Roadrat Alfine 8 with G370 hub build.

[Nealh]

It has been along while since I last touched the build and it has been languishing in the dining room of the house.
Finally fitted the double chain ring 32/42t set up and adjusted the derailleur changing, new chain fitted and links reduced.
The battery box I have put on hold mainly because I haven't had time to glass the box former, so for now will go with my small 12s 6ah HG2 drinks bottle build currently used on the Norco though this hasn't been fitted yet.
This week I fitted a to tube under slung bag and the 22a 9fet controller is sited within along with all the wiring. PAS fitted and worked first go as hoped, had teething issue with setting the parameters as the LCD4 has a tetchy down control button. Initially I used an unused yose branded lcd3 to set all parameters and powered up using a dolphin 09 case 29e battery.
Only a few jobs to go now before a road test and regular use to replace the broken Norco bike/frame. Mudguards to fit, the thule rear pack n pedal rack to ads from my spares bin, a front permanent light and of course the battery.

 

[Nealh]

Finally some 18 months after I started this build, it breathes and lives.
Over the weekend I tweaked and fitted the mudguards, Thule rack and this morning the Wolf tooth B- rad 3 slot bottle bottle /tool extender arrived so I could fit the battery. The latter saves me compromising the frames with more fixing holes ie, riv nuts.
Dug out a new set of Cordo panniers languishing in the garage for the last 5 years or so, one of the bargains (at £20) that often appear on Planetx that you can't say no to but know one day they/it will have a use. Much the same for the Pod sac under bar tool bag another Planetex bargain for about £5.

 

[Nealh]

First road test was to load the panniers full with glass jars & bottles and to take them to the recycling bin at Tesco, then off to Lidl for some shopping.
Shopping done loaded £32 worth of shopping into the largish panniers and trundled back home.
The tiny front Bafang G370 ( no larger then the alfine 8) on first initial thoughts is very good, no sense of it being powerful like the front BPM I have. For my 12st 12lbs weight it zipped me along very nicely. It is a 201rpm 36v model.
I'm putting 12s/44v through it with a 22a KT 9 fet though have reduced the current to 19a, as mentioned no sense of the immense power the BPM creates so there is no initial pull of the BPM or wheel scrabble or steering torque. Despite it's small size it has no issue propelling the bike or me (even loaded) along with ease.

Unlike the bigger Bafang's this one has gearing of 14.6 and tbh I didn't notice the lack of motor above the cut off speed, there being no sudden 'oh' up against it now as the weight of the motor is only 1.7kg so no big weight mass to overcome and with the better gearing very nice to ride.
The motor axle is not like most and is 10mm dia and only has a part flat axle, only enough to fit in the drop outs ( no torque arms for this little hub). The motor wire exits LHS and even prevents the use of a tabbed anti rotation washer on this side, but one can fit one on the RHS. The forks are steel Surley's and the axle slots in perfectly.

 

[Nealh]

Next ride out will be with no power to feel how it rides and must post a pic.

The Alfine 8 I like for the simplicity, the twist shift action so much nicer then a thumb shifter. The ability to change up on those occasions you forget having come to stop and the sheer quietness of no chain shifting up or down. Despite the lack of a rear cluster I do still have an Alfine tensioner fitted as I have the the front double for longer runs with inclines.
This bike will not only replace my Norco build but will also likely mean the demise of my Boardman build as well, time to cull some of my bikes and sell off some bit I don't require.
This bike I plan to be more multi functionable for commuting, light shopping and longer runs out, it will be used along with the Arkose 2 and the odd ride out on the Swizzbee. For my major load hauling I now have the Ute/Cf combo for my beekeeping and big mega shops.

 

[Nealh]

I have a feeling this little G370 could be a great little motor though obviously can't say how it will cope with steep inclines, but for a simple easy installation it will certainly be good for the very light rider and a light bike. At my weight which must be over 13st fully clothed and with two weighted panniers, it had no issues motoring along on the flat.
For anyone considering the motor there is another option at approx. half the cost, an Aikema 75sx which comes in at approx. 1.45kg and has a full flat sided axle so workable on ali drop outs with a torque arm.
Both motors are 250w rated for 36v and both can be had as 201rpm for a tad over 16mph, if 201 is a bit slow then 12s gives you a nice 245rpm or 13s 268 rpm. 245rpm should top out at approx. 21mph & 268 22mph respectively in 700c size.

