Distance numbers for my Umbria 100

This is probably going to be completely boring for anyone who isn't me. But I want to write it down somewhere, so it might as well be here.

• bought the bike in late April of 2006 (I have the exact date somewhere)
• put the bike computer on about May 28th 2006 (ditto for the date)
• as of May 28th 2007, I believe the odometer was about 5550 km (it was at least 5500 km, and I believe it was a bit more).
• at the end of my bike ride home from gaming on April 13th 2008, the odometer hit its 9999.9 km max distance. Some amount of distance was lost.
• Monday April 14th: +4.2 km on the commute to work, +some unknown distance commuting to dentist's and back (I think 4-6 km).

  Computer totally reset in the afternoon, before my commute home.

• May 28th 2008: during the day at work, the odometer read 723.46 km.

• Jan 4th 2009: before riding the bike in 2009, I reset the odometer. Pre-reset it read 4794.2 km. I carried over the April 14 2008 wheel size of 2170 mm.

• May 29th 2009: just at the departure from work, the odometer read 1867.5 km and I had biked 5.229 km that day. (I was just at the start of St George, so that's about right.)

Two balacing factors:

• this includes some amount of distance from walking the bike, especially on daily commutes (where I walk it a few hundred meters inside the building).
• the tire size is set slightly low. I believe I set 2170 mm (700x30 in the manual) versus 2180 mm (theoretically correct for 700x38 according to here), but I may have set lower.

  (Did I set it to 2070, the listed 700x18 size? I may have.)

  Update, June 9th 2008: I found my gear calculator program, dating from May 20th 2007, and it uses a wheel size of 2155 mm.

At the April 14 2008 reset, I put the wheel size at 2170 mm. This appears to be roughly correct within a cm or less, based on rolling tests at work (where there is a set of 1-foot floor tiles nicely lined up).

bike computer functions

• press left and right for 4 seconds on either display and you get to total reset. Doesn't seem to flip to anything else.
• press left for long enough on the clock/odometer (second screen) and you can reset the odometer.
• somehow I managed to get to set the time without totally resetting the unit, but I am not sure how any more.

  I've now reproduced this. Once the odometer is high enough, press and hold the left button on the second screen to change the clock; it may matter that this was shortly after a trip reset.
  (At least I assume it requires the odometer to be high enough.)

The Filzer product page is here. Also here.

Bike photos of me

I go on group bike rides. People take pictures. Sometimes I appear in these pictures. For various reasons, I have decided to save links to such pictures, so now you can see the lesser Toronto bike geek in his native plumage and habitat.

To make things slightly more challenging for the reader, these are mostly group photos; it's up to you to figure out which person is me.

(Note that some of these URLs may rot over time.)

July 2006 ravine/brickworks ride

one two three
one two three four

July 2006 Critical Mass

one
one two three

August 2006 BikeFriday

one two three four (source)

August 2006 Critical Mass

one two three four five six and an action picture (source)
(It was not actually raining during the ride, but it was kind of cool and we were riding slowly, and I got cold.)

Sept 25 2006 TBN Alan Gordon Metric Century ride

one two three four five six seven eight nine ten

Sept 2006 BikeFriday

one two three (from here)
one (from here)

June 27th 2008 Critical Mass ride

one (from the BikingToronto pool)

New gearing information for my bicycle

During my bike's tuneup on June 6th 2008 (I note these things down to keep track of them somewhere), not having the bike chain changed for over two years and 10,000 km finally caught up to me and I got a completely new drivetrain, including a new crank set and cog set. Which changes the gear ratios, for the obvious reason.

(For discussion and formulas, see Umbria100Gearing.)

The crank set (front gears) is a 22/32/42 Shimano Alivio, and the cog set (rear gears) is a Shimano 11-34T MegaRange. Sheldon Brown's gear calculator says that the freewheel version of the 11-34 MegaRange is 11-13-15-18-21-24-34, and I am pretty sure that I have a freewheel based rear wheel (the bike is not that expensive, and besides I once saw the bike shop people working quite hard to get the rear gears off the wheel).

So, handy chart time, using the same notation as Umbria100Gearing. The gear ratios (front to rear), with my guess at okay combos bolded:

	front 1	front 2	front 3
rear 1	0.65	0.94	1.24
rear 2	0.92	1.33	1.75
rear 3	1.05	1.52	2.00
rear 4	1.22	1.78	2.33
rear 5	1.47	2.13	2.80
rear 6	1.69	2.46	3.23
rear 7	2.00	2.91	3.82

(Good combos are only a guess now, since the gearing changed. I extended it by one on what it used to be out of general principles, plus I wanted the numbers for other things.)

It's clear why Shimano calls this a MegaRange set; the high to low ratio is 5.88, compared to the old gearing's 3.43.

