Okay, I'm fed up wth the noise coming from by bottom bracket and will change it before the London to Brighton ...
I'm investigating bottom brackets and how to change. I have a crank puller, and can successfully remove and refit the cranks. Once the cranks are off, how do you get the bottom bracket out? I've not tried, as I like to know rather than bodge it.
Also, my investigations suggest that a Kona Muni-Mula has a Shimano UN40 tapered bottom bracket. Should I consider an improved part? Can I stick in a UN52/3 or UN72/3 ... what difference will this make?
Okay, I'm fed up wth the noise coming from by bottom bracket and will change it before the London to Brighton ...
I'm investigating bottom brackets and how to change. I have a crank puller, and can successfully remove and refit the cranks. Once the cranks are off, how do you get the bottom bracket out? I've not tried, as I like to know rather than bodge it.
Step 1. Buy the correct tool. (for the existing BB and the new one) Step 2. Spray WD40 liberally over the old BB. Step 3. Get up early the next morning. Step 4. Check, check and recheck which way you need to turn the damn thing Step 5. Remove the BB using GREAT FORCE. Step 6. It's now lunchtime. Go out to the pub for a snack and celebration. Step 7. Liberally smear anti-seize lubricants over the new BB Step 8. Insert the new BB making sure you don't cross thread it. Step 9. Tighten using a lot of force Step 10. Enjoy.
(The BB I removed had plastic end caps at both ends and I had to resort to a stanley knife and hacksaw and someone here actually had the temerity to state that plastic doesn't seize up in the BB!)
Regards,
Tim.
-- God said, "div D = rho, div B = 0, curl E = - @B/@t, curl H = J + @D/@t," and there was light.
"Tim Woodall" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
elyob said:
Okay, I'm fed up wth the noise coming from by bottom bracket and will
change
Quoted message said:
Quoted message said:
it before the London to Brighton ...
I'm investigating bottom brackets and how to change. I have a crank
puller,
Quoted message said:
Quoted message said:
and can successfully remove and refit the cranks. Once the cranks are
off,
Quoted message said:
Quoted message said:
how do you get the bottom bracket out? I've not tried, as I like to know rather than bodge it.
Step 1. Buy the correct tool. (for the existing BB and the new one) Step 2. Spray WD40 liberally over the old BB. Step 3. Get up early the next morning. Step 4. Check, check and recheck which way you need to turn the damn thing Step 5. Remove the BB using GREAT FORCE. Step 6. It's now lunchtime. Go out to the pub for a snack and celebration. Step 7. Liberally smear anti-seize lubricants over the new BB Step 8. Insert the new BB making sure you don't cross thread it. Step 9. Tighten using a lot of force Step 10. Enjoy.
(The BB I removed had plastic end caps at both ends and I had to resort to a stanley knife and hacksaw and someone here actually had the temerity to state that plastic doesn't seize up in the BB!)
Thanks Tim. Am on the phone to my LBS at the moment 🙂 They charge £15 for the job, and that'll save me messing it up, and having to buy the correct tools ... 🙂
"elyob" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
Thanks Tim. Am on the phone to my LBS at the moment 🙂 They charge £15 for the job, and that'll save me messing it up, and having to buy the correct tools ... 🙂
Not a bad idea if you don't need to replace BBs often. (I don't know what the quality differences are twixt UN 40 and UN 52 but I do know that UN72's and UN73's have hollow shafts to lighten them whereas the 52 doesn't.)
The advantages to DIY are obviously only buying the tool once, being able to do the job at your convenience and most importantly being able to buy BBs from sources that may be cheaper than your LBS. (Says he who went to his local LBS then H*lfords who both didn't stock the appropiate size then went to next LBS who charged top dollar (well, pounds really) but was not in a position to argue).
