steve30
Guru
- Location
- Rotherham, South Yorkshire
In 2025 I noticed the drive side crank on my Vado was a bit wobbly. Turns out this is a common fault caused by issues with the manufacturing tolerances. In true steve30 fashion, instead of sorting it, I left it to gradually get worse and worse. Eventually, the splines on the crank and the splines on the spindle (pictured) were very worn.
I bought a replacement crank, which was obviously far less wobbly than the old one, but that left the issue of the spindle. Short of replacing it, or getting someone to weld it and recut it, the only real option was to glue it.
Loctite 660 is a special adhesive designed specifically for this kind of situation. It cures when in contact with metal (or the activator which you can spray on). Its rated to fill a gap of about 0.5mm. I didn't measure the gap here - it may be slightly more than 0.5mm, but I thought I'd chance it. The 660 is supposed to cure best with steel, but the crank is aluminium, and some of it is anodised (except the worn parts). As such I used the 7649 activator spray. The 660 is very thick, and very difficult to get out of the tube, but I gave it a good coating eventually. As its thick, it holds the crank in place nicely. It was solid later on that day, but I decided to leave it a few days to be on the safe side.
I went for a 20 mile round trip today and it held up perfectly
. On my way back, the damn bike wouldn't switch on; so I had to ride it all the way up hill with 100% steve power, which will have given the loctite a good test. I don't know how long it will last, but hopefully I'll get some decent life out of it.
Only downside is that the 660 costs about £60 and the 7649 costs about £20 (both from RS). And the new crank was about £40. So not a cheap repair.
Now to fix the electronic problem (probably a dead coin cell in the controller).
I bought a replacement crank, which was obviously far less wobbly than the old one, but that left the issue of the spindle. Short of replacing it, or getting someone to weld it and recut it, the only real option was to glue it.
Loctite 660 is a special adhesive designed specifically for this kind of situation. It cures when in contact with metal (or the activator which you can spray on). Its rated to fill a gap of about 0.5mm. I didn't measure the gap here - it may be slightly more than 0.5mm, but I thought I'd chance it. The 660 is supposed to cure best with steel, but the crank is aluminium, and some of it is anodised (except the worn parts). As such I used the 7649 activator spray. The 660 is very thick, and very difficult to get out of the tube, but I gave it a good coating eventually. As its thick, it holds the crank in place nicely. It was solid later on that day, but I decided to leave it a few days to be on the safe side.
I went for a 20 mile round trip today and it held up perfectly
. On my way back, the damn bike wouldn't switch on; so I had to ride it all the way up hill with 100% steve power, which will have given the loctite a good test. I don't know how long it will last, but hopefully I'll get some decent life out of it.Only downside is that the 660 costs about £60 and the 7649 costs about £20 (both from RS). And the new crank was about £40. So not a cheap repair.
Now to fix the electronic problem (probably a dead coin cell in the controller).
