How to remove crankset & chainset

FrankGrimes

I need to remove my DuraAce 7950 chainset and cranks with SRM power meter in order to send it back to Germany to have an issue (hopefully just premature battery exhaustion) investigated.

The whole world of bottom brackets, chainsets and crank compatibility and installation is Double-Dutch to me and it's the one area of the bike I'm really wary of going near but I have to get it done quick smart so I lose as little training time with power data as possible. So I'd really appreciate any advice on what's compatible, what tools I need, and how to do it.

My DuraAce 7950 chainset/cranks is currently on my 2008 PlanetX Carbon SL with this bottom bracket (Shimano Bottom Bracket Cups Hollowtech II Dura Ace SM-BB7900 BSA). First question is how to I go about removing the cranks and chainset (need to send both to SRM)?

I don't have the exact details to hand, but the cranks and chainset I'll need to swap in for the DuraAce while it's gone are the FSA Gossamer chainset and related bottom bracket that came with the PlanetX in 2008/2009. Do I need to swap bottom bracket or will the FSA chainset work with the above bottom bracket?

If I need to change it, what's involved in terms of tools and process?

Sorry for the loads of questions but I'd really appreciate any help on this as it'll mean I won't lose time training with no cranks on my bike while the chainset is off getting serviced. On the plus side, the mandate for justifying to the OH why purchasing a second bike is essential just got a whole lot stronger

ford2600

http://www.parktool.com/blog/repair-help/external-bearing-crank-systems-hollowtech-ii-megaexo-giga-x-pipe-x-type-campagnolo-ultra-torque


Bearing cup removal tool needed. Very easy with right tool.

macnab

Have a look at this video

http://vimeo.com/5780736

Gasco

Not familiar with the SRM, but I believe it is on the chain side of the crankset, I presume the opposite crank arm is a standard DA - if so all you need is a 5mm Allen wrench to loosen the pinch bolts. There is a retainer pin between the split at the end of the arm which you need to pop up. There is a fixing bolt which screws into the crank axle - there is a special tool which removes this, but I have improvised with an appropriate sized screwdriver. The LHS arm should slide off, and then it is a matter of pulling the drive side crank out - might need a tap with a block of wood on the axle to get it moving.

(I replaced my BB last weekend - the techdocs on the Shimano website are great)

I have used an FSA Gossamer crankset with an Ultegra 6600 BB with no problems.

petethedrummer

FrankGrimes wrote: »

I have to get it done quick smart so I lose as little training time with power data as possible.

I know who I'll be wheelsucking in A4 this year.

FrankGrimes

Thanks all for the pointers, much appreciated.

ford2600 wrote: »

http://www.parktool.com/blog/repair-help/external-bearing-crank-systems-hollowtech-ii-megaexo-giga-x-pipe-x-type-campagnolo-ultra-torque


Bearing cup removal tool needed. Very easy with right tool.

Nice one. I think it's the FSA® MegaeXo listed on that page that I have, so the question is whether the FSA cranks will slot into the DuraAce bottom bracket or whether I need to also change the bottom bracket?

I have a Park toolset and I think it has the tools listed on that page so hopefully I have what's needed if swapping the BB is required.

FrankGrimes

macnab wrote: »

Have a look at this video

http://vimeo.com/5780736

Thanks. I skipped through that video and may be missing it but it didn't look like the crank installation was covered? Great video though, definitely a handy one to reference in the future for other drive train maintenance.

lescol

Your FSA chainset will work with the DA BB already on the bike so leave it in place.

Here are the tech docs for the DA chainset:- http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Dura-Ace/SI_1KY0A_002/SI-1KY0A-002-ENG_v1_m56577569830651757.PDF



You'll need one of these. Loosen the pinch bolts then use the above tool to remove the cap. The crank arm should slide off, allowing you to pull out the right hand crank.

Push through the axle of the FSA, slide on the crank arm and tighten the cap (uses a screw driver, if I remember correctly), this only loads the bearings so you tighten the pinch bolts to hold the crank arm in place.

route66

FrankGrimes wrote: »

I
<SNIP>
On the plus side, the mandate for justifying to the OH why purchasing a second bike is essential just got a whole lot stronger

Did you get the Rose yet ;-)

FrankGrimes

Just wanted to say thanks for all the advice on this. My powermeter started working again for a while, so I thought I wouldn't need to do this but then it stopped working again.

Knowing the cranks were compatible and I wouldn't have to change out the bottom bracket helped demystify things and I was surprised at how easy it was to do once I had the right advice. Had to give the FSA cranks a few whacks to get it to fully go through the DuraAce cranks, but it seems grand now and I reckon it should be straightforward to swap out the other cranks when they come back from servicing.

There was a load of gunk in the bottom bracket so I gave it a good clean out. What type of grease should I use, if any, when putting the cranks back in?

FrankGrimes

route66 wrote: »

Did you get the Rose yet ;-)

Nope. I've decided to go elsewhere - turns out a mate is able to call in a favour and get me a great discount on my dream bike (don't want to jinx it so will wait till I have it and post up pics) so I'm going with that. Also a big attraction of Rose was the ability to configure the bike to my needs but it seems 3 weeks later they still don't have the configurator up and running (or at least not easily visible). I'm not allowed order the new bike till I hit my interim goal of having lost 5kg, and I'm not far off that so hopefully it won't be much longer, can't wait to get it.