A 5mm gap is on the large side. The top stem pinch bolt is definitely clamping the steerer and not air? I would prefer a 3mm gap, I'd be getting out my box of stem spacers and removing a spacer from beneath the stem and fitting a thinner one.

 

Ah, okay. I thought it did seem a bit of a bigger gap than I've seen in some photos online. I'm not sure if it's definitely clamping the steerer.

 

 

What happens when you push the ont wheel hard against a brick wall without touching the brakes?

 

 

I'll give that a try tomorrow (well, later today).

 

 

I have heard of movement in the front caliper can sometimes cause this. Can you borrow a different caliper from anyone? I have a mechanical one sat in my shed doing nothing, I could send it to you if you'd like. It is for a 160mm rotor.

 

 

Thanks for your kind offer, but it'll be easier for me to just get some spacers and cheap calipers on Amazon then send them back if they don't turn out to be useful. I'll probably do that later today if I don't fix it by then.

One more thought, you said you disassembled the headset and then put it back together. You got everything in the right order, right? You have fitted the compression ring correctly?

 

Let me ask you this: If you tighten the top cap bolt very tight it should be very hard to turn the forks, does that happen on your bike?

 

Have a look at this video on correct headset assembly, start at 3:45

 

 

And all this on a brand new bike you haven't even ridden yet!

Remove the front wheel and lift the bike by the bottoms of the forks, then push back and forwards. If you can detect any movement it's normally from the headset. It can be from the fork legs (bushes), but only in old worn out forks. You can see by looking if the movement is coming from the fork legs.

 

I can only detect the tiniest bit of movement, the amount I'd expect for anything to be able to move freely.

 

 

So, on re-reading this and on second thoughts I don't think there is anything wrong with your headset or forks.

 

You've tried a different front wheel.

 

All fasteners are tight.

 

All that leaves is the caliper, you need to try a different one.

 

Also, I really do think you should just try actually riding the bike, see how that goes.

I don't know any mech eng so a pinch of salt is called for, but you said all the bolts were tight... what if a mating surface weren't flat but slightly convex, would that snug up tight but rock under load? Like if a caliper mount were badly machined?

 

On your video the rim's moving a lot, so maybe a taut strip of masking tape between fork and caliper and another caliper to disc would show up where the movement is, for example pads rocking in the caliper.

It looks a lot like fork bushes to me. Are the forks old? Are you sure you couldn't feel any movement when you took the wheel off and pushed the forks backwards and forwards, like I asked you to do before?

It looks a lot like fork bushes to me. Are the forks old? Are you sure you couldn't feel any movement when you took the wheel off and pushed the forks backwards and forwards, like I asked you to do before?

 

I kind of discounted worn fork bushes because I think Hitway are a new retailer of e-bikes, the OP in his first post doesn't say if he purchased the bike brand new. Although he does say he assembled it in his other thread about his REAR wheel problem. Of course there's always the possibility that the forks were faulty from the factory.

 

Perhaps the only real way to get to the bottom of this is to replace each component one at a time, wheel, brake, forks, headset. Not an easy thing to do unless you have another similar bike or a mate nearby with one who'd be willing to help

I kind of discounted worn fork bushes because I think Hitway are a new retailer of e-bikes, the OP in his first post doesn't say if he purchased the bike brand new. Although he does say he assembled it in his other thread about his REAR wheel problem. Of course there's always the possibility that the forks were faulty from the factory.

 

Perhaps the only real way to get to the bottom of this is to replace each component one at a time, wheel, brake, forks, headset. Not an easy thing to do unless you have another similar bike or a mate nearby with one who'd be willing to help

I looked at the video again and came to the conclusion that the movement was more likely to be from further up than the forks, but he didn't show that part of the bike. The main point is that the bottom of the fork doesn't move, but the top does. This is consistent with play in the headset. He shouldn't attempt to replace anything. It should be simple and logical to find the cause.

I looked at the video again and came to the conclusion that the movement was more likely to be from further up than the forks, but he didn't show that part of the bike. The main point is that the bottom of the fork doesn't move, but the top does. This is consistent with play in the headset. He shouldn't attempt to replace anything. It should be simple and logical to find the cause.

Yeah, one thing that's bugging me is the 5mm gap below the top cap. The star nut is probably another 15mm away. That's quite a reach for the top cap bolt which could possibly induce some movement. The first thing I would be doing is reducing that gap.

Yeah, one thing that's bugging me is the 5mm gap below the top cap. The star nut is probably another 15mm away. That's quite a reach for the top cap bolt which could possibly induce some movement. The first thing I would be doing is reducing that gap.

In truth its just to aid some initial compression then its job is done on tightening up the stem bolts.

In truth its just to aid some initial compression then its job is done on tightening up the stem bolts.

 

Yeah fair one, well the OP has gone MIA, so he's probably fixed it by now and he's out enjoying his bike.

Yeah fair one, well the OP has gone MIA, so he's probably fixed it by now and he's out enjoying his bike.

Unfortunately not . After testing it with a new front caliper as well as different spacers, it still did the same thing. I've decided to just give up trying to fix it myself and am taking it to a bike shop on Saturday. It could probably do with a general looking over tbh. Thanks everyone anyway for all your suggestions.

Unfortunately not . After testing it with a new front caliper as well as different spacers, it still did the same thing. I've decided to just give up trying to fix it myself and am taking it to a bike shop on Saturday. It could probably do with a general looking over tbh. Thanks everyone anyway for all your suggestions.

 

Please let us know how you get on at the bike shop. I am very curious about what is causing this problem.

Perhaps the only real way to get to the bottom of this is to replace each component one at a time, wheel, brake, forks, headset. Not an easy thing to do unless you have another similar bike or a mate nearby with one who'd be willing to help

Let's hope the LBS hasn't been following this

Let's hope the LBS hasn't been following this

 

Yeah, the LBS can play a game of 'Parts Darts' as someone said on another thread today.

Two other sources of movement, although should not be present on a new bike:

 

Slightly loose disc mounting bolts, or worn centre lock splines.

 

Inadequate spoke tension allowing a few degrees of 'wind up' under braking.

 

I've had both on my front wheel, the first mileage related and the second when I rebuilt wheel without enough tension.