Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Mountain Biking Mountain biking is one of the fastest growing sports in the world. Check out this forum to discuss the latest tips, tricks, gear and equipment in the world of mountain biking.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 09-29-06, 06:06 PM   #1
KayGee
chain smoker
Thread Starter
 
Join Date: Sep 2006
Location: Glendale, CA
Bikes: 06 Specialized Stumpjumper HT; 07 Ellsworth Moment; 06 Specialized Rockhopper Comp
Posts: 176
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Problems with Cyclometer

I'm a first time poster so first off, I'd like to say hello -- so, Hello!

Second, I had a question. I went biking this morning and my cyclometer was totally off. The tripometer, odometer and speedometer were all reading my speed too fast (i.e., I was going about 20 mph and it said 33mph). I checked it out and nothing seems out of the ordinary. Does anyone know what happened?? Is it time to get a new one or is there some fix to the problem?

Thanks!
KayGee is offline   Reply With Quote
Old 09-29-06, 07:26 PM   #2
DirtPedalerB
unofficial roadie
 
DirtPedalerB's Avatar
 
Join Date: Jul 2006
Location: Out in the woods you see
Bikes: 2004 Marin bobcat trail, 2006 trek fuel ex7, 2007 iron horse road bike
Posts: 1,440
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
You should recalibrate it .. check your manual for instructions and make sure you do a rollout measurement.. Some models have support for multiple bikes make sure you didn't select bike #2 or something.. also make sure it's not on Kmph.. check that you have proper distance between the magnet and sensor(this is usually a slower reading though instead of faster)

other than that you could try taking the 2nd magnet off the wheel ... j/k

edit:: 33 Kmph = 20.49 mph there's your problem

Last edited by DirtPedalerB; 09-29-06 at 08:20 PM.
DirtPedalerB is offline   Reply With Quote
Old 09-30-06, 12:43 AM   #3
willtsmith_nwi
Senior Member
 
Join Date: May 2004
Bikes:
Posts: 1,398
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
How do you know you were going 20mph??? Was that what a friends odometer said? Maybe he was wrong.

Yes, you should do a rollout test. Make sure it is one with you on the bicycle. Suggestions have been made for using toothpaste, shaving cream and chalk to make marks on the pavement at the pavement using your wheel. Then just measure.
willtsmith_nwi is offline   Reply With Quote
Old 09-30-06, 11:30 AM   #4
DevilsGT2
ಠ_ಠ
 
DevilsGT2's Avatar
 
Join Date: Sep 2006
Location: SF
Bikes: One of the first Aluminum Rockhoppers to come with front suspension.
Posts: 624
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by willtsmith_nwi
How do you know you were going 20mph??? Was that what a friends odometer said? Maybe he was wrong.
There's quite a difference between 20 and 30 mph on a bike....
DevilsGT2 is offline   Reply With Quote
Old 09-30-06, 11:39 AM   #5
mlh122
Senior Member
 
mlh122's Avatar
 
Join Date: Mar 2005
Location: NW
Bikes: Trek 4500
Posts: 881
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by DevilsGT2
There's quite a difference between 20 and 30 mph on a bike....
yeah most riders with a little experience can ballpark it and be pretty close.

dirtpedaler has a point, if you think you were going about 20mph and happen to be right, you very well might be on kmph, my cyclometer has huge numbers but a tiny little icon that says kh or mh, i had it on the wrong one at first and took a while to notice it.
mlh122 is offline   Reply With Quote
Old 09-30-06, 09:19 PM   #6
Killer B
THIS BIKE'S 4 U !!!!
 
Killer B's Avatar
 
Join Date: Sep 2004
Location: Western, NC .... (Pisgah, Bent Creek, DuPont)
Bikes: HARO Xtreme X2, K2 Lithium 3.0, K2 Beast, K2 Flyin' Monkey, DiamondBack Accent EX, DiamondBack Axis TR
Posts: 1,272
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I bet your bike PC is a Cateye...

They come preset to kph. or at least my last two did...
Killer B is offline   Reply With Quote
Old 10-01-06, 02:12 AM   #7
willtsmith_nwi
Senior Member
 
Join Date: May 2004
Bikes:
Posts: 1,398
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Just roll a big one ...

Quote:
Originally Posted by DevilsGT2
There's quite a difference between 20 and 30 mph on a bike....
Yes, and there is also a difference between 17 and 20 mph. There is also a difference between 23 and 20 mph. If you're that far off, your cyclometer is WAY out of calibration.

Quote:
Originally Posted by mlh122
yeah most riders with a little experience can ballpark it and be pretty close.
Why do you need a cyclometer then. Just "ballpark" everything and you'll be pretty close. Perhaps even closer than a cyclometer that has not been calibrated using a rollout test on a given set of rims and tires (the tires being inflated to the same amount they are when used while riding).
willtsmith_nwi is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 03:00 AM.