Going round in circles!

[Rivieralad]

Hi all

Just joined and looking for some advice on kits...I’ve read through numerous threads and still not certain what’s best but v.impressed with the quality and quantity of advice here. However, just as I think I have my head around everything, something else pops up which makes me doubt my decisions and in some cases sanity!

I’m 57 years old, two dodgy knees, 95’ish kilos (and slowly dropping), average fitness but enthusiastic and plenty of drive (pun intended). I have just landed a new job reasonably local to me, about 7-8 miles each way, which means I can cycle commute to work instead of sitting in the car for 40 minutes plus an hour on the train each way, commuting from Dorset to Bristol as I have been for the last 3 years.

The route is 80% gravel tracks, the rest paved cycle path or on road, with inclines rather than hills. I can manage this reasonably easily and have been cycling two or three days a week so far but some days my knee(s) let me know they are not happy.

My bike is a Claud Butler Legend hybrid I bought a few years ago second-hand but hardly used. Quite happy with it, comfortable and seems to cope well with the tracks as well as the roads.

For my commute, I think a rear hub kit would be ideal, should help with both improving fitness and arriving slightly less hot and bothered. Not looking to break any speed records, quite happy to stick within the law with 250 watts, etc.

However, we have a 12 year old Border Collie who, despite acting his paw size, can’t quite keep going as long as he used to. So, when camping we take a dog trailer so we can go a bit further afield without having to use our old camper van to go everywhere and it gives him a chance to get his breath back between chasing balls, squirrels, sticks, swimming and generally having fun. Towing him in the trailer isn’t an issue until we get to the hills where the extra 30 or so kilos make quite a difference and we end up walking up the steeper ones. It also gets used at weekends. Most trips are in the region of 10-15 miles, so not a huge range.

I would also be looking to convert my wife’s bike as she would be quite upset if I left her behind even when I was towing the dog! Her bike is a ladies step-through so would need a rack mount battery...in which case I would follow suit so we could share towing duties and carry a spare battery either of us could use, just in case.

Although I am quite capable of tinkering and fitting individual components I would rather buy a full kit and use the time saved to get out and about pedalling!

New ebike are a possibility but I would rather save that option until we have more time to enjoy them.

Sorry if I have bored you all to sleep but if anyone is still awake here are the questions as this is where I get uncertain.
Although it would probably be fine on my commute would a rear hub cope with towing up the hills, bearing in mind I can pull him up the medium length or gradients, just, so would still be putting effort in the longer and steeper hills but with assistance from the motor?
Which kit would be best, i.e has the best torque for towing?
Would a motor with higher torque be okay on my commute where I can already maintain an average speed of 10mph?
Am I asking too much?
Is the world flat...if I find the right motor it will probably seem so!

Thanks in advance.

Chris

 

[Nealh]

If you wan't to be legal & adamantly want 250w rating simply go to Woosh bikes, two kits spring to mind and run both at 48v/13 cells in series.
For towing if using axle hitch mid drive will be more suitable then hub drive.
If any of the bikes have hub gears then mid drive kits.

SWXO2 250w 48v kit hight torgue for the wife.

For towing GSM mid drive(controller less version) couple the GSM with a KT 36/48v dual voltage 17a controller will give you very good torque with 5 levels of assist and you can use an adapter for twin front chain rings. For hills & towing bang it in a low gear in assist 5 and effortlessly waft up with 700 - 800 watts of power output.
You both don't have to have a rack battery as you can fit a downtube battery on one bike and the same battery can be fitted to a rear rack and battery locked in place.
Show us a pic of both bikes as it may be possible to mount sensibly with out need for a rear rack and handling would be better.
What ever you buy get the same 48v battery cradle fitting so batteries are universal.

Likely to be thick end of 1300 - 1500 quid if want a third battery as well.

 

[georgehenry]

If you do not want the faff of doing the conversions yourself Darren at Brighton Bikes could be worth considering but would cost a bit more.

 

[Benjahmin]

A BPM motor would suite your needs admirably. They are prodigious hill climbers despite being hub motors. If the climbing speed is kept in the region of 8mph minimum there's no problems. Have a look at Woosh rear BPM kit. It's marked 500w but there are ways round that, it doesn't mean it's more powerful, it just means it's rated higher, still limited to 15.5mph.
One of the lighter hubs would probably suite the wife's bike
Rear hub in combo with a rack battery is very tail heavy and will affect handling as the battery weight is quite high. If frame batteries aren't going to work, it might be worth considering pannier batteries - gets the weight lower.
My wife has a Woosh Big Bear that has a front BPM, never been any trouble with hills.
And no, the world isn't flat otherwise we wouldn't be having this conversation

 

[Rivieralad]

Thanks for the replies guys, much appreciated.

Should have mentioned budget in my first post, I was/am expecting to spend £1200-1500 on converting both bikes so no probs with your suggestions Neal.

Both our bikes have 700c wheels so the racks are indeed quite high and may affect handling with the extra weight on top.

So if the SWX02 would be ok for my wife’s bike would she be ok towing with it on the flatter roads?

She can maintain a good pace on the flat but slows down at the hills (she’s about half my size!) so we would swap the trailer on to mine for the uphill bits.
Just need to figure out where to put the battery!

