Some advice needed please...

[AJ_P]

A couple of years back I was given a very brief ride on a factory mountain ebike from a gent who had just come hurtling out of the trees on the side of one of the forest fire roads I use. I'm not sure what brand it was, but it was a coffee colour, very expensive and I believe it had a Bosch motor. It was a revelation to me as I had been encountering an ever increasing number of very fit people who could easily ascend trails that I found tiring. I didn't see battery packs on frames so I didn't assume they were on ebikes until I learned better. Ever since then I have wanted to convert both my wife's and my own bike but never really took it any further than considering all the different options.

I finally settled on Tongsheng 750w or Bafang 750w mid drives given that the paths we ride on are hilly and rough. I think the Tongsheng motor might be the better choice for my wife's bike as I think it is most likely plenty for her. She would be very easily dissuaded by a setup that was too snappy and she's not the best on the bike in any case.

My problem lies particularly with regards to my own bike. I have a child's tagalong bike attached to mine and I am wondering if the Tongsheng would be simply unsuited for this arrangement, even if I fitted a bigger rear cassette or smaller chainring? I'm aware of the overheating issue and the stripping of the blue gear. I have also just been told I have arthritis in both knees following some longstanding problems there and need to exercise them which may not be the Bafang's strong point and may be helped more by the Tongsheng torque sensing system. For those reasons, I am very much in need of some real world advice. I'm on a tight budget and don't want to buy the wrong one. I'd appreciate the sharing of anyone's experiences to help me decide, particularly those who may have had similar issues.

Thank you,

AJ

 

[AJ_P]

I've just ordered a Tongsheng TSDZ2B and 14.5ah battery for my wife's bike but I am still none the wiser as to what would suit mine.

As for the Tongsheng, I have read numerous reports of the case screws stripping. Would it be a good idea to change them while still new to stainless hex heads for instance just to make it easier to open in future if need be?

Regards,

AJ

 

[AGS]

Stainless steel screws and aluminium casings aren’t a good idea due to galvanic corrosion. The screw will rot away the aluminium and turn it into fine white powder.

 

[saneagle]

Stainless steel screws and aluminium casings aren’t a good idea due to galvanic corrosion. The screw will rot away the aluminium and turn it into fine white powder.

We've been using them in motorbikes and boats for donkeys years with no problems. If you have a reasonable bike, every screw and bolt into the aluminium frame is stainless steel. If you're the sort that panics about it, you can use some corrosion inhibitor in the threads, like Duralac.

115ml Duralac Anti Corrosive Compound Dissimilar Metals Marine Boat Land Rover | eBay

Use On Bolts, Screws, Rivets Etc. When Components Of A Structure Are Of Different Materials. ORIGINAL RECIPE 115ml Tube. For marine application where corrosion is accelerated by brine concentration.

www.ebay.co.uk

 

[AJ_P]

Thanks to both of you. I was aware of the issue with aluminium remembering the way the aluminium sheeting on old lorry bodies used to just corrode away around the steel fixing points. The white powder is familiar indeed. Mind you not the illegal kind! It's bad for you and I couldn't afford it anyway.

I had read that stainless was not immune to causing this problem but that it was somewhat better than mild steel for instance. I did read that somewhere on the internet though and as we all know, the internet cannot always be relied upon.

Now that you mention it saneagle, I do recall seeing stainless fixings on motorbikes. In fact, now that I am thinking of it, my van's engine mounts are aluminium, and they are fixed to the cast iron block and steel body with steel bolts. Those might be galvanised though if that makes any difference.

Either way, decent quality hex screws of whatever metal with or without Duralac (thanks for the tip) are going to be easier to remove than Phillips headed ones made of cheese. Very, very frustrating when that happens. It's something I think I'll do. I just hope it doesn't void the warranty though I won't be opening the case up. Best to do it now while they are still fresh.

Thanks chaps,

AJ

 

[AGS]

Duralac is a horrible messy stuff to use. If you really must use SS fixings on an aluminium frame then you are better off using a corrosion block grease because it won’t clog up the threads.

 

[Bikes4two]

.......... As for the Tongsheng, I have read numerous reports of the case screws stripping. ........

Regards,

AJ

I'm a fan of the TSDZ2 and the case screws issue is a new one to me - where did you read about it and I wonder what the bike had been used for ie. lots of immersion in water, maybe salty and not kept clean etc etc?

I've 6,000+ Km on my motor and I periodicly remove the motor case to ensure all is well - no signs of screws rotting for me.