A by hand chart mapping the gears I actually used from the old gearing to the closest gear on the new gearing:

(old)	(new)
1-2	1-4
1-3	2-2
2-2	2-3 (a bit lower)
2-3	2-4 (technically 3-2 is closer)
2-4	3-3
2-5	2-5
2-6	3-4 (low)
3-4	2-6 (high)

(I almost never used 1-4, choosing to upshift to 2-2 instead.)

There is no even vaguely good mapping after 3-4. I spent most of my time in the middle gear of the front chainring, and in the new gearing this has significantly wider range, going from 1.33 (2-2) to 2.46 (2-6) instead of 1.58 to 2.38; I'll call this a win.

km/h for cadences in various gears, based on a wheel size of 2170 mm:

rpm:	30	40	50	60	70	80	90	100	110	120
1-1	2.5	3.4	4.2	5.1	5.9	6.7	7.6	8.4	9.3	10.1
1-2	3.6	4.8	6.0	7.2	8.4	9.5	10.7	11.9	13.1	14.3
1-3	4.1	5.5	6.8	8.2	9.5	10.9	12.3	13.6	15.0	16.4
1-4	4.8	6.4	8.0	9.5	11.1	12.7	14.3	15.9	17.5	19.1
1-5	5.7	7.6	9.5	11.5	13.4	15.3	17.2	19.1	21.0	22.9
2-1	3.7	4.9	6.1	7.4	8.6	9.8	11.0	12.3	13.5	14.7
2-2	5.2	6.9	8.7	10.4	12.2	13.9	15.6	17.4	19.1	20.8
2-3	6.0	7.9	9.9	11.9	13.9	15.9	17.9	19.8	21.8	23.8
2-4	6.9	9.3	11.6	13.9	16.2	18.5	20.8	23.1	25.5	27.8
2-5	8.3	11.1	13.9	16.7	19.4	22.2	25.0	27.8	30.6	33.3
2-6	9.6	12.8	16.0	19.2	22.4	25.6	28.8	32.0	35.3	38.5
2-7	11.4	15.2	18.9	22.7	26.5	30.3	34.1	37.9	41.7	45.5
3-3	7.8	10.4	13.0	15.6	18.2	20.8	23.4	26.0	28.6	31.2
3-4	9.1	12.2	15.2	18.2	21.3	24.3	27.3	30.4	33.4	36.5
3-5	10.9	14.6	18.2	21.9	25.5	29.2	32.8	36.5	40.1	43.7
3-6	12.6	16.8	21.0	25.2	29.4	33.7	37.9	42.1	46.3	50.5
3-7	14.9	19.9	24.9	29.8	34.8	39.8	44.7	49.7	54.7	59.7

Now, for my own use, the useful bits of the same information, namely the speed bands for each gear and my target speed in the gear:

(gear)	(80-120)	(90)
1-1:	6.7 to 10.1	7.6
1-2:	9.5 to 14.3	10.7
1-3:	10.9 to 16.4	12.3
1-4:	12.7 to 19.1	14.3
1-5:	15.3 to 22.9	17.2
2-1:	9.8 to 14.7	11.0
2-2:	13.9 to 20.8	15.6
2-3:	15.9 to 23.8	17.9
2-4:	18.5 to 27.8	20.8
2-5:	22.2 to 33.3	25.0
2-6:	25.6 to 38.5	28.8
2-7:	30.3 to 45.5	34.1
3-3:	20.8 to 31.2	23.4
3-4:	24.3 to 36.5	27.3
3-5:	29.2 to 43.7	32.8
3-6:	33.7 to 50.5	37.9
3-7:	39.8 to 59.7	44.7

Some experimentation suggests that 1-1 and probably 1-2 are too low for anything except the most exceptional circumstances, as I wind up tired from frantically spinning at many RPM.

Gearing information for a Miele Umbria 100 bicycle

My bike is a Miele Umbria 100, either the 2005 or 2006 model (probably 2005 since I bought it early in 2006 and it was discounted). This is a 21-speed bike; 3 front gears, 7 rear gears. Because I am interested in such things, I have tried to work out the gear ratios and other interesting information for it.

Miele's website for the current 2007 model Umbria 100 says that it has a 28/38/48 crank set (the front gears) and a '14-28T' cog set (the rear gears). The only 7-speed rear gear set that goes from 14 to 28 on Sheldon Brown's gear calculator is 14-16-18-20-22-24-28. Since I have no desire to count gear teeth myself, I am going to assume that both are accurate for my bike. I did check my lowest gear, which is predicted to be 1:1 by this, and it is 1:1 or very close (one wheel revolution in reverse forces one pedal revolution).

