First conversion questions.

19jordan87

Finding my (electric) wheels
Mar 12, 2019
7
0
Hi all,

This is going to be my first attempt at converting a bike so pleased bear with me.

As this is my first attempt I need it to be simple and cheap, I currently have a Carrera 29er and would like to do a front wheel conversion. The kit I'm looking at buying is this from eBay;
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/153325633200
So my first question is this, will this 28inch conversion kit fit my 29er? Reason I'm looking at this is because I can save over £100. Second question is will my 29er tyres fit the 28inch rim? Unless I'm misunderstanding the posts I've been reading from various forums, the 28inch and 29er share the same rim size and it's the tyre that gives it the difference in diameter. So if I understand that right, I can remove the tyre that comes with this kit, 28inch and put my tyre on it and turn it into a 29er? I do apologize if this sounds absolutely ridiculous.
This is the battery I have brought from a mate, 10.4Ah 48V Dolphin Type Downtube Battery Lithium Ion LG m26 cells UK charger https://www.amazon.co.uk/dp/B01L2BK9TW/ref=cm_sw_r_cp_apa_i_6QbICbPJ39FDC
I probably will be doing around 10miles a day for work, will 10ah be suitable?

Thanks in advance.

Jordan
 

Attachments

scott gaza

Pedelecer
Oct 20, 2018
51
11
scone
Hi Jordan, The tyre will fit but you would have around 500wh to play with, if you could charge at work you should be ok.
 

19jordan87

Finding my (electric) wheels
Mar 12, 2019
7
0
Thanks for the reply Scott. So that conversion kit will be fine on my 29er? Not a problem charging at work, eventually I'll upgrade to a bigger battery but I didn't want to buy a cheap eBay one as I've been reading about the cells they use. Would rather by this decent battery even if it is second hand, it's it had a couple months use so still plenty of life left in it I'd imagine.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
1,243
173
Basildon
Unfortunately, I have to throw a few spanners in the works of your plan.

Firstly, do you know how old that battery is and what it was used for, or is it new? Iunless you're lucky, there's a fair chance that it'll be quite under-rated for that kit. Even if it is powerful enough, it would give you a range of about 10 miles max before you were down to pedal power, when all of a sudden, you'll notice the shortcomings of that kit, i.e. the effort to pedal it will be so high that you won't get out of bottom gear.

You have to understand how motors work. They have good power and efficiency at around 60% to 75% of their maximum speed. Once they go below 50% of maximum speed, efficency falls off a cliff, so the battery goes down rapidly, you get nowhere fast and both your motor and controller get turnrd into space heaters. That means if you have nice unhindered roads, where you can get that motor up to 25mph and keep it there, itll be briliant as long as you have a battery poweful enough to keep it at that speed and big enough to get any useful distance.

If that kit fits in with your expectations ask again and I'll give you advice on how to fit it.
 
Last edited:
  • Like
Reactions: tommie

19jordan87

Finding my (electric) wheels
Mar 12, 2019
7
0
Thanks for the reply vrf400. The battery I'm told is a couple months old. He upgraded to a 52v battery shortly after buying his bike, Probably for the reasons you mentioned. I'm happy to leave that battery then as I haven't actually collect it yet. So now another question would be, why did he upgrade to a bigger voltage battery, I understand that motors have a tolerance so I'm assuming 52v will be fine.I was contemplating getting a battery made by a local guy but was quoted £500 for a 48v 30ah one. I do have nice roads as I leave at 6 for work so there is barely any traffic, on the way home it's a little busier but it's mainly downhill anyway. What battery would you recommend? Voltage and Ah? Thanks
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
1,243
173
Basildon
You need to get one with good quality cells, like Samsung 30Q. If you can cruise at around 23 mph, you might get a range as high as 2 miles per amp-hour, but stop-start riding or anything off-road will cut that right down, so a 14Ah battery could get you around 28 miles. The problem is that you'll be in trouble if it runs out, so you always need to leave a bit in reserve. A good battery will cost a lot.

If you get a big battery with lots of amp-hours, the cells don't need to be so good because there are more of them to share the current.

A big battery will weigh a lot and it might be difficult to find a place for it. Do not try and put it on a rack. It'll make the bike unrideable.