To remove BB remove cranks, fit tool, re-fit crank bolts with washers to hold tool in place then turn LH cup ccw to remove and RH cup cw to remove. Don't forget to remove crank bolts once the cups start to turn. Re-fit new BB using PTFE tape or grease, preferably copper anti-seize stuff. If the old 'un is seized follow the advice of the other poster :-)
When going for your new bottom bracket take the old one or get the sizing code of the old 'BB' to make sure you get the correct length. Thanks, John
"Tim Woodall" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
elyob said:
Okay, I'm fed up wth the noise coming from by bottom bracket and will
change
Quoted message said:
Quoted message said:
it before the London to Brighton ...
I'm investigating bottom brackets and how to change. I have a crank
puller,
Quoted message said:
Quoted message said:
and can successfully remove and refit the cranks. Once the cranks are
off,
Quoted message said:
Quoted message said:
how do you get the bottom bracket out? I've not tried, as I like to know rather than bodge it.
Step 1. Buy the correct tool. (for the existing BB and the new one) Step 2. Spray WD40 liberally over the old BB. Step 3. Get up early the next morning. Step 4. Check, check and recheck which way you need to turn the damn thing Step 5. Remove the BB using GREAT FORCE. Step 6. It's now lunchtime. Go out to the pub for a snack and celebration. Step 7. Liberally smear anti-seize lubricants over the new BB Step 8. Insert the new BB making sure you don't cross thread it. Step 9. Tighten using a lot of force Step 10. Enjoy.
(The BB I removed had plastic end caps at both ends and I had to resort to a stanley knife and hacksaw and someone here actually had the temerity to state that plastic doesn't seize up in the BB!)
Regards,
Tim.
-- God said, "div D = rho, div B = 0, curl E = - @B/@t, curl H = J + @D/@t," and there was light.
"Peter B" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
"elyob" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
Thanks Tim. Am on the phone to my LBS at the moment 🙂 They charge £15
for
Quoted message said:
Quoted message said:
the job, and that'll save me messing it up, and having to buy the
correct
Quoted message said:
Quoted message said:
tools ... 🙂
Not a bad idea if you don't need to replace BBs often. (I don't know what the quality differences are twixt UN 40 and UN 52 but I do know that UN72's and UN73's have hollow shafts to lighten them whereas the 52 doesn't.)
On my Pine Mountain; UN 52, I wore out 2 in 1 year. UN72, it lasted 3 years of the same treatment - buy XT; you know it makes sense.
"Eatmorepies" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
On my Pine Mountain; UN 52, I wore out 2 in 1 year. UN72, it lasted 3
years
Quoted message said:
of the same treatment - buy XT; you know it makes sense.
Yeah. My Rift Zone came with a UN72 and lasted just over 3 years, I've just replaced it with a UN73, only one removable cup and it's plastic but hopefully the bearings and seals are of XT quality. I think XT quality tapered BBs are getting like hens teeth so next time round it'll be full upgrade to Octalink or ISIS. Assuming no new bike :-(
"Peter B" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
"elyob" <[email hidden]> wrote in message "]news:[email hidden]...
Quoted message said:
Thanks Tim. Am on the phone to my LBS at the moment 🙂 They charge £15
for
Quoted message said:
Quoted message said:
the job, and that'll save me messing it up, and having to buy the
correct
Quoted message said:
Quoted message said:
tools ... 🙂
Not a bad idea if you don't need to replace BBs often. (I don't know what the quality differences are twixt UN 40 and UN 52 but I do know that UN72's and UN73's have hollow shafts to lighten them whereas the 52 doesn't.)
On my Pine Mountain; UN 52, I wore out 2 in 1 year. UN72, it lasted 3 years of the same treatment - buy XT; you know it makes sense.
Amazing: our first set of UN72s just left the tandem - after 20,000 kms!
Tim Woodall <[email hidden]> wrote in message news:<[email hidden]>...
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(The BB I removed had plastic end caps at both ends and I had to resort to a stanley knife and hacksaw and someone here actually had the temerity to state that plastic doesn't seize up in the BB!)
It's not, in my experience, seizing that seems to be the problem with plastic BB cups, more the way that they tend to crack and/or chew up the minute you try and remove them :-(