 

[AJ_P]

I'm a fan of the TSDZ2 and the case screws issue is a new one to me - where did you read about it and I wonder what the bike had been used for ie. lots of immersion in water, maybe salty and not kept clean etc etc?

I've 6,000+ Km on my motor and I periodicly remove the motor case to ensure all is well - no signs of screws rotting for me.

I do believe I read it here somewhere though I have been reading and watching videos so much all over the place about the TSDZ2B that I could be wrong about that. It referred to the heads being very soft and rounding off and there is also the issue of dissimilar metals.

That you haven't experienced either of those problems on a well used motor is very good to hear indeed. I have just bought one myself and it is on it's way to me as we speak. I'm very much of the "preventative maintenance" school of thought and like things to last as long as possible. There is also something very gratifying about mitigating known issues so they don't become a problem down the line.

6000+km? My wife's bike will never see anything even remotely close to that it so in that case, I'll keep the TSDZ2B clean, greased, dry etc and it'll do her very well indeed.

Thanks very much for sharing that. I'm new to all of this and still finding my way. There's no substitute for experience.

Regards,

AJ

 

[AJ_P]

corrosion block grease

Good tip, thanks for that!

 

[Bikes4two]

I do believe I read it here somewhere though I have been reading and watching videos so much all over the place about the TSDZ2B that I could be wrong about that.

• Yes, lots of postings and vids about the TSDZ2 but of course forums attract the 'it's broke how do I fix it' type of postings rather than 'it's been sweet and gives no problems' type.
• On Endless Sphere for instance, there are postings about the Blue Gear wearing, axles breaking and the motor overheating, but invariably it is difficult to ascertain how the motor was being used.
• A lot of the folks on ES seem to run the TSDZ2 at higher powers, higher voltages and higher assist levels than my own modest ECO riding but in the 'fault' reports there's rarely info on what/how the bike was riden, e.g. was it a 500w/750w version run at max assist with the120kg rider doing jumps (and standing on the peddles) in semi tropical conditions? I'm sure you get my drift.
• Take axle breakages for instance - there are larger/longer axles than the one supplied as standard it seems and it is these that I detect as being more prone to breaking - for example, this post HERE mentions just this.
• And then there's the overheating issue which has been a non issue for me and after last summer's hot weather (2022) I had no problems as I posted about HERE, but there are those who like to fit heat pads and so on.
• I am like you in terms of favouring preventative maintenance but I temper this with 'if it ain't broke then don't fix it'.
• I look forward to hearing of your experiences with the 'B' variety of the motor.

 

[pedalfettal]

Copper grease can help prevent problems with binding/galling (Halfords/Eurocarparts). Hex screws are usually better than X-heads. JIS screwdrivers don't chew-up X-heads as much as phillips/pozidrive.

Tsdz2 suits its target market - riding transport cycles around large Chinese cities built on flood plains.

But there is no reason - with sensible use - that it won't suit your purposes.

The magic-pedalling effect always brings a smile

 

[AJ_P]

• Yes, lots of postings and vids about the TSDZ2 but of course forums attract the 'it's broke how do I fix it' type of postings rather than 'it's been sweet and gives no problems' type.
• On Endless Sphere for instance, there are postings about the Blue Gear wearing, axles breaking and the motor overheating, but invariably it is difficult to ascertain how the motor was being used.
• A lot of the folks on ES seem to run the TSDZ2 at higher powers, higher voltages and higher assist levels than my own modest ECO riding but in the 'fault' reports there's rarely info on what/how the bike was riden, e.g. was it a 500w/750w version run at max assist with the120kg rider doing jumps (and standing on the peddles) in semi tropical conditions? I'm sure you get my drift.
• Take axle breakages for instance - there are larger/longer axles than the one supplied as standard it seems and it is these that I detect as being more prone to breaking - for example, this post HERE mentions just this.
• And then there's the overheating issue which has been a non issue for me and after last summer's hot weather (2022) I had no problems as I posted about HERE, but there are those who like to fit heat pads and so on.
• I am like you in terms of favouring preventative maintenance but I temper this with 'if it ain't broke then don't fix it'.
• I look forward to hearing of your experiences with the 'B' variety of the motor.

Hello Bikes4Two,

You are 100% correct there and I have been guilty of that myself on occasion. When something goes wrong we feel aggrieved, incensed and therefore motivated to “warn” others by at least sharing our experience. It’s a very natural and understandable response when you think about it. That being the case, good experiences are not always written about whereas the negative gets more exposure. Every now and then a bad one crops up in any product. It is the law of averages and it is really only when consistent problems become the norm rather than the exception that we need to worry.

