Wisper 905se - torque arm (lack of)

[frank9755]

While trying to take the back wheel off my Wisper to change the tyre this morning I discovered a potentially serious problem.

My bike has done only 100 miles but the rear dropouts which house the motor wheel are showing significant wear. This is obviously due to torque from the motor axle. The aluminium dropouts seem to be too soft to cope with the power of the motor. I think the bike needs a steel torque arm (as is fitted to my wife's Powacycle, which has a much lower powered motor) to prevent the axle from shredding the droppouts and spinning out.

I'm going to make a torque arm by fixing an old (steel) spanner to the end of the axle to keep it from turning in the dropouts. I think this should do the job.

I've already sent the Wisper guys a mail to alert them to it. As I think it could be a safety issue I wanted to make others aware soonest.

Frank

 

[jimmyengland1000]

Yes, my 905e did that, amongst other things. The power cable ended up twisted round as the hub motor gradually crept round. I also ended up having to tighten the rear whjeel spokes after every 10 mile run. I think they beefed up the spokes on the SE version? Presumably you're going to put the spanner on the flat sides of the axle and attach it to one of the frame members? It's good that you're going to let Wisper know. On a £1200 bike, I'm surprised they hadn't thought about the effect of motor torque.

 

[Cyclezee]

Hi Frank, I wonder if you could be a little more specific with regards to "significant wear". Would it be possible to take a photo?
I have just taken the rear wheel out to examine the dropouts and can't find any signs of wear?
This is the bike used by my son for commuting and it has now covered over 300 miles without any problems apart from getting a rear puncture last week, the tyre was so badly damaged I replaced it with a Continental Travel Contact. I'm not going to tempt providence by commenting on the tyres resistance to puntures.

John

 

[jimmyengland1000]

While trying to take the back wheel off my Wisper to change the tyre this morning I discovered a potentially serious problem.
Frank

By the way... is removing the wheel realtively easy? On my 905e it was a huge problem to remove the wheel. The power wire was threaded through narrow tubes welded to the frame and then had a big block connector attached to it. I couldn't get my wheel off because the power cable was so short and the block connectro wouldn't go through the tubes. In the end I had to cut the tubes with a hacksaw in order to remove the power wire and give me enough slack to get the wheel off.

One other safety point. The 905e came with a 'quick release' front wheel (I don't know about the SE). The nut was alloy and, although not overly tight, it stripped its threads and I found my front wheel was only in place because the dropouts point down......

 

[frank9755]

John,

I should have taken a photo but I've put the wheel back in again now and bolted it in extra tight!

Imagine the drop-out as being a U-shaped slot with the flattened sides of the axle fitting in snugly against the flat sides of the U. That is how it should be. On mine the axle has rotated slightly within the U, gouging out a little bit of metal from the drop-out to make the U slightly distorted, looking like a cross between a U and a V.

As Jimmy describes, this would eventually lead to the motor spinning out and shredding its wires.

There's a good thread here where Jeremy and Flecc describe torque arms, why you need them, what they look like and how to make one.

 

[frank9755]

Jimmy,

Quick release and disc brake don't mix! Look here. Mine has bolts. I pointed this out to David from Wisper on an earlier thread and I think they are going to stay with bolts!

Taking the back wheel out is a dream. There is a connector so you can just disconnect the motor wire.

Did anything else go wrong with your bike that we should be aware of?

Frank

 

[Cyclezee]

John,

I should have taken a photo but I've put the wheel back in again now and bolted it in extra tight!

Imagine the drop-out as being a U-shaped slot with the flattened sides of the axle fitting in snugly against the flat sides of the U. That is how it should be. On mine the axle has rotated slightly within the U, gouging out a little bit of metal from the drop-out to make the U slightly distorted, looking like a cross between a U and a V.

As Jimmy describes, this would eventually lead to the motor spinning out and shredding its wires.

There's a good thread here where Jeremy and Flecc describe torque arms, why you need them, what they look like and how to make one.

Hi Frank, I knew what to look for, but just don't understand how this could happen unless the axle nuts were not tight enough to prevent free play allowing the axle to move?

