Help! Cyclotricity front hub disk screws foul fork blade

Geoff_L

Finding my (electric) wheels
Mar 16, 2014
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I've just taken delivery of a couple of Cyclotricity front wheel conversion kits. Unfortunately, at least one of these has a problem in that the screws intended to mount a brake disk or retain the supplied spacer foul the fork. I've waited most of the afternoon for one of their techs to return my phone call. Having heard nothing, I tried calling them back, but it's now past their opening time, so I'm turning to the forum hoping for words of wisdom!

I've attached a photo of the hub and fork. I suspect that I could move both fork arms out by a millimeter with suitable axle spacers (the other side is tight also, but not actually fouling). If it's possible to also lose the disk retaining screws and spacer, the issue would be resolved -- but I don't know whether that's safe to do; and I suspect I'd also need to plug the screw holes. Does this approach seem feasible? Can anyone say for sure whether it's safe to lose the disk retaining screws and spacer? Can someone point me to a source of the required spacers and plugs?

Thanks for looking, Geoff


Disk Screws 01.jpg
 

vfr400

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I've just taken delivery of a couple of Cyclotricity front wheel conversion kits. Unfortunately, at least one of these has a problem in that the screws intended to mount a brake disk or retain the supplied spacer foul the fork. I've waited most of the afternoon for one of their techs to return my phone call. Having heard nothing, I tried calling them back, but it's now past their opening time, so I'm turning to the forum hoping for words of wisdom!

I've attached a photo of the hub and fork. I suspect that I could move both fork arms out by a millimeter with suitable axle spacers (the other side is tight also, but not actually fouling). If it's possible to also lose the disk retaining screws and spacer, the issue would be resolved -- but I don't know whether that's safe to do; and I suspect I'd also need to plug the screw holes. Does this approach seem feasible? Can anyone say for sure whether it's safe to lose the disk retaining screws and spacer? Can someone point me to a source of the required spacers and plugs?

Thanks for looking, Geoff


View attachment 39127
You have the wrong type of forks to fit a hub-motor. you need them with inboard drop-outs, but your are in the middle. There are a few solutions:
1. If you don't have suspension forks you can use a washer (12mm) or two.
2. If you have rim brakes, you can remove the screws and the spacer and seal the holes with a bit of bath sealant. You only need sealant if the holes go all the way through, which they don't in about 50% of motors. If you do use sealant, only fill the holes. Don't fill the motor with it.
3. replace your forks with the right type. You can buy used ones on Ebay for not a lot, and it'll give you the chance to upgrade to disc forks and fit a hydraulic brake, which will be a million times better than rim brakes.

Where are the anti-rotation washers? They're normally fitted inboard, so would space the fork leg further away.
 
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Geoff_L

Finding my (electric) wheels
Mar 16, 2014
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You have the wrong type of forks to fit a hub-motor. you need them with inboard drop-outs, but your are in the middle. There are a few solutions:
1. If you don't have suspension forks you can use a washer (12mm) or two.
2. If you have rim brakes, you can remove the screws and the spacer and seal the holes with a bit of bath sealant. You only need sealant if the holes go all the way through, which they don't in about 50% of motors. If you do use sealant, only fill the holes. Don't fill the motor with it.
3. replace your forks with the right type. You can buy used ones on Ebay for not a lot, and it'll give you the chance to upgrade to disc forks and fit a hydraulic brake, which will be a million times better than rim brakes.

Where are the anti-rotation washers? They're normally fitted inboard, so would space the fork leg further away.
Thanks for the reply. One of the bikes I want to convert has suspension forks, but the bike in the photo has rigids.
Removing the screws and spacer would cure the issue with the bike in the photo and hopefully the other also. If it doesn't I'll probably have to replace the forks with rigid ones and ensure they have inboard dropouts! (Anyone point me in the direction of some cheapies suitable for an old hybrid?)
Both bikes have V brakes, so I don't need the disk fittings (although it would probably be a good idea to retain the screws and spacers in case I want to move the kit to another bike.
The torque washers are fitted inboard with the anti-rotation 'tabs' projecting into the dropouts.

Thanks again, Geoff
 

vfr400

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Thanks for the reply. One of the bikes I want to convert has suspension forks, but the bike in the photo has rigids.
Removing the screws and spacer would cure the issue with the bike in the photo and hopefully the other also. If it doesn't I'll probably have to replace the forks with rigid ones and ensure they have inboard dropouts! (Anyone point me in the direction of some cheapies suitable for an old hybrid?)
Both bikes have V brakes, so I don't need the disk fittings (although it would probably be a good idea to retain the screws and spacers in case I want to move the kit to another bike.
The torque washers are fitted inboard with the anti-rotation 'tabs' projecting into the dropouts.

Thanks again, Geoff
If it still rubs after removing the screws, just add washers behind the anti-rotation ones until it doesn't.
 
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D C

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How about replacing the bolts with short grub screws and threadlock?
 
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Nealh

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Removing the spacer and screws will work but as VFR has said if you can see the motor turning via the screw holes then seal them up. The easy way to tell if the holes are blind or not is to use a longer threaded M5 screw tightened up, if holes are blind hub will rotate if they aren't the screw will pinch and prevent the hub rotating.
 
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Geoff_L

Finding my (electric) wheels
Mar 16, 2014
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Removing the spacer and screws will work but as VFR has said if you can see the motor turning via the screw holes then seal them up. The easy way to tell if the holes are blind or not is to use a longer threaded M5 screw tightened up, if holes are blind hub will rotate if they aren't the screw will pinch and prevent the hub rotating.
Thanks. Also for the info that they're M5 without my needing to pull one to measure. I suppose that I could use grub screws and threadlock -- but I'd still be worried that one would become 'unlocked' and work its way into the motor. So I'd rather use platic blanking plugs -- the sort that's used in kitchen cabinets to blank unused screw holes -- and seal/retain them with a smear of Sikaflex 521 or silicone.
 

vfr400

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Thanks. Also for the info that they're M5 without my needing to pull one to measure. I suppose that I could use grub screws and threadlock -- but I'd still be worried that one would become 'unlocked' and work its way into the motor. So I'd rather use platic blanking plugs -- the sort that's used in kitchen cabinets to blank unused screw holes -- and seal/retain them with a smear of Sikaflex 521 or silicone.
Only if the holes go all the way through. If you can't see or are otherwise unsure, poke a cocktail stick down the hole as far as it goes and turn the wheel backwards. You'll be able to feel the motor turning if the hole goes all the way through. Most people would be able to see just by looking in the holes.
 
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Geoff_L

Finding my (electric) wheels
Mar 16, 2014
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Quick update for completeness. I've removed the spacers and disk retaining screws on both kits. Cyclotricity told me the screw holes were blind. However, I suspect that the design has changed since the tech guy I spoke with last looked because I could clearly see the rotating assembly through the holes when I looked -- so I needed to blank the holes. I bought some 5mm blanking plugs (~£1 on eBay) but they proved useless and so I ended up using DC's suggestion of short grub screws and thread lock.

Thanks to all for the help. Geoff
 
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