BIKE COMPUTER

fabs
Posts: 11
Joined: Tue Jan 23, 2007 1:57 pm
Location: Nz

BIKE COMPUTER

Postby fabs » Wed Jan 24, 2007 12:26 pm

Any suggestions on a good waterproof computer for roadbike, I was thinking of a wireless one but somebody told me they not reliable?
Dont want to spend heaps on one but I want value for money. Thanks.

User avatar
europa
Posts: 7334
Joined: Sun Jul 16, 2006 10:51 am
Location: southern end of Adelaide - home of hills, fixies and drop bears

Postby europa » Wed Jan 24, 2007 1:05 pm

Among my fleet, I've got or had four computers.

My son bought a Huffy from Big W which lived on his bmx. It cost about nothing and gave basic distance and speed and time and worked for two years before giving up. It never got wet but I wouldn't hold out much hope for it.

Both my son and I have Sigma Sport BC600 computers, both of which are four years old now though realistically only have about a year's use on the bike. They give basic speed, distance and time and have proven very reliable. I haven't had either of them wet so can't comment on that side of things but they don't look waterproof.

I bought a UnionXR computer. Dirt cheap from Torpedo7. Gives Heart Rate, Cadence and all the cycling functions. It lives on my horrible hybrid, the Sow's Ear and gets used regularly. I has never been wet and I wouldn't give you two bob for its chances as the buttons don't look waterproof. It is a mix of wire and wireless and both sides of it have proven reliable. But the mount is horrible, the unit itself is horrible and to be honest, it's well placed on the Sow's Ear (a bike that cops a lot of abuse, both in workload and in attitude).

For my Trek520, I have a Polar CS200cad. Yes, it is expensive, over $300 but if you want the functions, pay the money to buy a good one - having tried going cheap, it's not worth it. The CS200 gives all the cycling functions, heart rate, cadence and allows you to store a certain number of rides - very useful. For example, on my ride to the TDU, I recorded the trip down, my local running while there and the trip home - these were all different rides, different types of ride and it made using the information much more relevant.

The CS200 is completely wireless. I have had NO troubles with that side of things. How you set it up is critical - distances between magnets and sensors, getting the sensors and the magnets lined up properly, positioning of the units, however, once set up, it has proven completely reliable. Even the cadence sensor which looks horribly vulnerable has required no attention. Initially my cadence was dodgy but moving the magnet about 3mm so it swept the centre of the sensor fixed that. The position of the main unit seems to cause problems - on another forum, where they were discussing this beast, all those having problems had the unit mounted on the stem, no one who had it mounted on the handlebars reported a problem. So setting it up requires some attention to detail, but mine has done nearly 800 trouble free kilometres now.

Last saturday, I did a 68km trip, 50km at least of which was in heavy rain. I used a number of different functions, stored data in three different files (in other words, buttons were being pressed). It behaved flawlessly and still does now after any moisture has had a chance to seep in. In other words, I consider it waterproof.

Richard

User avatar
commi
Posts: 62
Joined: Tue Jan 02, 2007 1:10 pm
Location: Melbourne, VIC

Postby commi » Wed Jan 24, 2007 1:28 pm

How can I tell if my LBS has installed my computer up properly, in terms of accuracy??

e.g. I don't want to tricked into thinking I've actually ridden less than what the computer says.

User avatar
tuco
Posts: 2016
Joined: Wed Oct 11, 2006 3:36 pm

Postby tuco » Wed Jan 24, 2007 1:52 pm

commi wrote:How can I tell if my LBS has installed my computer up properly, in terms of accuracy??

e.g. I don't want to tricked into thinking I've actually ridden less than what the computer says.
Which brand and model is it?

User avatar
commi
Posts: 62
Joined: Tue Jan 02, 2007 1:10 pm
Location: Melbourne, VIC

Postby commi » Wed Jan 24, 2007 2:05 pm

Cateye Astrale 8

User avatar
Bernard
Posts: 24
Joined: Tue May 16, 2006 2:20 pm
Location: Artarmon

Postby Bernard » Wed Jan 24, 2007 2:20 pm

I've had the Cateye wireless computer for over a year and a half now and it has never missed a beat. Prior to this I had the Sigma wireless which died within 9 months. The Cateye has been in the rain a few times and is still fine. eBay is your friend for purchasing one, they are approx 1/2 the price of what the LBS will charge you.

