Bike Forums

Bike Forums (https://www.bikeforums.net/forum.php)
-   Rides and Races (https://www.bikeforums.net/rides-races/)
-   -   Toronto Fixed (https://www.bikeforums.net/rides-races/96956-toronto-fixed.html)

sweep242 05-16-07 09:13 AM


Originally Posted by cavernmech
Well right now I am only carrying the Nitto stuff from IRO...123's are about it. In a week or so when the brokerage is all set up I will be doing regular orders from EAI...home of many things pimpin'. What in particular were you lookin for?
3 posts in a row.....YAY!

Don’t suppose you’ll be getting t-shirts?(IRO)
I had the EAI site bookmarked cant find it now but i remember them having cool stuff!
Good news is good.

I_bRAD 05-16-07 09:17 AM


Originally Posted by jeremywhitehorn
Marzochi "bomber". about 2001 or so. probably not a high end fork, but if i can save it, all the better.

If it's still got the stickers you can usually figure out which model it is. Look on the lower rear of the rh side of the fork. There's also usually a date code cast into the slider at that point.

Some of the 'zokes forks are awesome- I've got one on my mtb and I wouldn't trade it for anything (well maybe not anything but I really like it)

cavernmech 05-16-07 09:57 AM


Originally Posted by I_bRAD

Some of the 'zokes forks are awesome- I've got one on my mtb and I wouldn't trade it for anything (well maybe not anything but I really like it)

Word to that. I had a 2001 Bomber Z2 on my bike for 2 years and loved the hell out of it. Had to swap/upgrade to 100mm so now my buddy Chris is rocking it.

I_bRAD 05-16-07 09:58 AM


Originally Posted by cavernmech
Word to that. I had a 2001 Bomber Z2 on my bike for 2 years and loved the hell out of it. Had to swap/upgrade to 100mm so now my buddy Chris is rocking it.

ha. That is the exact fork I have. :D

jeremywhitehorn 05-16-07 10:31 AM

the fork has a '97' stamped on the inside of the blade so i guess it's about 10 years old? it also has a "c2" or something, i can't quite make it out...

fisso416 05-16-07 10:31 AM


Originally Posted by cavernmech
Well right now I am only carrying the Nitto stuff from IRO...123's are about it. In a week or so when the brokerage is all set up I will be doing regular orders from EAI...home of many things pimpin'. What in particular were you lookin for?
3 posts in a row.....YAY!


I'm looking for a seatpot, a stem, and a rack

jeremywhitehorn 05-16-07 11:00 AM

found it: marzochi bomber z3, 1997. is it worth fixing keith?

Shiznaz 05-16-07 03:11 PM

Anyone know about electronics and such?

Here is my query:
On my trip I am bringing a cell phone, a digital camera and an mp3 player. I have a fancy battery charger with AC input that converts to DC and charges 4 nimh batteries ( http://www.semsons.com/pocpowban.html ). There is a USB port on the charger to then charge other devices off of the batteries or directly from the outlet. My mp3 player is no problem since it charges off of a USB cable.

The battery charger came with a USB to DC barrel type wire for charging non USB devices. The voltage is 5V coming out of the charger. The barrel is too big to plug into my cell phone which is 5V, so I am probably going to just splice the tip of the phone's AC adapter to the power circuit on a USB cable or make a simple DC barrel diameter reducer. Thats not really a problem either.

What is a problem is that my camera has a 4.5V proprietary DC input. If I get around the proprietary input and run 5V into the camera will I fry it? Otherwise I will have to carry an external battery charger for the camera along with an extension lead since it doesn't have a folding built in plug and kind of ruins the perfection of my charging setup!

operator 05-16-07 03:44 PM

Too bad i'm not an EE.

cavernmech 05-16-07 04:25 PM


Originally Posted by jeremywhitehorn
found it: marzochi bomber z3, 1997. is it worth fixing keith?

Hmmmmm...10 years old.....I will call the Marz service guys and ask if they have the requisite bushings and whatnot. If so then I would say sure. It is an older fork...and newer ones will be better performing and lighter..but since you dont really have anything to compare it against its not like you will complain that it isnt as good as fork B.

sweep242 05-16-07 06:09 PM


Originally Posted by duppy.conqueror
Yo Keith...
check out the latest DanceDanceRevolution master ;)
http://farm1.static.flickr.com/194/5...508450.jpg?v=0

I missed this, that’s awesome!

cavit8 05-16-07 07:16 PM


Originally Posted by Shiznaz
What is a problem is that my camera has a 4.5V proprietary DC input. If I get around the proprietary input and run 5V into the camera will I fry it? Otherwise I will have to carry an external battery charger for the camera along with an extension lead since it doesn't have a folding built in plug and kind of ruins the perfection of my charging setup!

