Crank removal for installing new crankset and BB ?

weeksy59

OK, so my new Crankset arrived.

When i fitted my BB a few weeks back i couldn't get the crank arms off so ended up taking to LBS to have it done.

So i now have a BB tool, with Octalink addon for the BB. So i'm good there, however getting the crank out seemed VERY hard even for this fella in LBS. I'd assume it may be a little easier now as he'll have in theory done the correct torques etc.

So i'm running a Truvativ GXP crankset and BB.

I have a 10mm allen key, followed by an 8mm allen key to remove the non-drive side..
Then... the drive side...

So my crank puller tool looks pretty much like the below... I'm assuming i screw this into the thread in the non drive side and that simply pushes the other side out ?

What's holding in the drive side arm ? If i look inside from non-drive side, i have a flower type pattern on the edge of thread, which is i guess the limiter for allowing the crank arm to only go in a certain ammount... is this sort of sprung to hold the arm in place ?

nicklouse

you dont need a crank puller.

just undo the 8mm leave the 10mm alone as it pull the arm off.

then push the axle through and the drive side comes off.

have a look at the GXP info on Parktools.

weeksy59

I've looked there mate. However i'm obviously missing something obvious here.

So, just undo the 8mm and then a bit of pulling etc.?

nicklouse

yep the allen headed parts on the non drive side are self extracting.

weeksy59

Thanks mate... sign in about 4.40pm i'll be needing you again when i get home and can't manage it for some reason

weeksy59

Well, that was (i hope) ridiculously easy. Crank pulling tool made getting the non-drive side off in a matter of seconds. The BB tool did the job superbly... I am well impressed with how easy it was.

My only concern, is with spacers and chainline. Because i wasn't swapping off like for like (Tuvativ to Shimano) i wasn't 100% on the spacers within the BB. I put 1 on each side, fitted it all up, tightened it all up and looked at the lines and the chain was rubbing on the inside of the mech and made it obviously not run straight. I don't believe this was the case previously so i removed everything, re-fitted with a second spacer on the drive side, moving the chainline 2.5mm outwards, it then runs perfectly within the mech and straight and true.

So the question is i guess..... Do i need to do it this way ? Or should i remove it all, refit the BB with 1 spacer and do whatever is needed to move the front mech 2.5mm towards the frame, therefore then making it aligned (but closer to the frame) ?

Pics below.

cooldad

Did you read the instructions?

cooldad

Depends on your BB shell - 73mm one spacer on the drive side. 68mm two on drive side, one on non drive side.

cooldad

ps your pics have given me a headache.

weeksy59

cooldad wrote:

Did you read the instructions?

Yes but even with the pretty pictures, they confused me slightly.

Edit, reading the Commencal forum i have a 68mm shell.

nicklouse

[quote="weeksy59"re-fitted with a second spacer on the drive side, moving the chainline 2.5mm outwards, it then runs perfectly within the mech and straight and true.[/quote]

sorry but you have noy changed anything. the only thing you may have done is killed the bearings.

for a 68mm BB you only have one spacer each side.

chain line is altered (is needed) by changing the non drive side spacers.

nicklouse

cooldad wrote:

Depends on your BB shell - 73mm one spacer on the drive side. 68mm two on drive side, one on non drive side.

NO.

weeksy59

OK then... so lets analyse it...

Firstly, what's my solution ?

I've not actually run the bike, i've only had it upside down working on it.

So, if i fit only 1 spacer each side, my chain is rubbing my mech...

my shell deffo seems to be 68mm... According to Commencals tech specs.

So... tell me the plan fella.

weeksy59

nicklouse wrote:

chain line is altered (is needed) by changing the non drive side spacers.

How exactly is that possible ? if i fitted 10 spacers (hypothetically) on the non-drive side, that won't affect the chain line as obviously the drive side is still only 2.5mm from the BBface.

nicklouse

adjust the mech.

sram and shimano have slightly different chain lines as normal.

only one spacer each side.

weeksy59

Even sitting here looking at the pics from the documentation from Shimano i don't get what you're saying. The diags quite clearly show the second spacers on the drive side.

nicklouse

opps sorry you are fitting a Shimano BB. not replacing the Truvative one.

yes shimano is 2 drive side and on non drive side. ( and it does adjust the chain line).

sorry to all a busy evening clearing trails and digging out drainage ditches clogs ones mind.

weeksy59

Hahahahaa awsome no worries at all fella.

Must admit, i had a sleepless night though

cooldad

nicklouse wrote:

opps sorry you are fitting a Shimano BB. not replacing the Truvative one.

yes shimano is 2 drive side and on non drive side. ( and it does adjust the chain line).

sorry to all a busy evening clearing trails and digging out drainage ditches clogs ones mind.

I even forgive you shouting at me.

weeksy59

Tested and working silky smooth, put a new set of Wellgo V8 copies on there too. Lovely, clean crisp and silent