My wife’s TSDZ2B will be used on forest paths, some of which are relatively steep. She’s not a mountain biker nor am I and I’m hoping it will serve her needs well. There’ll be no mad off roading while jumpng through the trees. I am interested in your report on heat so I will be reading that shortly. Climbing those hills in Turbo mode on a summer’s day which is what I know she will likely have to do at least at the outset is the only area where I suspect we might have to exercise care but we will see I suppose.

I will certainly chime in with my experiences of this setup when the time comes if it will be of any benefit to others.

I was very much tempted by the TSDZ2B for my own bike but at 14 stone plus bike plus tagalong bike on the back plus kid etc, I think the Tongsheng might not manage very well. I’ve been trying to do it with two arthritic knees and I’m not managing very well either, though at least somewhat better than I expected.

All the best to you,

AJ

 

[AJ_P]

Copper grease can help prevent problems with binding/galling (Halfords/Eurocarparts). Hex screws are usually better than X-heads. JIS screwdrivers don't chew-up X-heads as much as phillips/pozidrive.

Tsdz2 suits its target market - riding transport cycles around large Chinese cities built on flood plains.

But there is no reason - with sensible use - that it won't suit your purposes.

The magic-pedalling effect always brings a smile

Hello pedalfettal,

I use copper grease quite a bit and it works admirably except in vehicle brake caliper guide pins where it seems to sort of gum up after a while and stick. Probably the heat. No problems with it elsewhere though and I am sure it would do very nicely in this application.

As for sensible use, that's the million dollar question. I ride on rough, hilly forest paths with my kid in tow literally on a tagalong bike which is physically attached to mine. I weigh 14 stone so add the bike, the kid, the tagalong and whatever else we have brought along with us and it really adds up. I'm not at all sure what the solution is but more power usually comes up somewhere in the equation.

There is also the possibility of retaining the front derailleur and fitting a second chain ring to the motor. I could also look at fitting an eleven speed rear cassette for instance instead or indeed in addition to the second chain ring. This would give me plenty of gears to choose from to relieve the strain on the motor. The truth is I really don't know if this is viable or if I should just get a Bafang, or maybe even a Toseven if they prove themselves soon, but budget is a consideration and I don't want to spend any more than I really have to.

All the best,

AJ

 

[Bikes4two]

Apologies if I missed it, but what voltage is your battery? If 48v rather than 36v, then for any given power output the possible overheat issues are less so with the 48v version.

The heat is caused by the current through the motor and as Power is the product of current and voltage (P = I x V) then you can see the 48v version draws less current per unit of power.

 

[pedalfettal]

Hello pedalfettal,

I use copper grease quite a bit and it works admirably except in vehicle brake caliper guide pins where it seems to sort of gum up after a while and stick. Probably the heat. No problems with it elsewhere though and I am sure it would do very nicely in this application.

As for sensible use, that's the million dollar question. I ride on rough, hilly forest paths with my kid in tow literally on a tagalong bike which is physically attached to mine. I weigh 14 stone so add the bike, the kid, the tagalong and whatever else we have brought along with us and it really adds up. I'm not at all sure what the solution is but more power usually comes up somewhere in the equation.

There is also the possibility of retaining the front derailleur and fitting a second chain ring to the motor. I could also look at fitting an eleven speed rear cassette for instance instead or indeed in addition to the second chain ring. This would give me plenty of gears to choose from to relieve the strain on the motor. The truth is I really don't know if this is viable or if I should just get a Bafang, or maybe even a Toseven if they prove themselves soon, but budget is a consideration and I don't want to spend any more than I really have to.

All the best,

AJ

 

[pedalfettal]

Once the tsdz2b arrives and you get it fettled you'll get a better idea of the possibilities.

I'm 16 stone and have a double chain ring (52/34) with bodged built-out front road derailleur, ten-speed cassette (11-42), mtb rear derailleur. NB Cross-chaining restricts how many cogs actually get used (6 + 6).

Works very well with 28 inch wheels on the road, not noticeably more able with 27.5 inch with knobbly tyres off-road.

I do recommend adding extra bearings to the crank/spindle interfaces - provides extra support and prevents too-premature wear. It is also an idea to take it off the bike to work on - less likely to mash screws/bolts /threads on a work-bench!

 

[Bogmonster666]

where did you read about it and I wonder what the bike had been used for ie. lots of immersion in water, maybe salty and not kept clean etc etc?

