February 19, 20188 yr I want to electrify this it is a heavy bike and I am 14 stone - it also pulls a large Tomcat Trailer bike for my daughter I dont wat to go fast just, say 7mph, for a couple of hours. It pedals ok but its not easy riding its has the usual trike bolt on rear end What are my options?
February 20, 20188 yr 20" wheels? No diff? Are both wheels driven (can't see on that photo)? There are single sided wheel chair motors. Otherwise you need a motor somewhere in the drive train, mid-drive might be a little low slung.
February 20, 20188 yr We have a double post here one for AK to reply to and one for others to reply to . They need to be combined to keep all efforts in the same place. http://www.pedelecs.co.uk/forum/threads/researching-trike-conversion.30505/
February 20, 20188 yr Author Cheers Wheels are 24" I have measure the rear drop outs of the frame ( where the rear axle is bolted on) and it is 135mm. so I reckon the simplest option would be to remove the rear end and pop in a 24 driven rear wheel - but it doesnt have rack mounts so I would need some sort of bolt on rack for the batteries. this would free the rear up to make another Trike though?. Please keep the ideas coming
February 20, 20188 yr Author Just checked and there is about 10cm clearance from the second set of drop outs and the rear frame. So I could use the hub only option so long as the hub was less than 20cm diameter?
February 20, 20188 yr I saw the second thread after I posted... It looks like you might be able to install a samagaga.com differential (the site isn't responding for me so no photo). Then as d8veh suggested a geared hub with cassette gears further forward in the other dropouts. These people make cogs to bolt onto the disc mount on the motor: http://www.velosolo.co.uk/shopdisc.html Advantage two wheel drive and a diff so cornering isn't an issue.
February 20, 20188 yr Author Cheers anotherkiwi that sounds champion so now my shopping list looks like rear dif (assume this can mount either way around) Hub only motor 135 axle (needs to be less than 20cm diameter) disc bolt cog on the hub to provide drive to the dif given my hub motor diameter restriction - which volt model should I go for given that I want to pull 200KG? If I do this Battery space wont be an issue, Ie I could install 4 car batteries on the rear - adding a load of weight though
February 20, 20188 yr Author checked rear diff area:( I have 110mm clearance but looking a my drive shafts I am not sure the diff would go in easily? so I might connect the hub motor to the left hand drive shaft - to make sure it works and then fit a diff later on. So I will need a large cog here and a small one on the hub motor I assume the driveshaft with the key slot is a standard fitting?
February 20, 20188 yr The pictures keep getting better! So you do have two drive shafts. Concerning the total load I would suggest a 48 v Bafang BPM kit (from Woosh for example). You have the space, you just need to fabricate a bracket. Chainline will become an issue if the chain becomes too short...
February 21, 20188 yr Author OK to today I have made sure I can fit a 135mm hub in the rear stays, it was actually on 130mm (god knows why?) but I have packed it out at the rear and its is 137 now! should should take the Bafang 138, and it shouldnt work loose when riding it! Tolerances are very tight but looks like it will work. my 160mm Rotor is to simulate the drive cog and it is catching the coach bolt head - but I want a small drive cog on the hub to ensure it pulls ok uphill - Next I will do the drive shaft cog with spacers where it mounts so I should be able to get it spot on. The cassette just about clears everything - but again I am planning on going single speed so that should work out ok.
February 22, 20188 yr You can turn your axle the other way round (flip side to side) to bring the sprockets in lin on the final chain. If it has a freewheel thread, it might need changing to a right hand one or you can figure another way to fix the axle sprocket.
February 22, 20188 yr Author Cheers - the cassette is a 7 speed cheapo Shimano i just took it apart to see if I could jam it up, but It was too cold to fiddle around in my garage! I am planning on welding a sprocet on the left hand side black collar thing, after I get the powered hub in with the sprocet on the disc mount to make sure it lined up. Thinking about a cheap system like this https://www.ebay.co.uk/itm/122638459582?ViewItem=&item=122638459582 and 4 small car batteries
February 22, 20188 yr You've lost us... A geared hub motor is better than a direct drive one. How much do 4 small car batteries cost? Because you will need to replace them often, they can't do deep discharge...
February 22, 20188 yr The 1000w ebay DD motors are no good for your needs. The motor windings are fast about 370/390 rpm minimum, they are designed for fast riding conditions also they are heavier at about 5.5 - 6kg. You need to be looking at a 201 rpm (code 13) bpm or even less form a geared motor as you want the low speed power. Ideally for your slow speed requirement a code 15 or 16 36v bpm though they seem to be rare.
February 22, 20188 yr He doesn't need a geared motor because he can add his own gearing on the final drive. Those motors are very heavy. Add 4 lead batteries nad the thing will be a tank. Pedalling it without power will not be possible. A lighter motor and lithium battery would be a lot better. Even the tiniest geared motor would be able to pull that up a hill with the right gearing, but only slowly. Without suspension, that think will topple if you go much over 15 mph, so don't think about going fast on it. Everybody that I know that motorised a trike, crashed it badly at some time. You've been warned.
February 22, 20188 yr Author I am planning on a Cog on the motor 21 teeth smaller than a Granny ring - ordered from velosolo, then on the cog on the drive shaft i will do the same size 21 teeth, so it compares to pedalling on the granny ring and half way up the cassette normally and if you pedal very fast you are maxing out at 10mph but normally 5/6 mph? the 48V lithium Batteries are more than my car is worth - hence the idea to use car batteries - so do I need deep cycle batteries like on a caravan? I would like to get the batteries and charger for about £150? Also what does BPM mean? Also trikes dont lean on bends and on uneven surfaces they lean so I go very slow on it Edited February 22, 20188 yr by Headshok
February 22, 20188 yr Big Powerful Motor. You can get a 48v Li-Ion soft pack battery from Germany for £160 a charger from China with free shipping for a few £ more
February 22, 20188 yr With four car batteries and massive 1000w direct drive motor, it's going to be terrible and dangerous. I'd like to help you, but the only advice I can give is don't do it.
February 22, 20188 yr Trying to build an electric bike to a fixed budget is very tricky. Sure, it can be done, but you may end up with a bike you don't want to ride, or worse, as D8veh said, is dangerous. If your ideal components exceed your budget, then you start to make compromises and every one takes you further away from what you set out to build.
February 22, 20188 yr Author OK this is a fun project for me and I dont expect to get over 10mph, and I wouldnt want to on this rig anyway. I dont care much about weight - its never going to light weight anyway. what I need is low end power so the same as chugging along in low ratios on a land rover. Just done some quick calcs and on my 24" rims with a 1:1 ratio on 400RPM I would be going 14mph - way to fast, but with 1:2 I will at 7mph. So if I fit the 16T on the hub and have 30T on the Axle - 400 RPM will put me at about 7/8 MPH
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