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Wednesday, April 15, 2020

Boardman - Bottom Bracket replacement


These are renowned for their lack of durability especially when compared to the old square tapered ones.

I looked back over my Strava records and I reckon I have done roughly 1000 miles on the bike since I bought  it in October 2019.  The person I bought it off had already changed the BB so if that was a fairly new replacement, then the total mileage on it  may only be around 1500 at a guess.

There are so many different types of BB used on bikes and  I had trouble in finding a better option quickly so I bought like for like.   A good source of BB information is  here.

The crank spindle is 30mm diameter and the BB shell is 68mm wide with an internal diameter of 46mm, so a better replacement will be the Rotor PF 4630, but these are out of stock at the moment.

Once the crank is removed then getting the BB out can be a problem with push fits as they require special tools, but there is always YouTube.  Watching a video on  there, where he made a removing tool gave me an idea.  The tool he made was basically this one.

I bought this to remove head tube cups on another bike and as luck would have it I was able to use it on the BB.

A couple of taps with the rubber mallet and they were out.

Keep a note of the order they were fitted.

Replacing the new BB , its marked which side goes where.

This tool I made to clamp the head set cups in place and its ideal for this job too, cheap and all the bits from a hardware store.

All back together and only a slight adjustment to the front mech was needed.

How long will it last, we'll see.


  1. Glad fitting went well Dave!

    1. Thanks Mick. I took it for a test ride and checked the tension on the cranks afterwards.

  2. I am, as always, astonished by your mechanical ability. I remember when you replaced a headset, and now a bottom bracket. My approach, due to my limitations, is to take it to a bike store and hand the bike, and money, to the guy behind the counter.
    In response to your comment on my post, I think we are sort of in lock down. We're only supposed to go out for food or prescriptions. Restaurant food is take out only. No bars, gyms, or movies. It's not as strict as France, the police don't stop you and ask for your permission form. It's tedious.

    1. Thanks Alison, I enjoy jobs like this but when it comes to wheels I take it to the bike shop.
      I completely understand about the toilet rolls and we have the same here, because of all the panic buying which has gone before you can never be sure that there will be future supplies. We are allowed out for shopping and exercise and the vast majority have kept to that, there's always some that dont though. Living in a village in this situation is far better than a city. Take care.

  3. Good job on utilizing the tool for another project...and I know you saved a lot of money doing it yourself! It is good to have projects to keep your mind busy. 1,000 miles since Oct that's a lot!! Enjoy..

  4. Thanks Sondra. It's the same as when you do jobs, its not only the money you save but the pleasure you get from having done the job and also the learning thats comes with it. In this emergency bike shops are one of the key industries that are allowed to stay open so I could have taken it to a shop but then there's the hassle of transporting etc. and the time they would have needed the bike.
    Remember I ride with the club so if we go out twice a week thats around 100 miles per week and 1000 miles for this type of bearing when compared to similar set ups on other bikes is relatively short. But now I know how to fix it.........

  5. Something to be said, perhaps, for old fashioned cup and cone BBs?

  6. Indeed Avus or at least have some sort of standardisation.

  7. Wow...you are amazing. Not only able to fix your bike...but a 1000 miles. How I long to be in wide open spaces!!

  8. Thanks Wanda, its a labour of love!.


As you have taken the time to read my blog and comment then whenever possible I will always reply. Thank you. Dave