Just got back from a bike ride and on my way started to feel as if something wasn't quite right with power supplied when I put extra pressure on pedals. Feels like it sometimes misses and a bit 'grinding'.

At first I thought it might be the rear hub but when I turn power off bike changes gear and rides very smoothly. The bike has only done 120 miles. Looks like I'll have to have a chat with 50 Cycles - shame as we were going to take our 2 bikes down to Bath this week. My wife has the Agattu bought at the same time and rides beautifully.

That is a shame. I had some grinding which turned out to be an issue with the free wheel component of my hub. When the motor was not engaged there was no grinding but when I applied the assit then the grinding would start .. My bike was overdue a service at about 9 months old and had been abused through the winter months ... How long have you had your bikes? Do you store them inside the house? Do you use a lubricant on your rear hub?

Just got back from a bike ride and on my way started to feel as if something wasn't quite right with power supplied when I put extra pressure on pedals. Feels like it sometimes misses and a bit 'grinding'.

At first I thought it might be the rear hub but when I turn power off bike changes gear and rides very smoothly. The bike has only done 120 miles. Looks like I'll have to have a chat with 50 Cycles - shame as we were going to take our 2 bikes down to Bath this week. My wife has the Agattu bought at the same time and rides beautifully.

 

This sounds like the symtoms of a battery connection problem, but with only 120 miles on the clock, that would be unusal:confused:

Temp. Repair To Pro Connect

 

I have managed to temporarily repair fault. My son rode my 2 week old Pro Connect and I rode along side. I noticed every time he said it felt rough chain appeared to jump. On closer inspection it was the small jockey wheel after the motor sprocket that was slipping occasionally. The strange thing is that it never slipped when power was turned off.

 

My temporary repair consists of a cable tie fixed in a way to give more tension on the chain. It's as if the chain could do with a link being taken out. With cable tie in place bike rides smoothly as expected and when removed starts to slip again.

 

I phoned 50 Cycles and their mechanic seemed stumped as to the problem. Because I'm fairly mechanically minded I have managed to find a solution but I'm am a bit peeved to be fiddling around on a bike that is only 2 weeks old.

Are you sure it is not the motor sprocket jockey wheel/tensioner that wraps the chain around the motor sprocket? It could be that it is now static on your bike but in the good old days it used to be spring loaded and would need a bit of grease to free it up. I would be surprised if the new tensioner on the gear hub has gone slack or is sticky. Obviously doesn't apply if it is a fixed sprocket (as it is on all the derailleurs) and I would be surprised it this was still a problem on new bikes. You will have to take the guard off to check if it is working or have a good peer underneath.

I wonder if there is a stiff link in the chain as well that could cause this...

Stiff link already? As stated bike is only 2 weeks old. I can't see any other tensioner to adjust. Puzzle is as to why does bike ride ok with no power?

It is under the chainguard and wraps the chain around the motor sprocket. It is not strictly speaking a tensioner and may be static on your bike or have come loose.

Stiff link already? As stated bike is only 2 weeks old. I can't see any other tensioner to adjust. Puzzle is as to why does bike ride ok with no power?

 

As HarryB mentions, there is a chain guide under the chain guard. On my older Pro Connect, this is spring loaded and can stiffen up if not lubricated. On flecc's website, there is a dimension from the centre of the guide sprocket to the centre of the motor drive sprocket given. It might be worth looking this up and checking it. Also examine the guide for free movement if it is of the spring loaded type.

 

If it is the motor sprocket jumping, this would be consistent with your experience with power on versus power off.

 

Edit: The dimension is 60-65 mm. Details here

Edited July 12, 201114 yr by tillson

On the new Pro Connect it doesn't appear to have this tensioner - not one that can be adjusted anyway. On looking at 'Fleccs' website, pictures show a different kind of adjustment, I think possibly from an older style machine perhaps?

Edited July 12, 201114 yr by robelee

It does have a mechanism to wrap the chain around the motor sprocket - as I said it might not be spring loaded but it is there. Possibly it has come loose or something trapped in the sprocket? The fact that you are adding tension and it cures the problem points to this device.

The mechanism is there but as already stated is not adjustable. The mechansism is fully tightened and sprocket is completely clear of any debris and runs smoothly. I should have posted pics of item to illustrate my point more clearly. I've just got back from a 15mile round trip to Wimbledon, my temporary repair seems to be doing the trick, bike rides beautifully again.

 

We are off to Bath for a 4day break and the bike will get a good work out. I'll make sure I take some extra cable ties with me!!