 

[Nealh]

For lights I have opted out of adding more electrics, I have a Lezyne usb front light coming and for the rear I already have a six year old Lezyne usb which is very bright and has been excellent.

 

[Nealh]

The stem I used out of my spares is 115mm, I feel the reach is tad short as the wheel base feels a tad short as well so the Boardman has a 130mm stem which I will swap over to see if the fit is better.

 

[guerney]

Very cool build indeed! Roadrats look like proper hybrid road/trail bikes, will last for years too with that moly frame. You've cetainly got a soft-spot for well designed bikes.

 

[Nealh]

The beauty of the Cotic frame at first looks is not only the quality paint job but the immaculate clean tubes joints with no ugly welding in site, unlike a lot of bikes where one doesn't need to look hard to see them.
The wheel base is approx.75mm shorter then my other bikes and I was a little unsure of toe over lap but this has proved not so. The ride position needs a little tinkering due to the SWB, I can't go back much any farther on the seat rail as mentioned above I can add a longer stem and lower the bars by 30mm for a more comfy position.

 

[Nealh]

The bike in it's finished state panniers are now fixed and staying on as the faff is too much to keep removing them, they are handy for keeping the locks in.
Did another grocery run today and a honey sales run so it's getting used, I even got the tyres a bit dirty as I also visited one of my apiaries to check up on the bees.

The longer stem help with the sitting/reach position better, need to raise the saddle another 5mm maybe 10mm, but 5mm will be start.



Being light the G370 rides very nicely unpowered esp with the low 14:6 internal gearing, the motor may be a good choice for a light all up weight bike and with a smallish/light battery be a good choice for a 50- 100 miler bike.
For those who have ridden a larger heavier hub with 4 or 5:1 internal gearing you will know how the treacle effect feels with hub weight, the G370 gives non of that feeling and is extremely rideable due to it's 1.7kg light weight

 

[guerney]

The bike in it's finished state panniers are now fixed and staying on as the faff is too much to keep removing them, they are handy for keeping the locks in.
Did another grocery run today and a honey sales run so it's getting used, I even got the tyres a bit dirty as I also visited one of my apiaries to check up on the bees.

The longer stem help with the sitting/reach position better, need to raise the saddle another 5mm maybe 10mm, but 5mm will be start.

View attachment 44823

Being light the G370 rides very nicely unpowered esp with the low 14:6 internal gearing, the motor may be a good choice for a light all up weight bike and with a smallish/light battery be a good choice for a 50- 100 miler bike.
For those who have ridden a larger heavier hub with 4 or 5:1 internal gearing you will know how the treacle effect feels with hub weight, the G370 gives non of that feeling and is extremely rideable due to it's 1.7kg light weight

I very much like the look of the Roadrat - looks like an ever so slightly compressed racer (I miss my old racers), and it can actually handle offroad! Digging the blue rims...

 

[Nealh]

I have to say the 9fet Kt and G370 combo is pretty ultra quiet in use for a front hub set up and is so far to date the best hub I have fitted not only quiet but so light and rideable with no power, tbh with no power one wouldn't realise it really was fitted.
The alfine8 now I have refitted it to this bike is so much better then using a cassette and far smoother in use, giving it an oil bath and drip clean with ATF fluid I believe has been a good step in maintenance.

 

[guerney]

Are you in a flattish part of the country? How does it cope with hills? Have you christened it offroad yet? Of course, usually weight is the worry with steel alloys, but the motor mitigates that - your frame won't end up fatigueing itself to snapping point like an alumumium one would. That frame will last for years - easier and safer to get welded, if overloaded with honey to breaking point. Sweet!

 

[Nealh]

My first issue I have really had with KT set up occurred today, so need to see if I can find the cause.
It isn't a biggy but just a bit annoying, the lcd4 speed read out is erratic.
So not sure if ;
A. The lcd is faulty.
B. The controller is at fault.
C. Motor speed hall or motor magnet.
D. A wire kink in the loom from controller to display.

The fault is the speed initially reads fine then sometimes it reads max of 49.6mph and then normal again and so on, also when coasting it reads 0 but occasionally will read true.
Magnet count is six so that is set as so, I thought possibly a loose magnet but need to open up the hub. If a loose/displaced one I wouldn't expect it to be erratic just one or the other. Also the hall I would expect it to work or not at all so will have to check it for 5v and switching.

A. I can check by using an lcd3 I have to rule it out.
B. Like wise I can try another controller as it could be faulty.
C. I will test but also will have to open the hub.
D. Is a possibility if the white wire is compromised.

