Disc rotor bolts

[Peter.Bridge]

Another question - what's the best thing to do when you are swapping over a disc rotor and the bolts from the original are too long for the motor wheel. I've used a 'rotor spacer' but are there slightly shorter bolts available ?

 

[saneagle]

Another question - what's the best thing to do when you are swapping over a disc rotor and the bolts from the original are too long for the motor wheel. I've used a 'rotor spacer' but are there slightly shorter bolts available ?

The screws normally come with the motor. They should be already in it, and they're the correct length for the motor. They put a plastic spacer underneath the heads, which is the thickness of a disc. You remove the spacer when you install the disc. Normal disc screws for bicycle hubs are too long. You can buy any M5 screws of any length you want. If you've lost your original ones, you need to measure the depth of the hole then add on a bit less than the thickness of the disc.

Pardon our interruption...

 

[saneagle]

The screws normally come with the motor. They should be already in it, and they're the correct length for the motor. They put a plastic spacer underneath the heads, which is the thickness of a disc. You remove the spacer when you install the disc. Normal disc screws for bicycle hubs are too long. You can buy any M5 screws of any length you want. If you've lost your original ones, you need to measure the depth of the hole then add on a bit less than the thickness of the disc.

Pardon our interruption...

If you put a spacer under the disc, the disc won't line up with the caliper. You normally need to put a washer on the axle that side to move the disc inboard. The spacer would move the disc outboard and make it worse unless you put it outside the disc, but then the screws will come loose because of the plastic.

 

[AndyBike]

Have you access to a bench grinder ? could take a bit off. But I would warn about making whatever you get(or grind) too short as it could be dangerous.

Also, buy yourself a tube of threadlocker - Blue.semi-permanent

Im on the other foot. My big bike rotors are 2.3mm(Hope HD solid)which need longer bolts anyway, but because I need to add a magnet two of them need to be even longer, which arent easy to find exactly, so i need to grind some even longer ones down to size.

But mind the threadlocker - its about a fiver and for heavens sake dont get the red, thats permanent and the allen head will possibly chew before getting those undone

 

[Peter.Bridge]

Thanks - the motor did come via the wheel builder but there were no bolts with it - The standard ones are M5*10, I have ordered M5 *8 round head allen via your link

 

[harrys]

Has anyone else had trouble with caliper screws that appear to be Torx head, but are not. Just crappy machining and neither a metric or Torx wrench can grab them.

 

[chris_n]

Has anyone else had trouble with caliper screws that appear to be Torx head, but are not. Just crappy machining and neither a metric or Torx wrench can grab them.

Splined? You probably need a special tool!

 

[Nealh]

There are some splined screw caps that have closer ratio finer spline then the wider spaced Torx , that said not come across them on push bikes.

 

[saneagle]

If they have cap heads, you can get then from the side with mole-grips.

 

[Raboa]

If you mean a screw head that resembles a Torx but isn't, you could be referring to a security Torx head (also known as Pin Torx or Tamper-Resistant Torx), a Torx Plus head, or a multi-tooth/XZN head.
Here's a breakdown of these alternatives:
Security Torx (Pin Torx):
These have a pin in the center of the six-point star socket, preventing standard Torx screwdrivers from fitting.
Torx Plus:
This design, introduced in 1990, has a "plus" shape with five lobes, offering improved torque and reduced wear compared to the original Torx.
Multi-tooth/XZN:
This drive has twelve small teeth, offering a large area for driving force and high torque transfer, similar to Torx.

 

[thelarkbox]

A wide rubber band can aid a poor fitting bit in a chewed up screw head when sandwiched between the 2 metal pieces, on occasion doubling up the rubber layers can help too..

Failing that a snapped junior hacksaw blade can be used to cut a blade slot, the rubber band can help the gip here too if a wonky cut is the result.

 

[Raboa]

A flat head screwdriver, round the corners with a file to fit in the torx shape or use a Dremel to cut a slot

 

[AndyBike]

If you mean a screw head that resembles a Torx but isn't, you could be referring to a security Torx head (also known as Pin Torx or Tamper-Resistant Torx), a Torx Plus head, or a multi-tooth/XZN head.
Here's a breakdown of these alternatives:
Security Torx (Pin Torx):
These have a pin in the center of the six-point star socket, preventing standard Torx screwdrivers from fitting.
Torx Plus:
This design, introduced in 1990, has a "plus" shape with five lobes, offering improved torque and reduced wear compared to the original Torx.
Multi-tooth/XZN:
This drive has twelve small teeth, offering a large area for driving force and high torque transfer, similar to Torx.

 

[Benjahmin]

View attachment 62682

No wonder my bit set has so many mysterious never used hex drive bits in it. And still there are times when nothing is the right size

 

[Raboa]

You get Torx Paralobe as well now

TORX PARALOBE™ Internal - Acument

fontanagruppoagtna.com

 

[AndyBike]

No wonder my bit set has so many mysterious never used hex drive bits in it.

Handy to have though just in case.
I'd some workies in a bit back, working on the electric front door buzzer system. They got 1/2 way through then said they needed to leave because the outdoor junction boxes were security fitting and they didnt have that type of bit.

I did, so the job was done in a day and not 2 or 3.

 

[matthewslack]

Normal hacksaw can cut the ends off if you can get enough grip in a vice.