So, handy chart time. All of these use the gear notation that the bike's shifters use, as opposed to the various confusing notations that bike people like, and something like '1-2' has the front gear written first, so it is the lowest front gear with the second lowest rear gear.

(When mapping between this and gear teeth, remember that the low gear on the front chainring has the lowest number of teeth, but the low gear on the rear chainring has the highest number of teeth. So my lowest gear is 28 teeth to 28 teeth, for a 1:1 front to rear ratio.)

The gear ratios (front to rear); the gear combinations that the manual says are okay to use are bolded.

	front 1	front 2	front 3
rear 1	1.00	1.36	1.71
rear 2	1.17	1.58	2.00
rear 3	1.27	1.73	2.18
rear 4	1.40	1.90	2.40
rear 5	1.56	2.11	2.67
rear 6	1.75	2.38	3.00
rear 7	2.00	2.71	3.43

(Certain combinations of front and rear gears are to be avoided because the chain runs at too much of an angle. This is how you turn a 21 speed bike into a 13 speed one.)

Surprises: 2-6 and 3-4 are almost identical, but 1-4 and 2-2 are not.

The Umbria 100 gearing counts up straightforwardly for the gears you are supposed to use, although it's not linear outside them; 2-1 is between 1-3 and 1-4, 2-7 is between 3-5 and 3-6, and 3-3 is between 2-5 and 2-6. (All of these gears are usable for at least short periods of time.)

My bike computer doesn't have a cadence counter, but one can use its km/h display to reverse engineer a brute force one. This chart maps various pedal cadences in specific gears to the displayed km/h (using the fact that I know what wheel size the bike computer is set to):

rpm:	30	40	50	60	70	80	90	100	110	120
1-1	3.9	5.2	6.5	7.8	9.1	10.3	11.6	12.9	14.2	15.5
1-2	4.5	6.0	7.5	9.1	10.6	12.1	13.6	15.1	16.6	18.1
1-3	4.9	6.6	8.2	9.9	11.5	13.2	14.8	16.5	18.1	19.7
1-4	5.4	7.2	9.1	10.9	12.7	14.5	16.3	18.1	19.9	21.7
2-2	6.1	8.2	10.2	12.3	14.3	16.4	18.4	20.5	22.5	24.6
2-3	6.7	8.9	11.2	13.4	15.6	17.9	20.1	22.3	24.6	26.8
2-4	7.4	9.8	12.3	14.7	17.2	19.7	22.1	24.6	27.0	29.5
2-5	8.2	10.9	13.6	16.4	19.1	21.8	24.6	27.3	30.0	32.8
2-6	9.2	12.3	15.4	18.4	21.5	24.6	27.6	30.7	33.8	36.9
3-4	9.3	12.4	15.5	18.6	21.7	24.8	27.9	31.0	34.1	37.2
3-5	10.3	13.8	17.2	20.7	24.1	27.6	31.0	34.5	37.9	41.4
3-6	11.6	15.5	19.4	23.3	27.2	31.0	34.9	38.8	42.7	46.5
3-7	13.3	17.7	22.2	26.6	31.0	35.5	39.9	44.3	48.8	53.2

(I am only bothering to list the gears I am supposed to use.)

Now, for my own use, the useful bits of the same information, namely the speed bands for each gear and my target speed in the gear:

(gear)	(80 - 120)	(90)
1-1:	10.3 to 15.5	11.6
1-2:	12.1 to 18.1	13.6
1-3:	13.2 to 19.7	14.8
1-4:	14.5 to 21.7	16.3
2-2:	16.4 to 24.6	18.4
2-3:	17.9 to 26.8	20.1
2-4:	19.7 to 29.5	22.1
2-5:	21.8 to 32.8	24.6
2-6:	24.6 to 36.9	27.6
3-4:	24.8 to 37.2	27.9
3-5:	27.6 to 41.4	31.0
3-6:	31.0 to 46.5	34.9
3-7:	35.5 to 53.2	39.9

(Disclaimer: I may change my mind about my target cadences someday.)

Formulas

For my own reference if nothing else, here's how to calculate these.

Let:

fgt	be the number of teeth on the current front gear
rgt	be the number of teeth on the current rear gear
cad	be your pedaling cadence in RPM
circ	be the circumference of your wheel in millimeters (as programmed into your bike computer)

Giving:

gr	fgt / rgt	the gear ratio, how many times the rear wheel goes around when you pedal through a complete circle.
mmm	gr * cad * circ	(the speed in millimeters per minute)
kmh	(mmm * 60) / (1000 * 1000)	the speed in km/h

Or, in fully worked out form:

kmh = (fgt * cad * circ * 60) / (rgt * 1000 * 1000)

I find it more convenient to do the km/h calculation in three steps, because it makes it clearer where all the numbers are coming from.