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Semi vintage bbshd frankenstein hybrid build

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  • Retrorockit
    commented on 's reply
    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.

  • AZguy
    commented on 's reply
    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
    replied
    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.

    Leave a comment:


  • Retrorockit
    commented on 's reply
    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.

  • ncmired
    replied
    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.
    Last edited by ncmired; 01-27-2023, 10:22 AM.

    Leave a comment:


  • Retrorockit
    commented on 's reply
    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.

  • Maxxim
    replied
    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.

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  • Retrorockit
    commented on 's reply
    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.
    Last edited by Retrorockit; 01-24-2023, 06:57 AM.

  • Maxxim
    replied
    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.

    Leave a comment:


  • Retrorockit
    commented on 's reply
    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.
    Last edited by Retrorockit; 01-23-2023, 09:15 AM.

  • Retrorockit
    replied
    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.

    Leave a comment:


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

    Leave a comment:


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

    Leave a comment:


  • Maxxim
    started a topic Semi vintage bbshd frankenstein hybrid build

    Semi vintage bbshd frankenstein hybrid build

    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.

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    The bike in orginal shape with road tyres.


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    After some wheel and fork swap.


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    Last edited by Maxxim; 01-23-2023, 09:16 AM.
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