Emergency, bottom bracket issue.

Captain Havoc

Hi all, the other bike is in the LBS again (or still in) so I went to the shop on the road bike. When I peddle it's kind of vibrating a bit, I believe the bottom bracket to be the issue. I'm supposed to be going out in the morning. I know, I need to learn more about the bike instead of going to the LBS with every single issue but is there something I can do to a) diagnose what exactly is wrong and b) once we find out what the issue is, can we fix it?

I'm assuming the BB is broke or loose in some way. If the BB is broke can I (someone with the decent head for figuring stuff out) fix it, what would be a decent BB to buy and from where? (I obviouslly know I won't have one by the morning)

short circuit

On a bike every sound will seem to come from the BB ... but BBs can take some level of punishment unless they are installed incorrectly. Best thing is to eliminate the rest before touching the BB unless you know how to and you have the right tools.

Seatpost, Saddle, pedals, tyres, quick levers, valve nuts, headset ... do a quick check on all these before going near the BB.

What groupset do you have and what BB ... is it an external BB .. if so, swapping is easy with the BB tool ...

105, Ultegra BB are easily available for under 35euro. If its FSA, the BBs are not readily available locally and you will have to go online or prepared to wait a few days. But having said that, some people on the forum have mixed Shimano and FSA BBs and Chainset without any problem.

Get hold of the cranks and try moving them violently ... they shouldn't ... if they do you've a problem. Else you might be OK. Sometimes a replacement might not be required .. just taking it out, regreasing and getting it back in.

Replacing should take less than 15mins if you have a bike shop open in the morning .. you might still be able to get a ride in tomorrow.

Captain Havoc

Thanks for that, the only bike place open tomorrow is Halfords. I'm on Hollowtech II. There's a slight movement in both pedals which is why I think it's the BB area. I'm supposed to be going with the club in the morning, it's something I only get to do every 3 weeks (as I work most Sundays) which is why I'm anxious to get it sorted. If my mountain bike was fixed I'd just bring it out to the farm but the bike shop isn't lending it out to me this week.

short circuit

What tools do you have ...

If nothing, then there is only 1 thing you can try ...

On the non-drive side, there should be 2 allen bolts holding the crank arm to the chainset, loosen them fully ... tap the chainset using a rubber or wooden mallet from the drive side into the BB. Push the non-drive crank arm as far onto the chainset as possible and retighten the allen bolts.

What taking out and regreasing the BB would look like would be ...
1. Take off the allen bolts from the non-drive side crank arm
2. Take off the cap on top of the non-drive crank using the Shimano tool
3. Pull off the non-drive side crank
4. Pull off the drive side chainset
5. Use BB tool to take off the cups on both sides .. there is an arrow to indicate how they go on and how they come off on the shimano ones
6. Clean the BB area and regrease the threads. THe BB itself is not servicable
7. Reverse the above taking care that the cap which goes on the non-drive side crank is just to press down on the bearings and is not a load bearing screw ... so only about 5Nm. Its the allen bolts on the non-drive crank which hold the entire thing together.

Hope its of some use.

Video for BB installation
http://www.youtube.com/watch?v=N9y3RlVRGz8

irishmotorist

Captain Havoc wrote: »

There's a slight movement in both pedals which is why I think it's the BB area.

Just to be clear, is the bb axle moving laterally rather than rotationally? That should be fairly fixed in that regard and shoudn't wobble that way. Could it be the pedals that are wrong?

Captain Havoc

irishmotorist wrote: »

Just to be clear, is the bb axle moving laterally rather than rotationally? That should be fairly fixed in that regard and shoudn't wobble that way. Could it be the pedals that are wrong?

I tried to move it when stationary and it seems normal but when I was riding, it felt like there was a wee wobble or vibration. It could be, I'm going to take a look at it in the morning.

The tax man

Lidl have a very good returns policy IIRC. Just dump the bike with the checkout person and tell them it's broken. Instant refund if you still have the receipt.*:D




*only joking man, hope you get things sorted out in the morning.

+1 on the advice from short circuit. If you don't have those tools, you really need to get them. You'll have the perfect shed to carry out all your own repairs soon.;)

Captain Havoc

That'd be one of these:

, correct? Anything else cheap I should order while I'm online? (without taking the p1ss if that's possible )

The tax man

Make sure you get the BB tool with the little thing to remove the end cap off the left crank.


Found above on CRC.

short circuit

If you are going to do it, do it properly ... I recommend this ..
http://www.wiggle.co.uk/p/cycle/7/LifeLine_Workshop_Tool_Kit/5360031531/

Have had this for a year now ... and apart from fitting or removing headset, this can do pretty much everything. I know people will say just buy what you need now and build it up ... and that the kit above counts a multitool, a small parts cup and tyre levers in what they offer. But if you buy individually, you will spent 8 to 10 euro every time and spend a lot more.

Stuff I have used the most
1. Cone wrenches for the wheels
2. Cable cutter
3. BB tool
4. Spoke wrench - especially when an individual spoke breaks or loosens
5. Chain tool ... though I broke it last week (don't ask .. long story)
6. Chain whip

Over the last year, I am sure I have saved a lot more than what it cost.

SC

blorg

I have the same kit as short circuit; got it when it was discounted. Also check out PBK, they do similar/the same kits. It works out a lot cheaper than buying all the tools individually; the cable cutters alone costs around £20 IIRC (and a cable cutters really is essential.)

Captain Havoc

Thanks for all the help fellas, I took short circuits advice, I don't know exactley if it's regulated as I was in the loose cleats today but I put in a good solid performance so that's grand. blorg, you are a bad influence, I just ordered a tool kit, sorry I mean this one but while I was there I saw these and thought about how pretty they'd look with my MCC jersey and my black and yellow helmet, they were in the clearance section with €10 off. I've had bloc before and they were the only decent pair of glasses I've ever used so I decided to go with them. Seriously blorg, I need to do more of this stuff myself otherwise my bike will spend most of the time in the bike shop and I'll keep on throwing money his way while I'm skint, so I do see it as money well spent, plus it's a good job you pointed out PBK as it's the same as the wiggle one only €18 cheaper.