Inexpensive computer for stoker - basic functions only

[Mike Ayling]

Any suggestions?

All we want is speed, distance ridden, average speed.

Maybe a model with the sensor on the rear wheel would be the way to go?

What do othertandem riders have?

Mike

[mickeg]

I don't suggest a particular model for a basic unit as there are so many to choose from.  But I will comment that if you go with a wireless, you may have trouble finding one that can have the sender and receiver at a significant distance from each other.  I put a wireless VDO on my Nomad with the sender on the rear wheel instead of front wheel, the wireless signal is so weak at that distance that I have to change the battery several times each year.

If you have a wireless for the rider in front and if the sender for that has a strong wireless signal, could that sender provide a wireless signal to both front and rear computers?  If so, then you need a compatible unit so that both computers share the same sender signal.

One that uses GPS for speed function instead of a wheel sensor might solve these potential problems.

[Danneaux]

Hi Mike!

On my tandem, I use two Vetta C-15 wired computers -- that alone will tell you how long they've been in place, working reliably. They were inexpensive and have proven durable. I have avoided installing wireless computers on any of my bikes. I've trialed many, but found a number of issues with reliable signal transmission, a problem made worse on tandems due to the greater distance between transmitter and receiver.

I wired both my Vettas to a single front wheel pickup to minimize variations in tire size. What? "Variations in tire size"?!? Yes. I take a variety of stokers with me, and so rear tire pressures vary depending on whether the person weighs 47kg or 164kg and whether we are day-riding or fully loaded with trailer (when the lot including riders can reach 272kg).

Weight and inflation change the effective rollout, so I had a terrible time keeping two separate computers/heads in sync. The solution was to split the leads so a single pickup sends "counts" to both heads. It was easy, has been reliable, and worked well. I have a long-travel adjustable stoker stem I Tig'd/brazed together, so I just left a loop in the lead to allow the stem to vary in length.

All I really need/want in a bike computer is time, speed, trip/total distance, average speed (TSDA), waterproofness, and a reliable lead. This means I don't spend a lot on them, nor do I need to upgrade often. I've had good luck with basic Vettas, CatEyes, and the occasional Specialized (Comp models), and now PlanetBike. All of these are easy to hack for pairing to a single pickup. I use PlanetBike Protege 9.0 computers on my one rando bike and the Nomad and like it very much except for one flaw which irritates me greatly, but not enough so far to switch: It figures average speed on a 10-hour time base. If you ride more than that (i.e. the 17-24 hours I sometimes do), it will display an error on average speed. Otherwise, it works well and has no buttons -- the case slides in its mount to change the 4-line display. I have my GPS on the stem as a double-check on long day rides in unfamiliar areas when TSDA is more critical.

If you don't mind good-natured arguments about who "rode" furthest or fastest, then wiring two computers separately (one to each wheel) is wholly viable. If you always have the same stoker, then mismatches can be minimized to almost no variance with careful calibration and setup.

Hope this helps.

Best,

Dan.

[Mike Ayling]

Thanks for those replies.

WE have ordered a Cateye long wire kit for the back wheel and a basic Cateye computer to suit.

Mike

[robert-S]

I use Garmin bike computers -  500 for most of my riding and a Tour for, well, touring. So I just bung both of them on the tandem! Tour on the front (helps with navigation), and the 500 on the stoker bars. No wires, all GPS enabled.

Robert

[energyman]

Aldi in UK have a simple computer for £5 on offer this week.

[philothewhisp]

Man he say: "Basic functions" for the poor diminished stoker. The lesser. The inferior. Is that it?

The stoker there merely to stare, gormless, uninformed, at the front-man's sweaty backside, missing the countryside view but providing a bit of motive power for bike and ego.

Did I say "Ego"? This is a miserable wretch's treatment of the wife/girlfriend who would do better to find a decent man, a bike each and equality in the event.

It is insufficient to be relegated to the back of a bike, it needs the insulting epithet "stoker" to back it up.  Relegated then kicked when down.

Stoker? It is not even funny.

[Danneaux]

I'm currently on-tour with my tandem. While I may "captain", my stoker is the Rear Admiral (and weapons and signal officer) and so outranks me.

The Smart Captain knows if the stoker ain't happy, nobody's happy, and so treats them with all respect. We are a blissfully happy team, getting along well.

By the way, our old Vetta C-10 computers have not missed a beat no matter the weather or conditions. I have wired both to a single front pickup, so readouts are identical. We usually leave them set to current speed and trip/day distance. I pull and reset the batteries before each tour so cumulative distance is recorded automatically. Just good, cheap, basic time, speed, distance computers that also figure average speed, a function I prefer be included, as it makes pacing and time-to-destination easy to figure.

Best,

Dan.

[John Saxby]

Well, I don't ride tandems, but I do paddle a canoe, and Everybody Knows that the core similarity between canoes and bikes is that you can't steer either of these wonderful devices unless you're moving. It's notable that front in the canoe is really just there for power, and the more the better in most conditions, and occasionally for steering in whitewater if told to do so by the stern (who may be cheerful by nature, but must be a stern stern to keep the front in line). The stern position is, of course, the one which requires the brains, judgment and dexterity.  A bit more weight, too, so that the boat's trim is as it should be in all circumstances except a headwind on flat water, but we don't usually talk about weight as a qualification for the stern, because it's, well, unseemly.

[Mike Ayling]

Man he say: "Basic functions" for the poor diminished stoker.

I have got basic functions on the front too mate!

Mike

[jul]

I've seen a model that i like , it's the "VDO M4 WR"
https://www.rosebikes.com/article/vdo-m4-wr-bike-computer-wired/aid:715346

I"m interested with this one because it have an altimeter and it can  use with wire (not wireless)

However, i have a doubt about the altimeter ..

Do you think it is a good option and is it really reliable ?

[David Simpson]

I've seen a model that i like , it's the "VDO M4 WR"
...
However, i have a doubt about the altimeter ..
Do you think it is a good option and is it really reliable ?

I have the VDO MC20 WR, which also has the barometric altimeter.
     http://www.vdo-mc2.com/en/functions

I have found the altimeter to be quite accurate. My commute is about 13km, and the first 4km of my commute has an elevation drop of 150m. When I get home, the altimeter is normally within 1-2m of what it was when I left home.

The problem with barometric altimeters is that they sensitive to air pressure changes due to the weather changing. If the weather changes during the day, the altimeter can be off by 5-10m at the end of the day. The MC20 has 2 "home altitude" settings. I set one to my home elevation (153m) and the other to my work elevation (10m). At the start of each ride, I reset the altimeter to the appropriate "home altitude", so the altimeter is fairly accurate for the duration of that ride. For a longer (multi-day) ride, I would want some way to reset the altimeter each morning, especially if the weather is changing.

As for whether an altimeter is a good option, that is a personal preference. I am the kind of person that likes numbers and measuring things, and I live in a mountainous area, so I like the altimeter.

- DaveS

[jul]

Ok Dave,

However, if i ride each day in differents places, and i don't know about the altitude where i am..

Is it necessary to reset in this situation ?

Or is it preferable to reset when i know exatly the altitude where i am ?

[David Simpson]

No, it is not necessary to reset the altimeter, but if the weather changes, the altimeter could be off by 5-10m. The altimeter never NEEDS to be reset, except when you first install it.

I would only reset it when you know the exact altitude (to within 5m), since the altimeter will probably be within 5-10m anyway.

- DaveS

[jul]

Thank you !