Semi vintage bbshd frankenstein hybrid build

[Maxxim]

Hello!

I'm new here on the forum and also no bike specialist, I'm very noob with bicycles. Even so I started to do a little bit strange build of my old Nishiki 401 hybrid bike. Didn't wan't to buy a new one as I have bought this new over 20 years ago. Me and my wife we bought same series hybrids, she got a little smaller women model frame, other wise they are the same. So I have a little bit of an emotional bond to this bike. :D

Anyway ordered a Bafang BBSHD electric kit and it should arrive any day now. But I wanted little beefier wheels with more grip on bad surfaces and a little bit of MTB look. Found a pair of used 27.5" wheels with stud tyres which is good now for the winter. Also the brakes will be updated to hydraulic disc brakes. Ordered a Shimano MT200 kit wich should also soon be here. To clear the wider wheels I changed the front fork to a Suntour NCX air fork with 63mm travel. It's not any high end, but should be ok for road, gravel and light MBT use. This bike has been a little bit harsh on the wrists with hard tyres.

I will update the progress when parts arrive.


The bike in orginal shape with road tyres.



After some wheel and fork swap.

[ncmired]

Hi, and welcome to the form. And, thanks for sharing your progress, pictures, and details - they always help.

[Maxxim]

Thank you. Just to inform, my native language isn't english so there may be wrong spellings and other typos in my text.

[Retrorockit]

Looks good to me. Keep that front derailer on for a chain guide. The move to 27.5 is perfect.
I would suggest going to a 200mm front rotor. Stick that small one on the rear. You might read the thread on Tannus Armour tire liners in DIY forum. They do a lot for a HT. Maybe wait until the snow tires come off. Old round tube metal bikes are perfect. Anything you can think of just bolts right on.

[Retrorockit]

It isn't going to be obvious until you install the BBSHD. But when you double the speed of a bike you need 4x the brake capacity to disperse heat
Even 50% more than doubles it. 1.5x1.5=2.25. Almost all of this will be on the front brake. I would look for a DH rated 4 piston brake for the front.
Things to watch out for when testing brakes.
1- Increasing hand pressure as the bike slows from top speed. This means something is getting too hot. Maybe the linings, maybe the fluid.It should decrease as you slow down.
2-Brake lever sinks after a stop. This means the pressure of braking is keeping the fluid from boiling ,but when you stop the heat soaks in and it boils then.
Some hydraulic brakes can accept a metallic lining upgrade, some just heat the fluid more.The fix for item 1, can cause item 2.
3- Better tires =better brakes.This is where the move to 27.5 will pay off.

[Maxxim]

Thanks for the tips. I will keep in mind the brake advices. I already ordered different adapters so I can fit 180 or 203mm rotors. The MT200 brake kit would propably be a huge gain in braking force compared to the orginal V-brakes. Of course they couldn't be used with these 27.5" wheels anyway. But if it seems that there will be some problems, then it's easy to upgrade the front brake to 4-piston, for example Shimano MT520.

[Retrorockit]

I'm kind of the brake grouch here. But hydraulic brakes can fool you because they all feel so smooth. But they can have heat issues that a cable disc can't.Especially since they weren't designed for motorized use. When TRP wanted to use their 4 ptsyon DH brake as an EU certified 50kph Pedelec brake they changed the lining compound, the fluid, the plastic hoses, and the thickness of the rotors. A 1500W BBSHD will go that fast. Their DH riders now use the Ebike brake.
The only thing that costs more than doing it right the first time is doing it right the 2nd time.

[Maxxim]

The Bafang kit arrived. Everything was ok, got the extras, shift sensor, smaller chain ring, programming cable, brake sensors, right battery etc.. just like ordered.

The bike has a big frame so the battery could be mounted in two different positions. Which would be the best? I like the vertical mount on the seat tube maybe more.

[Retrorockit]

For street riding I would put it forward to help avoid wheelstands. For offroad I would probably put it back to unload the front tire in soft stuff.

[ncmired]

The guidance I've read is to keep weight on or close to the middle of the bicycle/motorcycle, and near/on the axle line. In our triangle frame situations, I think the down tube or the seat tube location works about the same.

But ... With aluminum frames and heavy shark-style batteries, my concern is relying on just two, relatively weak aluminum water bottle bosses. In the early days of lightish weight 36 volt shark 1 cases - maybe. But with your battery, I'd help out the two existing bosses with some of the strap-on bosses. I'd also Locktite all of the bolts if you haven't already - the steel bolts will, over time, try and saw out the aluminum boss threads if/when they loosen up.

Good to see you're up and runnable.

[Retrorockit]

Several places sell a Triple Bob battery bracket that bolts to the water bottle holes but adds some hose clamps to support the battey better.

[AZguy]

On that note I'd also recommend strapping the battery to the frame to keep it from wobbling, etc

Voile straps work very well for this and I've used them on a few builds: https://www.voilestraps.com/aluminum-buckle-straps.html

[Maxxim]

Yea, the water bottle mounts would not be enough for the battery weight. I'm ready to drill holes for rivet nuts. Seems that the mounts are orginally also made with rivets. But either mount I use, it would need a bracket underneath the battery that leans and supports to the frame to avoid the sideway sway.

