Ferrouscious 

I posted this on the Classics Rendezvous Google Group and was met with what I perceive to be confusion and "why?!". I did not include this diagram I just drew in the first post. I will be keeping up with both threads and updating both as such. As for the idea, see below background:

I was researching my next wheelset I'm planning to build and ran into a slight roadblock. I planned to use Kinlin XR-200 rims, but the highest drilling they come in is 28 hole. I was also intending to use a freewheel hub as I rather like my Suntour freewheel. When I searched eBay for fitting hubs, they were all "quite expensive" (relative to the rest of the wheelset plan), but all the cassette hubs were dirt cheap. I also wanted to use cartridge bearings as I can order in obnoxiously high quality bearings. I got to thinking about converting a Shimano freehub (the only brand I've pulled apart that would work AFAIK) to a freewheel hub. Here's what I came up with:

*I am aware that I could wait and eventually find what I need, or ask around for the right hubs (I have other options lined up), but now I just want to know if this is possible. Plus, I think it's freaking cool. I could probably 3D print a model at school, but I want to finish the idea first. I also have my local LBS interested and have access to their stock of old hubs.

ratfink76

This looks like it could be something found on this website: https://problemsolversbike.com/

I've often turned to them for solutions in the past... maybe they'll build it with you!

Danny S

Rube Goldberg LIVES !

mpetry912 

as I said to the OP in a PM, almost anything can be done if you have access to a machine shop.

The drawing looks fine but it does not take into account the wall thickness of the hub shell once you start removing material. e

consider for a moment how much force you are going to be applying at the interface betw. the cassette ratchet and the hub shell.

Simplest way to solve this problem is to find a 28h rear FW hub. You can probably find one for under 100 bucks.

I could imagine machine shop costs running to many times that. I'd be concerned about reliability too. Would such a mod fail miles from home ?

good luck on this.

Mark Petry
Bainbridge Island, WA USA

masi61

I can’t be of any any real assistance but I like how you think!

Not sure about the feasibility of putting sealed bearings into Shimano hubs though. While I’m sure you could get rid of the cones and the loose bearings, this could get really technical fast and require a complete re-engineering of what is already an incredibly durable, well engineered product.

As to a converter that will allow you to mount a freewheel onto the freehub splined mount, this sounds very interesting and I wish you great results in accomplishing it. I can see your logic in wanting such a product.

Now if I could only find someone who is re-manufacturing (via CNC machining or 3D printing) Dura Ace 7400 freewheel cogs and spacers, I would be overjoyed. Same with Uniglide cassettes.

Ferrouscious 

Yeah, that isn't gonna happen. This system would be cup & cone on one side and cartridge on the other.

squirtdad

Wny? this seems overly complicated, expensive, with no real benefit, no market demand and no technical advantage.

it does not adhere to the key principal of engineering, coding and life: K.I.S.S (Keep It Simple S (sillly or stupid)

cone and sealed bearing is a good example

If you want to do just because....more power to you, but don't think you are coming up with better, durable solution

randyjawa 

Even with the diagram I still cannot help but wonder why? Is it just a dollars and cents thing, then I get it but I question the rational when cost effectiveness is the issue. If it is the challenge of doing it, that I can understand. That said, I tend to agree that too much metal would have to be removed from the hub, perhaps rendering it either undependable and/or unsafe.

mpetry912 

here's a 28h Mavic rear hub asking 40 buck on eboy. these are very nice hubs.

https://www.ebay.com/itm/Mavic-501-R.../352698593553?

what's the over locknut dimension ?

Mark Petry
Bainbridge Island, WA USA

seypat

So you're trying to build a wheelset around a freewheel?

What's so special about that freewheel? Why don't you just find a freehub/set of hubs that will go with the rims and get a cheap cassette? When I check online it says that rim comes in a 32H. If that's the case, I'd go 32rear/28front or 32h on both. Get some decent hubs and a cassette from the Bay and call it a day.

