Topic: 1966 S90 - FRONT END SWAP SUGGESTIONS * PLAN B

[RAFster122s]

Did you figure out your parts diagram question on the center stand?  Appears to be 11, 12, 13, 14 and that is likely because of different stands being used on different chassis numbers.

Picking up a used centerstand from someone on the S90 Yahoo list is probably going to be less expensive usually than dealing with an ebay seller.  Lots of knowledgeable owners there.
Some have built cafe styled bikes from their's and others have restored to stock, and some have just ridden/ride'em, while a few just collect them.

[SKTP]

I did get a new full footpeg bar with a kickstand mount welded on. I order it from Indonesia. I also bought 2 different actual kickstands...one of them fits....the actual welded on kickstand mount hits the engine case slightly and will need to be modified. I might wait to modify it for the new engine...but this project has really taken a backseat. I am not sure what to do with it right now. Funds are not really there for it to be a priority. That being said, I still have a lot of fun with it....you just have to park it on a perfectly flat surface.

Here it it yesterday

https://www.instagram.com/p/BW7mGf9FpBA/?taken-by=harvisbarvis

[grcamna2]

That's completely vintage stock 

[SKTP]

Well the time has finally come. After taking it out for a Halloween night ride...it bogged down and hasn't been the same since. Initially I thought is could be a carb issue, so I pulled that and cleaned it and got a rebuild kit from 4-into-1. It definitely improved the idle and showed me that carbs are far less scary than I had been lead to believe....but it still bogs hard under load and shoots a bunch of white smoke out of the pipe when you really rev it...it also leaks all over the place and the plug gets black and wet VERY QUICKLY...I need to do a compression test to know that it is the top-end for sure, but all signed point to yes. I have a baby on the way so I don't see the full restore/engine-swap happening...so I think I will pull the motor do a top-end rebuild and clean it up...probably go with a slightly oversized piston...

Here's a video of it at idle
http://ve.media.tumblr.com/tumblr_pite3h4J3j1qkjqdm.mp4

[strynboen]

i have made a mod,vith a upside Down china cross bike fork..put it on a china dax....had to make a lot mods..to get the hveel to fit..and make the spedo drive fit..shaft thiknes and vide of the hub..(and the fork)..need to be viden aut to give room for the spedo drive..and veld and machine a new holder for the caliber...but the parts is easy to find used..and cost almost nothing...and the kvality is fine

[SKTP]

Carb clean. Compression test says 140psi cold. Still Boggs down with throttle. Plug gets black and oily fast. Idles well.

Going to try a new plug and spark-plug-cap next.

Open to all suggestions

[SKTP]

Well this bike has been sitting for over 2 years...I took it to a mechanic to fix as I have zero time...it's just going to be stock and working for now

[mc426]

Adding to this thread, as it gave me a lot of direction for my S90 front fork and brakes upgrade. Here's the setup...

S90 modern fork and brake upgrade option - 2009 Aprilla RS125 parts

After reviewing the YouTube video (https://www.youtube.com/watch?v=d-qOmBr9CEI) posted earlier in this thread on using Aprilla RS125 front forks as a swap for the CB125 I decided to dive down this path for my Honda S90. The bearing sizes are such that cutting a custom steering stem and using stock S90 bearings make the swap straight forward.

Attached is the engineering diagram of the custom steering stem for those wanting to follow the DIY approach. A machinist local to you should be able to cut a new shaft out of 1-1/8" 41L40 and press it into the Aprilla RS125 lower triple tree clamp. The shaft length is left long in the diagram and will need a few inches taken off for a stock ride height setup. (Double check measurements for your application!) I ended up using a couple thin spacers to get the bearing loading I wanted. I also added a Scott's steering damper directly above the top nut, so I spent some time on exact height for my setup. My photos show custom nuts I had cut, which are necessarily needed.

McMaster-Carr part number 6776T22

My S90 is of the 65-69 variety using bearings sizes of: upper: 22.5 x 41 x 12.5 and lower: 24 x 41 x 12.5

I purchased the entire front-end of a wrecked 2009 Aprilla RS125 off ebay for the project. Approximately $600USD, including all brake parts. Depending on where you are in the world I've seen these parts even cheaper.

The modern fork and brake upgrade makes this bike far more fun to ride. For our build we did an electric conversion using a kit from https://www.electroandcompany.com/ The goal was creating a scrambler/cafe hybrid style and I'm pretty happy with how it turned out. Nothing quite like doing burnouts with a motorcycle.

Message me and I can connect you with my machinist Thomas (Utah, USA) who will cut up more of these shafts if there is demand. Cost is around $800 USD pressed-in.

I hope this post helps others with this upgrade path.

Long live the S90!

[grcamna2]

Very Nice project S90 Electric sporty bike type build;will it roll ok w/ those tires even in sand ?