Why I just replaced rear disc with calipers.

[john peck]

It was an involuntary decision which began with a broken spoke. To replace the spoke, one 1st has remove
the disc. To do that needs removal of several screws wtth stripped heads or threads. The stripped round heads
had to be cut away to remove disc. This done, I was left with no options but calipers or a new motor wheel.
. In 60+ years of riding I very rarely had occasion to to fix a spoke until going to rear hub ebikes. I´m of
the opinion that the added power of motor together with the stress of a disc can be a spoke killer. In any event.
a disc can be a real nightmare just to change a spoke

 

[rich c]

Are you calling rim brakes as calipers? Otherwise I'm confused. A tip for stripped hex on round head bolts is to cut a single slot across the head and use a huge straight blade screwdriver. Maybe even a small adjustable wrench on the shank of the screwdriver.

 

[john peck]

A rose by any other name, caliper is more specific as opposed to V-brake or center pull. The screws
were stars, not slot, hex, or phelps. I guess you were confused. I tried cutting a slot to no avail, & there
was no way to grip the round head. My point is they´re a dam sight easier than having to pull a
brake disc to change a spoke,

 

[opimax]

Stars=torx screws?

 

[ian fisher]

your rear rim has a machined surface for using caliper type brakes? I agree, those discs can be difficult to remove, the retaining screws are likely held with loctite. A tip for spoke maintenance, cleaning the rear wheel and add a small drop of lubricant on each pair of spokes at the point where they cross each other, just a drop or two and then wipe the excess off, doing this to reduce the friction and help to prevent each pair of spokes binding and chaffing. Spokes will flex slightly on any wheel under power and ebike rear wheels although they will generally have a larger diameter spoke than most non electric bikes are also under a good deal more stress so a little bit of maintenance can help reduce the risk of broken spokes. Of course, using wet lubicant can collect dust and dirt so it is essential to wipe off any excess. You could use a drop of wd40, or even some thing like amor all. Grab any pair of spokes in one hand and squeeze slightly, you can hear how they are sometimes stuck together at the point where they cross, or you can hear a sort of dry binding/chaffing, the idea of the lubricant is to reduce this wear and tear on the spokes.

 

[Marcela]

Those torx screws are tough. I replaced some discs and went directly to using hammer and impact driver. Lucky I didn't have any trouble. Mine had loctite and serrated washer both.

 

[john peck]

Stars=torx screws?

Yes? Required a star shaped bit, tempered steel screws much harder than the 6061 alu they were into.
the resultant stripping meant 3 turned easily but would not unscrew. Got the disc off after grinding away
the heads & then cut the stubs flush. No longer possible to remount a disc, hence calipers. That was
the easy part. Motored hubs with discs overstress spokes?

your rear rim has a machined surface for using caliper type brakes? I agree, those discs can be difficult to remove, the retaining screws are likely held with loctite. A tip for spoke maintenance, cleaning the rear wheel and add a small drop of lubricant on each pair of spokes at the point where they cross each other, just a drop or two and then wipe the excess off, doing this to reduce the friction and help to prevent each pair of spokes binding and chaffing. Spokes will flex slightly on any wheel under power and ebike rear wheels although they will generally have a larger diameter spoke than most non electric bikes are also under a good deal more stress so a little bit of maintenance can help reduce the risk of broken spokes. Of course, using wet lubicant can collect dust and dirt so it is essential to wipe off any excess. You could use a drop of wd40, or even some thing like amor all. Grab any pair of spokes in one hand and squeeze slightly, you can hear how they are sometimes stuck together at the point where they cross, or you can hear a sort of dry binding/chaffing, the idea of the lubricant is to reduce this wear and tear on the spokes.

My spoke lacing doesn´t allow crossing spokes to touch. My 1st ebike did, which eventually led to damaging
wear on the spoke bores making the motor useless for a bike.

 

[john peck]

Those torx screws are tough. I replaced some discs and went directly to using hammer and impact driver. Lucky I didn't have any trouble. Mine had loctite and serrated washer both.

Indeed, washers might have made the task easier, but the screws were likely placed with a power tool
that stripped both thread & socket. Getting them out was a nightmare. that wheel would have been useless
without some kind of rim brake. Luckily, I had some heavy-duty mtn. calipers that mounted by shortening
the sheath with ease. The wheel allows rims, but I still need to get the decals off. A grommeted wheel
would be a plus. I shall use denatured alcohol to remove the decals.

 

[john peck]

Nix on the alcohol, don´t work, but the brake grabs just as well as the disc decals & all.

 

[AlanDB]

My Gazelle Arroyo ebike has Magura hydraulic rim brakes. When I was first looking at ebikes, I wanted disc brakes, so it was a disappointment that Gazelle Arroyo used the rim brakes. But I liked everything else about the Gazelle and decided to go with it. Now that I have owned it for 3 years I will have to say the Magura brakes have worked beautifully. They have plenty of stopping power and so far do not squeak or squawk like the mechanical disc brakes do on my other 2 bikes.

 

[rich c]

A rose by any other name, caliper is more specific as opposed to V-brake or center pull. The screws
were stars, not slot, hex, or phelps. I guess you were confused. I tried cutting a slot to no avail, & there
was no way to grip the round head. My point is they´re a dam sight easier than having to pull a
brake disc to change a spoke,

The confusion of calling the rim brakes calipers was that you also took off calipers. Surely you would admit to that?