John

 

[flecc]

There's a surprising amount of variation in frame mayterials in any one design. The Lafree Twist series bikes were an example, some suffering dropout distortion on the hub gear spindles, while others never had the slightest sign of it happening. Clearly the metal hardness was varying over time. My Lafree frame never had a problem, but some were like A to B magazine's David Henshaw's bike, where he had to make a locating plate to hold the spindle still.

P.S. I've just seen Aldby's above post. This can happen if the material is too soft, and can be worse with overtightened nuts. It seems the soft frame material flattens under the pressure and can get looser as it distorts and the dropout slot expands.
.

 

[Cyclezee]

By the way... is removing the wheel realtively easy? On my 905e it was a huge problem to remove the wheel. The power wire was threaded through narrow tubes welded to the frame and then had a big block connector attached to it. I couldn't get my wheel off because the power cable was so short and the block connectro wouldn't go through the tubes. In the end I had to cut the tubes with a hacksaw in order to remove the power wire and give me enough slack to get the wheel off.

One other safety point. The 905e came with a 'quick release' front wheel (I don't know about the SE). The nut was alloy and, although not overly tight, it stripped its threads and I found my front wheel was only in place because the dropouts point down......

Hi Jimmy,
like Frank I found rear wheel removal easy as on a normal bike. The power cable is attached to the frame with a couple reuseable plastic clips, then you just need to unplug the block connector.
The front wheel is not quick release and the axle nuts are steel, so no problems there.
I have assembled several of these bikes, 905e and 905se, first time it took me 3 hours, but I can now do one in and an hour and a half, the longest job is swoping the mudguards from sport to city style or vice versa and fitting the rear carrier, 3 hands would be useful for that job.

John

 

[jimmyengland1000]

Jimmy,
Did anything else go wrong with your bike that we should be aware of?
Frank

I wrote a full report about my 905e and you're welcome to a copy if you want. Just e-mail me. I wasn't really happy with it at all. I bought it last April direct from Wisper for £620, cheap at the time as they had just started selling them. It had loads of problems, to be honest. I liked the performance and the looks and the lightness but my impression of all the cycle parts was that they were cheap and nasty. Bottom bracket bearing collapsed, steering head is 1" threaded and cheapo ball bearings. The forks were completely useless, unadjustable and more decorative than anything else. Replacing them was difficult due to the 1" threaded steerer. Spokes loosened on the rear wheel all the time. Some came completely undone after a 5 mile run. The tyres it came with were really cheap and developed sidewall hernias after 50 miles of road use. The derailleur was basic Shimano and OK but anything else was better and I replaced it. Mudguard at front snapped off as it was only held on by one central bolt. Rear mudguard design meant that it was easy to drift off centre and then not work. Sprung seat post rotated by 5 degrees all the time when in use. Twistgrip fascia on the battery indicator came off. Battery indicator only registered to say that the battery was flat (pretty apparent, I'd say). The seat was fiendishly uncomfortable. Lights were cheap and not very visible. Front disk brake was pretty ineffective and I replaced it with a hydraulic one. Rear brakes were poor with very small brake blocks and I replaced them with better V brakes. Many ferrous parts on the bike rusted. The wiring was a nightmare, with the red wire of the battery supposed to be connected to the black wire of the controller and black to red, for example. Wiring chafed in the hole from which it emerged under the bike.

Performance in terms of distance was about 30 miles. Speed was good (29mph once with throttle and pedalling) but, despite that, I modified all the faults (about £160 to do), then got rid. I thought about the 905SE since I believe they have addressed many of these faults??? Then I saw the price. I don't believe it's worth £1200, so bought something else instead.

 

[frank9755]

I've fitted my torque arm! Being a novice metalworker, it took me a couple of hours. The spanner didn't work so I used a strip of steel from an old gardening tool, got the right shape holes in the right places and tightened it up. I feel confident to ride the bike again now with the dropouts protected by a 5mm thick piece of steel. If anyone is interested I'm sure I could work out how to post a picture.

This can happen if the material is too soft, and can be worse with overtightened nuts. It seems the soft frame material flattens under the pressure and can get looser as it distorts and the dropout slot expands.

Flecc,
Interesting. To prevent just this outcome I had made sure my wheel nuts were really tight. It sounds like this might actually have made it worse!

