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?

http://kinstarbattery.com/Product/45/173

 

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.

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?

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

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.

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.

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!

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?

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.

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.

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.

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! [ATTACH type=full" alt="20220620_170115.jpg]47708[/ATTACH][ATTACH type=full" alt="20220620_160915.jpg]47709[/ATTACH]

 

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.

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

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.

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.

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)

SA hub specs.pdf

The RD5 is for 135mm OLN/drop out size yours is shy by 20mm, certainly one wouldn't spread the drop out on such an aged bike.

The X-RD3 70mm or 90mm drum version is for 117.5/118 mm OLN so one will be ok with just 2.5/3 mm stretching. One will have to settle for 3 spd with drum to keep the bike looking to outwardly modern with external gearing.

Edited June 21, 20223 yr by Nealh

The RD5 is for 135mm OLN/drop out size yours is shy by 20mm, certainly one wouldn't spread the drop out on such an aged bike.

The X-RD3 70mm or 90mm drum version is for 117.5/118 mm OLN so one will be ok with just 2.5/3 mm stretching. One will have to settle for 3 spd with drum to keep the bike looking to outwardly modern with external gearing.

OLD = Over Locknut, got it now thanks. Yes looks like you are correct if I want a rear drum. Might need a bit more power from the motor / controller with only 3 speeds though? (Will be used on some fairly gentle hills but also dont want to be peddling like a lune on the flat / downhill.) I guest that also raises another question, front and rear sprocket sizes. Spec for the RD£ says can accept from 13 - 24 teeth?

It's possible to put 2 sprockets on a sturmey hub to give you an extra gear range. It usually has a 1/8" sprocket and 1/16" spacer. If you remove the spacer you can use 2 3/32" sprockets (eg I have a 15t and 20t on an old raleigh twenty to effectively make it A4 speed with all equal steps). The larger sprocket needs to be a double dished type. You would need some form of chain tensioner, but could then either change gear by manually moving the chain when needed, or fit a cheap old derailleur and shifter. I've used an old short cage 5 speed derailleur ( widened by the addition of a washer on the jockey wheels), and a friction shifter mounted under the saddle on the seat stay. It may spoil the vintage look slightly, but if you went for a tensioner and manual chain shifting it would take some close inspection to notice it.

I would opt for 44 or 48v if possible , the former means usally a bespoke or home welded/mad pack. A heavy motor like a BPM is 4.4kg so one has to think about how much weight on the front, ideally it needs a good steel fork then one shouldn't need torque arms, other wise opt for may be an AKM 100h/sx .

The sx variant is marked/rated 250w the h isn't.

 

For such a bike one expects a 201rpm will be best for a heavy bike, downhill one could freewheel almost as the bikes mass will help.

Most hubs have high internal gearing 4.4 or so with the lighter hubs they tend to be a bit higher geared the AKM100SX 12.6 in 201rpm form.

Edited June 21, 20223 yr by Nealh

It's possible to put 2 sprockets on a sturmey hub to give you an extra gear range. It usually has a 1/8" sprocket and 1/16" spacer. If you remove the spacer you can use 2 3/32" sprockets (eg I have a 15t and 20t on an old raleigh twenty to effectively make it A4 speed with all equal steps). The larger sprocket needs to be a double dished type. You would need some form of chain tensioner, but could then either change gear by manually moving the chain when needed, or fit a cheap old derailleur and shifter. I've used an old short cage 5 speed derailleur ( widened by the addition of a washer on the jockey wheels), and a friction shifter mounted under the saddle on the seat stay. It may spoil the vintage look slightly, but if you went for a tensioner and manual chain shifting it would take some close inspection to notice it.

Thanks, will give that some thought. It is already maybe going to be a bit "busy" back there with the gear and brake cabeling though!

Gearing will have to be played with both front and rear, one can change the front chainring possibly if using a modern BB or spider and the rear play with sprocket sizes if using for inclines. Ulitmately you are going to have to sacrifice speed for lower gearing most likely for an easier ride, high cadence will be better for the knees on the flat and the motor will be doing most of the work. With the hub motor the lower the gearing the more torque one will feel as well as they don't like being laboured or stalled.

 

Rear sprocket wise a higher tooth number will be better then alower one.

Use the gear calc to see how one can model the gearing for speed etc.

Bicycle Gear Calculator (gear-calculator.com)

Select the SA s3 for the drive.

Good luck with your bottom bracket. I resurrected a 1986 Specialized Crossroads from a charity cycle shop and fitted a mid-drive. I was unable to shift the bottom bracket at all. In the end I took it back to the shop and 2 mechanics with a railways issue 4 ft spanner finally managed to shift it after many heating/cooling cycles.

Good luck with your bottom bracket. I resurrected a 1986 Specialized Crossroads from a charity cycle shop and fitted a mid-drive. I was unable to shift the bottom bracket at all. In the end I took it back to the shop and 2 mechanics with a railways issue 4 ft spanner finally managed to shift it after many heating/cooling cycles.

Yep, I may have a crack at it today. Will keep you posted! (Went to a local bike shop to order new headstock bearings and cups this week. He said the same kn the BB. He ended up having a bar welded onto the nut to free it off!

So I got this far by simply unscrewing the LH side of the bottom bracket assembly, surprisingly easily! How does the shaft come out though???

There should be an english thread on both sides so the crank arm and chain ring should come off, behind the chain ring should be another threaded bearing holder similar to the one on the lhs.

Bearings should be old money so 1/4", replace all after a degrease and clean.

 

Crank & chain ring might be one piece also may be rusted on ? Try plenty of penetrating oil and tapping off or apply the heat snd cooling method to see if it will budge.