Why the TETS kit didn't work

[AndyOfTheSouth]

Hi folks

Well, got the bike and kit back from TETS in Oxford today and have their explanation for what went wrong.

They said that the problem was the motor, that its internal wiring had been damaged when the wheel had opened up the dropouts. So they have put a new motor into the wheel and that should be the end of the story.

However… I am afraid I have another pair of questions for my elders and betters on this forum.

The wheel is slightly out of true in the fork. I have tried slackening off the nuts and moving the wheel within the fork and retightening and it stays in the same position. Is this a problem or does something further need to be done? (I am not sure that the brake looks quite right, either.)

The other question is whether a torque washer is essential. You will see from the photos that within the dropouts are ordinary washers. Last time there was a special washer with a bent extrusion which fitted into the slot. I thought this was necessary to stop the wheel tending to rotate within the dropout. Is this true? Could there be a reason why they didn’t fit one?

TETS is now closed until Wednesday, so I cannot ask them until then.

Thanks again for your help.

Andy

 

[Dynamic Position]

Hi folks

Well, got the bike and kit back from TETS in Oxford today and have their explanation for what went wrong.

They said that the problem was the motor, that its internal wiring had been damaged when the wheel had opened up the dropouts. So they have put a new motor into the wheel and that should be the end of the story.

However… I am afraid I have another pair of questions for my elders and betters on this forum.

The wheel is slightly out of true in the fork. I have tried slackening off the nuts and moving the wheel within the fork and retightening and it stays in the same position. Is this a problem or does something further need to be done? (I am not sure that the brake looks quite right, either.)

The other question is whether a torque washer is essential. You will see from the photos that within the dropouts are ordinary washers. Last time there was a special washer with a bent extrusion which fitted into the slot. I thought this was necessary to stop the wheel tending to rotate within the dropout. Is this true? Could there be a reason why they didn’t fit one?

TETS is now closed until Wednesday, so I cannot ask them until then.

Thanks again for your help.

Andy

Andy,

One or more spokes not having the right tension could be the cause, it would be worth giving each one a close inspection.

 

[flecc]

If you mean the small amount the wheel is off centre within the forks, but runs true side to side otherwise, that doesn't matter at all. That error is small and not a problem. If you wanted to be really fussy about it, the wheel could be retrued with a slight offset to centralise the rim.

If the flats of the spindle are a tight fit in the fork dropouts, that will be the equivalent of an anti torque washer so using one won't bring an improvement. Just make sure the wheel nuts are always tight. I would always prefer to see a proper anti-torque arm fitted, but few do that.
.

 

[Dynamic Position]

Andy,

I did not notice the attached photographs.

The gap does seem ominous! Is the ordinary washer a replacement fitted by Tets? It looks as if the washer is fitted on the wrong side of the drop-out but I am not familiar with your bike but pehaps Flecc would know?

 

[flecc]

Andy,

I did not notice the attached photographs.

The gap does seem ominous! Is the ordinary washer a replacement fitted by Tets? It looks as if the washer is fitted on the wrong side of the drop-out but I am not familiar with your bike but pehaps Flecc would know?

I think the gaps are just because Andy has left the wheel nuts loose for the photos.

If the fork doesn't fit tightly on the spindle flats, he can fit an anti-torque washer and I've no doubt TETs would give him one.
.

 

[AndyOfTheSouth]

Thanks for these comments.

Yes, as Flecc guessed, the photo was taken with nuts slackened off.

When I bought the bike, the shop fitted the previous motor wheel for me. Their effort looked a bit different. They used some sort of non-standard, toothed washers and, if I remember correctly, more of them.

On the subject of the spokes not having enough tension, the chap in the bike shop who fitted that previous wheel made some rather disparaging remarks about some of the spokes needing tensioning and I think he also said something about having to realign/adjust the wheel in some way.

I don't know if this was correct, though he did seem very knowledgeable.

 

[flecc]

On the subject of the spokes not having enough tension, the chap in the bike shop who fitted that previous wheel made some rather disparaging remarks about some of the spokes needing tensioning and I think he also said something about having to realign/adjust the wheel in some way.

I don't know if this was correct, though he did seem very knowledgeable.

Slack tension spokes are very common in normal production and any wheel builder will comment in this disparaging way, I've often done so myself, having little respect for mass produced wheels.

However, the key was what he said about realigning, which was what I said above:

the wheel could be retrued with a slight offset to centralise the rim.

This is the rear motor wheel on one of my bikes which I built with an offset to centralise the rim in the forks, and you'll see the rim offset is very large in this case. Your's is only very slight:

 

[flecc]

Looking at your dropout photos above Andy, you can largely correct the offset yourself. You'll see there is space inside both sides of the fork with the wheel nuts loosened, so all you need to do is add a couple of additional washers on one side only of the spindle inside the fork, using up that spare space to shift the rim position sideways.

That way you'll gain around 1/8" or so of rim offset, and since your offset starts at about 1/4", that will be enough correction to make it virtually right.

You need washers with 12 mm holes, not standard 10 mm bike spindle ones, TETS may have some.
.

 

[AndyOfTheSouth]

Thanks for this great advice, Flecc. Will do.

I wonder if this what the bike shop had done last time around ie automatically selected the right type and number of washers...

 

[AndyOfTheSouth]

Went out for a ride this evening. After a while the power cut out. Jiggled the wires entering casing containing the controller. It started again. Rode for a while and it cut out again. Gave up.

This time I'm not going to try fixing it myself, but spend a bit of time composing a letter.

 

[flecc]

That's the best way Andy, get them to face their responsibility to put it right.
.

 

[AndyOfTheSouth]

Thanks for your support, Flecc. I will post the outcome.