BackOnJax

Okay, so I'm aware this is probably pretty common but my circumstance is a little extreme.

Because of the unique scenarios in play it's been quite the task to figure out.

Before I start I do want to say that I already looked around and tried finding answers, but none were helpful.

I've been down this adventurous, and first time quest for about 4 months and am running into some things that I would appreciate advice on.


I have a custom built electric/gas hybrid bike. It's sitting on an old steel body triangle frame I found, with two disc-brake mag wheels (been informed on the mood about these), a 24 tooth rear freewheel sprocket, and a newly installed wide arm front crank with a 44 tooth sprocket (the old arms were scrubbing the engine and tearing apart the motors covers).

Only problem is that the new front crank sprocket has caused a near 1 inch offset from the rear freewheel single I have installed in the back.


A little more parts information:

The new crank came with a 10 inch bar, almost 3 through center, approximately 4 on each side.

The sprocket uses a lock bolt that ties it to the bar about a half inch from the center hub.


Tried:

I tried running the chains over some bearings to direct the line but this is proving, complicated, and loading the frame down with brackets and bearings.

I'm looking for something simpler and more efficient.


Any ideas appreciated?

As stated, this is a rather unique concept.


So, in short:

Rear sprocket is a near 1 inch difference from front sprocket, causing the chain to (obviously) run off.

How can I compensate and fix this?






​​​​PS

Normally a DIY, don't ask for help, trial and error type. If more information is needed or i did something wrong, that's because this is a very rare occasion of me asking for help.

veganbikes

This is a bicycle forum. I think you maybe want a motorcycle forum,

BackOnJax

The primary issue is with the pedal sprocket for the bicycle, not the motor. Ironically, I was able to work most the motor issues out by the grace of God.
My issue is related to the pedal sprocket not lining up with the rear sprocket. Forgive me if I wasn't clear enough on that.

veganbikes

No it was clear that is why I said what was said. Generally though if things are misaligned so poorly it is probably because the wrong parts are being used it could be you have the wrong hub or freewheel or your cranks are oddly offset for some reason probably due to the death trap attached to it needing more space because a bicycle isn't designed for gas it is designed to be pedaled.

Yes I did say death trap just to be clear and honest gas belongs in a proper motorcycle that is built to handle a gas motor. Having seen enough conversions in my life and the problems they all have I could not recommend one to anyone at any point for any reason unless they were a true enemy that I wanted to vanquish. Bicycles aren't designed to handle a motor. Plus you then take what could be something I could ride nearly everywhere and turned it into something I can only ride with cars around but since it is not a motorcycle with all the safety features therein it is not going to be very safe and I would not feel comfortable sending someone out on it.

LesterOfPuppets

I'd probably get a freehub rear wheel, good old Hyperglide (HG) style, a singlespeed spacer kit, and a steel Hyperglide rear cog.

This setup will allow you to put the rear cog well outboard of where a freewheel would sit

LesterOfPuppets

Here is an example of a kit.

https://www.modernbike.com/product-2...SABEgJXbvD_BwE

LesterOfPuppets

Hopefully your rear spacing isn't 120

BackOnJax

Thank you so much for the helpful advice!
Unfortunately it isn't a free hub, it screws on? (Sorry, I'm not a bike pro and dont know the term for that.)
That's been my primary issue. I don't really know if there is a way to double the screw on by converting it to the other style, then applying one of these spacers though?

I have already forked a lot into this build and am done with experimenting on trial and error. Hence seeking the advice.

BackOnJax

As much as you have a right to your own opinion, I think maybe you should do some research. Some of the earliest "motorcycles" were built upon bicycles. You know, because "motorcycles" wasn't a thing at that time. Yes, it was back in the "good ol'" steel frame days, admittedly. That said, over time, the frames evolved to even better accommodate the massive amounts of power and vibration that the larger and more boisterous engines produced. This continued for decade upon decade.
That said, my concern has nothing to do with the engine portion of the bicycle in any way.
As anyone can clearly read.
Thank you again for your opinion and concern.

Trakhak

I imagine that I'm not the only one who has tried and failed to picture what you're describing. Photos are crucial.

You can continue posting until you've reached 10 posts (5 maximum per day), at which point you can begin uploading photos in your posts. Or you can upload photos to your Bike Forum gallery and then add a post to this thread asking for them to be retrieved, whereupon other posters can stick them in the thread.

I, for one, would like to see at minimum a reasonably close drive-side photo of the whole bike and a photo from behind, taken at sprocket level, that shows the chain line from the sprocket to the chainring.

veganbikes

I have done research this is a bike forum I have been on for a while, it was never a motorcycle forum. I also have seen enough homebrew kits slapped onto a bicycle not meant to be a a motorcycle and they constantly had issues.

Yes they were built upon chassis based on bicycles a long long time ago. That is less relevant here as whatever you are building was probably not built as a motorcycle chassis or to handle being a motorcycle.

If the question were about bicycles then motorcycles wouldn't be a factor, a gasoline motor wouldn't really be in a bike forum. I wouldn't go to a rose growing form and ask about fixing my weed whacker.

BackOnJax

Thank you so much for the advice. I wasn't aware that was a concept. I'll get to those some time today, I'm currently tinkering around with some pulleys to try and see if maybe I can use them to gently guide the chain into place.
As soon as I am irritated enough with multiple trials and errors, I will stop and do that.
Thank you for the helpful advice!