Jimmy,
You had a bad run, but it sounds like the motor shredding your dropouts was the worst of it. The new Wisper has adressed most but not all of those problems. In particular, the front brake is good, there is no dangerous quick-release, the seat-post seems to do the job, the forks look like they are good quality being lockable (I keep mine locked) and adjustable. A shame you had so many faults as the underlying performance of the bike was good.

Frank

 

[flecc]

The best answer to dropouts known to be soft is a thick and large diameter steel washer, preferable the type with centre dished and a raised ridged periphery. Then the grip from the wheel nut is placed well away from the dropout slot and tends to hold the sides together.

A thin flat washer is worst, since that dishes under the wheel nut pressure into a convex shape against the dropout slot, forcing the two sides of the slot apart.
.

 

[wisper new milton]

torque arm

Hi Frank,

Doug here from New Milton, , and as David is in China at the moment, I have posted this in his absence. He will when in China check out your observation and put it to our assemblers and frame makers, as any improvement we can make that is worthwhile we always will. I have also emailed you directly on your personal email as you did mail me direct about this, but am waiting for a reply.

I note that you have problems with a rear drop out and have suggested that you should contact your supplier immediately and he will deal with any problem as distributors buy at the price to be able to do this in their own workshops, and as stated before we have experienced NO problems of this sort from the hundreds of bikes we have shipped anywhere in the world, so we would like to get it sorted.

I have tried to trace your purchase Frank but have no record of it anywhere, so you haven't bought from us, please advise!

I also note that other Wisper users have posted that they have checked since reading your report that thay can not see any wear at all despite using the bike for many hundreds of miles.

In fact we also know of one rider who travels 25 miles 5 days a week riding hard for the last year without any wear at all! Steve Jones, a police officer, he has posted on here before, so Steve if you read this please feel free to post a response.

I am aware as others on here probably are, of a similar problem another manufacturer had, and after exhaustive and extensive research it was found that there was not a manufacturing or safety problem, but that the wrong washers and the wrong torque applied to the nuts when replacing the wheel after a puncture. If you contact and send the bike back to your supplier he will check and rectify immediately!

All Wisper distributors have a built in contingent to cover any eventuality for every bike they sell, so please get in touch with them and I am sure it will be sorted. best regards Doug Gosling

 

[frank9755]

Doug,

If you read my email again it should be clear it was intended to make you aware of this problem so you could correct it on future bikes and even send out torque arms to current owners to head it off. Given the safety implications of losing a wheel at high speed, I felt an obligation to inform you. It should also be clear from my mail that I wasn't looking for help myself, thanks, as I've now made my own torque arm which seems to be stopping the deterioration.

I am very pleased to see that you now appear to be taking the problem seriously, as this was my objective. I can understand why you may have been sceptical at first if you have not been made aware of this problem by other users, so far. However, as you'll see if you read earlier in this thread, one of the two other Wisper owners currently posting regularly in this forum did have it, so my observed failure rate - 67% - is somewhat higher!

I wasn't aware of this problem ocurring with another make of bike but can understand that this could arise if washers were not correctly fitted. Obviously, given that my Wisper has no washers on the axle, only the nut, this is not the case here.

The good news is that a torque arm must cost next to nothing - its just a little piece of steel - so this is easy for you to fix.

Regards,

Frank

 

[frank9755]

A couple of people (including Wisper) asked me to post some pictures of my dropouts to show the deterioration after only 100 miles of use. I took the wheel out again yesterday to upgrade the tyres and took some pictures.
Apologies for the indifferent quality of the pictures, taken of a small part of a black bike in a dark garage!

1. Side on view showing how the U-shaped slot has been slightly distorted at the bottom right corner. Also shows paint removed from wheel nut having been twisted against the dropout by the motor

2. Paint and some metal gouged out by the axle turning in the dropout

3. Other side showing scratch marks from the screw thread on the axle

4. End-on view - dropout is below the mudguard

I'm pleased to say that I've done another 125 miles since fitting the torque arm and that there has been no further deterioration (I did take a picture of the torque arm but it was just a dark blur - sorry!).

