Bicycle Computer Recommendations?

[masterho]

My HD buddy with a Zumo550 said my R11RT speedo is 5mph fast at an indicated 70mph(his HD speedo was spot-on..GRR!)

 

I'm considering adding a wired/wireless bicycle computer and need your input on what works/doesn't work.

 

TIA!

[BFish]

don't bother TADT. my rt is is 3-4% off (low) from the GPS.

 

now you know.

[masterho]

don't bother TADT. my rt is is 3-4% off (low) from the GPS.

 

now you know.

 

I already know how much it's off(see original post). What I want to know is who's using which brand of bicycle computer. That was the question.

[W8NONU]

I use a Sigma wired 1200. It is very handy with additional odometer, avg speed, max speed, etc. It was easy to install and is located on my dash where it is very easy to read and change to the mode that I want to use or look at. They are relatively inexpensive, I paid $25 and it is very easy to calibrate. It runs 1.2mph different from my GPS.

 

Hope this helps.

[velomoto]

I already know how much it's off(see original post). What I want to know is who's using which brand of bicycle computer. That was the question.

I've got over a dozen Cateye computers (these are similar to the Sigma and can be calibrated quite accurately to your wheel diameter) but I only use these on the family bicycles. I considered using a bike computer when I realized my RT's speedo was off but ended up getting a GPS which I assume is providing an accurate reading.

 

FWIW - I found the RT's speedo accuracy is non-linear. It will be dead on at certain speeds, but will be upwards of 5 mph off at other speeds (alway "optimistic" - ie. reading faster than the GPS). This behavior is similar to what I've see with my Toyota vehicles. OTOH, GM vehicles which I've recently rented seem to be much more accurate and always matched the GPS.

 

I expect if the speedo is off then the mileage is likewise inaccurate. In other words if the bike reads 5% fast then my odometer is going up 5% faster than it should and my fuel mileage is optimistic by the same 5%. No???

[Heck]

I expect if the speedo is off then the mileage is likewise inaccurate. In other words if the bike reads 5% fast then my odometer is going up 5% faster than it should and my fuel mileage is optimistic by the same 5%. No???

Yes. as is the warranty on your vehicle...

[GregB]

I expect if the speedo is off then the mileage is likewise inaccurate. In other words if the bike reads 5% fast then my odometer is going up 5% faster than it should and my fuel mileage is optimistic by the same 5%. No???

A bunch of experience with cars has shown me that the odometers are far more accurate than speedometers. I did several passes with one of those "Your Speed" radar detectors setup by the city the other day and the X-Moto digital speedo was within 1mph at 45!

[motoguy128]

Don't forget that your speedo error will increase as your tire wears or with lower tire pressure.

 

When compared to my GPS, my RT is only off by about 3%. My car reads about 2% slow! which is the first vehicle I've had that actually read slow. Most of my motorcycles were off by 5-10%. I suspect the MFG's are forced to make the speedos read fast for liability reasons and in case you install a tire with a little more tread than the OEM.

 

A bicycle computer is only as good as you are able to calibrate it. You need to manually measure the wheel diameter on the pavement when fully loaded. Then I'd calculate the diameter with a fully owrn tire and split the difference.

[gregpopovich]

Garmin 305 is great! & you can move it from bike to bike.

[Kritou]

Wired setups are generally cheaper and do not suffer from radio frequency interference. You may find your choice of mounting points for the wheel sensor limited as the gap between the supplied magnet and the sensor is a recommended 2-3mm. I epoxied a small rare earth (cheap as chips from eBay)magnet to the wheel rim and mounted the sensor to a piece of flexible plastic which was in turn attached to a convenient mudguard bolt. This allowed a gap of up to 10mm if I recall. It all worked very well but then I discovered GPS!

[GlennW]

Many bicycle computers will not display speeds high enough for motorcycle use. The Sigma BC800/1200/1600 (all are wired) will read speeds up to 180 mph. I used the BC800 on my Kawasaki ZRX with only minor modifications (spliced a longer wire between the sensor and the computer). I'd steer clear of the wireless units; my experience is that the bike's electrical system creates too much radio interference for the speed sensor's weak transmitter to overcome.

[mrsoup]

Sigma BC1200 has worked great for me. Make sure you get the wired version. I tried the wireless with NO success, too much interference. I picked up magnets from Radio Shack and put it on the rotor, I used a cable tie to attach the sensor to the fork leg.

[W8NONU]

Good point about the Radio Shack magnets. I purchased the rare earth magnets, small ones, but very powerful, used two magnets to get a good read on the computer. Attached them to the brake rotor and used the speedo cable for the pick up. Have had the RT fracture a speed law or two since installing the Sigma without any magnet movement. The Sigma 1200 has worked very well for me.

[Charles Elms]

Attached them to the brake rotor and used the speedo cable for the pick up.

 

Could you post a picture of this. How are the magnets attached, and exactly where on the rotor? Same for the pickup.