You camera has a proprietary battery? Hrmm.... A quick online search found a few similar questions to yours but no "Yes I did it and it worked" answers...

You could try making a simple voltage divider using two resistors in series and tapping off from around one resistor. If you were to tap around R1 the voltage drop around R1 would be

V_R1 = (R1/(R1+R2))*input voltage

So you'd want a resistor combo that gave you 4.5V=(R1/(R1+R2))*5V

Note that I have absolutely no idea what I'm doing... I'd definitely test this with a meter to make sure you're getting the voltage you want and enough current.

Offhoff 05-16-07 07:44 PM


Originally Posted by duppy.conqueror
Yo Keith...
check out the latest DanceDanceRevolution master ;)
http://farm1.static.flickr.com/194/5...508450.jpg?v=0

Thats rocking it hard Duppy! Awesome.

cavit8 05-16-07 07:47 PM


Originally Posted by duppy.conqueror
Yo Keith...
check out the latest DanceDanceRevolution master ;)
http://farm1.static.flickr.com/194/5...508450.jpg?v=0

You need to build up the combo version so she can whup you.
http://www.geocities.com/ddrhomepad/

I have a couple of dead controllers if you want to get a start on it :D

Shiznaz 05-16-07 08:04 PM

I went to Sushi Marche with my mum tonight. Amazing! Seriously! Thanks for the recommendation.

LordFoo 05-16-07 09:12 PM


Originally Posted by cavit8
You camera has a proprietary battery? Hrmm.... A quick online search found a few similar questions to yours but no "Yes I did it and it worked" answers...

You could try making a simple voltage divider using two resistors in series and tapping off from around one resistor. If you were to tap around R1 the voltage drop around R1 would be

V_R1 = (R1/(R1+R2))*input voltage

So you'd want a resistor combo that gave you 4.5V=(R1/(R1+R2))*5V

Note that I have absolutely no idea what I'm doing... I'd definitely test this with a meter to make sure you're getting the voltage you want and enough current.

I am an EE :o , so I'll throw in my two cents.
Warning: lesson in circuits ahead! Also, note that I'm tired and may have made some mistakes, so I'll state the disclaimer than if you rely on this advice, you may electrocute yourself.

The voltage divider formula is correct on its own, but slightly incomplete. It works perfectly when the device that uses the "tap" has infinite input resistance (impedance), but that's not necessarily a good assumption. Let's call the device's internal resistance RL (L for Load)

I'll use some toy numbers which might be reasonably close to your setup (but definitely aren't exact, since I'm pulling them out of my head)

For example - let's say R1=100 Ohm, R2 = 900 Ohm, and RL is something infinite (or maybe just huge, relative to R2 -- here, assume it's 1 MOhm = 1000000 Ohms):


+ --------R1-----o----------- +
| |
V_in R2 RL VL
| |
- ------------------o----------- -

(The vertical bars here were supposed to connect R2 and RL to the circuit in parallel)

The two resistors R2 and RL are in parallel, so they have an equivalent resistance defined as 1/R_eq = 1/R2 + 1/RL.

The equivalent circuit has R1 and R_eq in series, tapping VL off of R_eq.

If RL is infinite, then 1/RL = 0, so R_eq = R2. In the finite (but big) case:
1/R_eq = 1/900 + 1/1000000, so R_eq is basically still 900 Ohms (since RL is so much bigger than R2, then 1/RL is much smaller than 1/R2.)

Problem: In the real world (and on your camera), the device's impedance is probably something much smaller, so we need to take it into account. Let's say it draws 100 mA constantly while charging (something that could be checked) -- this means it has a load resistance of 4.5 V / 100 mA = 45 Ohms.
This isn't very big, but let's pick R1=1 Ohm and R2=9 Ohms to help our case (so that RL > R2).

In this case, R_eq = 9*45/(9+45) = 7.5 Ohms, so we get VL = 7.5Ohm/(7.5Ohm+1Ohm) * 5 V = 4.4 V. Pretty close to what we wanted - however, this leads to another problem.

