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Bike Fit... what would YOU do??(15 posts)

Bike Fit... what would YOU do??JBergland
Jan 2, 2002 11:03 AM
I have a 99 LeMond Zurich and a 97 Bianchi Champione. I have both bikes set up identically as far as handle bar height/reach, and saddle height/position. The difference is in the BB area. The LeMond has a longer Toptube (slack seat tube angle) causing the BB to be a little further ahead... feels more like sitting on the very back of the saddle and pushing forward. This set up worked fine for me last year, but I'm rethinking some things.

* Should both bikes be as truly 'identical as they can be in regards to set up?
* What are some advantages/disadvantages to being 'behind the crank and pushing forward'?

All thoughts and suggestions are welcome!!
re: Bike Fit... what would YOU do??gtx
Jan 2, 2002 11:22 AM
I have a simular situation in that I have a Merckx and also a custom road frame. The Merckx has a more slack seat tube angle and longer top tube (though the cockpit on the two bikes when you account for the difference in STA is pretty close). However, I ALWAYS set my seat in the same position relative to the cranks, regardless of the bike--whether its a road, mtb or cross--otherwise I feel funny. This is always my starting point when determining if a bike will work for me. I set up my ideal seat position relative to the cranks and then set up the bars. If I can't get the bars where I want them to be without a weird stem setup, the bike isn't gonna work for me. I generally prefer bikes with seat tube angles of 72.5 - 73. So in other words, the thing I always worry about first is the thing that you have chosen to consider last. Doesn't mean I'm right or you're wrong, just different. Some people vary their saddle setback for time trial bikes or mtbs, etc., but I don't.
re: Bike Fit... what would YOU do??JBergland
Jan 3, 2002 7:11 AM
gtx,
How does each bike 'feel' when you ride it? What differences (if any) do you notice?

Thank!!
re: Bike Fit... what would YOU do??gtx
Jan 3, 2002 12:20 PM
the Merckx feels a bit more laid back and compliant--I think this has a lot to do with the longer c-stays and lower bb. I also feel like my weight distribution while seated is farther back on the Merckx--and the front end on the Merckx doesn't feel quite as grounded or solid. But when climbing or sprinting out of the saddle on the Merckx my weight distribution is much more neutral--I'm less likely to spin the rear wheel while climbing up a very steep, wet hill than I am on my other bike. In fact, on the same steep hill which is often very wet, I have to consciously adjust my weight ditribution to keep the rear wheel from slipping on the other bike, whereas I've never managed to get the rear wheel to break loose on the Merckx--this is with the same tires/inflation on each bike. I don't really prefer one over the other, but they are definitely different. Kind of fun, actually!
I agreeNessism
Jan 3, 2002 12:05 PM
I also have a couple of different bikes with different geometery. Last summer I noticed that one of the bikes was easier to spin circles on. A check of the setback showed that the poorer performing bike had more saddle setback causing me to be more behind the bottom bracket. Pushing the saddle forward a little, matching the other bike, improved my spin.

When it was all said and done, my perfect saddle position was with the true KOP position. I know it is only a rule of thumb, but to me, it is a good one.
I agreegtx
Jan 3, 2002 12:21 PM
yes, I think KOP works quite well for most people--it's definitely a good starting point. I prefer a position just behind KOP.
I believe that conventional wisdom is that the ...sprockets
Jan 2, 2002 11:37 AM
rearmost seating postion is more of a power position, having better leverage. It is not necessarily incumbent upon you to have the same setup, as long as each meets your needs and fits you. For instance, I ride a road and mountain bike and the setup is nothing alike. My point-you can ride what ever you want, and neither detracts from the other. You can see if one gives you an advantage in certain types of terrain and use that to your advantage. FYI: I read that Lance says that he sits further foward than he used to, and we all know about his high cadence thingy.
ok to varyDog
Jan 2, 2002 1:13 PM
I intentionally have some bikes set up differently, depending upon use. Also, unless it's causing a problem, a different setup may exercise more muscles, too.

If LeMonde bikes follow Greg LeMonde's theory on bike setup, then the slack angle probably reflects this. I read that this may not work for some, though, as LeMonde has exceptionally long femurs in relation to total leg length, which skews things a bit.

I wouldn't worry about it much, but then you could move the saddle forward a bit. If you then get cramped in the arms, longer stem.

Dog
ok to varyJBergland
Jan 3, 2002 6:59 AM
Dog,
I know you have a couple different bikes. Other than the ones you have set up for special events (climbing, 500+ mile rides, etc.) do you compensate for any differences in geometry between any 2 (or more) bikes? Do you set up each bike individually (foot over spindle, bars hide the hub, etc.) or do you also factor in making each bike feel/ride similar to others?? Or does it end up being the same thing??

