Bottom bracket options for 2010 trek 2.1 alpha road bike

Discussion in 'Cycling Equipment' started by heavypic, Aug 27, 2016.

  1. heavypic

    heavypic New Member

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    Hello all -

    I am new to this forum. I recently resumed using my road bicycle again after a few years away. I need some help/advice regarding bottom brackets.

    I have a 2010 Trek 2.1 alpha road bike (Shimo 105 components w/ a compact R-600 50/34 crank) purchased in the U.S., that I have used only on a Cycle-Ops trainer for less than 10 hours total since the bike was new. I have never ridden the bike on the road, but I am hoping to do so soon.

    With the help of youtube, I have serviced/adjusted the front/rear derailleurs and everything is quiet and shifting crisply when freewheeling on a bike stand. However, I experience a grinding type of vibration that seems to come from the front crank when using the trainer. I backed-off the trainer resistance wheel from the bike's rear tire, and I still get the grinding vibration when pedaling freewheel while lightly applying the rear brake to simulate riding resistance. It appears the vibration is worse as pedal force is increased and with higher gears. I am suspecting the bottom bracket may need service or replacement. The BB has never been serviced.

    I removed the chain from the front chain-ring and checked the crank for play/looseness...everything seems tight and in good order. The crank turns freely with no roughness, grinding noise or resistance. However, as I turn the crank slowly, I can hear a subtle 'clicking' noise intermittently. I suspect this may be the ball bearings moving and contacting each other in the bearing housing?

    Can anyone suggest what might be the problem? Does the BB needs cleaning/repacking/replacement?

    Can anyone recommend BB options for this model? I don't mind upgrading over the stock BB. I believe this model uses a Shimano Hollowtech II bottom bracket...the BB has the following markings "BC 1.37 x 24". I believe the frame is 68 mm at the crank location. Also, I found a website that claims to have better quality bearing sets (larger, harder, ball bearings)...I'm not sure if this is the best option vs. replacing the BB altogether.

    I have tools ordered. I will be performing the service on the bike.

    Advice appreciated...

    Regards
     
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  2. Froze

    Froze Well-Known Member

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  3. heavypic

    heavypic New Member

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    Froze -

    Thanks for your reply and the link to the Shimano instructions. I'm awaiting delivery of some tools, and then I'll have a go with repacking the BB bearings. I hope that solves my problem.

    Regards
     
  4. alfeng

    alfeng Well-Known Member

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    FWIW ...

    Because you only have 10 hrs of "riding" on your bike on your trainer, if you haven't already done so then before you do any maintenance on your BB, you may want to lower the roller so that it isn't in contact with the rear tire and then see if the vibration is actually from your trainer rather than your bike ...

    BB noises are sometimes difficult to diagnose ...

    Although I have done it (not sure why, sometimes!), replacing the bearings in Hollowtech II BB cups is very tedious BECAUSE the seal which also reduces the inner diameter from 25mm to 24mm can be difficult to remove ...​

    Ditto for the bearings themselves!​
    This may NOT be the case for you, but maybe it is ... so, let me mention that ~80% of the time I will simply remove a pulley wheel (rather than break the chain) when removing-and/or-replacing a rear derailleur ...

    More than once, I have NOT looped the chain correctly between the pulley wheels ... with the immediate result being that the chain will be riding along the intermediate "guard" and thereby cause both a grinding noise AND a light vibration ...

    BEFORE you try to do something with the bearings, if the problem wasn't with the chain passing through the rear derailleur, then AFTER you remove the crankset (you really just need the appropriate size Allen Wrench for the crank arm's pinch bolts... you may-or-may-not be able to remove the adjusting cap without a tool AFTER you loosen the pinch bolts).

    If you are convinced that there is grit in the cartridge bearings, then if you manage to successfully remove the seal, then you will want to use an X-ACTO type knife to gently peel an edge of the cartridge bearing's seal away from the cartridge's outer race ...
    • Flush with a light oil .... I strongly recommend that you NOT use any degreaser and that you consider WD-40 as the "solvent" ...
    • Repeat MANY times until the bearings run free ...
    • Inject the LIGHT grease of your choice (e.g., WHITE LITHIUM GREASE) ...
    • Try to PRESS the seal back down against the bearing as well as you can ...
    • PRESS the reducing seal back in place ...
    • Re-install in the frame.
    Alternatively, if you are really ambitious, you can try to remove the bearings from their cups and then replace them with almost any 6805 bearings ...

    You can order the bearings directly from China or you can order them from a domestic retailer for possibly as much as about 5x as much.

    One bearing which I have NOT tried one, yet, in a BB is the 6805ZZ metal shielded cartridge bearing which seem to spin with very little resistance.​
     
  5. heavypic

    heavypic New Member

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    alfeng - Thanks for your reply/suggestions.

    My 2010 Trek 2.1 apha road bike has Shimano 105 components (Shifters Shimano 105 STI, 10 speed; Front Derailleur Shimano 105; Rear Derailleur Shimano 105; Crank Shimano R-600 50/34); Cassette Shimano 105 12-27, 10 speed). I purchased the bike new in 2010...it's had very little use on a trainer, and never ridden outdoors...and the bike is kept indoors (dry, low humidity). As such, it hasn't been exposed to the elements, nor has is ever been dropped on the derailleurs. I hope to use it on the road soon.

    I had ruled-out the trainer earlier. I backed-off the trainer resistance wheel from the bike's rear tire, and I still get the grinding noise/vibration when pedaling freewheel on the trainer, and while lightly applying the rear brake to simulate riding resistance. It appears the vibration is worse as pedal force/speed is increased, and with higher gears.

    I checked the bike again after reading your reply above. The chain appears to be moving through the derailleur wheels without rubbing the guards, however, the derailleur may indeed be the source of the problem as the noise/vibration seems characteristic of a chain passing over derailleur cogs wheels. That vibration may indeed be transmitting through the frame to the BB and crankset. You can feel the vibration when turning the cranks by hand when freewheeling on a stand. The derailleur alignment appear to be fine. I followed Art's Cycles online tutorial for adjusting both front and rear derailleurs/cog-cassette alignment, cable tensioning, indexing, and upper/lower limit adjustments. I have to look into this further and rule-out possible causes. Having worked on motorcycles, I am painfully aware of how noises/vibrations can be transmitted to areas other than the source of the problem, making diagnosis difficult. But that's part of the fun of DIY!

    Perhaps I'll remove the rear derailleur cog wheels for cleaning/relube of their bearing. I have only lubed these cogs bearings with light chain/cable oil. I do recall a youtube where these cogs where lubed with oil, and then followed with derailleur specific grease.

    Given the relatively limited use, and quite a period of no use, I set out to order tools and go over the bike and make adjustments with the help of youtubes (Parks and Art's Cycles, etc). While storage conditions were very good, I assumed that inspection and lubrication of various parts was needed before road use.

    While I don't expect rear derailleurs to be noise-free, I do not get this vibration from my Specialized hybrid (aluminum frame, with similar, albeit slightly lower quality components (3 ring front / 8 cog cassette). I'll keep plugging away and post again when I've found the source of the problem.

    Thank again...
     
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