Front hub conversion on vintage delivery bike. Battery suggestions and best motor query

vidtek

Esteemed Pedelecer
Mar 29, 2015
317
153
72
Bournemouth BH12
I used to ride one of these on Saturdays as an 11 year old in the 1940s, delivering weekend joints and collecting the money for the local butcher. This style of trade bike always had 26" wheels. The BPM motor that sjpt mentioned would be a good powerful front wheel choice, but the battery should definitely go onto a rear rack to give better weight balance. Those high front goods baskets do make them a bit unstable when loaded.

Weekdays I used to ride a very different trade bike delivering newspapers. That had a small front wheel with a flat goods platform just above, on which the papers were stacked.

How I would have loved to have motors on those two in hilly Bournemouth.
.
Wow Flecc-you and me both. As a weedy 14 year-old I had a Saturday job at William Way greengrocers in Tuckton Bournemouth, one of those Granville bikes and lugging 56lb sacks of potatoes up Belle Vue Road hill to the nursing home on top! I would have dearly loved a motor then too.....
 
  • Like
Reactions: flecc

flecc

Member
Oct 25, 2006
50,827
28,656
Wow Flecc-you and me both. As a weedy 14 year-old I had a Saturday job at William Way greengrocers in Tuckton Bournemouth, one of those Granville bikes and lugging 56lb sacks of potatoes up Belle Vue Road hill to the nursing home on top! I would have dearly loved a motor then too.....
Small world. My job was with Ralphs the Butchers in Charminster Road, the other side of the road from today's Crescent Suzuki and same side as Crescent Yamaha. And when I left school my first motor trade job was with Crescent, way back in 1950.
.
 
  • Like
Reactions: vidtek

Rocket Raccoon

Pedelecer
Feb 10, 2020
34
6

Bonzo Banana

Esteemed Pedelecer
Sep 29, 2019
385
184
Looking at battery options still. Anyone come accross these? Posted as ebike battery, but look more like they belong in a laptop? Discharge rate suitable for a 250w front hub uphill?
The discharge rate will depend on the controller you buy and how you set it up if it has a LCD display to go with it or perhaps the default values if it doesn't. Hub motors just work with what they are given by the controller. Despite the 250W rule controller output varies enormously. Some mid-drive motors are delivering close to 800W despite the 250W rule. I've seen 4A, 6A, 7A, 9A rated controllers all sold as 250W legal and they typically peak at over twice their rated current.

Is that a good shape battery for your basket. If it will fit along the edge of the basket closest to the bike headtube the better for balance. I sort of wonder if too much of the weight is going too far out to the sides and a slighter squarer battery would be better. but you definitely want it so nothing rests on top of the battery, it needs its own cage within the basket really.

Also as a rough calculation use 10Wh per kilometre range but I guess for this bike it will likely be less due to weight. I.e. if you think you want 25 miles range you would normally need 400Wh (40km) but with the extra weight maybe you might want 500 or 600Wh to get that range. If you want to run the motor at full torque you have to make sure the battery is capable of it. What is the gearing of the bike currently. How many teeth on the front chainring and the rear cog and what are the ratios of the hub gears? Maybe consider a larger rear cog if necessary to lower gearing and allow you to assist the motor more for very steep hills.
 
  • Like
Reactions: Bikes4two

Bikes4two

Esteemed Pedelecer
Feb 21, 2020
346
150
Havant
Just took put the front wheel. Looks to be 88mm between the drop outs.
Rear frames made of steel can be 'sprung' to increase the OLN dimension but I've no idea if front forks can be done.

I'm sure if you posted the question on the Cycling UK forum, you'd get an answer to this. There might even be a YouTube on the topic?
 
  • Like
Reactions: davell

Rocket Raccoon

Pedelecer
Feb 10, 2020
34
6
Rear frames made of steel can be 'sprung' to increase the OLN dimension but I've no idea if front forks can be done.

I'm sure if you posted the question on the Cycling UK forum, you'd get an answer to this. There might even be a YouTube on the topic?
Already Googled thanks! As the forks are steel, as long as not too corroded, I should be able to cold set them wide enough thanks
 
  • Like
Reactions: Bikes4two

Rocket Raccoon

Pedelecer
Feb 10, 2020
34
6
The discharge rate will depend on the controller you buy and how you set it up if it has a LCD display to go with it or perhaps the default values if it doesn't. Hub motors just work with what they are given by the controller. Despite the 250W rule controller output varies enormously. Some mid-drive motors are delivering close to 800W despite the 250W rule. I've seen 4A, 6A, 7A, 9A rated controllers all sold as 250W legal and they typically peak at over twice their rated current.

Is that a good shape battery for your basket. If it will fit along the edge of the basket closest to the bike headtube the better for balance. I sort of wonder if too much of the weight is going too far out to the sides and a slighter squarer battery would be better. but you definitely want it so nothing rests on top of the battery, it needs its own cage within the basket really.