As for me, I sat down and worked out the distance to work which is actually almost 8 miles so I’m averaging almost 12 mph with no problem, so would expect to average 15 or 16 mph assisted and hopefully I could keep up going at least 8 mph uphill.

The BPM sounds good even if it is 500w (just looked on the Woosh site and it lists it as 350w but that is immaterial if it gives the performance you mention Benjahmin) but how would it compare to the 250w GSM crank drive on both hills and flatter sections? I would be happy to stick within the legal limits if it gives me what I want but I am not afraid of “stretching the rules” if it gives me the best all round experience. Still confused, d’oh!!!

Pictures of both bikes below, not great quality as a bit late in from work and in a rush ‘cos dinner was ready.

We both have panniers, so pannier batteries could be an option. They also make fitting a battery on top of the rack slightly problematic as we use the panniers quite a bit. A down tube would probably fit mine but not an option on my wife’s, where I think it would have to be rack or pannier.

It’s not easy to see in the picture but the top tube on my wife’s bike is curved, not straight, so wouldn’t take a battery.

 

[Nealh]

By what attachment method do you use for the trailer ?

BPM front not ideal for towing as it will be lighter and more skittish /wheel spin.
Battery will easily fit in triangle of first bike.
Step through has curve down tube so not ideal, battery base plate no doubt can be bolted to top of rear rack for battery to lock in to.

 

[Rivieralad]

Trailer is mounted to a hitch through which the axle is fitted, so the hitch is between the rear wheel QR and the stay.

The BPM would be a rear wheel hub, I know that as soon as the trailer is added the front wheel is likely to lift off too easily on the rougher tracks, hills and in the wet.

Derailleur gears on both bikes, so easy to fit rear hub or mid drive.

I might forgo the option of having a spare battery we can share, just get the highest capacity ones we can instead. That way my wife can have a rack mount as she wasn’t too keen on losing her panniers to fit a “normal” battery on top of the rack, not happy with it spoiling the looks of her bike!. Either way the weight will be quite high so I can’t see there being much difference between them wrt handling.

I’ve looked at the kits on Woosh and am interested in the SWX02 48v for my wife’s bike but probably with a rack mount battery (if I value my life).

The BPM rear hub kit looks and sounds good but the GSM looks like it could be equally good, just need to look at about controller and battery options for it.

 

[Benjahmin]

A GSM drives through the bikes gears, so you have to be in the right gear to keep the motor revs within it's performance range. Same as a car really, if the revs are too low the motor will bog down and stall. Some riders have said they have difficulty matching their preferred cadence to what the motor requires, guess it depends on how 'cadence sensitive' you are?
Not sure how a rear hub would work in conjunction with the trailer hitch, Woosh might be able to help there.
The rack mounted batteries come with their own double decker rack. Some won't allow pannier clips to fit (there isn't enough clearance between battery and side tube to allow pannier clips to seat), however the throw over type will fit.
With a kit install there is always the option of running a parallel battery/second battery connected on the bike. Gives great range and stresses the batteries less. You simply make up a Y splitter lead to connect the two together, so long as they are within half a volt of each other (I always measure mine before connection) then all will be well. My second battery was supplied by Insat, has a layer of high density foam round it and sits in the bottom of my pannier when I want to use it.
The wattage marking on a motor is merely it's continuous rating. That is the power it can have going through it, over a long period, without over heating. It has bog all to do with it's actual consumption. There is a way to make labels with all the required info, stating 250w etc, hey presto - legal machine. All bikes consume way more than 250w in use and testing the continuous rating is nigh on impossible.

 

[Nealh]

Hub axles are 12 x 10 mm, most trailer hitch's are for 9mm QR type axles. You would need to find out whether a hitch would work as most hub axles are tight on axle length with little or none left showing once fitted and a torque arm is fitted.

 

[Woosh]

just need to look at about controller and battery options for it.

we can supply 17AH in rack from next week and the 48V SWX02 kit is only available with 48V 12AH HL downtube battery.
Please contact me directly via support@wooshbikes.co.uk if I can be of any further help.
Tony

 

[Rivieralad]

Ok, finally got some time free at last, TGIF!

Thanks for raising the point about the trailer hitch as it was something I hadn’t considered and naively thought it would be ok. Had a look online and their are options available, some cheaper than others. Same with longer axles, if needed.

As for being cadence sensitive, the answer has to be yes. I am for ever changing gear to keep my legs going round at the same rate, it’s probably an age thing, too fast and I don’t feel like I’m getting a good return for my effort and too slow is just too slow and I start bogging down.

Going to give what you chaps have said some serious thought tonight and see what the boss prefers for her bike...that could well end up with me doing ALL the towing.

Tony I may well drop you an email over the weekend with a couple of questions about kits, options and availability.

 

[anotherkiwi]

Hub axles are 12 x 10 mm, most trailer hitch's are for 9mm QR type axles. You would need to find out whether a hitch would work as most hub axles are tight on axle length with little or none left showing once fitted and a torque arm is fitted.

I drilled out my hitch so that it would fit on the Mxus axle and it still works on a QR axle too.

 

[Benjahmin]

I'm the same with cadence, that's why I've kept 16 gears on my main bike, though many say you don't need it. It's a question of not knowing if the rpm the motor needs to be sweet will match the cadence you need.