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Replacing crankset and bottom bracket

Posted: Fri Aug 03, 2012 9:31 pm
by steve_hobart
Al and carbon bike has a Gossammer crankset and I am thinking about changing it over to a new Hollowpoint Ultegra 6750 with new bottom bracket.

I've never attempted this before though (however I am keen to learn) and just wonder if this is too ambituous a project for me to attempt.

Are there any helpful instructions or videos of how to do this?

Also, how I can I tell if my frame will accept the ultegra hollowpoint BB?

cheers

steve

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 9:52 am
by Bentnose
I think you mean an Ultegra Hollowtech 2 bottom bracket, as long as your drivetrain isn't too badly worn you could do this, if the cassette and chain are worn you would need to change them also. The Park Tool website has some good how to's, the main thing is you'll need to buy some tools, have a look at the Park Tools website first.

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 10:34 am
by A_P
Frame type? Is your existing BB a screw in type (either external or internal)? If so, then its a relatively simple job.
You will need the shimano BB wrench at least, and some allen keys.

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 11:32 am
by RonK
Looking at the FSA web site I can see there are several different types of bb's used with gossamer cranksets.
What type do you have?

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 2:47 pm
by steve_hobart
Thanks for all the info so far.
The existing crankset is a gossamer megaexo 34/52t with integrated spindle.

I'll have a look on the website and see what bb I currently have...

The learning continues!
Cheers
Steve

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 4:53 pm
by RonK
No need - the mega exa is an external bottom bracket, the same as the Shimano Hollowtech. These are very simple to install, as the external bearing cups simply screw into each side of the bb shell, the integrated spindle is inserted, and the left crank fitted and locked on the the other side.
As has been stated you will need the Shimano tool for the external bearings but you should be able to get one from a decent lbs for around $40.

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 5:18 pm
by steve_hobart
thanks. Looks like it is reasonably straight forward - although the shimano instructions for removing and replacing cranks looks a little fiddly

I'll probably change over to an ultegra rear cassette (from the 105) and Ultegra chain as well - then I guess there will be fron and rear derailur adjustments.....

I'll keep investigating and having a think about whether I should take this on myself...maybe a bit ambitious for me at this stage of my experience...

(STeve - the challenged mechanic!)

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 5:30 pm
by AndrewBurns
Doing what you want to do is pretty easy, as has been stated if the chain and cassette have wear you may as well change everything at once because mixing parts with different levels of wear can cause shifting problems and accelerated wear of the newer parts. You will probably have to adjust the derailleurs slightly but that's easy as well. I say go for it, once you get it done you'll never have to go back to getting somebody else to look after your bike.

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 5:44 pm
by steve_hobart
AndrewBurns wrote:Doing what you want to do is pretty easy, as has been stated if the chain and cassette have wear you may as well change everything at once because mixing parts with different levels of wear can cause shifting problems and accelerated wear of the newer parts. You will probably have to adjust the derailleurs slightly but that's easy as well. I say go for it, once you get it done you'll never have to go back to getting somebody else to look after your bike.


Thanks for the encouragement. Actually my plan is to learn enough so that I don't have to keep going back to the lbs every time I need some adjustment...the lbs r really good but I feel silly going in every few months to get dereailur and brake adjustment when I should be able to do it myself... And I guess I'll eventually save money... Maybe even build my own bike one day....

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 7:46 pm
by Stuey
Steve, the best thing is that no-one here takes the mickey if you ask questions. So go for it.

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 8:22 pm
by Mulger bill
Go for it Steve, it's actually a fairly straightforward job, perfect really to start getting your hands dirty.

Apart from the parts and tools, you'll need grease, a couple of rags, some kero, coffee (during) and beer (after :wink: ).

YOUTUBE has plenty of how to vids to get you started. Feel free to ask here if you get stuck, there should be someone hanging around The Shed who can talk you through it :D

Let us know how you get on.

Shaun

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 11:01 pm
by steve_hobart
Ive been having a look at the Wiggle web site..Not sure how I determine what axle length I need (165 mm etc) - I am assuming that this refers to axle length?

