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Posted

Xavier and I got out for an urban assault/skills practice day yesterday
34d4e68b4b6dac6b3d143614c2fdd55f.jpg
dcbfde163c0111438143e48ecf697a79.jpg

Had a blast, and we both worked on getting wheels off the ground a bit better. Xavier is rolling over large curbs like a boss and killing it on stairs.

Example A:



Example B:


Notice the arms of victory in B

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  • Like 4
Posted

Just picked my bike up from the shop - they replaced the axle and bearings free of charge, so that was nice.

Will make sure to dismantle and regrease at least once a month from now on, just to make sure it never happens again.

  • Like 3
Posted

jajaja no, no... it´s piece of cake. Only 42 kms probably we´ll only gain 1.500 or 1.800 m 

I live near there so I'm used to going up and down to Las Palmas city and Teror village. This is like one more training. 

  • Like 2
Posted

Revision traumatology for a throbbing pain in my left knee. I have been treated only with anti-inflammatory and painkillers.

I have a partial tear of the outer ligament of my left knee. In principle the break is welded naturally but I have ordered total rest for two weeks.

I'm a little fucked up.

  • Sad 1
Posted

Well, the saga of the bottom bracket continues.

It started making a noise again, so i pulled the axle and inspected the bearings.

They made a slight grinding noise when turning, and it almost felt like they had sand particles inside!

Having only ridden around 300km on the new bearings (in dry conditions), i was obviously not happy with the situation, so it went back to the shop today.

The guy behind the counter was oviuosly having a bad day, and was not happy to receive the bike -  he even told me its normal for bearings to feel gritty!

 

Hope they take it seriously and figure out why the bike keeps eating bearings...

Posted

The guy behind the counter was oviuosly having a bad day, and was not happy to receive the bike -  he even told me its normal for bearings to feel gritty!

Uh, no it isn’t normal for bearings to feel gritty. Guy is a dumbass for even suggesting that!
What kind of crankset!/BB is this?


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Posted
27 minutes ago, Pars said:


Uh, no it isn’t normal for bearings to feel gritty. Guy is a dumbass for even suggesting that!
What kind of crankset!/BB is this?


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Yeah i know, i was really close to blowing up when he said that, but in the end i just calmly explained that he was wrong and i was right.

Didn't want him to refuse looking at the bike after all.
 

it's cannondale caad12 with a BB30a SI hollowgram cranks. 

i suspect the new bearings they put in must have been knackered from the factory, and they just didn't check them properly before inserting them, or there is something wrong with the machining tolerances on the frame, making the bearing slightly misaligned and thus ruining them quickly.

Posted (edited)

Yeah, i'm worried that might be the case - but unless the dealer suspects the same thing, actually proving it and getting a new frame might be difficult.

Crossing my fingers the mechanics has a bit more brains then the shop-clerk.

Edited by bjarnetv
Posted

I would think the bike shop should be able to face it, ensuring that they are parallel? Or don’t they do that anymore (I’m used to steel frames).


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Posted

It also depends on the threads being cut parallel in the bottom bracket. Not sure how that is done on a carbon frame. Threaded inserts bonded in? In any event, if the threads are not parallel and/or have a linear offset it is a manufacturing fault, and there is no alternative but a replacement frame.

Posted

In a carbon frame they are press-fitted. In theory, if the frame has no defect, the bearings (at the end of their seat) should be parallel.

It´s possible that frame has some burrs in the area or something that misalign the bearings (paint, resine, fiber…) The normal thing would be to remove the caps from the bottom bracket box and check with a vernier caliper (or better a laser) the measurements on both sides.

like this: 

 

bb90-madone-37mm-cart-bbshell-2.jpg

 

I prefer Shimano PF or BB90/95

 

7MWMjMT.jpg?1

Posted

The caad is aluminium and uses press fit BB, so the only way to mess things up too badly (except for making the opening to big so that the bearing can wobble around) is not aligning the two sides properly when machining them, thus making the axle improperly centered.

So in theory, pressing the bearing directly into the frame is superior to pressing them into cups, as there is one less part to misalign and with the potential to creak.
Unfortunately, it seems a lot of manufacturers get quite sloppy with the tolerances, so it doesn't matter how you mount the bearings, because they will start creaking anyway because they dont fit properly. 
At least they are cheap and easy to replace, so at least thats something... 

Posted
3 minutes ago, bjarnetv said:

The caad is aluminium and uses press fit BB, so the only way to mess things up too badly (except for making the opening to big so that the bearing can wobble around) is not aligning the two sides properly when machining them, thus making the axle improperly centered. 

Oh sorry. I have not seen your photos well. So it's simpler, Do you have a "torno" or CNC machine on your area? 

A "torno" could rectify and align the frame quickly and for very little money.

*I'm sorry I do not know how to say "torno" machine in English.

Posted

i think realigning the BB would be impossible without converting it to another standard, since removing material would make the holes to big for the bearings.

The bike's only 3 months old, so if the BB is indeed badly machined and keeps eating bearings, i would think getting a replacement frame from Cannondale wouldn't be to hard for the dealer.

I suspect they will replace the bearings one more time before considering replacing the frame though.

Posted (edited)

if only has 3 months… Yes, possibly the dealer does that.

Even so, it seems very suspicious that a modern bicycle burns the bearings. 

Edited by jose
  • 2 weeks later...

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