Those direct drive motors are unbelievably heavy. When you add a big battery, the bike becomes unpleasantly heavy. It won't be like a bicycle anymore. You need good brakes and tyres. It's not at all like riding a normal bike at 25 mph. The worst thing is that the car drivers are pre-programmed to expect bikes to be going at 10 mph, so they'll be pulling out on you all the time and running you off the road. I know many people that tried those kits for a while, but they all gave up with them and went to lighter slower electric bikes because they found the fast bike experience not very pleasant. It seems like fun at first, but then comes the realisation that it isn't.

As I said, they're great for fast open roads, where you don't get interrupted.
 

19jordan87

Finding my (electric) wheels
Mar 12, 2019
7
0
Hmmmmmm you got me thinking if I should even bother now. Maybe I'll just try find a cheap second hand electric bike. Worse case I'll have to buy a new battery for it but at least I'll know the set up would have been designed specifically for that bike. Thanks for the info you've gave me, might have just saved me wasting a few hundred pounds.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
1,243
173
Basildon
Your 48v battery might be fine with a normal medium sized geared hub motor conversion kit. If you get a 36v motor and run it at 48v, you get 30% more speed and power without stressing the motor. The only problem is you need to buy a separate 48v controller and control panel because the 36v motor kits come with 36v ones.

With that battery and motor, you'll only be adding about 7kg to the bike, which is acceptable. You'll get a cruising speed of around 20 mph if you pedal with a bit of effort.
 

Eagle

Esteemed Pedelecer
Aug 31, 2012
377
132
19jordan87,
There is no shortage of good used electric bikes at decent prices if you look around.
I don’t know whereabouts you live, but here is one in as new condition with a Samsung 15.6ah battery:
https://www.ebay.co.uk/itm/freego-eagle-electric-bike/323731948369?hash=item4b5fed8351:g:GdkAAOSwj1VchmfW

This one probably needs a new battery:
https://www.ebay.co.uk/itm/Freego-Hawk-Electric-Bike/202619890537?_trkparms=aid=222007&algo=SIM.MBE&ao=2&asc=20160323102634&meid=f7c39055236c405494f7457ae67c9f58&pid=100623&rk=2&rkt=6&sd=323731948369&itm=202619890537&_trksid=p2047675.c100623.m-1

For a replacement battery, contact Jimmy or Cem at:
Insat International
1a Gateway Mews,
Ringway
Bounds Green
London
N11 2UT Tel : 0208 361 1790

https://www.bga-reworking.co.uk/
https://www.bga-reworking.co.uk/contact/
https://ebikebatteries.co.uk/


Alternatively, go for a Woosh crank drive/mid drive conversion, such as the Tongsheng 48V 250W TSDZ2 kit with new VLCD5:
http://wooshbikes.co.uk/?cdkit

Woosh will advise on a suitable donor bike, so do check compatibility before purchase:
http://wooshbikes.co.uk/?contactus

Examples of possible donors:
https://www.ebay.co.uk/itm/163593614262?ViewItem=&item=163593614262

https://www.ebay.co.uk/itm/Cannondale-RZ-140-Large-in-Immculate-condtion-Hardly-used-by-very-mature-rider/183719583993?hash=item2ac68a60f9:g:Iz0AAOSwIP9cgVHn
 

19jordan87

Finding my (electric) wheels
Mar 12, 2019
7
0
36v motor running off a 48v battery, that sounds better, I'll start looking at that sort of set up and see what sort of price it comes out at.

Thanks for the links Eagle , I'll check that all out when I get time. I'm from the Isle of Wight so any travelling will include and extra £50 ferry cost for me .
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
7,142
2,720
55
West Sx RH
36v motor running off a 48v battery, that sounds better, I'll start looking at that sort of set up and see what sort of price it comes out at.
You can only do this for hub motors or the GSM without controller from Woosh.
All other 36v BBS type motor will blow the internal controller.

You need 36v hub, 48v rated or dual voltage controller max 25a but typically 17 or 20a. LCD matched to controller and PAS. If using a throttle then a brake cut off is required to prevent a fried controller also a torque arm.
 
Last edited:

19jordan87

Finding my (electric) wheels
Mar 12, 2019
7
0
Think I'm just going to save up and buy a bike then fit a derestricting kit. Think I'm out of my depth here lol. Thanks anyway guys. Appreciate the replies.
 

Related Articles

Advertisers