First build: Nirve Brookhaven + HS 142f

So with school (pocket college) starting, I want to be less reliant on driving and finding a place to park, plus gas economy. also, parking in the mini-downtown area is a PITA. so, I picked up an HS 142f kit on "Amazin", and there followed two weeks of searching for a bike it would fit in

The result: a 700mm mens NIRVE Brookhaven, wearing high pressure tubular street slicks.

nice big front subframe, even has a rear cargo rack, Score!

But... it has a 7-speed internal-hub, which is huge and does not fit the bolt pattern of the standard kit's sprocket

that spline has the same OD as the sprocket's center ID, and is meant for a Shimano specialty hub brake system. However, I have other plans for it.

I am difficult to discourage, and I have a drill press!
Problem Solved.

that cheese chain is very stretchy, and despite sizing the chain length to a nice secure tension with about a half inch of deflection slack, it promptly grew by a bit over a half-link. I can't move the motor back and remove a whole-link because the left pedal would collide with the belt drive cover.

and that static idler pulley just is not cutting it. this afternoon, the kit for the spring-loaded tensioner arrived in the mail, score!

here she is, as of putting away for the night. a pedalrun up and down the block had a blessedly-smooth chain roll, much better than the rapid derailing I was getting before. full test ride video pending daylight because I don't yet have a headlight, and this thing steps out when you get on the gas even a little!

 

[FurryOnTheInside]

Tubular tyres?

 

[Hyratel]

Tubular tyres?

Yep, rather than tube-and-tire, or tubeless-on-bead. Think a tube, but heavy-wall to ride as the tire. They're meant for high pressures, like 130 psi, so they ride fast on smooth pavement but they'll rattle your spine on unsmooth roads

 

[FurryOnTheInside]

It's an unusual choice.

 

[Hyratel]

I really didn't have much option. I'm doing this on a shoestring, and that's what the bike had on it when I bought it, so that's what I'm using. the only 'other' things I've spent anything on are the idler tensioner, and a bipod kickstand

 

[Old Busted Hotness]

I see you moved the tensioner down to its proper place, good call.

You can get a half-link for the chain, but I'd recommend upgrading the whole chain. Dealing with chain stretch is a PITA, and the rubber kit chain means you'll be doing it a lot.

Your rag joint solution is interesting, but it's going to stress the spokes a LOT. If the bike has a good quality wheel you might be able to get away with it, but at a minimum I'd add another set of plates to spread the load to all the spokes. If it was me, I'd find a compatible brake rotor to fit the spline and bolt or weld it on.

 

[The_Aleman]

That's a neat bike, I've never seen a Nirve like that one. Bet it's pretty fast!

Hope ya paint that engine cover tho, it's kind of an eyesore

 

[FNTPuck]

While I agree the sprocket setup is going to stress the spokes a ton, that bike looks crazy fast to motorize.

Just keep an eye on the transmission. The basic 4stroke kit uses a simple chain transmission and the internal chain is just as crappy as the drive chain so it will stretch and cause issues if you don't give it constant maintenance. I would replace the chain with a stronger one at the same time you do the drive chain - and even better, save some money and eventually get the belt drive setup which is NICE. Quieter, smoother, and lasts way longer.

 

[Hyratel]

While I agree the sprocket setup is going to stress the spokes a ton, that bike looks crazy fast to motorize.

Just keep an eye on the transmission. The basic 4stroke kit uses a simple chain transmission and the internal chain is just as crappy as the drive chain so it will stretch and cause issues if you don't give it constant maintenance. I would replace the chain with a stronger one at the same time you do the drive chain - and even better, save some money and eventually get the belt drive setup which is NICE. Quieter, smoother, and lasts way longer.

I need to get more rags to get the proper clamping, too.

This kit actually has the tooth belt, not a chain drive, as bought!

Crazy fast hells yeah. I'm using a fingertip brake lever for throttle instead of the cheese grade grip twist throttle, because it'll try to pull out from under you if you're not careful.

I'll see what I can do about the rag joint, but it's a lot more solid than the standard rag setup, and reliably centered as well, because it's riding flat on the hub, centered by the brake spline. Believe me, I searched for a spline adapter for the ISO 6-bolt brake rotors and the only one I can find is a german bikeshop that custom machines them and asks €50, which is money don't have for that part

And yes, the right side cover needs some decolor.

I had to replace the metal stabilizer tab for the rear end of the reduction drive cover - it stress-cracked at a too-sharp bend

 

[Hyratel]

Raided the garage for parts off some kids bikes we've been holding onto, so now I have a much more comfortable seat, and semi-upright handlebars - no more backache from bending way over

Except...

I felt something running rough, stopped and checked and .... it turns out these are NOT tubular as I thought, but conventional tire-and-tube. apparently, the hard impacts against road joints were too much for the valve stem, which straightup ripped out of the inner tube when I tried to pump it up

no more riding for me for the weekend :/