Cranks quite stiff to turn on new bike

ForumNewbie

Had my first proper ride yesterday to test my new Cube road bike. The Ultegra cranks seem quite stiff to turn and a bit noisier than I would expect. Thought at first this was because the bike was new, but defintely was more of a struggle to pedal a light carbon bike than it should have been, even when new. It could presumably be a problem with the bottom bracket - it is a press-fit bottom bracket.

Can this sometimes be a problem with new bikes if they are badly put together in the factory, and is the cause easily identified and fixed?

Smokin Joe

They can be a little stiff till the grease thins out, but nowhere near enough to be even the slightest bit noticeable when you are riding. Take the chain off and spin the cranks by hand, they should turn freely and keep spinning after you let go.

It is possible you may have a tight or broken bearing. If so get it replaced under warranty as these are non-adjustable.

ugo.santalucia

I am no expert on BB30 and the likes (I assume this is what you call a press-fit BB), but the Hollowtech has a plastic cap to help fitting the left cranck arm. If this is overtightened, it will cause the arm to press against the bearings (or at least it does in normal Hollowtech BB). Could this be the problem?
If so, it's easily solved with a trip down to your LBS or by yourself if you have the tools

ForumNewbie

Smokin Joe wrote:

They can be a little stiff till the grease thins out, but nowhere near enough to be even the slightest bit noticeable when you are riding. Take the chain off and spin the cranks by hand, they should turn freely and keep spinning after you let go.

It is possible you may have a tight or broken bearing. If so get it replaced under warranty as these are non-adjustable.

Thanks for the advice. I've not tested cranks yet with chain off as I can't see a connection link to easily take off the chain, so I think I will have to take it down to LBS to take the chain off (as I don't have the tool to do it) and they can then test the cranks spinning. However before I do that I was wondering if it might be possible to lift the chain clear of the front rings without actually removing it, i.e. make it loose by pushing in the rear mech to enable me to take the chain off the big ring and then hold it up under the front mech but clear of the chain rings to allow me to test spinning the cranks free of the chain? I was thinking with the pedals off it might be possible to do that safely but not sure?

nicklouse

a 30mm diameter does provide more friction on the seals than the old designs. dont worry about it.

yes it is possible to move the chain if you really want to spin the cranks. But dont bother just go ride and things will improve.

balthazar

If there is detectable drag when riding, something is significantly wrong, which will be obvious to any inspection. You don't need to remove the chain- you're looking for something much larger than drivetrain drag can conceal. Seal drag from different designs of BB seal is not detectable when riding, so it cannot be that.

Put the bike in a low gear, lift the back wheel off the ground and spin the pedals by hand. The cranks/chain/sprockets should turn easily and spin at least a bit more (and the wheel will spin on until braked). If this happens on your bike, you don't have detectable drivetrain drag, and are referring to something else. If the cranks are difficult to turn and stop immediately you let go, there is a BB problem.

(If the cranks turn smoothly backwards, your rear brake is probably binding on!)

Bidston_Kid

Hi. I recently took delivery of a new Cube road bike and on turning it upside down to check the serial number on the BB found that the internally routed front changer cable ran across the crank spindle! I can see it through the slot in the BB shell where the cable emerges and which should be covered by a plastic component which also guides the cable smoothly around the bends.

From the pix you can see how vulnerable the whole set-up is to water and grit ingress - not good for bearings!

After lots and lots of email exchanges the Cube distributers (based in the Netherlands) agreed to send missing parts. So far they've sent them twice and each time got lost in transit. I am therefore a very unhappy bunny.

I am NOT impressed by Cube for letting this out of their assembly plant nor by Cube-Bikes NL.

There is therefore a chance that your bike has a similar defect and taking it to a Cube dealer would be a good idea if you can't see what's going on.

moonshine

that cable bend does not look good at all - if that is fitted correctly, it is an atrocious design. :shock:

in fact looking at the bottom picture, i am certain it is incorrect as there is a screw and hole to hold a plastic cable guide - i am certain there is a part missing from your BB something like this http://www.chainreactioncycles.com/Mode ... elID=33951 or this http://www.chainreactioncycles.com/Mode ... tedKingdom but Cube Specific

keef66

"After lots and lots of email exchanges the Cube distributers (based in the Netherlands) agreed to send missing parts. "

Read the words as well as the pictures

(It does look like a rather ragged hole in the BB though. Presumably the plastic insert tidies it all up cosmetically as well as functionally)

Bidston_Kid

I must apologise for inadvertantly high-jacking this thread but I thought there may be a common factor.

The missing parts arrived late today together with a 60cm length of small bore plastic tubing a piece of which I presume should enclose the cable as it exits the BB shell thereby providing some basic splash-proofing.

Pic No 3 - The upper item has is threaded and I assume is held in place inside the BB shell by the set screw seen on the other pix. The other item appears to slot into the hole in the BB shell.

Pix numbered 2 and 1 - Just show the outer guide in place and it appears to be held in place only by the cable tension - but this should be OK.

There's no sign of the thin plastic tubing so I'm not sure where this goes or whether it was sent in error.

As the bike is fitted with press-fit BB bearings it looks as though the bearings will have to come out (at least on one side) to enable the inner guide to be fitted. This is not something I would contemplate!

I've requested cube-bikes nl to arrange warranty repairs through the local Cube dealer (who I didn't buy the bike from as they couldn't source one) and I'm now awaiting instructions.

I'll post any developments.

Twostage

BidstonKid, Have a look at the elite cable routing document here :-
http://www.cube.eu/en/service/manuals/? ... 4a23d5f756

It shows the cable routing going around the BB shell through a small plastic pipe. Looks like the pipe is there to keep the cable from rubbing against the BB.

Bidston_Kid

Hi twostage, I had actually seen that piece before I ordered the bike but it seems to be quite a different set-up with a much larger hole in the BB shell and it's a carbon bike though I guess the principle is the same with the small-bore tube.

My problem was sorted satisfactorily by the local Cube dealer using the parts I'd been sent and I'm presently awaiting a refund of my costs from CRC.

Twostage

Glad it's sorted.