Ok; I picked up a bell wireless cyclocomputer tonight at WalMart this way I can start paying attention to my rides better ( mileage; speed; appx. # of cal's burned; etc.). It is the Platinum Series 15 Function model # 1005341.....well; looked in the manual; and found the largest tire/wheel size listed in the chart is 29 X 2.23. My fatbike's got 29 X 2.25's on it. I was wondering if this slight difference will drastically change distances and speeds recorded; or is it so slight that it will be accurate enough for my needs. Also; if anyone does know the correct programming # to input for this; I would greatly appreciate it....I looked all over on line and haven't been able to find much information on this matter.
trying to program my cyclocomputer
- Thread starter Diggs27
- Start date
check the manual for custom wheel sizes, they tend to be more accurate anyway
goodvibe
Well-Known Member
The best way is to measure the wheel size. Here is what you should do:
1. Place the bicycle on the floor with the valve stem at the 6 o' clock position.
2. Place a piece of tape on the floor to mark the position of the stem.
3. Move the bicycle forward until the bicycle wheel takes a full rotation.
4. Mark the location of the valve on the floor.
5. Measure the distance between the first and second piece of tape and convert to MM.
(you can use this site for easy conversion: http://www.worldwidemetric.com/measurements.html )
6. Put that number in your cyclometer and you will get the most accurate reading.
1. Place the bicycle on the floor with the valve stem at the 6 o' clock position.
2. Place a piece of tape on the floor to mark the position of the stem.
3. Move the bicycle forward until the bicycle wheel takes a full rotation.
4. Mark the location of the valve on the floor.
5. Measure the distance between the first and second piece of tape and convert to MM.
(you can use this site for easy conversion: http://www.worldwidemetric.com/measurements.html )
6. Put that number in your cyclometer and you will get the most accurate reading.
Ok; did the roll out method; and got a measurement of 89.5"....figured out the mm's for this and came up with 2273.3. when I compared this # to the chart; did not make any sense to me because the 29 X 2.1 number is 2288; and the 29 X 2.23 is 2326.....I would assume that my #'s should read a little higher than the 29 X 2.23 due to the tires being 29 X 2.25's. Is there some sort of mathematical equation I could use to figure out the difference....maybe figure out the difference between the 2 and multiply by .02 to give me the little extra then add to the 29 X 2.23 tire size?? having problems with this issue; and really want to get this solved so that I know I am accurate with my odo and trip readings. Also; when you divide the 89.5 by pi (3.14) I get a number of 28.5.......which absolutely makes no sense to me considering the fatbike has 29" tires
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JDurk
Well-Known Member
Your calculations should be accurate enough. The charts are only estimations. Tire actual widths will vary from what's printed on the sidewall.
Wobbegong
Well-Known Member
The number stamped on the tire is not accurate. Look here to see what I mean.
http://www.mtbtires.com/specs/index.html
Measure twice and go with what you have. Leave the complex math to the rocket scientists. 🙂
I Ride Bikes
Well-Known Member
Listen to Wobbegong. All tires with same listed size will be slightly different. Using the roll out method just do it a few times and go with your average.
Ok; thank you very much.....I will try a roll out again tomorrow (thinking about trying it 5 X's) and then figure out the average and convert that to MM's. Just had me confused that the first measurement was not coming out to 29" (was roughly 28.5) when I divided the 89.5 by 3.14 to figure out actual diameter....I was not aware that even though the tires them selves say 29" that it could be off by that much.😱