Misfit Board Tracker

[Ralph hop]

The issue with the jackshaft mount is that the bearing hangers weren't clearing the stays mostly due to the way the engine mount straddles the bottom bracket. I'm looking to move the back wheel rearward and upward some to gain clearance and a nice ride height. The issue with the fork steer tube needing length added comes from the long headtube on the frame and high stack height of the sealed bearing headset requiring 7.25" of steer tube but added an extra .25" to give room for adjustment. I could have cut some out of the frame but with the risk of lowering the front end too much. Could have also used mountain bike forks with the correct length but I like this style of fork much better.

 

[indian22]

Way less than builder friendly frame design Ralph, but I'm sure you will be able to sort it out. Cutting the frame tube would have really changed the steering geometry & I've built a couple of bikes using high end Rockshox suspension forks & though they rode well the stance was uphill & I ended up going back to classic fork designs. In the end adding length to the steer tube was the reasonable option, but it's not one that should have been necessary. The truss style fork you chose is one that I've used a few times, on three different style frames , and I always had to cut the steer tube down, which is the normal procedure. Sorry you had to do all this extra work because of a misfit frame blunder. Who the heck designs a drop loop frame for mountain bike length steer tubes, crazy stuff that you just can't make up!

In spite of it all you are on your way to a great build

Rick C.

 

[Ralph hop]

Head tube was also for a 1 1/8" fork but I used pressed in shims to convert to 1". Had to order a special size shim for the seat post but can't recall the size although I remember finding special size mountain bike seat posts that would fit for a hefty price. The shim was five dollars and used a regular steel seat post.

 

[MEASURE TWICE]

When I look back at posts Tony had with pictures of the 212 engines, the gear ratio by eyeball, I see the ratio needed is maybe a 1/3 less gearing down compared to my Briggs 3.5hp bike. You probably don't need what I felt 20:1 ratio on what I have.

Just a picture I took in the past showing chain stretch. I can check the dates from the picture and it is 3 years. Will be chaining chain and trying out the 1.5 length offset links that are all press fitted already. No tiny cotter pin.

I have not removed the chain yet to see if it is as much stretch as last time, but think prior period was 3 years on a chain doing off-road trail riding.

https://motorbicycling.com/attachments/cam39256-jpg.96915/

 

[Ralph hop]

Do those types of links skip a tooth? One trick I like to do is use the shank end of a drill bit to line up the chain on the other side of the breaker when replacing pins. Then peen the pin with a flat punch against a vice or piece of railroad I use as an anvil.

 

[MEASURE TWICE]

Chain sticking/clicking/grinding...Need help!!
Discussion in 'Instructions for Building and Repairing Motorized ' started by fadam00, Mar 3, 2020.

Excerpt from above thread (look at Diamond Offset Link has 3 rollers)
===============
Just wanted to add that I use half link and a master link. I found it helpful since my engine platform I made only has a little adjustment. Once a chain is worn stretched, it is looser and may try to jump. I had had replaced the chain about 2 years ago. I lubed it and check tension, but this last time I notice the half link was not straightening out after it was no longer on the teeth of either sprocket. My plan was and still is to get a new half link to replace it. Though I saw a type the call a 2 pitch offset link. No cotter pin and is recommenced over the half link. Looks like I will use the chain breaker on my chain to use this offset link which is longer by 50% comparatively. But by removing one link of the regular chain and adding this link you achieve the same half link addition that is stronger.



https://www.diamondchain.com/faq/what-is-a-roller-chain-offset-link/

https://www.ebay.com/itm/NEW-DIAMOND-OFFSET-S-S-STAINLESS-CHAIN-LINK-35SS-GAU-1282-P-GAU1282P-LOT-OF-9/231223655139?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

The one below has a better picture, not in the bag. This though is not the 35 chain type I use. The one above is.

https://www.ebay.com/itm/NOS-DIAMON...385415&hash=item260f403d7b:g:nRIAAOSw65FXqJ5z

#23 MEASURE TWICE, Mar 15, 2020
Last edited: Mar 15, 2020

 

[indian22]

Now really is a good time to determine how you will achieve a straight chain line on both sides of the bike and how to easily run the correct chain tension of both through a full 360 degree wheel cycle. Your frames axle drops aren't designed for any adjustment and try as you might with combinations of half links and master links & with motor mount adjustments to offset wear and stretch; chains problems are going to keep you busy.

Your rear axle drops are the type used for multi-speed cassettes, think 21 speed etc. MB's or road bikes, and are only practical when used with spring tensioner, even with a single speed setup

Rick C.

 

[Ralph hop]

Got the steering sorted and I'm confident these bars and forks are staying put! I made a quill bolt from some hard stainless all thread and had to use a cut off wheel instead of a hacksaw to cut through it. It works like a normal quill bolt except after the bars are tightened the bottom is tightened. The bearings are buttery smooth and I'll be adding a steering damper shock soon, mostly to keep the forks from crashing the tank and because it'll look neato.

 

[Ralph hop]

Spent the afternoon today working on the bike but there's not much that's show worthy. There's a big cold front that is forcasted to stick around for awhile but that is fine with me since the oaks are pollinating and that's the one that gets me every season. I started off making a bracket for the oil catch can which has a clamp on design, then decided to move the motor down some more and tilt it back some so it's riding more level. Picked up a pulley and a bolt for the clutch. The pulley is just mocked up in the bottom bracket bearing.

 

[Ralph hop]

Oil catch mount.

 

[Ralph hop]

Plumbing pieces came in today so I got to install my "custom exhaust". All stainless steel including the exhaust manifold with 3/4" npt thread. Got a nice deal on some brass lock nuts also. I'll probably put a muffler on it for a more relaxing ride. Maybe have two different pipe nipples, one with a tip cut on the end and another with a low tone muffler. Still waiting on a barbed brass connector for the oil catch tube. There's an inadvertant theme going on with brass, dull metal, and chrome that I didn't really plan at first but I'm gonna stick with it.

 

[Tony01]

Lookin good. For the front mount it’s better to go with a solid piece as short as possible, ie horizontal. I cut a piece of tubing, flattened it on the ends and drilled holes. I used a heim link in the past which would eventually wear out.

 

[Ralph hop]

I thought that might be the case. I like having some adjustment so I've thought about building an end link type of arm and to make a bracket that anchors to the TAV bolt holes also. There's still some gap on the rear mounts so I'll be making a beveled shim from an aluminum strip with a belt sander.

 

[Tom from Rubicon]

Looking good Ralph, where did you find the 3/4NPT manifold? That is totally trick a$$.
Tom

 

[Ralph hop]

Amazon but also eBay. Found by searching predator exhaust flange. I think it was around twenty bucks.

 

[MotoMagz]

Looking good Ralph, where did you find the 3/4NPT manifold? That is totally trick a$$.
Tom

https://www.ebay.com/itm/Predator-7...rsOtherItemsV2&_trksid=p2047675.c100047.m2108

 

[Ralph hop]

I hadn't seen the 79cc flange, thanks for sharing.

 

[MotoMagz]

I hadn't seen the 79cc flange, thanks for sharing.

I thought that was a 79cc with the flange. I’m confused.lol love the bike the stainless looks great.

 

[Ralph hop]

The motor does look small in there. It has a 3/4 shaft and it's wide as heck so must be a 212. It's an older one, non hemi.

 

[MotoMagz]

Ya I forgot you had the bigger frame. I was also thinking of Tom who has a 79cc..lol loosing my mind!