I have not heard about the outer case screws and I think most of these are hex machine screws so you can get a good purchase on them? I think some regular maintenance is required anyway so by my thinking, if they are not left in situ for years without even being removed maybe you could have a problem. However, I have heard about the screws that hold the internal motor in place seizing. These are not hex and apparently have heads made of a soft cheese like substance. You need to be able to remove these if and when you need to replace the blue gear - I think these are candidates for replacement if you are likely to not perform regular maintenance? No 1st hand experience mind you. I do think the needle bearing is noisy on my unit so I have a replacement blue gear, may get around to fitting at the weekend...

 

[Bikes4two]

.... However, I have heard about the screws that hold the internal motor in place seizing. These are not hex and apparently have heads made of a soft cheese like substance. ...

The screws are are slot headed and are very tight to remove so ensure the screwdriver you use is a good fit in the slot and apply plenty of downward pressure when undoing.

On the two motors I've dismantled the screws have seemed unreasonably tight (maybe there's a reason for this?) so I can imagine that the less experienced (of things mechanical) could begger up the screw heads.

I do think the needle bearing is noisy on my unit so I have a replacement blue gear, may get around to fitting at the weekend

Have fun - for the mechanically curious it is good to get inside these units as you come to realise that all the parts are easy to get to and replace,( for the mechanically adept at least) - put that question to a Bosch Active Line owner - lol!

 

[AJ_P]

Apologies if I missed it, but what voltage is your battery? If 48v rather than 36v, then for any given power output the possible overheat issues are less so with the 48v version.

The heat is caused by the current through the motor and as Power is the product of current and voltage (P = I x V) then you can see the 48v version draws less current per unit of power.

It’s a 48v 14.5ah Hailong cased battery with Samsung cells which I am hoping will suit the 750w motor well in terms of being sufficient for a day out in the forest.

It also looks like it may not fit on the down tube of my wife’s bike, at least on the upper side anyway but I will know more once it arrives. Anything cheaper that I was able to find had Chinese cells so that was a no no and smaller, quality batteries were a lot more expensive than this one.

Thankfully my wife ignored my plea to allow me to buy a better specced bike for her at the time and logically chose hers based on colour instead. For that she has rim brakes, twist gear selectors and little room in the frame triangle...

All the best,

AJ

 

[AJ_P]

Once the tsdz2b arrives and you get it fettled you'll get a better idea of the possibilities.

I'm 16 stone and have a double chain ring (52/34) with bodged built-out front road derailleur, ten-speed cassette (11-42), mtb rear derailleur. NB Cross-chaining restricts how many cogs actually get used (6 + 6).

Works very well with 28 inch wheels on the road, not noticeably more able with 27.5 inch with knobbly tyres off-road.

I do recommend adding extra bearings to the crank/spindle interfaces - provides extra support and prevents too-premature wear. It is also an idea to take it off the bike to work on - less likely to mash screws/bolts /threads on a work-bench!

That’s sounds very interesting indeed. In your opinion, would a similar setup suit my needs? I presently have seven speeds on the back and three on the front. If I kept the rear as it is and added a second chain ring to the TSDZ2B at the front, would that be sufficient to enable me to manage the weight and the terrain without damaging the motor? I have arthritis in my knees and need to pedal enough to build up strength in the area but equally I need to do so without straining too much and damaging myself further in the process which am told is something I must avoid.

When you say “cross chaining”, do you mean that alignment issues reduce the number of available gears? In that case then more gears on the rear wouldn’t actually benefit me as I simply couldn’t use them without the chain being at too much of an angle? II have read that factory ebikes use only one chain ring but they then have eleven gears or so on the back. I don’t need speed so much as I need hill climbing ability so maybe a smaller chain ring and a few more gears on the cassette? The other view is that if I start spending money on it, I will soon be at the price of a Bafang BBS02B which has more grunt to begin but no torque sensor.

I’m afraid I’m still learning here but hands on experience is the best teacher of all and I’ll get it kicked into touch at some point. I very much like the idea of making something so versatile out of it with a little tinkering.

Regarding the bearings, I would have to open the case and thereby void the warranty on a brand new motor. Is it worth taking that risk at this stage or should I wait? Is it likely to do much damage as is in a year of fair weather riding or however long the warranty is?

Hopefully my wife’s motor will arrive soon and I will get it up and running at least. I will then be able to see first hand what the TSDZ2B is actually like and maybe I will then have a better idea what to do with my own bike.

All the best,

AJ