A little more speed?

[point5clue]

Hi All,
I've completed my 17.5 mile each way commute a few times now on my Dawes Sonoran conversion.
Its Q100C rear wheel with a S06S/S-LCD6 controller/display. The motor was specified as 201 RPM. Power is from a 36V battery which seems to be performing well - yesterday after 35 miles voltage was showing at 36.0V as I got off the bike.

Riding along on the flat with plenty of input from me I can sense the motor topping out at around 18mph and see the watts drop down to single digits in PAS3 or PAS5.

I went in to the controller setting looking at speed restriction but it was already set to 99mph.

From the little I know I suspect this is set by the 201 RPM winding of the motor ? Is there any way to get a little more speed out of the motor ? I'd love to be able to make my journey in under an hour, but any marginal gains means more time in bed each morning.

All of this is on the private roads of my vast country estate by the way.

 

[Nealh]

18mph sounds correct for your set up, finding a down hill route will be best for more speed .
The only way now to increase speed is to use more volts so either 48v, 12 or 13s.

Wiring a 3s lipo or 3s 18650 small booster pack in series will give you 48v and an extra 3 -5 mph on your country estate .

 

[Deleted member 4366]

The easiest way to get more speed will be to change the motor to a 260 rpm Q100H, but that's a freewheel motor, so you'd have to do something to your gears. Maybe a 201 rpm (actually 260 rpm) Q128C would be better.

Your motor will come to life if you run at 12S (44v), but that brings all sorts of complications and the cost of a new battery. Some people have trouble running KT controllers (e.g. S06S) in the middle voltages, like 44v.

Booster batteries are good for experimentation, but are not good as a long-term solution because they bring all sorts of risks.

 

[point5clue]

The easiest way to get more speed will be to change the motor to a 260 rpm Q100H, but that's a freewheel motor, so you'd have to do something to your gears. Maybe a 201 rpm (actually 260 rpm) Q128C would be better.

So is the Q100C 201rpm really 201 whilst the Q128C 201rpm is 260 ?

Wouldn't want to spend out on a new motor to end up with the same top speed ?

 

[Deleted member 4366]

So is the Q100C 201rpm really 201 whilst the Q128C 201rpm is 260 ?

Wouldn't want to spend out on a new motor to end up with the same top speed ?

Yes, up until now, but we can never be sure that it will stay like that.

 

[point5clue]

There is a 328rpm option for the Q100C - would that be viable - happy to put more effort in up hills if it lets me have a significantly higher top speed on the flat. 700C wheels by the way.

 

[Deleted member 4366]

There is a 328rpm option for the Q100C - would that be viable - happy to put more effort in up hills if it lets me have a significantly higher top speed on the flat. 700C wheels by the way.

It's too fast for its power, so not very efficient. it's for 20" wheels.

 

[point5clue]

The easiest way to get more speed will be to change the motor to a 260 rpm Q100H, but that's a freewheel motor, so you'd have to do something to your gears. Maybe a 201 rpm (actually 260 rpm) Q128C would be better.

I'm planning to go for the Q128C - I'm not in a hurry, so I was thinking of ordering the bare motor and building myself to save postage costs - I'm fairly happy with the build process, but unsure how to buy the right 700c rim and correct length of spokes/nipples for it - does anyone have a the right spec ?

 

[Nealh]

Buy the rim first then once you know the ERD use an online spoke calculator to measure the spoke length before ordering. Look for a double wall rim of 19 - 24 mm depending on the tyre size you are going to use.
Cost of new rim about £20 on ebay.
Once you know the spoke length use Ryanbuildswheels on ebay and get 14g Sapim strongs cut to order.

 

[Deleted member 4366]

Look for a double wall rim of 19 - 24 mm depending on the tyre size you are going to use.

It's a 700c rim, so 19mm max wide. I'd add that you need 36 holes for the motor:
https://www.ebay.co.uk/sch/i.html?_from=R40&_sacat=0&_nkw=700c rim 36 holes&rt=nc&_mPrRngCbx=1&_udlo&_udhi=20

 

[Nealh]

I was meaning tyre width I use 19 or 21mm exal rims.

https://www.ebay.co.uk/itm/2-x-Exal-Ex19-Strong-Alloy-Rims-622-700c-28-x-19mm-36h-Electric-Bike-New/232624850983?_trkparms=aid=222007&algo=SIM.MBE&ao=2&asc=43781&meid=6c1ef49110d547af93ff07319cddd8f9&pid=100005&rk=1&rkt=6&sd=231515608316&itm=232624850983&_trksid=p2047675.c100005.m1851

https://www.ebay.co.uk/itm/REDUCED-PAIR-EXAL-ML21-ALLOY-RIMS-622-21-28-700c-TOURING-36H/331244217194?_trkparms=aid=222007&algo=SIM.MBE&ao=2&asc=43781&meid=6c1ef49110d547af93ff07319cddd8f9&pid=100005&rk=2&rkt=6&sd=231515608316&itm=331244217194&_trksid=p2047675.c100005.m1851

 

[Benjahmin]

Apparently those first ones have an Ear Indicator - interesting.

 

[anotherkiwi]

https://www.bike24.com/p281113.html

This is what I am going to build the Mxus into.

 

[Neil5403]

I took that same route. Bought the bare Q128C 201/48V motor and had the below rim and some Sapim strong spokes( Having tried cheaper ones first that were no good)

https://www.ebay.co.uk/itm/Mavic-Rims-A119-Bk-36/152275474581?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2648

 

[point5clue]

I copped out in the end, and took it to my hub to my LBS. £90 for supply of spokes and rim and build.

No load speed on a stand went from 18mph on the Q100 to 22mph on the Q128. On the road with plenty of input from me I'm getting 19-20 fresh off the charger, and still 18mph 36 miles later with one bar left.

Any, yes, my commute now takes just a fraction under an hour

With rubbish weather and floods closing the roads I've already done over 900 miles of commuting. Given my drive would take a longer route I've already displaced a 1000 miles of car miles. I think I'm building up a vague target to offset 4k car miles in 2018

 

[Deleted member 4366]

That's good. The Q128C will run happily at 48v, so if you want a bit more speed in the future a 48v battery and controller will sort it out to give a 22 to 24mph cruising speed, but the faster you go, the more battery you need.

 

[point5clue]

but the faster you go, the more battery you need.

Yes, one day I'd love to do it, but the cost of a 20+ Ah 48V battery will have to come down a bit - hopefully by the time this one is worn out there will be gigafactories all over the world churning these things out for pence