Carrera E replacement.

[Neil5403]

View attachment 22964 View attachment 22962 View attachment 22963 View attachment 22962 My rim has an E R D of 607mm. As the Q128C motor isn’t here yet would anyone know how to workout what size spokes I would need so I can get some delivered for when the motor arrives?

This is my attempt but not confident!

I tried another and got very similar result. I think I will go for a 238mm spoke unless I am doing something wrong??

 

[Nealh]

DON'T order spokes you are wrong somewhere, give me a few mins to go over your calcs.

Reason being I use 236/237mm for 1X for 594 erd with Q128c.

 

[Nealh]

Right your spokes are too short as you have used the wrong hub diameter sizing.
You need to use spoke hole C/L diameter which is 129mm not 144mm which is overall flange diameter.
For 607mm erd rim you will need spokes 244 right & 242 left , if spokes are too long you will not get tension right as thread end will be reached, better to go a mm short.

 

[Neil5403]

Great thanks for that. I haven't ordered yet but will order 36 spokes tomw at 244mm, or should I go 18 at 244 and 18 at 242?

 

[Nealh]

I have always used the same length spokes for both sides so go with the shortest ones as a couple mm works alright for me, although not professional sometimes I may have a mm or two of thread showing on left side.
If doing it proper like you would use two different lengths.

 

[Nealh]

Great thanks for that. I haven't ordered yet but will order 36 spokes tomw at 244mm, or should I go 18 at 244 and 18 at 242?

Using your spoke calc page it comes out at 244.4 & 243. The spoke calc I use says 244.2 & 242.6.
Sapims calc says 246 & 244.
If it were me I would go with 242 or 243, I think 243 is best bet.
Ryan builds wheels on ebay custom cuts to order for £22.50 using Sapim Strongs. They are 2mm dia except the J bend which is 2.3mm, if you want them in black £29.50.

https://www.ebay.co.uk/itm/Sapim-STRONG-Spokes-SILVER-Butted-Nipples-Custom-Cut-ALL-SIZES/152196897337?ssPageName=STRK:MEBIDX:IT&var=451388353503&_trksid=p2057872.m2749.l2649

 

[Neil5403]

That’s really useful thanks.
I think I will go for them all the same size at 242mm. I’m not adverse to a bit of thread showing...

 

[Nealh]

RBW offers a superb service.
Sunday I placed an order for some more spokes. Monday p.m they called me to say their server had eaten the ebay email with spoke size on, so rang to ask me the size required. Just after noon today arrived by 1st class RM.

 

[Neil5403]

Sounds good, I may give them a try.

 

[Neil5403]

2 to 4 weeks. Be careful, we're approaching Chinese new year when everything stops.

You are right, BMS and PSW Power have had my orders a week now and still only at the 'packing' stage. New Year getting in the way !

 

[Nealh]

I order very little from China in Jan or Feb due to this reason.

 

[Neil5403]

Just a thought whilst I am waiting for the end of Chinese new year! They are still listed as 'packing' as we are into week 2 from order...
The thought is, will I be able to test the kit without a thumb throttle?
I do not want a throttle on the finished kit, PAS only, but think it may have been wise to order one to test it with. If needed I suppose I could just get a cheap ebay one, if they connect up to the controller??

http://www.ebay.co.uk/itm/Thumb-Throttle-Speed-Control-for-E-Bike-Electric-Bike-Scooter-3-Wires-Universal/282459997334?epid=601441036&hash=item41c3ed8496:g:musAAOSwCQZZCx8m

 

[Deleted member 4366]

A throttle is very useful for testing.

 

[Neil5403]

Will the one listed above do the job?
Do they have the 3 wires as per the throttle or need a special connector.
I won’t bother ordering one from China !

 

[Deleted member 4366]

All throttles have three wires and work the same. The only thing you need to do is connect the wires to the right three on your controller.

 

[Nealh]

Any generic 3 wire throttle like that will work ok, just get the pin out correct. It isn't clear in the description but will require a sm3 male connector to mate with the female one on the KT controller.
The throttles I have had, one is sent loose in the bag so you can wire the pin outs up correctly.

 

[Neil5403]

Ok thanks. I will order the eBay one as it only for testing.
Just got to decide on the battery now.
48v Q128H motor 17a controller.
Would prefer not a physically too big battery, but a smaller one won’t have the power! I do like the idea of a rack one but think the balance of the bike will be too rear heavy with battery, motor etc on the rear.

 

[Neil5403]

Following on from another thread I am now looking what battery to get for this kit. Is it Lithium Ion as below, or go for the smaller Li-po batteries.

https://www.ebay.co.uk/itm/EU-NO-taxes-48V-14-5Ah-lithium-ion-Hairon-LG-cells-inside-ebike-battery-pack/253314155529?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

I like the idea of having a smaller, more stealth battery compartment, but understand that Li-po is not straight forward and more to it than meets the eye, especially for us novices.
Would a 12S Lipo ( 2 x 6S ) do the job on this 48V setup.
I have ordered the Q128C motor at 48V 201 rpm. Am I right in saying that this can also be run at 36V, if I went that route on the battery or is the 36V a different motor to the 48V?
The 17A controller is listed as 36/48V.

 

[anotherkiwi]

Following on from another thread I am now looking what battery to get for this kit. Is it Lithium Ion as below, or go for the smaller Li-po batteries.

https://www.ebay.co.uk/itm/EU-NO-taxes-48V-14-5Ah-lithium-ion-Hairon-LG-cells-inside-ebike-battery-pack/253314155529?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

I like the idea of having a smaller, more stealth battery compartment, but understand that Li-po is not straight forward and more to it than meets the eye, especially for us novices.
Would a 12S Lipo ( 2 x 6S ) do the job on this 48V setup.
I have ordered the Q128C motor at 48V 201 rpm. Am I right in saying that this can also be run at 36V, if I went that route on the battery or is the 36V a different motor to the 48V?
The 17A controller is listed as 36/48V.

Short answer: depends on the LiPo.

Long answer: LiPo ratings have to be taken with a grain of salt. A 10 Ah 10C LiPo pack can in theory give 100 A constant output but in reality the R/C guys and the US hot rod e-bike guys say that 20% to 25% of that number is more realistic. My own personal experience tends to agree with those numbers.

Now 20 A constant isn't too shabby and in line with the better 18650 celled batteries but it does still sag quite a bit, probably because the chemistry isn't the same. That is why I would go for a 20 Ah 15C LiPo battery in my neck of the woods and you can not call that stealthy. At all...

The 10 Ah or 20 Ah are nominative you don't get that in real life, some more real world examples:

Multistar 10 Ah 10C packs you get between 80 and 85% so look at those as an 8 Ah battery

Graphene 10 Ah 15C packs you get 90% so that is a 9 Ah battery.

Those are real world verified numbers on a GSM mid motor with 15 A controller.

 

[Nealh]

Over volting 24 to 36 or 36 to 48 often work fine the motors can take it just depends on the controller main input capacitor. Speed and torque are increased more so in the 24v case.
Doing the reverse and under volting is pointless as you will lose speed and torque and effiency will be poorer.
Though what you do and want to achieve really do depends on the actual motor winding.