[Retrorockit]

If you want to drill for rivnuts, make a wooden drill guide to locate the holes. It takes a pretty big hole for the rivnuts, and the drill bit will want to wander drilling into a round tube. Bolt it to the existing holes, and drill though the guide holes in the wood. The drill bit will not follow a pilot hole in a round tube.
You may need an angle drill and short drill bits also to work inside the frame. It can be done, but be prepared and use caution. I've installed rivnuts for battery mounts and torque arms, and it's not easy to get the holes in the right place. The clamp method is simpler and probably stronger too.

[Maxxim]

Thanks, that is sure the right way to do it. M5 rivets propably need 7-8mm hole, need to go and buy some. The orginal rivest seems to be electro coated steel ones, so I guess they would do. I will machine a aluminium bracket that sitts between the battery and the round frame tube.

[Retrorockit]

I went to 6mm which needs 9mm hole. I have also drilled out factory steel rivnuts to 6x1.0mm thread successfully. Tried it on an extra one first.
The difficulty drilling freehand into round tubing is the bit is only hitting in 2 places, and pulling in opposite directions.That's why I suggest a guide for the drill.

[Maxxim]

Tested that everything works. Connected the motor, battery, screen and throttle. Everything is ok, the 500C screen came configurated for 52V battery like promised(not all of these screen firmwares support 52V).




Before I secure the motor in place, I have to shimm it as it hits the frame and doesn't go all the way in. It's maybe 2mm out. I will lasercut 2- and 3mm shimms next week at work.

[Maxxim]

Was thinking a second time about the battery mount... Would have drill holes and install rivnuts, but still the mount would have needed something between the battery and frame tube to prevent sideway wobble. So why not do something more simpple like clamping it down with pipe clamps..?

Well couldn't find any kind of clamps to fit 32mm pipe that was slender enough and would support the bottom of the battery bracket. Designed my own clamps with cad and lasercut them out of 10mm steel. Drilled and tapped holes for the screws and painted them black. Came out quite nice and the battery it very well secured, there is no wobble at all.

[Retrorockit]

Why not have the robot make 3 or even 4 of them? It's still hanging by 2 small bolts.

[Maxxim]

AZguy Thanks. Yes, I saw those earlier, but they may not be much difference from holes and rivnuts, maybe a little bit less wobbly as it has a separate support part..

ncmired thank you. I'm working at a metal workshop, mainly doing only mild steel products.

Retrorockit could make more if it seems to not hold. Mainly only two brackets for the looks. But in the end it shouldn't break as it's not flexing any. A M5 8.8 grade bolt tensile strenght is ~800kg so it can take a huge load when torqued down properly. But it won't hold for long if the bolts flexes and bends. It will break in no time.

[Retrorockit]

The main loading is going to be in shear on a threaded section.So tensile strength eventually may not be the deciding factor. It probably is strong enough. But with 3 slots in the battery bracket why not? Also being a retired truck mechainic i would go for 3x6mm bolts, just because. But avoiding the chore of drilling for rivnuts is a very good idea.

[Maxxim]

Found also new padals, these was on clearance sale locally. Crankbrothers Stamp 1 flatpedals.

[Maxxim]

3mm shimm did the job, now there is about 1mm clearance to the chain stay. But now when I look closer at the chain ring location it's clear that there will be a issue with the chain line. It may be a straight line to the longest gear, but the shortest one would be a problem. Will see if I modify the orginal 42T gear or order a new offset gear. Hate to wait a month for every ordered part though...

[Retrorockit]

Measure from the seat post to the center of the cog and add 1/2 the seatpost dia. That is your chain line dimension.
Then go to Sheldon Brown bicycle gear calculator

https://www.sheldonbrown.com/gear-calc.html

and figure your speed @90rpm ( or other if you like). So you know what size chain ring will give you a good cadence ( the motor doesn't care so much).
You can enter several chain rings at once.
Then you have a couple options.
1-- The normal solution is to get the right sized inset chainring. 40t is one piece, 42 and up are 2 piece so you can replace just the worn part, or change sizes.Wide/Narrow only comes in even sizes.
2- Plan B- Get a serious chain guide going. This is covered in the zip tie mod thread.

https://electricbike.com/forum/forum/main-forum/diy-discussion/156222-mid-drive-cassettte-zip-tie-mod

I use this and spend most of my time in the top 5 gears, the lower 3 work just fine as needed. But my 26" bike needs a 50T ring and inset isn't going to happen at that size. So I really had no other option.
The key to this is the Terra Cycle 15t Sport Plus idler for recumbents.

https://t-cycle.com/collections/idlers/products/sport-power-idler-15

Icletta may have them in EU.

https://www.icletta.com/en/kontakt.en.html

If they don't have the 5hole bracket

https://t-cycle.com/collections/chain-management-accessories/products/5-hole-vertically-adjustable-clamp-on-idler-mount

It seems you have the ability to make your own bracket. I set mine all the way to the rear, pushed it down until the cogs touched, and raised it up just using the seat post clamp. But because I also have the torque arm on the seat post I needed the offset clamp the Terra Cycle part provided.
3- Some people find they don't really need all those gears any more, and short stack the cassette for 6 speeds.A longer LO limit screw is all that's needed. Unused cogs can be moved behind the cassette to maintain spacing.This can get you riding while waiting for parts.

