unfortunately, it was all uphill (Ironbridge Gorge), so I needed the motor to help, otherwise I'd have switched it off.

 

[Benjahmin]

Pas disc ordered Fridat am, arrived Saturday am, fiteed this afternoon. All working fine.
Thanks guys.
Kept the old stuck together disc just in case !