Edited July 12, 201114 yr by robelee

I have the same Panasonic unit as you then so no need for pictures to illustrate your point. You said there was no such mechanism that is why I was confused. I suppose it is possible that your bike was built with the wrong chain length installed unless there is a way of adjusting the tension. It does sound like it is skipping on the motor sprocket.

Thanks for all your input everyone. I shall persevere and see how bike performs but as I keep saying it's only a two week old bike and just covered 120 miles so this shouldn't be happening. Anyone who wasn't mechanically able would have been very dissapointed but with my 'fix' at least I'm able to enjoy it. I shall be on the phone to 50 Cycles when I return from Bath - not the easiest company to get through to though!

Hi Rob,

 

Which Pro Connect model is it? Interesting to see Kalkhoff are using Sturmey Archer components.

It's the Pro Connect Disc 8 Speed.

Just got back from a bike ride and on my way started to feel as if something wasn't quite right with power supplied when I put extra pressure on pedals. Feels like it sometimes misses and a bit 'grinding'.

At first I thought it might be the rear hub but when I turn power off bike changes gear and rides very smoothly. The bike has only done 120 miles. Looks like I'll have to have a chat with 50 Cycles - shame as we were going to take our 2 bikes down to Bath this week. My wife has the Agattu bought at the same time and rides beautifully.

 

I got a PC Disc in Feb. and I haven't been happy with the sprocket/chain running. It is just as you describe. I hadn't thought of turning the power off as you mentioned but I did today and it runs perfectly smoothly.

 

I had the chain coming off about a month ago and found the vertical arm chain guide shown in your photos was very loose. Tightening it up solved that problem but I have now pushed it back furthur to take up chain slack but it is still rough sounding and I get an odd vibrating feeling through the pedals under power. I am aware of the noise atracting attention as I cycle along and I feel like something is going to break at any time.

I hope this can be resolved as it is spoilng the ebike experience of an otherwise great bike.

Hi,

 

I had a similar experience last year, which turned out to be due to a mixture of loose chain guide and, because of the problem that caused, a stiff chain link. I fixed the chain guide properly, put a new removable chain link in, and lubed it all - result happiness and no problems since.

 

I was surprised about the chain link - it wasn't very stiff, but it was just enough to make it run really rough under load.

 

Good luck to both of you.

What I thought odd about the picture of robelee's pro connect is that it shows a chain with a split link and I would have assumed it would be a continuous chain as my Agattu was. I still think that the chain is too long and should be shortened by taking out a link or so. That way the tensioner would have more tension and the motor sprocket would be less likely to jump. With Deraileurs there is a risk with the chain being too short (when using the largests sprockets) but this wouldn't be a problem with hub gears. Shouldn't be necessary in a new bike of course.

My PCS chain has a replaceable link and it doesn't cause any issues, also I did mention the possibility of a stiff link earlier in the thread...

I don't think it is a stiff link or that the link is causing a problem, rather a chain that seems too long and not allowing the tensioner to do its job.

Edited July 13, 201114 yr by HarryB

When I bought my Pro Connect LX (Deraileur Gears) last august but within a couple of weeks there was an intermittent rumbling like a chain slip noise when the power was on yet when the power was swithched off the bike pedal silently. I did wonder if it was the motor. 50 cycles suggested I look at the chain to see if it is rubbing against the chain guard. I did but I found the problem myself. The gear cable had stretched and the chain seemed dry. I adjusted the gear cable by tightening it and fine tuning the gear changing and lubed the chain. Now the bike rides like the reviews say it does; it is silent and it is smooth running and a delight to ride. The rumbling noise has gone but when the gears dont change as sharp as I like, I fine tune the changing by adjusting the gear cable at the deraileur end.

I was a bit sceptical about this 'fix' but I gave it a try today (using a 'matching' black cable-tie) and it did as you said.

 

Now we need to know why!

I bought PC disc in April this year. It grinds and clatters just as described. It stubbornly refuses to change gear down especially when going up hills when lower gear is most needed. 50 cycles suggested I lubricate gear change cable. This had no effect.

 

After reading these I turned bike upside down and cleared all sprockets and chain with engine degreaser. Then lubricated everything with silicon spray grease. This helped a lot but it is still a bit noisy and gear change is still hesitant.

 

As stated by others it runs perfectly with power off. Course I did not spend two grand on electric bike to cyle without power! Rather disappointing.

Denbol have you tried getting it into a bike shop for them to have a look?

 

I had a persistent issue with my pro connect which a chap at the Fred Baker shop in Bristol fixed within 10 minutes for a fiver. Once he got it up and pedalling he could see things which simply went over my head