Carbon fiber frame spliter
 

So being the curious kind, I wanted to try a belt conversion for my bike. Since we have an engineer on hand and a carbon fiber 3D printer we elected to design our own. So here goes ...

This set of carbon fiber frame splitter that require nothing but cutting the upper rear wheel support 1.5 inches. The part are epoxied in place and we used off the shelf JB Weld with great results. So this mod can be performed with minimal tools and costs.

We are still in the final testing phase but will releasing these to the general population and bike shops. With this post we are looking for general feedback on the whole thing.

Thank you to all the community.

Pat

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Yeah, naah. Thanks though.

Ugh. Hopefully you didn't ruin too nice of a frame.

Well, it’s called the “seatstay” for starters, but beyond that it assumes that all seatstays are the same, which they are not, so you would have to produce dozens of different designs. Then, the seatstay is tapered, so the locations of the two cut points would have to be very precise to avoid too loose or tight fit. Frankly, I think your market size is one, namely yourself.

Looking at those rims, I’d venture a guess that it is not.

Not to worry ...
 

The frame was a donor bike that we can do destructive testing on ... LOL

As for the tapered factor the parts can be sanded down to accommodate the different sizes without altering the structural integrity, we can even provide custom made ones for square tubing and all.

I do understand that this is not for your 6k$ bike frame but to allow for those with lesser quality frames to get the benefits of running a belt drive without buying a dedicated new frame.

Thanks for the constructive criticism ... As always.

On a side note, please understand that for many of us it doesn't make sens having a high quality ,pricy and blinggy commuter bike that gets stolen the minute you chain it outside your workplace or school.

I think it's an interesting design. Looks like a fine way to do it IMO. That said, I'm just meh about belt drives. Seems like more trouble than it's worth.

Well then, what's the point of cutting up and installing a belt drive on a beater?

For me it's the convenience of a low maintenance solution that doesn't require regular chain cleaning and also the chain greases up everything i wear when I get the bike up the stairs ... I know it sounds ridiculous but so freaking annoying ...

Again really appreciate the criticism.

Thanks !

Pat

with so much bicycle infrastructure out there compared to america, why do european art students insist on overdoing EVERYTHING when it comes to the bicycle?

Serious question if you are going to sell these...

Who going to pay when they break and cause bodily injury of some kind? What is your liability? No, a waiver is not going to hold up in court.

Install a full length chainguard. Problem solved.

We have been doing 3D printing for the aeronautical industry on top of the motorcycle racing community for quite a while. I think our insurance company is good for it :D

But thanks for asking

Pat

Here's where my concerns would be:

1. Impact on handling and stability.
Seat stay is a load bearing component both vertically, and to a lesser extent torsionally under pedaling load. How does the asymmetrical construction material affect the rear triangle? As you have a full tube of one component on one side, and a cut tube with a different material on the other, will this cause any twisting or deflection of the rear wheel under loads? Additionally, if this is an end user installation, how do you ensure that the end user makes their cuts the proper length, changing the length of the stay and thus rear wheel alignment?

2. Frame warranty.
This obviously voids any warranty on the frame. Will you accept liability for any other frame issues that would have otherwise been covered by the manufacturer?

3. Questions I'd ask if I were an investor... What is the market?
Given 1 and 2, what is the marketability of the product? I can see that it does serve a purpose, and I would maybe entertain doing it on an old beater fixie, but will it be priced low enough to be a viable product? I'm not going to spend $100 to perform this upgrade on a frame thats worth < $400, and I'm not going to cut an inch or two of seat stay out of one that's more than $700. So can you produce it and make money off of it selling it for $25?
Additionally, will shops actually stock it? I think you might have a problem getting it in a bike shop with them knowing they (or the customer) will have to destroy the frame to install it.

I don't mean to be negative. I think it's a good idea and I do think that there is a market for it in some areas, but I think it's extremely limited.

Question 1 : This is still in the developpement stage and if installed properly the impact on the seat stay from our tests is minimal, obviously if you are looking for how much flex difference is there from one triangle to the other it is negligible for the average to medium rider. I would obviously not vote to put this on a higher end frame where higher end wheels and frame flex become a major issue. However, for the discussion the strength of these pieces are higher than a full bar of the same size 5052 aluminium. That said it has very little flex.

Question 2 : Obviously void and no.

Question 3 : This is not a startup by any means and we do not rely on any of this as sustainable incomes ... There are far better ways to make a buck in this world. This I made for myself to begin with but had a lot of request to make more ...

We are going to offer it to the community should they be interested but otherwise it will only for special orders and friends.

Always nice to get feedback !

Thanks

Nah.

I'd be interested to see if the technique could be used to create a breakaway travel frame.

There was someone on here recently with photos of a bike he cut up and clamped together and was touring Japan with it. Think he might have been an Aussie.


-Tim-

oh yeah, the world needs 3d printed s&s couplers. get a new hobby.

Why are "engineers" so detached from the way things actually work on this planet?

Usually because of managers.

C'mon guys. Speedbird is being innovative. I give him credit. Maybe Speedbird's next brainchild will have us all wondering why no one thought of that before. Without dreamers like Speedchild, we might all be stuck riding bikes with only one gear!

Thank you ! Very considerate on your part and yes, the status quo brings no innovation what so ever. Why aren't the purist still riding steel bikes or penny-farthing for all that ... Well, I was expecting all the negative comments and in our field of work we are very used to it and look at it with a constructive eye. Pushing limits and ideas ahead means a lot of shaking peoples views and beliefs and people usually don't like having those shaken. This is what makes change very hard in any part of life.

Again and alway thank you to all for the comments good or bad.

Pat

Personally, I'm just not a fan of people who try to crowdsource market research for free.

The biggest problem is getting good chainline which is more critical with belt drive. With a cheaper frame, and with a destroyed seatstay, it's going to be really hard to keep the belt in line and on the front ring. And what's the cost of components? Who is going to spend 3-400 (guessing) to install on a beater that will have trouble working properly.
Think about how much the back end of a bike flexes when a commuter takes off from a set of lights in the ring gear.

this is perfect for someone who thinks "man, my single speed bike is great, but it's just so high maintenance"

Has anyone noticed that the OP’s modified test bike is still chain drive ?