Computer For MTB

> Hi,
>
> Anyone got any recommendations for a bike computer, preferably wireless, that will work on a
> mountain bike with suspension forks.
>
> For what it's worth, I've tried a Sigma Computer 1200 RDS (to be returned to Wiggle), and there is
> no way the sensor could possibly get within the required distance (5mm) of the spoke magnet
> without welding bits onto the forks! Seems stupid really, seeing as the thing can be calibrated
> for all sorts of wheel sizes...
>
> Thanks in advance,
>
> Kieran

I had the same problem when I got my computer just a couple of years ago. The other problem was that
because I did a lot of off-road bumpy stuff, including banging my wheels down on tree roots, etc the
spoke magnet would either slip or come out of line.

Since then I've never bothered with it and instead rely on the map (and more recently acquired GPS)
to tell me how far I've travelled.

I'd have to dig the box out to figure out which model it was but I won't bother with one again. Too
fiddly and temperamental IMHO.

--
...meandering mule...

Kieran Moore wrote:
> Hi,
>
> Anyone got any recommendations for a bike computer, preferably wireless, that will work on a
> mountain bike with suspension forks.
>

I have a Polar s720i on my bike, fork is a dual-crown Manitou XvertR (on the outside inside rebuild
so it's like a Black on steroids) and so far I have had no problems. Only thing is I had to mount it
further from the center of the wheel than I liked due to it being wireless with limited range, but
it's not something I'd call a problem.

I know the s720i is much more than a bike computer - speed, distance, heart rate, pulse zones,
altitude, temprature plus it logs everything for you to analyze on your PC - but I do find it
very usefull.

Also a friend of mine bought a Sigma bike computer and he has had no problems mounting it on his
Black fork, so maybe you can just try another Sigma or perhaphs its a question of a mounting kit.

Hope this helps.

Kind regards

Bruno

"Kieran Moore" <[email protected]> wrote in message
news:W%[email protected]...
> Hi,
>
> Anyone got any recommendations for a bike computer, preferably wireless, that will work on a
> mountain bike with suspension forks.
>
> For what it's worth, I've tried a Sigma Computer 1200 RDS (to be returned
to
> Wiggle), and there is no way the sensor could possibly get within the required distance (5mm) of
> the spoke magnet without welding bits onto the forks! Seems stupid really, seeing as the thing can
> be calibrated for all sorts of wheel sizes...

What are you fitting it to? I've never experienced a problem fitting Sigmas. As it cordless, go
lower on the fork leg - thus reducing the leg to spoke distance

"Adam Dugmore" <[email protected]> wrote in message
news:[email protected]...
>
> What are you fitting it to? I've never experienced a problem fitting Sigmas. As it cordless, go
> lower on the fork leg - thus reducing the leg
to
> spoke distance

I'm trying to fit it to a Manitou SX-R fork with Bontrager Race Disk wheels. I'll have another
look, but I'm pretty sure that I'm never going to get within the required 5mm or so for the
sensor/magnet gap....

Ta,

Kieran

"mule" <[email protected]> wrote in message
news:[email protected]...

> I had the same problem when I got my computer just a couple of years ago. The other problem was
> that because I did a lot of off-road bumpy stuff, including banging my wheels down on tree roots,
> etc the spoke magnet would either slip or come out of line.

Well, I'm not going too far off road, and use the bike more as a fast 'fitness bike', which is why I
would like the stats on speed/distance. I'm too old now for my other bike (25 year old racer) and
it's 13-19 block, and appreciate the MTB comfort a lot!

Regards,

Kieran

"iddqdATworldonline.dk" <[email protected]> wrote in message
news:[email protected]...
> Kieran Moore wrote:

> Also a friend of mine bought a Sigma bike computer and he has had no problems mounting it on his
> Black fork, so maybe you can just try another Sigma or perhaphs its a question of a mounting kit.

As I said in another reply, I'll take another look, but are there any computers which are good at
coping with wide spoke/fork gaps. I don't know, but maybe being wheels for disk brakes (Bontrager
Race Disk), maybe the gap is greater...

Regards,

Kieran

Before my mountain bike was stolen, I have a Cateye Cordless 2 on some Marzocchi Bombers.

Like you mention, attaching the sensor directly to the fork leg is a chocolate fireguard. To get
round this, I padded out the part of the fork which re-enforces the V-brake bosses - and attached
the sensor to that. It worked perfectly for years and required no further adjustment.

I padded it out by tightly wrapping an old narrow (10mm) climbing sling round on itself until it was
'fat' enough for the sensor's clasp.

I hope this helps.