The lcd or controller might have buggy programming.
Usually we would say it's a speed setting but as it isn't one or other it won't be.
I have tried setting one speed magnet but once I hit 12.4 mph it reads no higher, the reading of 49.6mph suggests magnet count is wrong but then it will read correctly sometimes. Likewise coasting this is often a wrong magnet count setting but again not effect so I'm thinking it may be a programming glitch.

 

[guerney]

My first issue I have really had with KT set up occurred today, so need to see if I can find the cause.
It isn't a biggy but just a bit annoying, the lcd4 speed read out is erratic.
So not sure if ;
A. The lcd is faulty.
B. The controller is at fault.
C. Motor speed hall or motor magnet.
D. A wire kink in the loom from controller to display.

The fault is the speed initially reads fine then sometimes it reads max of 49.6mph and then normal again and so on, also when coasting it reads 0 but occasionally will read true.
Magnet count is six so that is set as so, I thought possibly a loose magnet but need to open up the hub. If a loose/displaced one I wouldn't expect it to be erratic just one or the other. Also the hall I would expect it to work or not at all so will have to check it for 5v and switching.

A. I can check by using an lcd3 I have to rule it out.
B. Like wise I can try another controller as it could be faulty.
C. I will test but also will have to open the hub.
D. Is a possibility if the white wire is compromised.

The lcd or controller might have buggy programming.
Usually we would say it's a speed setting but as it isn't one or other it won't be.
I have tried setting one speed magnet but once I hit 12.4 mph it reads no higher, the reading of 49.6mph suggests magnet count is wrong but then it will read correctly sometimes. Likewise coasting this is often a wrong magnet count setting but again not effect so I'm thinking it may be a programming glitch.

As you know, I know absolutely knothing abou this stuff Nealh, but if everything is fine initially and you're pulling heavy cargo while using a relatively small battery - could the error be due to voltage sag?

 

[Nealh]

No I have real voltage data read out and voltage sag is minimal < 0.04 - 0.05v, I'm using quality 20a cells or a hi rate discharge lipo .
The performance from the batteries is good actually on a 11 mile route, I'm seeing start cell V's of 4.15 -4.18v and end V's at 3.88v so at least 22 miles range towing.

 

[Nealh]

Next week I shall find time to open the hub and double check the speed magnets.
Then I shall retro fit a lcd3 for testing when towing to see if the same issue exists.
There is something a miss somewhere as a couple of time I've seen the erratic speeds before towing started in earnest, so feel it might be glitchy lcd4.
When I first fitted the lcd4 the down button was a bit sticky and wouldn't down change easily, it does now so wonder if it is the display. The lcd4 in all but the name is identical to the Bafang sw102.

 

[guerney]

If they're the type: Underlying blister/bubble type buttons do degrade over time - it's like that with my Denon amplifier remote... I have to press quite hard on often used buttons nowadays to register a press, it's only a matter of time till I'll have to ditch it for a Harmony all-for-one. What are the chances that the magnets have demagnetised with heat over several years? Ok... that's extremely unlikely... but easily remagnetised using another strong magnet.

 

[Nealh]

Nearly a year on and an update of the Road rat.
The lcd4 did in the end play out as being buggy or faulty with regards to the odo read out, I made a new ali bracket to lay on the stem secured with the head set cap/bolt and fitted a lcd3 from myold Yose kit that I nver used. The odo readout has been faultless and works correctly , though the lcd4 is nice discreet unit it isn't worth using if it isn't functioning correctly. May be a poor software batch.


The rear fixed codoro panniers from Planetx were replaced for QR style panniers , I bought a pair of 27l/30l clone Ortlieb/ Vaude roll top panniers made by Rhinowalk china approx. £70 the pair . Using the similar QR handle system and lower adjustable retainer clip, these have proved very good as one can load and pack the panniers on the go using smart shop at the larger supermarkets. Then simply plonk them on the bike outside.

I have added a set of touring hooped panniers racks to the front forks for extra load carrying and have bought some more cheaper roll top QR panniers , this time I bought a pair of UK Alpha Plus brand panniers for £50 again utilising the similar QR system and bottom retainer, this panneir set also not only are roll top but also have a WP hinged top cover/flap to enable max capacity when the roll topis of no use.

Electronically and mechanically the KT/Bafang g370 have been faultless so no more to add on that front, no break cut outs are used as over run is non exsistant.

 

[Raboa]

Can I ask why you used the Alfine 8 instead of the Alfine 11.