liefbike

Have just completed a conversion to a 1998 GT FS bike, using a Bafang BBS02B 48v 750w, and from the amount of space in the triangle it looks like you could fit the usual shark style battery on your downtube. Check first to match any kit with your bottom bracket width AND chainstay clearance. I'm also in the middle of a restoration build using a 1991 Cannondale SR800 road bike frame, beginning with a full respray using Dupli-Color paint. I don't think that these type of road bikes are really suitable for conversion, in terms of the addition of 10kgs to their lightweight frames.

Mine are a work in progress, having found like others, that the hydraulic sensor system is finicky, especially with unsuitably shaped levers and brake bodies. Lever travel is the biggest issue, however my Avid Juicy 5's have an extra click stop that adds to the distance, sufficient for it to work (still not exactly sure why these brakes have that extra stop), however unfortunately having to leave the brakes in that outer position whilst the motor is running means they are in a less comfortable position for grip. The adjustment screw brings the levers in but that then conflicts with the minimum distance requirement. On mounting I filed a flat spot for the magnet, on the bottom of the brake body, so that the araldite could make a good bond. I also found that the supplied magnets were not strong enough, so bought some thicker ones of the same diameter. (particle mass is relevant to magnetic strength). With necessary help from another person, I have carefully tested the motor on motor off position for the sensors and having lightly sanded the back of the sensors to make a better bond, I will glue them to the levers today, after re-testing ('measure twice cut once').

Have taken up your suggestion and purchased a Lekkie 42T (not cheap at A$175); I also decided to ditch the existing 9 speed 11-34 cassette for a 10 speed 11-40, that I had. Also then have had to order a matching 10 speed XT shadow clutch rear derailleur (said to improve hang on ability), 10 speed XT shifter and chain.

Yep, although if you shop around, you might be able to upgrade to 48v/ 750w for the same or similar cost.

For off-road as well, you will only be happy with a mid mount, however for that money you should be able to match the latest Bafang BBS02B 48v 750w kit to a suitable second hand full suspension or hard tail. You will need some tools and basic skills ie the ability to think around issues, but if you do your homework viz making sure first that the kit will go on the bike, and is a suitable setup viz gearing, hydraulics etc, then you will end up with a good all rounder.

I bought both sockets, as I already had a big torque wrench for bottom bracket removals / fitting . Bafang sent me their basic instructions when I asked and I did find a setting for the lock ring, which I think from memory ranged from 36 NM. I have ordered a spanner but in the end was not really happy trying to estimate, especially when the drive is powered by an electric motor.

I have discovered the same problem with the cover and the lock ring, although I thought Bafang said the BBS02 was suitable for both 68 and 73. Anyway having purchased a lock ring socket from Luna Cycles, and with it torqued to at least the spec, I have just been able to get the cover to thread, but not much beyond a gentle tighten with its socket. Whilst the aftermarket motor looks fine, the battery and wiring will distinguish it as a kit bike, however not prepared to spend much more for an equivalent commercial. How does your kit build look ?

When I was younger the idea of 70 year olds on bikes was weird. Now I am one amongst a group of at least 50 ( we are all ex-servicemen), of at least that age, the taunts we receive as MAMILs are easily rejected, because we are in fact past middle age !

Another issue is that rear wheels with hub motors are a pain to remove, whereas a mid mount gives you more flexibility, in terms of ease of transport; punctures notwithstanding.

Well now, I'm one of you; in the sense that I am plus 70, with a heart condition (recent stent) and live in a hill bound location; eg have an 18% round the corner. Having also put on a bit of weight, I have made a gradual transition from a sprint (CAAD 9), to CX (CAADX), to a 36v pedal assist rear hub 27.5. Whilst the 25k weight e-bike is manageable on road and trail, with a tweeked 40kph powered top speed and 100k flat road range; it does have very limited capability for mountain / single track. With the latter in mind as an additional aim, I am now converting a late 90s, 26 inch full suspension mtb. Given the majority view is that mid mount is better for this specific kind of riding, I have opted for the reasonable cost of a Bafang BBS02B. A work in progress; with the hope that the 750w will handle a mountain, a big hill and cruise easily on the flat. I ride with many like us, and others have, as road/trail riders, mostly gone for rear hubs of varying degrees of power and size (mostly 27.5 and 29 depending upon their height); their having a second dedicated mtb if needed, for that purpose. I still ride my road bike sometimes, if I don't have to face big hills, or if I am not with the group; however e-bikes do mean that you are easily persuaded, to take the easy option.

Cheers I gather you are suggesting that it might be better to move the chain line inward (aim being the centre of the cassette). For the Lekkie, I gather the offset is 4mm more than the stock, so it may still clear the chainstay by the said minimum recommended of 3 mm; otherwise I wasn't aware that the Bafang chainring mount could cope with the addition of washers, so thanks. Chainline aside, and in terms of speed, the 44T with the current 11-34 will apparently give a range between 29.84 kph and 9.65 kph at 60 rpm, which sounds reasonable. The 42T would narrow that range a bit.

Further to old school mid mount clearance issues. With supplied 44T chainring, it appears to line up with about the second or third smallest cog, out of the 9 on this cassette. Given the stock chainring is only about 1 cm away from the chainstay, the bigger offset of a Lekkie may be a problem.

Webbing looks the same and its being wider was my concern, subject to the diameter of the closest chain ring.

Thanks for your assistance; width measured at the front pivot is just under 70 mm

It gradually widens further back, to about 100mm, however at that width it is beyond the reach of the current chainwheel. Found this estimate on a thread looking at chainring diameter and without undertaking the math, viz tooth size and spacing etc. 28T = 116mm 32T = 132mm 34T = 141mm 36T = 149mm 38T = 157mm 44T = 182mm 48T = 199mm Not sure what size the 44T one provided with a BBS02 will be, however perhaps there is the option of buying an aftermarket (recommended per weight saving) small chainring, in combination with a wide ranging cassette (eg 11 speed HGS has 11-51T available); OR a bolt on adaptor with a front derailleur / second larger chainring system in use. Ballpark cost for both is around A$250. On the actual use of 'Lekkie' type chainrings and perhaps adaptors, said to improve chainline for Bafang mid drives, I was waiting to see what that actually looks like on the bike.