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Making bike "B" fit like bike "A"

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Making bike "B" fit like bike "A"

Old 09-15-21, 08:05 AM
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cccorlew
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Making bike "B" fit like bike "A"

I have a Roubaix that I had professionally fitted and fits great.
What measurements should I take to make get other bike come close to fitting like my Roubaix? I realize this may require a new stem, but what are the the critical measurements? And bonus love if you can point me to a video or chart.
Thanks
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Old 09-15-21, 08:12 AM
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Not official measurements, but I recently did:
Center of BB spindle to top of saddle
Used a level to get a straight line up from the center of the BB spindle and then did distance of that back to the nose of the saddle
Center of front axle to top of stem/bars straight up from it
Once stem height and saddle positioning were set, nose of saddle to tip of hoods
Verified by center of bottom bracket spindle to tip of hoods.
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Old 09-15-21, 08:16 AM
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Seat Height , angle and setback.
If using the same saddle measure distance from tip to handlebars or if not use the BB as a reference.
Measure height of saddle in relation to handlebars.
Use the same handlebar rotation in the stem and same position of brake/shifters on the handlebar.
Here is a formula for getting the same height/distance from using different stems on different bikes. Stem Comparison Tool | yojimg.net
Measure width of Q factor (width of pedals from each other) Some people are super sensitive to this, others not much.

I probably forgot something but this covers most of it.

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Old 09-15-21, 08:51 AM
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Park Tools has you covered. There is a fairly expensive tool that can help.
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Old 09-15-21, 09:15 AM
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I'd measure the saddle height from the pedal furthest away from the saddle. That will get you a more correct saddle height if the crank lengths are different.

Then from some place on the saddle to the hoods or where every you normally keep your hands on the bike.

That's pretty much all I do when transferring to another bike.

However if the bikes have different enough seat tube angles. Or one bike the saddle is set back on the post further than the other, then you will likely feel very different on the other bike. Stack will also come into play, but that is minor IMO.
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Old 09-15-21, 03:40 PM
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Each of my road bikes has a document just like this:

CORSA EXTRA FIT

Stand over= 79.8cm/798mm
Saddle height from center of crank to mid point= 73cm/730mm
Saddle height from top of BB shell to mid point= 71cm/710mm
Saddle set back @ mid point= 18.9cm/189mm
Saddle mid point to bars= 68cm/680mm
Saddle mid point to brake hoods= 82cm/820mm
Saddle angle= Nose level
Saddle to ground @ mid point= 96.9cm/969mm
Tops of bars to ground= 92.9cm/929mm
Difference= 4cm/40mm
Drops to the ground= 81.5cm/815mm
Difference= 15.4cm/154mm
Bar angle at bottom of drops= 86 degrees



NOTES

Inseam = 82.5cm. Current crankset 172.5mm; 170MM increase 2.5mm, 175mm decrease 2.5mm


MEASUREMENT METHOD

BB shell 4cm/40mm OD, = 2cm/20mm
Center of BB to saddle top @ mid point.
Top of BB shell against BB cup to saddle top @ mid point, subtract 2cm/20mm from C to C measurement.
Bars and levers are measured from mid point of saddle.
Saddle width @ mid point 103mm.


MERCKX CORSA EXTRA EQUIPMENT

SADDLE= Specialized Power Expert 143mm wide, 240mm long, midpoint 120mm. Saddle width at length midpoint is 103mm.

SEATPOST= Campagnolo C Record, unfluted, 27.2mm, 25mm setback; 210mm length

CRANKSET= Campagnolo Centaur 172.5mm

PEDALS= Look Keo 2 Max

SHOES= Giro Apeckx II, size 44.5, Look Keo cleats

HANDLEBARS= Soma Highway one, 130mm drop/75mm reach, 42cm C to C

STEM= Nitto Dynamic II zero degree, 120mm length, 26.0 clamp

MERCKX CORSA EXTRA FRAME MEASUREMENTS

Seat tube center to top 55cm/550mm
Seat tube center to top of seat lug 56.0cm/560mm
Seat tube center to center 54.0cm/540mm
Top tube center to center 54.7cm/547mm
Head tube length 12.6cm/126mm



MERCKX CORSA EXTRA HISTORY

Date of measurements: 04-26-21
Date of lubed seat post and stem: 12-06-20

NOTES:
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Old 09-16-21, 11:23 AM
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Don't be shocked if every measure matches but they don't feel the same. Fact is stranger than truth.
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Old 09-16-21, 01:13 PM
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I recall jamesdak uses a yardstick(s) with the the positioning marked to quickly set up a new bike
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