Ferrouscious 

There is nothing special about the freewheel. The issue I run into is that Hyperglide cassettes shift TOO well. Part of that is due to the downtube shifters having a large barrel. If there are cassettes without shift gates (aside from Uniglide, which is getting expensive for me), I want in. I am aware of demultiplicators, I just don't really want to use one. The other bit is I just want to work this out. I've set my mind on seeing this through. I most likely will buy a set of 126mm 28 hole freewheel hubs. Plus, other people (including the LBS and some of my teachers) are interested as well. Lastly, I'm still young so this is an excellent test of applying my knowledge and resources to something I enjoy. I'm getting a bit tired of explaining why I'm doing this. I'll be measuring some hubs when I get home, so stay tuned.

non-fixie 

I perceive the same thing here.

Go for it and make this the most interesting thread of the year.

seypat

You should have noted that this is a engineering project and not a getting a bicycle ready to ride project. There is another thread going about trying to put an extra sprocket on a Campy rear hub. You should read that thread and compare notes with the OP. It might be helpful. Good luck.

Dave Mayer

Dura-Ace freewheel cogs? Uniglide cogs from lesser Shimano freewheels such as 600 and Sante - or even lower fit.

Or you can make your own cogs by disassembling a recent HG22 or 37 Hyperglide freewheel, and after a few minutes of grinding each cog, they slide right on.

The Hyperglide cogs sure shift better than the clunky Uniglide ones ever did.

Dave Mayer

So I assume the O.P. Is looking for a freewheel hub with cartridge bearings. Mavic immediately come to mind; I have several pounds of these NOS - somewhere. Plus more than a few Suntour Superbe Pro hubsets.

So take a Dura-Ace or Record freewheel hub. These have 28.0mm diameter (bore?) where the 2 cups are pressed in. This matches the diameter of a 6001 cart bearing, which has a 12mm I.D. The removal of the old cups and installation of the carts takes the same tools and techniques as replacing cart bearings.

I've done this before in order to recover an old Record hub. But I don't know why anyone would prefer cartridge bearings in hubs when loose-ball angular contact balls (cup and cone) are superior in every respect.

Note that lesser freewheel hubs have a smaller diameter bore, so this hack doesn't work.

Ferrouscious 

Yes, I was looking at a set of Mavics on eBay. I should have mentioned that this was more of an engineering project, but it still has the potential to be cost effective (no matter how unlikely).

JohnDThompson 

Much as I like my freewheel hubs (I don't actually even own any cassette-type wheels), I have to agree. The only advantage I can see is that it would allow mounting a modern cassette on a vintage hub, and even that is a dubious advantage. Freewheel-type hubs have a weakness: broken axles, and this weakness gets more pronounced the more cogs you try to pile onto the hub. My experience is that anything more than a 7-cog cluster becomes problematic on a freewheel hub. Cassette hubs allow locating the drive side bearing further outboard, avoiding the weakness of the freewheel hub supporting wide clusters. And given the ready availability of 7-cog freewheels, even with modern, smooth-shifting "Hyperglide"-type tooth profiles and affordable cost, I can't see much reason to pursue this idea.

canklecat

Coincidentally I was looking for something like this a year or so ago, just out of curiosity. I was surprised it didn't exist, or wasn't available any longer.

So, there's at least one other fan of clever engineering that doesn't necessarily solve a problem for most folks.

Besides, sometimes a cleverly engineered but useless doodad can strike a spark for another project... then another...

Ferrouscious 

This "contraption" (adaptor) would actually do the opposite: Convert a cassette hub to use freewheels. As I mentioned before, I want this to "worsen" my shifting (ghost shifts are an issue for me with modern stuff). The freewheel is 7-speed and I am 140 lbs. Bent axles are a non-issue.

I'll be meeting with an engineer who has some CAD stress testing experience in the next couple weeks. I'll bring parts with me. If all goes well, I'll consider calling Problem Solvers to see what they think of it.

madpogue 

You used line paper turned sideways? You must not have had a napkin handy....

