Glue that can withstand the heat of a brake rotor

[Macstar]

Hey'all

Have you ever asked the shop attendent at Mitre 10 or Repco etc for technical advice...?

Can someone please let me know if they are aware of a brand of glue that will bond metal to metal (i.e. a speedo magnet to a disc rotor) and that can withstand super hot temperatures?

Cheers.

[geoffm]

Epoxies let go around 60-70 degrees. You woul be lucky to get more than that with glue. Put the magnet further away from the dis, on a rim or on the sprocket?
For the on bike data aquisition system i was playing with at one stage, the spricket was the best place
Geo

[crazefox]

yeah mate i got just the shit its called panel glue we use it at work for glueing new panels on cars insteed of welding.F##KING strong

[Macstar]

My locktite is good up to 160 degrees celcius apparently, and I have tried using some of this for now. The cable for the sensor is not long enough to reach the rear sproket.

I'll look into this "Panel Glue" but again it's heat, not sticknesses that I'm worried about.

Cheers.

...And upside down KTM forks would prevent mounting it anyway but the disc rotor.

[marty]

metalset is good for high heat, but i would say that brake rotors would get too hot.

why can't it go on the rim? one way of avoiding glue would be to drill into the rotor, and use a hammer-in rivet to secure the magnet.

[Macstar]

metalset is good for high heat, but i would say that brake rotors would get too hot.

why can't it go on the rim? one way of avoiding glue would be to drill into the rotor, and use a hammer-in rivet to secure the magnet.

Yeah I looked Metalset up (80 degrees C). I have upside down forks that offer no attachment point for the sensor to read a rim-mounted magnet.

Drilling and hammer'n I reckon.

Thanks.

[Ixion]

JBWeld is rated to 500 F about 260C . You can get it from trademe and probably other places

[Warr]

I tried a magnet mounted on the disc. It didnt work too well as the pickup picked up extra pulses off the mounting screws.
Best place it to glue the magnet onto the rim. I didnt use the magnet that came with the unit I used a piece of hard drive head magnet. I broke a piece off in a vise and put it into some heat-shrink, heated it and then used some 2-pot glue to attach to the rim. All worked sweet.

[Pancakes]

I tried a magnet mounted on the disc. It didnt work too well as the pickup picked up extra pulses off the mounting screws.
Best place it to glue the magnet onto the rim. I didnt use the magnet that came with the unit I used a piece of hard drive head magnet. I broke a piece off in a vise and put it into some heat-shrink, heated it and then used some 2-pot glue to attach to the rim. All worked sweet.

There's your answer, install or magnetise your mounting bolts and divide the wheel circumference by the number of bolts? Will increase your resolution too.

Or swap the sensor out for an optical pickup? It is just an on/off pulse.

Or use a Hall effect sensor and the gaps in your rotor?

[imdying]

JB weld or Araldite, it won't fall off due to heat.

[Macstar]

That JB weld stuff looks like the go. $12 on trademe and up to 300 degrees celcius. I'll let you know you good it is in a few days...

Oh yeah, and I did put two magnets on and divide the total wheel circumference as someone suggested, it gives a more reliable reading.

Thanks again fellas

[Warr]

There's your answer,
1) install or magnetise your mounting bolts and divide the wheel circumference by the number of bolts? Will increase your resolution too.

2) Or swap the sensor out for an optical pickup? It is just an on/off pulse.

3) Or use a Hall effect sensor and the gaps in your rotor?
Nothing theoretically wrong with any of those options apart from
1. Push bike speedo wheel circumference didnt divide down that far.
2+3. Would all have needed external power, and not readily available off the shelf.
But granted extra sensors could be the go, however the upper speed range of most pushbike speedos is 200k's, the limit I figure being something to do with how fast the reed switches can operate. If you have more sense points this would reduce the max speed.

[Taz]

www.dirtbike.co.nz do a range of magnets for speedo's. One's that replace a rotor bolt or fit into a 3/8" (10mm) hole. Maybe these would be better?

[Macstar]

Ah man, I bought the glue already! Those magnetic bolts are $18 a piece though...

My Koso speedo can take up to 6 sensors, you just divide the total wheel circumference by the number of sensors and then enter them in to the speedo unit, thus the top speed is not affected.

P.S. I tried a bicycle wireless speedo before on my KTM before the Koso but it was hopeless. The top speed was less than 100kph and there was serious lag time between the sensor and displayed speed on acceleration or braking. One second you're doing 10kph, the next you're doing 30kph.

[Warr]

Ah man, I bought the glue already! Those magnetic bolts are $18 a piece though...

My Koso speedo can take up to 6 sensors, you just divide the total wheel circumference by the number of sensors and then enter them in to the speedo unit, thus the top speed is not affected.

P.S. I tried a bicycle wireless speedo before on my KTM before the Koso but it was hopeless. The top speed was less than 100kph and there was serious lag time between the sensor and displayed speed on acceleration or braking. One second you're doing 10kph, the next you're doing 30kph.
Do you have a link for your speedo... my search had alot of scooter stuff ??

[Macstar]

Do you have a link for your speedo... my search had alot of scooter stuff ??

This guy sells my Speedo:

http://www.dirtbike.co.nz/default.asp?pageid=12#

(Koso Digital Speedo/Trip/ODO)

I bought mine from Cycletreads on Auckland's Northshore for $110 though... The speedo looks cool with the blue LED light background, and the digital display is large enough to read with average eyesight abilities!

The Koso comes only with an adhesive pad for mounting however, so i had to make up an alluminium mounting plate to stick it to.

[Daffyd]

I was always taught in electrical class that heat destroys magnets.

[Pancakes]

Nothing theoretically wrong with any of those options apart from
1. Push bike speedo wheel circumference didnt divide down that far.
2+3. Would all have needed external power, and not readily available off the shelf.
But granted extra sensors could be the go, however the upper speed range of most pushbike speedos is 200k's, the limit I figure being something to do with how fast the reed switches can operate. If you have more sense points this would reduce the max speed.

Your right, I just threw in my 2c and thought it might help spur on other peoples brain juice. Get a bit lateral ya know....


I was always taught in electrical class that heat destroys magnets.

Doesn't destroy them, the heat excites the molecules and randomises the spin/their alignment. It will realign as the magnet cools in the vast majority of instances. Takes bugger all to switch those reeds tho and there are some high quality magnets out there.


PS, my bike speedo reads accurately up to 300KPM and has a second cadence input. Won't be going 300 on the pushie anytime soon!!

[Pixie]

Nothing theoretically wrong with any of those options apart from
1. Push bike speedo wheel circumference didnt divide down that far.
2+3. Would all have needed external power, and not readily available off the shelf.
But granted extra sensors could be the go, however the upper speed range of most pushbike speedos is 200k's, the limit I figure being something to do with how fast the reed switches can operate. If you have more sense points this would reduce the max speed.

Block off one end of one of the large rivets that allow the disc to float on it's carrier.Fill blocked rivet with silicone RTV.Imbed magnet into silicone surface.

The max speed readings on some cyclo computers I have seen go beyond 400 km/hr. the rate at which a reed switch can cycle is beyond this rate by several factors.