Another problem: Since we had to pick R2 much smaller than RL in order for the divider to work, it now draws a current of VL / R2 = 4.4V / 9 Ohms = 488mA. That means that the power supply needs to be able to provide 588 mA of current to its load, and most of it is being wasted as heat! Power = V*I = 4.4V*0.488A > 2 Watts! (This also means you need a R2 resistor rated for at least this much power dissipation)

The moral of the story -- yes, a simple voltage divider may work, but even if it does, it will waste a lot of power as heat. This analysis also relies on the fact that the 5V provided as the input is constant -- it is possible than if the power supply isn't regulated, its output voltage may change based on the load, which messes with all the previous analysis.

This post is already getting way too long -- if you want to discuss it further, feel free to send me a PM.

jeremywhitehorn 05-16-07 10:40 PM


Originally Posted by cavernmech
Hmmmmm...10 years old.....I will call the Marz service guys and ask if they have the requisite bushings and whatnot. If so then I would say sure. It is an older fork...and newer ones will be better performing and lighter..but since you dont really have anything to compare it against its not like you will complain that it isnt as good as fork B.

thanks for the info. yes, i do have the advantage of ignorance, being that this is the first sus fork i've ever owned. i was hoping that i could just lock it out and run it rigid and be done with it. if i were to put a standard rigid fork on there how badly would it affect the handling?

and no, i'm not complaining because fork A was free. if i finish building it up tomorrow i'll bring it by for you to have a look.

operator 05-17-07 12:06 AM


Originally Posted by Shiznaz
I went to Sushi Marche with my mum tonight. Amazing! Seriously! Thanks for the recommendation.

Your mom? hahahahahahhaaha

LordFoo 05-17-07 06:07 AM


Originally Posted by Shiznaz
Anyone know about electronics and such?

Another afterthought, after sleeping on it -- if the output is 5V regulated, you might be able to get away with just putting a diode in series with the load (rated for the appropriate current drawn by the device, of course). One of the weird thing about diodes is that as long as they're operating, they have a voltage drop of about 0.7V --so that'd give you a bit closer to 4.5V (probably within acceptable tolerance?) and regulated.

Again, if the charger is unregulated, it's a whole different ballgame.

EDIT: For something more complicated, you could use a transistor based circuit, see "Emitter-Follower buffer":
http://hyperphysics.phy-astr.gsu.edu...c/emitfol.html

EDIT AGAIN: Now that I think about it, the easiest way would be to use a normal voltage divider followed by an op-amp configured as a voltage follower -- this basically acts as a buffer between the load (device) and the supply circuit. It'll work only if the charging current isn't too large - typical op-amps can deliver 20-30 mA and "high current" ones are around 200mA.
http://hyperphysics.phy-astr.gsu.edu...opampvar2.html

duppy.conqueror 05-17-07 06:12 AM


Originally Posted by cavit8
You need to build up the combo version so she can whup you.
http://www.geocities.com/ddrhomepad/

I have a couple of dead controllers if you want to get a start on it :D

cooooooooool!

shapelike 05-17-07 06:12 AM


Originally Posted by operator
Your mom? hahahahahahhaaha

1. Mother's Day
2. After you start buying your own clothes, moms stop being lame.

cavernmech 05-17-07 06:53 AM


Originally Posted by jeremywhitehorn
thanks for the info. yes, i do have the advantage of ignorance, being that this is the first sus fork i've ever owned. i was hoping that i could just lock it out and run it rigid and be done with it. if i were to put a standard rigid fork on there how badly would it affect the handling?

and no, i'm not complaining because fork A was free. if i finish building it up tomorrow i'll bring it by for you to have a look.

The P2, as well as many others, are suspension corrected so they wont adversely affect handling. The Marzo boys are checking the specs and stock to see if they have what may be needed.

cavernmech 05-17-07 06:54 AM


Originally Posted by shapelike
2. After you start buying your own clothes, moms stop being lame.

hahahahaha ZING!!

duppy.conqueror 05-17-07 07:48 AM

this 'ish is funny...

Shiznaz 05-17-07 07:52 AM

Uh oh that brings up the bright red Scotia "HEY LOOK AT THIS PERV LOOKING AT PERV STUFF!" page


All times are GMT -6. The time now is 04:46 PM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.