In regards to accuracy you will need to check the manual and make sure the wheel size has been set correctly, otherwise go for a ride over a set distance, or use your car to measure the distance and ride the same route afterwards.
Merida CX 4

User avatar
tuco
Posts: 2016
Joined: Wed Oct 11, 2006 3:36 pm

Postby tuco » Wed Jan 24, 2007 2:26 pm

Bernard wrote:In regards to accuracy you will need to check the manual and make sure the wheel size has been set correctly, otherwise go for a ride over a set distance, or use your car to measure the distance and ride the same route afterwards.
If you had a Flightdeck I could have helped.

Bernard is on the right track.

User avatar
commi
Posts: 62
Joined: Tue Jan 02, 2007 1:10 pm
Location: Melbourne, VIC

Postby commi » Wed Jan 24, 2007 2:32 pm

Thanks for the advice. There's one part of my bike route which i can't drive on so i can't measure against car.

but i could try to check the wheel size thingy. And where the magnet is affects accuracy, too?

Mine is a wired one, btw.

P.S. Tuco, who is that a picture of in your avatar? Looks like some old western movie...

User avatar
sogood
Posts: 17168
Joined: Thu Aug 31, 2006 7:31 am
Location: Sydney AU

Re: BIKE COMPUTER

Postby sogood » Wed Jan 24, 2007 2:41 pm

fabs wrote:Any suggestions on a good waterproof computer for roadbike, I was thinking of a wireless one but somebody told me they not reliable?
Similar to home cordless phones, analogue wireless are more affected by interference while digital models are resistant to it. So, wireless can be highly reliable depending what you have. The fact that there's no wires to damage or corrode or seal around in the rain is a plus from a reliability point of view.
Bianchi, Ridley, Tern, Montague and All things Apple :)
RK wrote:And that is Wikipedia - I can write my own definition.

User avatar
Bnej
Posts: 2880
Joined: Fri Jun 30, 2006 11:43 pm
Location: Katoomba, NSW

Postby Bnej » Wed Jan 24, 2007 3:16 pm

commi wrote:but i could try to check the wheel size thingy. And where the magnet is affects accuracy, too?
You'll have a table of wheel size/tyre size to diameter, you enter the diameter number into the computer. e.g, my tyres say "26x1.5" on the side, so I look up that number in the table that comes with the computer. Yours will probably say "700c x (something)"

The position of the magnet doesn't matter so long as it registers, it just has to pass the sensor once per rotation so it knows the wheel has turned one wheel diameter.

User avatar
commi
Posts: 62
Joined: Tue Jan 02, 2007 1:10 pm
Location: Melbourne, VIC

Postby commi » Wed Jan 24, 2007 4:05 pm

Yeah. it is 700 x 28c (28 - 622)

What do the first two numbers mean?

28 is inch diameter? or width of tyre?

What is 700 then?

So with this info I should be able to check the manual and input/check the number that has been entered into the computer?

User avatar
europa
Posts: 7334
Joined: Sun Jul 16, 2006 10:51 am
Location: southern end of Adelaide - home of hills, fixies and drop bears

Postby europa » Wed Jan 24, 2007 4:19 pm

commi wrote:Yeah. it is 700 x 28c (28 - 622)

What do the first two numbers mean?

28 is inch diameter? or width of tyre?

What is 700 then?

So with this info I should be able to check the manual and input/check the number that has been entered into the computer?
That's all you need. :D

Like all things cycling, the terminology is all mucked up. 700c wheels are called 28" wheels, but that diameter is for rim and tyre ... sort of. The old 27" wheels have a rim diameter of 27" ... sort of. As a result, a 700c (or 28") wheel and tyre is smaller than a 27" wheel and tyre :? But those diameters depend on the tyre fitted.

Just check your manual. The charts are easy to read (usually) and either 700x28 or 28-622) will give you the number you need to check. Like everything with bikes, the reality is nowhere near as scary as the anticipation.

Richard

User avatar
commi
Posts: 62
Joined: Tue Jan 02, 2007 1:10 pm
Location: Melbourne, VIC

Postby commi » Wed Jan 24, 2007 4:24 pm

europa wrote:Like all things cycling, the terminology is all mucked up. 700c wheels are called 28" wheels, but that diameter is for rim and tyre ... sort of. The old 27" wheels have a rim diameter of 27" ... sort of. As a result, a 700c (or 28") wheel and tyre is smaller than a 27" wheel and tyre :? But those diameters depend on the tyre fitted.Richard
Well you've got me confused!!! :oops:

Anyway, thanks. I'll check the manual

User avatar
commi
Posts: 62
Joined: Tue Jan 02, 2007 1:10 pm
Location: Melbourne, VIC

Postby commi » Wed Jan 24, 2007 7:06 pm

I'm a bit confused/disappointed.