This may have been ok for a while. Indeed I wouldn't have checked it had I not tried to change the tyre. However I'd advise anyone with a powerful motor in a bike with aluminium dropouts and no torque arm to have the occasional check!

Frank

 

[Cyclezee]

Hi Frank, I notice you still have the rear light on the left side.
I have moved mine to the right and attached it to the carrier bolt (see attached photos). All I needed to do was enlarge the size of the hole in the light bracket to accept the carrier bolt, attach a longer cable, feed it round to the dynamo and re attach the cable. This also means you can use pannier bags without obstructing the light.

John

 

[wisper new milton]

Hi Frank, I notice that you have contacted Dick regarding the wiring on your German SE as you are experiencing problems in one of the modes. I understand that it was yourself that wired the throttle to the controller, and It looks as if you may have wired incorrectly, this could cause damage due to the importance of the voltage from the charger to the battery and motor. Please take a clear photo and send a diagram to us and we will check for you. The German Spec for electrics (and components) is as you know different to the full UK spec due to in part voltage and differring speed restrictions, and the de-limiter cut off on the german spec will drain the battery very quickly. Also for your lights to be legal they must be changed over to the right hand side.

You did say in a previous email that you would get back to me with the details of the carriage issues when signing, but despite several mails to you I have not had a response. Could you let me know the details so we can take them on board.

best regards Doug

 

[wisper new milton]

Hi Frank, with regard to the Torque arm "problem" I have made investigations and it appears that the only 3 cases ever to have appeared are from the bikes bought from Germany where the throttle mechanism had to be installed by the purchaser. There has to my knowledg never been a problem with any Wisper bike made for the UK market as the nuts etc are tightened to specific torque. We will though in future look at this and amend if there is a safety issue.
The German bikes were as you know made to a much lower specification on the insistance if the German distributor. We would never sell this quality in the UK and have taken steps to make certain that any of our distributors only sell the products designed for their country with their own specific requirements, only sell to the local market.

Could you also get back in touch with me regrding the company you reccomend for deliveries as this would make a great difference.

Best regards Doug

 

[frank9755]

Doug,

I don't quite know where to start!

You make several points not consistent with postings on this forum - including in this thread and made by yourself in others, emails I've sent you and evidence from the wider e-bike body of knowledge on torque arms.

I won't go through everything as it may be tedious reading but one thing I would really like to see you clear up once and for all is those "German" 905se bikes. At times you say they are:
1. 'Crap', as in this thread
2. the same as the ones you are selling in the UK, as posted elsewhere in this forum
3. the best you have ever made as your German website says.
These can't all be right. I vote for No 2. I know you have asserted several times that they are different but as far as I'm aware you have not been able to cite a single material difference. In fact I'm so sure they're the same that I'll offer a reward - let's say I'll send a bottle of champagne - to anyone who can prove to me otherwise.

I feel you are too harsh on the "German" 905se. Some of the components might not be quite fit for purpose, it may not be quite as fast as a Torq, it may not have the build quality of a Powacycle or the dealer back-up of Powabyke. Perhaps it's not worth a price of £1,200. But hey, I'm pleased with mine. I've done nearly 300 miles on it now and it's not let me down. It's fast - gets me to work a full 5 minutes quicker than anything else I've ridden. It's just about the the biggest battery anyone has put on a bike which gives it a massive range. It's light, quiet and easy on the eye. It's really not that bad! Please don't do a Ratner on it!

I think the market needs good competitors. I've tried to help. I felt you made a great start last year. Some quality problems are now coming to light and the "German" bikes issue has clearly upset you. However I genuinely hope you keep focused, take constructive feedback from customers in the spirit it is intended, learn from it, re-launch the bike successfully, stay in the game, and not blow it through own goals!

Best,

Frank

 

[Cyclezee]

I couldn't agree more with your views Frank. At the price you and I paid for them, they represent excellent value for money. They are pretty tough too, not even my son has been able to wreck one.
The increase in the value of the Euro recently has made the German imports rather more expensive, but still cheaper than a UK sourced bike.
As for the difference between the UK and German bikes, I have not been able to get a clear detailed explanation from Doug as to what they are, just some vague and non specific ramblings.

John