Also as a rough calculation use 10Wh per kilometre range but I guess for this bike it will likely be less due to weight. I.e. if you think you want 25 miles range you would normally need 400Wh (40km) but with the extra weight maybe you might want 500 or 600Wh to get that range. If you want to run the motor at full torque you have to make sure the battery is capable of it. What is the gearing of the bike currently. How many teeth on the front chainring and the rear cog and what are the ratios of the hub gears? Maybe consider a larger rear cog if necessary to lower gearing and allow you to assist the motor more for very steep hills.
Thanks for this. Ref placement, if this is a suitable battery, I would mount in the Frame triangle sandwiched between two thin sheets of aluminium where a traditional sign would be placed. Controller could go up front still.
 
  • Like
Reactions: Bikes4two

Nealh

Esteemed Pedelecer
Aug 7, 2014
17,222
6,728
59
West Sx RH
The kinstar with 35e is only 3 parallelc cells so the max controller current need to be idealy no more then 12a, although an 8a rated cell they won't last very long above 4a discharge each. Once above 4a discharge as with any good cell onec one goes past the magical 50% discharge rate they will all suffer form longevity and life cycle.
One reason why some of us folks like to spec 15 or 20a cells esp when using few cells in parallel.
 

Rocket Raccoon

Pedelecer
Feb 10, 2020
34
6
A bit more stripping today! Stem came out with penetrating oil and some persuasion. Off to the local bike shop tomorrow as there is definitely a bearing issue! 20220620_170115.jpg20220620_160915.jpg
 
  • Like
Reactions: Bikes4two

Rocket Raccoon

Pedelecer
Feb 10, 2020
34
6
The kinstar with 35e is only 3 parallelc cells so the max controller current need to be idealy no more then 12a, although an 8a rated cell they won't last very long above 4a discharge each. Once above 4a discharge as with any good cell onec one goes past the magical 50% discharge rate they will all suffer form longevity and life cycle.
One reason why some of us folks like to spec 15 or 20a cells esp when using few cells in parallel.
Thanks for that. Would several packs in parallel work that being the case?
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
17,222
6,728
59
West Sx RH
Two in parallel should be enough then it gives affectively a 6 parallel set up with double the capacity. Several aren't needed each battery will have 30 cells.
 
  • Like
Reactions: Rocket Raccoon

Nealh

Esteemed Pedelecer
Aug 7, 2014
17,222
6,728
59
West Sx RH
Head set certainly not seen grease for a very long while, one should leave at least 1 ball space or even two and severely pack it out with grease. Two missing balls will allow for more grease to sit in the cups.
 
  • Like
Reactions: Bikes4two

Rocket Raccoon

Pedelecer
Feb 10, 2020
34
6
Head set certainly not seen grease for a very long while, one should leave at least 1 ball space or even two and severely pack it out with grease. Two missing balls will allow for more grease to sit in the cups.
Didn't know that about leaving out a ball, thanks. Top set was quite loose too, suspect water got in hence the rust. Going to bike shop to see if can get replacements today.
 

Bonzo Banana

Esteemed Pedelecer
Sep 29, 2019
385
184
A bit more stripping today! Stem came out with penetrating oil and some persuasion. Off to the local bike shop tomorrow as there is definitely a bearing issue! View attachment 47708View attachment 47709
I've never seen bearings in that state before, they are impressively corroded to the point where they have lost their smooth state. I'm still loving the fact a bike of such age and condition will get resurrected. I do think you will need to inspect everything thoroughly though for safety sake. If the bearings are like that perhaps parts of the frame and forks have deeper corrosion.
 

Rocket Raccoon

Pedelecer
Feb 10, 2020
34
6
I've never seen bearings in that state before, they are impressively corroded to the point where they have lost their smooth state. I'm still loving the fact a bike of such age and condition will get resurrected. I do think you will need to inspect everything thoroughly though for safety sake. If the bearings are like that perhaps parts of the frame and forks have deeper corrosion.
Forks are out and seem OK. I'm stripping the frame right back then getting the paint all off too, so far nothing structurally scary
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
17,222
6,728
59
West Sx RH
Forks are out and seem OK. I'm stripping the frame right back then getting the paint all off too, so far nothing structurally scary
And all that lovely patina with it too ;), seriously with the rust seen in places it is in retrospect I think agood idea to strip it back to check conditon esp as it is planned to be put back in to serious use.
One will need to check the rear wheel hub bearings if keeping the same wheel and the BB bearings, infact it would be best to renew all bearings concerned.
 

Rocket Raccoon

Pedelecer
Feb 10, 2020
34
6
And all that lovely patina with it too ;), seriously with the rust seen in places it is in retrospect I think agood idea to strip it back to check conditon esp as it is planned to be put back in to serious use.
One will need to check the rear wheel hub bearings if keeping the same wheel and the BB bearings, infact it would be best to renew all bearings concerned.
 

Rocket Raccoon

Pedelecer
Feb 10, 2020
34
6
The plan is to use new rims and renew all bearings - headstock are already out, need to get the bottom bracket apart as a next job, never done that before - all advice appreciated! Ref wheel bearings, front will be a new hub motor and hopefully rear a Sturmy Archer geared hub with brake if one will fit. The distance between the rear drop outs is 115mm, not sure how that translates onto the SA spec sheet attached? (Looking at the RX-RD5)
 

Attachments