I just checked my manual and it turns out my LBS had set up my computer to 2105mm, which is for a 700 x 25c tyre.

But mine is 700 x 28c, which means computer should be set to 2136mm.

So i've had to reset the whole thing, because I'm guessing the Odometre would have been wrong if its set incorrectly?

Is there a reason why it would be set one size down by my LBS? On purpose? or mistake?

User avatar
Bnej
Posts: 2880
Joined: Fri Jun 30, 2006 11:43 pm
Location: Katoomba, NSW

Postby Bnej » Wed Jan 24, 2007 7:08 pm

700 is supposedly the diameter of the whole wheel (rim with tyre) in millimetres. But of course, that's stupid because tyres are different sizes. So the second number is the size of the tyre. The "c" means "clincher" type. 622 I think is the diameter of the inside of the rim.

For some reason, road bikes have these in millimetres, mountain bikes have 26" wheels and the wheel & tyre are measured in inches.

Generally, a narrower tyre rolls better and takes a higher pressure, so is good for going fast. A fatter tyre is better on rough ground but puts more weight and drag on the bike. So you might swap your 700 x 28 tyres for some 700 x 23 tyres if you were going racing, but then of course you'd need to change the setting on the speedo again. ;)

OTOH, you've got over 2 metres for a full roll of a road wheel, so a few mm out is only going to put you out of whack by a couple of percent - probably it will be more accurate than your car's speedo, which has a 10% or so tolerance IIRC.

User avatar
commi
Posts: 62
Joined: Tue Jan 02, 2007 1:10 pm
Location: Melbourne, VIC

Postby commi » Wed Jan 24, 2007 7:30 pm

Bnej wrote:OTOH, you've got over 2 metres for a full roll of a road wheel, so a few mm out is only going to put you out of whack by a couple of percent
But it still doesn't explain why my LBS set it incorrectly. The shop has been perfect up til now.

The first time I went in to enquire about different bikes I took 40 mins of the salesperson's time and he explained everything to me in a language I understood.

The second time I went to actually test my final 2 choices and again asked heaps of questions to a different person.

The person who eventually made the sale I think was the owner/manager and I asked more questions.

There was no pressure put on me to buy any accessories. I bumped into the manager at Borders a few days later in the magazine section. He remembered me and turned out we were both reading the same bike magazine! I quizzed him about bikes for half an hour and he was more than happy to talk to me.

I've been back to the shop a couple more times. Once to look at accessories and the second time was two days ago when I bought the computer. I went to pick it up after closing time and they didn't rush me out the door or anything, taking their time to show me how to use a floor pump (yes, I've never used one before and never seen a tyre with the fancy nozzle either)

So its a little disappointing to find that my computer was on the wrong setting. Its not going to stop me going back there though. Their customer service skills are excellant.

User avatar
McPete
Posts: 621
Joined: Fri Dec 22, 2006 7:08 pm
Location: Wollongong

Postby McPete » Wed Jan 24, 2007 7:54 pm

If you want to know your wheel size for sure, grab your bike, a measuring tape and some chalk. Line the front wheel up so the valve is right at the bottom, and mark that spot. Then walk the bike forward until the valve is at the bottom again, and mark it. measure between the marks and, Walah! Your wheel circumfrence exactly!

User avatar
commi
Posts: 62
Joined: Tue Jan 02, 2007 1:10 pm
Location: Melbourne, VIC

Postby commi » Wed Jan 24, 2007 8:22 pm

This method makes sense, but are you suggesting that what the side of the tyre is not right, or that manufacturers incorrectly label tyres for some purpose?

e.g. Why wouldn't I just trust what the tyre says, instead of the chalk and roll method?

And I know I keep going back to it, but how hard was it for the LBS person to look on the tyre and set computer to the right setting?

