A few questions for a fat blokes first kit!

wonderer99

Pedelecer
May 15, 2020
33
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Hi guys and gals. Been lurking for a couple days trying to arm myself with some knowledge but wanted to run a couple questions by you if OK?

I am looking to add a conversion kit to my 29er Aizan Voodoo (see below)

-Firstly would this be suitable? I do love the bike so would be great if it is suitable. I have upgraded the tyres to puncture proof Schwalbe Marathon Plus's.
-As mentioned I am, er, not exactly what you would call slim. I am 19 stone. So I am looking for recommendations for something that will not grind to a halt after 5 minutes of me sat on it.
- In addition to the weight the area I live has numerous hills, some quite steep. So with these things in mind would I be looking at a pretty high powered kit to overcome those two obstacles?
- While I intend on pedalling for the most part along with the motor there will be times I would like to kick back and catch my breathe.
- I would also like to get a decent range out of it, at least 40 miles if possible.
- Would there be a preference to front or rear wheel kit for a heavier person?

Are there high enough powered kits that can do all the above while still not needing a license? The part I am struggling to understand at the moment is the various voltages and watts and whatnot! I would very much prefer to use a UK company also rather than an eBay job.

Any advice regarding all this would be much appreciated.

Kind Regards
Rich35450
 

Benjahmin

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Nov 10, 2014
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A rear hub would do you nicely. Woosh are kit supplier from Southend. Have a look at their BPM kit, renown for being a high torque motor so good for hill climbing and weight carrying. As it's rated at 350w it is not technically legal, however limited to 15.5mph can't see it being a problem. I've been riding with a equivalent motor for the last 6 years now with no issue.
The 350w rating does not make it more powerful, it is merely the continuous rating. Power delivery is governed by the amp rating of the controller.
I know :rolleyes: welcome to the murky world of e bike law!
 
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sjpt

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Jun 8, 2018
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I'm sure Woosh will be along with suggestions, his kits and service are well recommended. Probably a rear kit. Only real advantage I can think of for a front hub is that it might reduce broken spokes at the rear. A crank drive kit takes advantage of the gears so it is good for hills, but it might not be possible to keep the front triple.

The Woosh BPM would do what you need, but at 350w is technically illegal on the road.
The https://wooshbikes.co.uk/?hubkits#swx02-48v-kit or https://wooshbikes.co.uk/?hubkits#fatkit are pretty powerful; actually more torque (which is what you need for getting weight up hills) than the BPM.
 
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Woosh

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wonderer99

Pedelecer
May 15, 2020
33
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Thank you guys, I appreciate the advice. I would be happy to go with a 350 if it would be the better ride and give me more oomph up the hills. What would be the main difference of the 350w over the 250w?

@Woosh the bike has 29 inch wheels, sorry im not that clued up re cycle terminology so not sure if that equates to 27.5 rims?
 

sjpt

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Thank you guys, I appreciate the advice. I would be happy to go with a 350 if it would be the better ride and give me more oomph up the hills. What would be the main difference of the 350w over the 250w?

@Woosh the bike has 29 inch wheels, sorry im not that clued up re cycle terminology so not sure if that equates to 27.5 rims?
Quite possible the 250/350 difference is just what is stamped on it. (eg you'll see Woosh's front (250w) and back (350w) BPM's quote the same torque; he'll know how much difference there really is). Make one motor and stamp it 250 for European market and 350 for US market (as that's legal there and people don't want to feel they are missing out). Then some US ones get to Europe.

Tyre/rim sizes have gone crazy. They always were a bit and then ETRTO standards made them almost comprehensible ... so the marketing people didn't like that and went mad with 29", 27.5" etc.
 
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wonderer99

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May 15, 2020
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Quite possible the 250/350 difference is just what is stamped on it. (eg you'll see Woosh's front (250w) and back (350w) BPM's quote the same torque; he'll know how much difference there really is). Make one motor and stamp it 250 for European market and 350 for US market (as that's legal there and people don't want to feel they are missing out). Then some US ones get to Europe.

Tyre/rim sizes have gone crazy. They always were a bit and then ETRTO standards made them almost comprehensible ... so the marketing people didn't like that and went mad with 29", 27.5" etc.
Yeah its all a bit wibbly wobbly (especially in my head). So my bike has 29 inch wheels (a 29er, I got that much lol) so does that mean the rims are 29 inch rims or 27.5?