[Retrorockit]

Frequent lubrication makes a big difference on a cross chained bike.The chain will lift off when it gets dry. Every other ride works for me.

[Maxxim]

Thank you.

[Maxxim]

Haha, did go a little bit cheapo way... Did a offset chain ring of the orginal 42T. :D

[Maxxim]

Thanks. Yea, it's not cheap to pay for some machinery these days. Have done a lot with car engines. We have very good machines at work, but I also have some old machining equipment in the garage. Could make almost anything out of metal, the most difficult and expencive thing is to get the material(stainless and aluminium). Will post a couple of pics of the machines... :)

[Retrorockit]

Even if got the machinery for free I couldn't afford a place to put it in my area.I stopped working on my own cars and switched to bicycles due to that.
I spent some money having an offset single speed chain ring made for a TSDZ2 IGH project to get the chain line just right.Then realized a multi speed chain could run out of line and solve the "problem" that way. It looks like it's easier for you to fabricate a custom chain ring than to short stack a cassette.

[Maxxim]

You are right, car things are very expencive. Havn't done lot in few years... Main interest lately has been mostly in boats and fishing. Lithium battery build things are familiar from this boating experience. Electric bike on the other hand is a totally new thing for me and I really appreciate all the hints and advices you guys give here. :)

[Maxxim]

Some pics of the garage machines and my passion... Well the Colchester lathe is older than me, but gets the job done. :D

[Retrorockit]

What sort of inline fives are those? The heads look twin cam and maybe 4 valve? Volvo and Audi both did 5s I think.

[Maxxim]

Good eyes there. Those are Audi I5's. The only and the right engine ever made haha :D And yes, twin cam 20 valve heads.

[Retrorockit]

I had to edit my question form six to five because my retro eyeballs were playing tricks on me. LOL

[Maxxim]

Finally the brakes arrived. Bought also a 203mm brake rotor for the front and a adapter for the caliper. Well it didn't go as planned, it was a 180 to 203mm adapter and my front fork is for 160mm rotors, so I will need a 160 to 203mm adapter. Well have to buy the right one...






The rear got a 180mm rotor, the adapter was right but the other hole in the frame bracket was threaded for some reason, so will need to drill it open.



Also the right side hande was difficult to get right, would had liked to get the brake handle more closer to the center, but the throttle and shifter was hard to get working right. This was the only order for everything functioning, the shifter just works, the upshifting hits the brake handle braket but it shifts.

And a left side throttle isn't a option, right hand throttle is the only right :)

[Retrorockit]

I'm pretty sure riding in Finland doesn't bear much resemblance to what I do. So my setup probably isn't what's needed. For some momentary situation I will use the brake witches to cut power. Especially in tight spots where taking time to push a button twice isn't ideal. To call where I ride dynamic and unpredictable would probably be an understatement.Only sometimes, and only in some places. But it can get real.

[Retrorockit]

Even among street riders my bike is probably under 1%. I wouldn't be surprised if it's unique. MTB guys pushed a lot of good street stuff out of the market. Now that Ebikes are getting big I think some of it needs to come back. Rapid Rise (LO Normal derailer) Gripshifters, and Front Freewheel setup are all working great for me. In fact they complement each other. I'm not going to say my cable disc brakes are "better" than 4 piston hydros. But they're sure as hell reliable no matter what. I like that in brakes.The performance is more than adequate if you set them up properly..At least the Avid BB7s are.

[AZguy]

Dynamic and unpredictable in my riding world is when out in the backcountry and it is plenty of both =]

Urban riding out here for me is mostly limited to the multi-use trails and that's pretty much neither for the most part... still plenty of fun and it's amazing how much of it there is and how far you can go... right out of my back yard (either my house or shop) is hundreds of miles of contiguous dedicated multi-use right in the middle of all this PHX metro area urbanity

We're planning a ride from the Tempe Town Lake along the Snotsdale green belt (so nice, all the street crossings are tunnels that have the dual use of flood drainage when we get the monsoon storms) up to the Arizona canal with a visit to the Arizona Falls ( https://en.wikipedia.org/wiki/Arizona_Falls ) which are cool in a cool sort of way - you can ride under and over the falls for some evaporative cooling in the hot dry air, and then down the cross cut canal through Papago Park next to the botanical gardens and the zoo - will hit a brewery or two along the route and maybe ride through the middle of the snotsdale civic center mall... these routes are usually not terribly crowded but not going to try during this stupid game and golf thing that are in town (yuck!)