Singlespeed & Fixed Gear - 105 BB vs Pista Stock BB

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Hobartlemagne
12-15-06, 01:20 PM
Ive been riding only my bianchi pista for the past 3 months, and yesterday got out
the panasonic and noticed it rides a lot faster. The gearing is almost identical.
Could my Shimano 105 BB in the panasonic allow less pedal rotational resistance than
whatever is stock for the pista BB?
Are there other differences? Frame weight? Tires, wheels...etc?
I doubt if BB differences would make it noticeably faster unless there were problems. Are both sealed bearing units?
colnago57
12-15-06, 01:32 PM
Are you still riding the stock wheels? I know on my Pista, the bearings in the stock Bianchi hubs spun like they were filled with glue. Not that good for meeting deadlines but works for resistance training.
Hobartlemagne
12-15-06, 01:37 PM
Same tires on both, 20yr old 105 wheel and so-so mavic rear wheel on the pista.
36spoke Vs on the panasonic. IRO rear hub, Shimano Deore front hub. The Panasonic is 1lb heavier too.
Im just trying to identify some possible component advantage that I can reproduce if neccessary.
unless you repacked the bearings with loctite bearing resistance is never going to result in a bike "riding a lot faster." The fact that the gearing is only almost identical outweighs it. The difference is probably in rider position or your head.
Hobartlemagne
12-15-06, 01:43 PM
:) maybe I was excited to get my #1 bike back.
mihlbach
12-15-06, 01:51 PM
Ive been riding only my bianchi pista for the past 3 months, and yesterday got out
the panasonic and noticed it rides a lot faster. The gearing is almost identical.
Could my Shimano 105 BB in the panasonic allow less pedal rotational resistance than
whatever is stock for the pista BB?
Are you absolutely sure that one bike is really faster than the other? I seruously doubt it, unless one of them has a serious mechanical problem or maladjustment. Minor differences in BB, chain, or hub friction should not cause an overwhealming difference in speed. More likely one bike may feel a little faster due to differences in fit and handling. I have an old fixie conversion that weighs as much as a tank and I also have a much lighter, sleeker and more expensive track bike. They are both geared the same, but everytime I get on the junky conversion I could swear it is faster that my much sleeker track bike. But turns out to be an illusion. My cyclcomputers tell me that I am riding similar speeds on both, and actually tend to travel with a slighlty faster average speed on my track bike.
Aeroplane
12-15-06, 02:05 PM
unless you repacked the bearings with loctite bearing resistance is never going to result in a bike "riding a lot faster." The fact that the gearing is only almost identical outweighs it. The difference is probably in rider position or your head.
I concur. There was some breakdown of the resistance when riding a bike. Bearing friction was near 1%*, drag from the rider was about 60%*.
* - completely pulling #'s out of my ass, but the point is the same. You save more energy by using your drops than by greasing your bearings.
Hobartlemagne
12-15-06, 02:09 PM
Are you absolutely sure that one bike is really faster than the other? I seruously doubt it, unless one of them has a serious mechanical problem or maladjustment. Minor differences in BB, chain, or hub friction should not cause an overwhealming difference in speed. More likely one bike may feel a little faster due to differences in fit and handling. I have an old fixie conversion that weighs as much as a tank and I also have a much lighter, sleeker and more expensive track bike. They are both geared the same, but everytime I get on the junky conversion I could swear it is faster that my much sleeker track bike. But turns out to be an illusion. My cyclcomputers tell me that I am riding similar speeds on both, and actually tend to travel with a slighlty faster average speed on my track bike.
Its not an illusion, My computer showed my total time as 1:07 for a hilly 16 mile ride. Ive never been able to do it faster than 1:30 before
mihlbach
12-15-06, 02:14 PM
HMM..maybe its a fit/setup issue. Is it possible that you are too dropped down on your Pista?...that would decrease you ability to sustain power when climbing hills.
baxtefer
12-15-06, 02:15 PM
*nothing* is going to help you gain ~45 sec/mile
except maybe a miscalibrated computer. Are you sure the difference is not in total elapsed time vs. time spent in motion?
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