User avatar
Hotdog
Posts: 928
Joined: Thu Sep 28, 2006 11:00 am
Location: North Strathfield, Sydney
Contact:

Postby Hotdog » Wed Jan 24, 2007 9:53 pm

McPete wrote:If you want to know your wheel size for sure, grab your bike, a measuring tape and some chalk. Line the front wheel up so the valve is right at the bottom, and mark that spot. Then walk the bike forward until the valve is at the bottom again, and mark it. measure between the marks and, Walah! Your wheel circumfrence exactly!
If you really want more accuracy than just looking up your tyre size in the tables in cycle computer manuals (or if you've got unusual tyres that aren't in the table) then you need to do the measurement while sitting on the bike (which would require getting someone to help you). The deformation of the tyre under your weight reduces the effective circumference of the wheel by enough that an unloaded measurement is less accurate than simply using tables. You'd also want to measure the total distance from several revolutions of the wheel and divide to get better accuracy. I've never bothered myself though, the circumference figures in the manuals will be right to within a percent or so for normal loads, tyre pressures and tread patterns, which is good enough for me.

http://www.sheldonbrown.com has more than you'd ever need to know about tyre sizing and calibrating cycle computers.

User avatar
Bnej
Posts: 2880
Joined: Fri Jun 30, 2006 11:43 pm
Location: Katoomba, NSW

Postby Bnej » Wed Jan 24, 2007 10:16 pm

commi wrote:And I know I keep going back to it, but how hard was it for the LBS person to look on the tyre and set computer to the right setting?
They probably just misread the table. I did when I first set mine up, the writing tends to be pretty small. I wouldn't hold it against them.

User avatar
sogood
Posts: 17168
Joined: Thu Aug 31, 2006 7:31 am
Location: Sydney AU

Postby sogood » Wed Jan 24, 2007 10:32 pm

Hotdog wrote:If you really want more accuracy than just looking up your tyre size in the tables in cycle computer manuals...
Correct. But don't forget to pump up the tyre to your regular riding pressure.
Bianchi, Ridley, Tern, Montague and All things Apple :)
RK wrote:And that is Wikipedia - I can write my own definition.

User avatar
commi
Posts: 62
Joined: Tue Jan 02, 2007 1:10 pm
Location: Melbourne, VIC

Postby commi » Wed Jan 24, 2007 10:32 pm

Bnej wrote:I wouldn't hold it against them.
I don't. Its just that I expected them to be perfect this time, because they had been up to that point.

So unless there is a huge price benefit to going to another shop for same/similar item, I will always support my LBS (I always try to buy/eat local everything).

User avatar
tuco
Posts: 2016
Joined: Wed Oct 11, 2006 3:36 pm

Postby tuco » Wed Jan 24, 2007 11:27 pm

commi wrote: P.S. Tuco, who is that a picture of in your avatar? Looks like some old western movie...
Excellent work . . . it's Eli Wallach as Tuco from The Good, the Bad and the Ugly. One of my favourite films.

Eli Wallach is a legend and made many western above average just by his performance.

Anyway, back on topic :
Sounds like it may be best to drop into your lbs next time you're riding past and get them to check the computer settings. If it's wrong then they'll be aware of their error and may be more careful in the future.

User avatar
commi
Posts: 62
Joined: Tue Jan 02, 2007 1:10 pm
Location: Melbourne, VIC

Postby commi » Thu Jan 25, 2007 9:04 am

tuco wrote:Anyway, back on topic :
Sounds like it may be best to drop into your lbs next time you're riding past and get them to check the computer settings. If it's wrong then they'll be aware of their error and may be more careful in the future.
I've reset to the correct size. And turns out that when it was incorrectly set one size down, my computer was out by 100 meters e.g. was telling me distance to work was 7.58km, now its 7.68km. I found this fasinating, but I'm sure you all knew that would be the case!!

Yes, Tuco...I'll be sure to mention to them next time I'm in my LBS (I'll work it into the conversation casually).

P.S. I've not seen The Good, the Bad and the Ugly. I've been watching war films and mafia films recently. Might have to start watching westerns!!

User avatar
tuco
Posts: 2016
Joined: Wed Oct 11, 2006 3:36 pm

Postby tuco » Thu Jan 25, 2007 10:03 am

commi wrote: Yes, Tuco...I'll be sure to mention to them next time I'm in my LBS (I'll work it into the conversation casually).

P.S. I've not seen The Good, the Bad and the Ugly. I've been watching war films and mafia films recently. Might have to start watching westerns!!
If you can't then, "Oh by the way, that bike computer . . . " is a good start.

The Good, the Bad and the Ugly isn't to everyones taste. It's a spaghetti western so expect bad lip sync. The actors spoke their native language and were dubbed. Some of the voices are comical but the story is good.
War films, you can't go past Where Eagles Dare.

Who is online

Users browsing this forum: Google [Bot]