Is there only 1 ultegra chain that I should choose? Im also guessing that any of the ultegra rear cassettes would work?

cheers

Steve

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 11:08 pm
by AndrewBurns
The 165, 172 etc refers to the length of the crank, for your purposes the axles are all the same length. There is only one kind of 10 speed Ultegra chain that I know of, just be sure that it's the 10 speed one (unlikely that it would be anything else). You can also use pretty much any other 10 speed one, KMC make good chains too.

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 11:15 pm
by bosvit
Generally Ribble is cheaper than Wiggle

www.ribblecycles.co.uk

This is a great site for comparisons

http://frugalrouleur.com/

The advantage of buying from your lbs is they will more likely be willing to give you instillation advice, but is it worth the extra cost?

Re: Replacing crankset and bottom bracket

Posted: Sat Aug 04, 2012 11:20 pm
by steve_hobart
Many thanks.

I have been overwhelmed by the assistance offered by everyone, your willingness to help and your patience with a noob like me who is probably asking silly questions and trying to take on an overly ambitious project especially with my lack of knowledge and experience :-)

thanks again

steve

Re: Replacing crankset and bottom bracket

Posted: Sun Aug 05, 2012 8:24 am
by Bentnose
With the Ultegra cassette, now is a good time to look at your gearing, what do you have now and would you like the gears to be harder or easier? You can also install a compact 34/50 or normal 39/53 crankset, you need to have a think about this as you can fix any gearing issues that you have.

Re: Replacing crankset and bottom bracket

Posted: Sun Aug 05, 2012 10:42 am
by RonK
steve_hobart wrote:Ive been having a look at the Wiggle web site..Not sure how I determine what axle length I need (165 mm etc) - I am assuming that this refers to axle length?

Is there only 1 ultegra chain that I should choose? Im also guessing that any of the ultegra rear cassettes would work?

cheers

Steve

As posted this is the length if the crank arm. Typically a road bike of around 56cm will have 172.5mm arms. Bigger frames may be fitted 175mm arms, smaller frames with 172mm arms. 165mm is a very short arm.
Your current crankset likely has the length marked on the back of the arms.

Re: Replacing crankset and bottom bracket

Posted: Wed Aug 22, 2012 11:43 pm
by steve_hobart
It has been a while since I have posted this thread, however since this thread I have completely changed over my drivetrain to Ultegra including bottom bracket, Ultegra 6705 (compact crank), installed a 6700 rear cassette (11-28) and replaced the chain with an Ultegra 6701. All for less than $300.
I have also retuned slightly the front and rear derailer.

I have never done any work on a bike before, so I am thrilled with the job, Everything went very smoothly - in fact it was a straightforward and relativey easy change that took 2 hours all up.

The bike is noticeably lighter and changes much more smoothly than my previous set up (which was a Gossamer compact crank, 105 rear cluster, 105 chain with Ultegra rear derailer. It is now running and changing gears very smoothly (in the work frame).

Looking forward to my first test ride this weekend.

I will post some progressive photos in the next few days.

Many thanks to all of you on the forum, "ZInn Road Bike Maintenance" and "Bicycle Tutor" (on line).

Cheers

Steve :-)

Re: Replacing crankset and bottom bracket

Posted: Thu Aug 23, 2012 6:19 am
by AndrewBurns
Well done Steve, we all knew you could do it 8)

You can do almost anything to a bike with a few fairly cheap tools and the internet to guide you, I started riding maybe a year ago now and have never taken any of my bikes to a bike shop for repairs because I almost enjoy servicing them as much as riding them :P

Re: Replacing crankset and bottom bracket

Posted: Thu Aug 23, 2012 6:36 am
by RonK
Confidence Steve - next thing you'll be building up your own bikes. Nothing more satisfying than that.

Re: Replacing crankset and bottom bracket

Posted: Sun Sep 09, 2012 9:16 am
by Releng
Steve,
Well done on the upgrade, a good example to build the confidence of all of us amateurs. And the thread is a good example of just how good this forum is.

Are you planning to offload the old crankset? It is just what I need for my commuter, I get down to Hobart quite often and would be happy to discuss adequate compensation. PM me if you are interested.

Mick