"mule" <[email protected]> wrote in message
news:[email protected]...
> > Hi,
> >
> > Anyone got any recommendations for a bike computer, preferably wireless, that will work on a
> > mountain bike with suspension forks.
> >
> > For what it's worth, I've tried a Sigma Computer 1200 RDS (to be returned to Wiggle), and there
> > is no way the sensor could possibly get within the required distance (5mm) of the spoke magnet
> > without welding bits onto the forks! Seems stupid really, seeing as the thing can be calibrated
> > for all sorts of wheel sizes...
> >
> > Thanks in advance,
> >
> > Kieran
>
> I had the same problem when I got my computer just a couple of years ago. The other problem was
> that because I did a lot of off-road bumpy stuff, including banging my wheels down on tree roots,
> etc the spoke magnet would either slip or come out of line.
>
> Since then I've never bothered with it and instead rely on the map (and more recently acquired
> GPS) to tell me how far I've travelled.
>
> I'd have to dig the box out to figure out which model it was but I won't bother with one again.
> Too fiddly and temperamental IMHO.
>
>
> --
> ...meandering mule...

Kieran Moore wrote:
> As I said in another reply, I'll take another look, but are there any computers which are good at
> coping with wide spoke/fork gaps. I don't know, but maybe being wheels for disk brakes (Bontrager
> Race Disk), maybe the gap is greater...
>

My friend is away for the weekend so I can't say exactly what he did but I'm sure the would have
mentioned it if there was problems . If you'd like I can snap a picture of who the sensor is mounted
on my fork and mail it to you.

The hub is a Hugi FR Disc with a Mavic rim, so it should be much the same as yours.

Kind regards

Bruno

"Drinky" <[email protected]> wrote in message
news:[email protected]...
>
> I padded it out by tightly wrapping an old narrow (10mm) climbing sling round on itself until it
> was 'fat' enough for the sensor's clasp.

This is beginning to sound like a mission! I opted for a cordless one on the basis I wouldn't have
to add to the number of wires and stuff on the bike! It seems I was very naive!

Regards,

Kieran

> My friend is away for the weekend so I can't say exactly what he did but I'm sure the would have
> mentioned it if there was problems . If you'd like I can snap a picture of who the sensor is
> mounted on my fork and mail it to you.
>
> The hub is a Hugi FR Disc with a Mavic rim, so it should be much the same as yours.

Hi again. I think my understanding of how these things work is not what it might be. I assumed that
it was significant where the sensor was mounted on the wheel, in terms of distance from the hub.
Surely, if the sensor is not mounted at the optimum position, whatever that may be, the calculations
performed by the computer will not be correct, in terms of having programmed in a particular wheel
size. Have I got this wrong? I mean, can you mount the thing anwhere between hub and rim without
having to adjust the wheel size programmed into the computer? An area of ignorance on my part...

Thanks for the offer of the pictures. If I can get over the hurdle of being confident that the thing
will produce reasonably accurate results, I think I can get it to work about 2" from the hub (ie
right at the bottom of the fork!).

Thanks for the help!

Regards,

Kieran

In message <djk%[email protected]>, Kieran Moore
<[email protected]> writes
>Have I got this wrong? I mean, can you mount the thing anwhere between hub and rim without having
>to adjust the wheel size programmed into the computer? An area of ignorance on my part...

Yes, you have got this wrong. The only important thing is that the distance between the sensor and
magnet is small enough for the sensor to register the magnet. The computer works by counting the
revolutions of the wheel and converting this into distance and speed using a wheel circumference
which you input into the computer.
--
Michael MacClancy

www.macclancy.demon.co.uk

Hi,

Just to say thanks to all for encouraging me to persevere. The computer is now up and running,
positioned about 2 inches away from the hub. All I now have to do is resist the temptation to
'chase' ever higher speeds, destroying my cadence along the way!

Again, thanks!

Regards,

Kieran

"Kieran Moore" <[email protected]> of ntl Cablemodem News Service wrote:
>Hi again. I think my understanding of how these things work is not what it might be. I assumed that
>it was significant where the sensor was mounted on the wheel, in terms of distance from the hub.
>Surely, if the sensor is not mounted at the optimum position, whatever that may be, the
>calculations performed by the computer will not be correct, in terms of having programmed in a
>particular wheel size. Have I got this wrong? I mean, can you mount the thing anwhere between hub
>and rim without having to adjust the wheel size programmed into the computer? An area of ignorance
>on my part...

You do have this wrong. All the sensor is doing is telling the computer *when* a complete revolution
of the wheel has occurred. How far up or down the sensor is mounted makes no difference to the time
interval between the magnet going past the sensor. Wherever you mount it, there is still going to be
one click per wheel revolution. All you need to arrange for is that the sensor and magnet pass close
enough to each other for the sensor to pick up the magnet. The readings on the computer are
determined entirely by the number you put in for wheel size.

--
From troubles of the world I turn to ducks. Beautiful comical things.
F. W. Harvey Steph Peters delete invalid from [email protected] Tatting, lace &
stitching page <http://www.sandbenders.demon.co.uk/index.htm

My mtb usually travels in the car boot with the front wheel out.

When I get to the trailhead and slot the wheel in I find the sensor has moved on the fork during
transit and I have to waste minutes in riding around trying to adjust the clearance.