Fat bike - mid vs rear hub

[MikeFB]

OK, so I most recently decided I wasn't going to get a fat bike, although it was my initial reason for getting into ebikes.

I instead bought a Woosh Fat Boy and also built my first conversion just the other week using a Trek mountain bike!

Well unfortunately someone local to me was selling a fat bike at a good price and upgraded with hydraulic brakes and larger front disc, so it ended up in my garage!

It's not an expensive model, it's a Coyote Fatman, but that's great as all I want to do is throw it about off road and fall off it!

Now the decision of what kit to fit? The main issues I see is that the rear dropout is 180mm (not 170/175 or 190, but 180?). The BB is however 120mm, although there is next to no room between the bracket and crank, maybe around 5mm at most. So, can I get a rear hub kit that will fit the rear dropout or would a Bafang BBS02 be the answer. The other issue is that my max budget is around £600 for the kit and a battery. Oh and I would prefer more than 250w given that this is a big bike, plus it for use away from public access, but not interested in a direct drive kit.

Your thoughts? (Not on the fat bike, but on a suitable kit! )

 

[Woosh]

https://wooshbikes.co.uk/cart/#/product/uid-215-fatkit12ah/bafang-g06-g060500dc-48v-rear-hub-kit-with-48v-12ah-battery

 

[wheeliepete]

Your budget is not going to get you a mid drive, as with a 120mm BB, your only option is gonna be a Bafang HD and even that may not fit. Don't worry about the slightly odd sized rear D/O, it will give/take 10mm or so. I would have a look at Woosh's fat bike kit.

Edit.....as if by magic

 

[MikeFB]

Haha already familiar with the Woosh kit. I think I did mention it to Woosh before when I first joined. However I'm really after a bit more oomph. The bike is going to see some strong rough hill trailing/climbing and mountain biking and it's a big old bike.

Just want to see what options I have. If need be I may have to up the budget to a BBS03 or BBSSHD buying from China, but that takes all my initial budget leaving me having to fork out another £250-300 for a battery.

 

[MikeFB]

https://wooshbikes.co.uk/cart/#/product/uid-215-fatkit12ah/bafang-g06-g060500dc-48v-rear-hub-kit-with-48v-12ah-battery

Still an option, but want to know if the display allows me to alter as I see fit any parameters I need?

 

[wheeliepete]

Another option is the 48v 750 watt version of the Bafang rear hub. You could run that hub with a 30-35 amp KT 9/12 fet controller, which would work out cheaper than a HD mid drive, but would still need a decent £400 battery. One thing to check is your rim hole count, most fat rims are 32 hole and AFAIK all suitable motors are 36 hole.

 

[MikeFB]

Another option is the 48v 750 watt version of the Bafang rear hub. You could run that hub with a 30-35 amp KT 9/12 fet controller, which would work out cheaper than a HD mid drive, but would still need a decent £400 battery. One thing to check is your rim hole count, most fat rims are 32 hole and AFAIK all suitable motors are 36 hole.

Cheers, solid rims no holes. I did get one Chinese seller of kits on ebay to agree to a solid rim instead of the one with holes they offered and it was no problem, as long as it was black. But just can't bring myself to buy a cheap Chinese kit.

 

[wheeliepete]

solid rims no holes.

Spoke holes

 

[MikeFB]

Spoke holes

Spoke holes

ooops haha, got it. Must engage brain more often
Will have to check, but already this is getting expensive for a bit of fun as I'm also planning a 3rd self build conversion for a rear hub mountain bike, but that's another story for another day

 

[peter.c]

Another option is the tsdz2 fat bike motor 100mm or 120mm its available in 250 watt 36v up to 52v 750watt
with display options ,takes abut a month to get here.
Still problems with pedal cranks hitting stays so can be an expensive mistake [this one has sold] just got another with rockshocks bluto parts on order

 

[MikeFB]

Another option is the tsdz2 fat bike motor 100mm or 120mm its available in 250 watt 36v up to 52v 750watt
with display options ,takes abut a month to get here.
Still problems with pedal cranks hitting stays so can be an expensive mistake [this one has sold] just got another with rockshocks bluto parts on order View attachment 37860

Yeah, did look at those, but put off by the various issues I keep reading about, such as the blue gear and crank issues. I know you can and do get issues with all makes and models, just seems more on them than others?

 

[peter.c]

The bbshd attracts a premium for 100mm or 120mm and it needs a good quality battery could not source a bbs02 for a wide bb
The first thing to try before spending any money is will a battery fit in the triangle, it can be a very tight fit on small and medium frames , this is a steel frame med/ large frame with a standard 73mm motor fitted
Has extra wide rear stays 200mm so rear hub kit would not fit

 

[MikeFB]

I have a 36v 15ah hailong battery that I believe is the same size casing for many hailong 48v casings I think? That battery fits with enough room to put it on and take off.

And I just realised it looks exactly the same frame as the one you are showing above.

 

[peter.c]

You are correct the case is the same, the steel frames are very similar that one can take a 5inch tyre extra wide rims and the pedal arm caught the stays but overcome in the end

 

[MikeFB]

To be honest I assume I have a Coyote Fatman or similar? There are no decals on it and the seller bought it like that as well? So just went by the frame style.

One thing I did notice is that there is just around a 1 mm gap between the 4" tyre and chain! So I guess wider tyres on mine are a no then?

 

[peter.c]

The tyres cost a small fortune once you go over 4 inches and want a decent make , the jumbos are around £100 each but will run tube less, the chain line was a problem with the tyre so had to stick to 4 inch
The basic Kenda juggernauts are ok for light use ,but some of the cheap steel wheels tyres weigh more than than the alloy fat bike complete
The hardest thing with the steel fat bike was trying to lift it over a 5 bar gate had to admit defeat
The alloy even after conversion will lift over the same gate
Fat bike conversions look great, but take planning in advance and trial and error ,the 3rd attempt is now under way parts ordered awaiting the slow boat from china should be here next month

 

[MikeFB]

Sounds good. Trying to keep the cost down though for the fat bike as I am also planning my 3rd build, in the end I may just go for the Woosh Fat G06 kit.

The 3rd build is going to be a rear hub mountain bike for trail riding. Having tried some of the trails I'm not keen on using my Woosh Fat Boy on them, as it's in pretty damn good condition and like it for road use anyway. Although my first build is a front hub mountain ebike that did surprisingly well on the trails which I'll probably keep for a spare ebike.

 

[MikeFB]

Well, order placed for the Woosh Fat G06 kit. Decided I wanted the ability to use the bike at anytime and anywhere. Therefore need to keep it fully legal (needs to be legal for personal reasons, just in case you think I'm being.......)

 

[peter.c]

That should make a nice conversion remember they need for a torque arm

 

[MikeFB]

That should make a nice conversion remember they need for a torque arm

I have a torque arm. But do you think I will need one on either side or do you think one will suffice?