When looking at kits I thought either a 29 inch wheel or 700cc would be fine. They are both the same thing right, just worded differently?
 

sjpt

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29" and 700c have the same rim ledge diameter (622) which is the absolute critical measurement. You also need the width to be appropriate (not so exact here). eg a 700c racing rim will be very narrow, good for racing tyres and OK for narrow touring tyres; or a very wide rim will be suitable for 29er style tyres and OK for wide touring/hybrid tyres. Some of the kits don't even specify rim widths, you'd have to double-check with the seller. There used to be a 1::1.5 rule of thumb for rid width::tyre width; I think some modern very fat tyres still need wide rims, but not as wide as that rule suggests.

For example, our 700c XF07 from Woosh is ideal for typical wide touring/hybrid tyres (eg 700x35) but I don't think it would be good for a racing tyre (700x20) or a very fat 29er tyres.
 

darren66

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Feb 23, 2020
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29" and 700c have the same rim ledge diameter (622) which is the absolute critical measurement. You also need the width to be appropriate (not so exact here). eg a 700c racing rim will be very narrow, good for racing tyres and OK for narrow touring tyres; or a very wide rim will be suitable for 29er style tyres and OK for wide touring/hybrid tyres. Some of the kits don't even specify rim widths, you'd have to double-check with the seller. There used to be a 1::1.5 rule of thumb for rid width::tyre width; I think some modern very fat tyres still need wide rims, but not as wide as that rule suggests.

For example, our 700c XF07 from Woosh is ideal for typical wide touring/hybrid tyres (eg 700x35) but I don't think it would be good for a racing tyre (700x20) or a very fat 29er tyres.
It's only been a trend over the last few years to offer wider rims, this gives the tyre a squarer profile, making it more stable when cornering and less likely to fold over. I remember back in the late 90's having 19mm rims with 2.2" tyres with no problems, since the advent of tubeless set ups, wider rims are required as the tyres tend to be run at lower pressure, sometimes less than 20psi, my MTB running tubeless has 30mm rims.
 

Nealh

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29 rims are usually wider to take larger volume tyres, typically 700c up to 45- 54mm tyres for the 19/21mm rims.
700c drop outs are dependant on the width between the narrowest point of the rear stays and to some extent the front forks.
Also confusing with 700c you can fit the slightly smaller 650b rims which allow a larger volume tyre between the stays as they taper rearwards.
 

sjpt

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29 rims are usually wider to take larger volume tyres, typically 700c up to 45- 54mm tyres for the 19/21mm rims.
700c drop outs are dependant on the width between the narrowest point of the rear stays and to some extent the front forks.
Also confusing with 700c you can fit the slightly smaller 650b rims which allow a larger volume tyre between the stays as they taper rearwards.
There might be problems with that if you have rim brakes, depending how much adjustment on the brake.

But Nealh has a good point, the tyre/rim combination must be correct, but a new rim does not necessarily have to the the same as the old one.

A common change was to replace old UK standard 27" with 700c; the rim difference was pretty small so brakes could usually accommodate, you got a tiny bit more clearance, and a much wider choice of tyre.
~~~
For most of the horrors on tyre sizes see https://www.sheldonbrown.com/tire-sizing.html
26" are the worst for confusion.
 

wonderer99

Pedelecer
May 15, 2020
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OK guys you are all just talking a foreign language lol! OK so the more research I do the more I think for my needs I would be better off with a mid motor? SO.......can I get some opinions on whether this would be suitable for my needs?


Will this be fine power wise up hills? If so am I right in thinking all I would need in addition is a correct size battery. Would this work well with the Bafang motor?


Also (sorry for all the questions) is my bike even suitable for a mid motor kit? What would I need to check or measure?

thanks again
 

Nealh

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PF cells are ok but the Samsung 29E is far better.
 
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Woosh

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wonderer99

Pedelecer
May 15, 2020
33
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Hi Rich, I remember now. I did fit an XF08C in 700C rim to a Voodoo Aizan a couple of years ago.
https://wooshbikes.co.uk/?hubkits#xf08ckit
You can have it with 13AH or 17AH HL battery.
Thanks. So couple more questions. Firstly would you agree that based on my weight and hilly location I would be much better serviced with a mid motor like the Bafang BBSO1 rather than any kind of hub? Also based on these factors would I be best served with a 36V battery? Would 48V be much difference?

Secondly, if so, would you know or remember if the Aizan Voodoo is suitable for the Bafang kits you sell? Does the bikes bottom bracket fall within the standard 68-73mm range? Im not sure what I need to measure.
 
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Woosh

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I can't remember much. I think the BBS01B touches the right chainstay.
That's why I ended up fitting the XF08C to it. For your weight, the DWG22C would be better but it's out of stock until end of June.
 

Nealh

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I can't remember much. I think the BBS01B touches the right chainstay.
In this situation Wheeliepete would advise the delicate use of his lump hammer :p.