Thanks!!
only one measurementDog
Jan 3, 2002 7:14 AM
There is only one measurement that I make the same no matter what the bike or setup, and that's top of saddle to center of crank bolt. I've memorized my "ideal" measurement, and always pull out a small tape measure and set it the same. I use all the same crank lengths, so that helps. I might fudge a little depending upon the shoes or pedals.

Most of the other factors I don't worry about too much. I just sort of move it around until it feels comfortable. Doing that, I probably do compensate for some differences, as my 1980 Bianchi is slacker than my 2001 Colnago.

Like I said, I don't worry too much. Even putting in lots of hard miles, I can't tell much difference in a few mm's one way or the other. I don't think you want any setup really out of whack, but I think it doesn't make sense to get too anal about it.

Dog
only one measurementJBergland
Jan 3, 2002 10:49 AM
"I don't think you want any setup really out of whack, but I think it doesn't make sense to get too anal about it."

Ya, that is very true. I'm sure you (as well as many others) know how it can be when you start fiddling with this or that... then all of a sudden BLAM!! You're thinking about/working with such small amounts that they really don't make a difference. That Softride I got last summer/fall was a nightmare to try and set up (I still don't have it 100%). That experience has me looking/thinking about all my other bikes and how they are set up.

Thanks!!
re: Bike Fit... what would YOU do??Len J
Jan 2, 2002 1:28 PM
I have the same problem, though not as drastic. I have a 00 Lemond B/A & a Trek 5500. What I did (as others have suggested above) is that I set both bikes up with the identical knee position over the pedal spindle (for me that is a little bit in front of KOP as I am a spinner). On the Lemond this required moving the seat forward (You may need a non-setback seatpost to do this depending on your setup).

Once the seat is positioned identically relative to the pedals, I then did a normal fit to determine the appropriate stem length on each bike.

Len
re: Bike Fit... what would YOU do??JBergland
Jan 3, 2002 7:07 AM
Len,
How does each bike 'feel' when you ride it? Can you notice a difference based on the geometry? My Bianchi and LeMond feel pretty similar, but not 100% identical. The biggest difference I notice is when I'm out of the saddle. The LeMond feels like it's got narrow handlebars... not as much leverage. Upon measurement, both handlebars are identical. What is your experience??
My experience......Len J
Jan 3, 2002 7:22 AM
May not apply to you because of the differences in materials & construction. The Lemond, being steel (853 main triangle with 525 seat & chainstays) is wonderfully compliant and not as vertically stiff as the Trek OCLV 120. I have ridden both bikes on 50+ MPH descents with no problems. The Lemond flexes more than the Trek. Center of gravity on the Trek is a small amount more forward than the Lemond, but I haven't detected any real effect of this. The Trek is about 3.5 lbs lighter than the Lemond so it climbs better (Lemond has 105 group/ Trek has full D/A and lightweight wheels).

I'm not sure what you are looking for when you ask about feel. I can change the "feel" of my bikes more by changing wheels than I can detect as a difference between the two bikes when ridden with the same wheels. What type of feel are you worried about?
feel when descending
feel when sprinting
feel over a 25 mile ride
feel over a 125 mile ride
feel when climbing
feel in a crosswind

Your comment about the feel of the handlebars makes me wonder about weather or not the distance between the seat & the bars is different between the bikes, a longer reach to the bars will result (given the same width) in a compression of the chest, making it feel like the bars are narrower.

Len
My experience......JBergland
Jan 3, 2002 11:13 AM
Len,
"Your comment about the feel of the handlebars makes me wonder about weather or not the distance between the seat & the bars is different between the bikes, a longer reach to the bars will result (given the same width) in a compression of the chest, making it feel like the bars are narrower."

I'll recheck that, but I'm pretty sure they are they same. The main time I feel this difference is when I'm out of the saddle.

As far as what I'm looking for with 'feel' I'm not sure myself. I have gone through the standard fitting process with both bikes (knee-spindle/handlebar through the front hub/small bend in the knee @ BDC, etc.). Over the holidays both bikes were side by side and something didn't look right. I lined both BBs up using a square and came to find out the bikes at least 'look' to be set up different. With the BBs parallel, the handlebar and saddle on the LeMond are about 2-3 inches further back. If I line up the handlebars and saddles, both bikes are the same. However, when I do this the BB on the LeMond has now moved forward 2-3 inches. I would think I would notice this difference while riding??

I think Dog is on the right path... if it ain't broke, don't spend too much time trying to fix it!!

Thanks!!