Why do you have "shorten axle" in there? Yeah, the spacers will be completely different, but the OLD will be unchanged, no?

Seems to me this contrap.... er.... invention would locate the freewheel further outboard than its cassette predecessor would be, or a freewheel on a conventional freewheel hub. Will that cause any chainline and/or clearance issues? Maybe the whole thing will need to be smaller, and the freewheel threads will be almost "on top" of the area tha engages the freehub base. Question then is - would that provide for enough thickness of the body of the device to be as strong as it would need to be?

mpetry912 

there have been several attempts in the marketplace to have quick - detach freewheels or cassette.

Cinelli Bivalent for example (I have a set) or this one Home - Liberty Wheel Systems

they all seem to fail because there's so much force on that hub to sprocket (whether cassette or freewheel) interface that you can't give it enough surface area to avoid wear.

The advantage of cassettes is that the outer end of the freehub carrier has a bearing to absorb the force. this gets around the cantilevered load of the freewheel design with it's thread on interface.

what the OP has proposed MIGHT be an interesting exercise if you were an expert machinist (because otherwise you're paying shop time).

My suggestion is - let's go back to the original problem statement. what exactly are you trying to accomplish here. I heard over-shifting. that could be an adjustment problem.

I wish you luck with this ! but I think you are embarking on a voyage of discovery that may end up leading back to where you started.

Mark Petry
Bainbridge Island, WA USA

madpogue 

Well, the Helicomatic combines a secure fitment between the freewheel and hub (helical splines) with a significantly lower torque locking mechanism than the Shimano (et al) freehub/cassette or the early Suntour cassettes that relied on the smallest cog as the locking part. The tool is thin enough to fit in a jersey pocket and requires no leverage handle or arm. Its shortcoming was the small bearings it employed. If they had gotten around that, and of course if they had the market penetration that Shimano was quickly gaining BITD, it could have become the dominant design. 'Course, it doesn't provide the front/rear interchangeability that the Bivalent and its counterparts do (IIRC, there were others), but that's a separate question.

Ferrouscious 

I would shorten the axle in case I used a 130 OLD hub. Otherwise, yes, the axle length would stay unchanged. Clearance issues? Naah, my frame has enough extra room that I can run a 128 8-of-9 setup with relative ease. I am uncertain how much this would shift the freewheel over, but it shouldn't be more than a couple millimeters. It would be tight, but so is 10 speed. To answer your strength question, honestly, I have no idea. I need to measure more parts and build a CAD model. Only then can I run stress tests. Aluminum alloy would be ideal, but steel could also be substituted. In regards to "rapid wear of the system", there shouldn't be any. This is not intended to be something you swap out each week; this is much more permanent. I wouldn't want to leave on a freewheel for a couple decades though.

ryansu

Seems like a doing it because its there thing or a solution looking for a problem but if its keeping you off the streets then why not

masi61

There was a company in California in the 1980’s-1990’s era making some high quality hubs of their own unique design called “Winner”.

I checked eBay and there aren’t any on there to reference to right now.

But I mention them because they made their rear hub in multiple freewheel body or freehub body configurations. I picked up a Uniglide 8 speed hubset cheap and later picked up a rear hub only that has its own Dura Ace freewheel body on it to accept freewheel 7 speed sprockets. These hubs were very well made.

I never actually made one up into a wheel yet. These were zero backlash freehub/freewheel body designs that did not use pawls. Instead it used roller bearings in a ramped configuration where they would stop rotating freely when in drive mode but when coasting they would silently freewheel like butter. But as soon as you start pedaling they lock up near instantly.

It it was a great idea that never caught on. I guess the Achilles heel of the design that the buttery freewheeling action was a fair weather situation only. As soon as you rode in the rain (from what I read), the internals would get mucked up and cease working in a pristine manner and become gravelly.