Hi,

I'm trying to replace an old Shimano Front Freewheel bottom bracket with a new one. My only problem, is that I can't figure out how to take the stinkin' chainring off the freewheel mechanism, so that I can put it on the new freewheel mechanism (yes, I have a completely new FFS BB to install here). Is there a spline tool that fits on the freewheel to "unscrew" the chainring? I'm not familiar with this type of chainring.

Thanks for your help!

No such luck. It's a 3-piece crank, yeah, but the rings are permanently affixed to the right arm. Just replace as a unit. BTW this is the same BB diameter as the Ashatabula arms, the bearing races screw in to the BB. It's freakin yooooge, and completely proprietary; no other crank will fit. On the other hand, the Integer unit considered on its own is a well-thought out solution to not that big a problem: you can shift while coasting. It got a bad rap because it was foolishly married to that necrotic hemmorhoid of an indexing 'system' Positron. It's not a bad crank for what it is, and kind of attractive in its stamped, chromed way.

Welcome to the forums Wheelson,

I am not very familiar with this system but what is posted abouve sounds right, they were odd and not very popular.

I would love to see lots good pics of this. one of my bosses at a bike shop built a fabulous Mixte (I think an '86ish Univeha?) for his wife with system and she rode it about 6 miles. he would not sell it to me (he thought 4 bikes was enough LOL) but did sell it at our sidewalk sale one year.

Thanks for the welcome Bianchigirll!

I don't have a handy pic of the old chainring on the BB freewheel, but I've attached a closeup of my new BB that I'd like to install. You can also see the chainring unit (unmounted) on Sheldon's page: https://www.sheldonbrown.com/shimano1982/pages/35.html

Captain Blight, is the integer FFS really that different from the selecta FFS? The BB I'm replacing appears just like the new BB I've attached a picture of, except I can't see how the chainring unit comes on/off the freewheel. It appears as though it's sandwiched between the 2 rows of teeth pictured in my attachment, I just don't see how they did that. I think someone referred to it as a "snap ring." Is there a special technique here?

The FF concept is neat, but this chainring interface business is silly. A snap-on chainring? Wow. LEGO parts!

I've never seen one exactly like that but it appears from the picture that the ring at the bottom of your picture slides over the spindle and the tabs around the inner hole press against the spindle to hold it together. If that's the case, I'd guess the only way to get the old chain ring off would be to destroy the old retaining ring by bending the tabs back until it comes off the spindle.

Hello,

I found this forum entry doing a google search for information about my KHS Shimano FF. I looked at your picture and it is what I have on my bike.

First, I can help you a bit. The chainwheel internally splined and fits over the splined hub shown in your photo. On my bike a large snap ring fits in the notch in the hub and holds the chainwheel in place. It is easily removed with a pair of small screw drivers once you spot the gap in the ring. Use eye protection. In your photo, I see what seems to be a large nylon ring. I don't seem to have one of these. Could it be a replacement for the snap ring?

Second, can you help me? I have owned my bike since new and ride it nearly every day. The chain ring (front sprocket) and cassette have finally worn out. I can find the correct cassette on ebay, but the sprockets all seem to be from 1 piece crank systems. The sprockets from these don't appear to be interchangeable with the 3 piece design. Where did you fine replacement parts?

Thanks,

Mike -- Phoenix

Hah! Thank you very much! I've neglected it since the previous post here, you've saved me a great deal of time, I see exactly what you mean. The rustyness and greasiness of the unit made it hard to discern the notched ring sandwiched in there. I haven't actually taken it off yet, I tested it with a screw driver and it seems a bit more persuasiveness will do the job.

I found this unit on ebay, NOS (new-old-stock) is continually getting posted all the time. My chainwheel is the "Integer II", whereas many I see online are the previous "Integer" model, which may indeed correspond to the 1-piece crank systems. The chainwheels seem to be the most expensive part being sold online for the FFS. My chainwheel is rather rusted and cracked, I was probably going to take similar chainrings from another bike and machine-fit them to my unit somehow.

In the pictures I see on ebay I notice the notched ring now, and I suspect installation will be the same if the internal spline is also the same. I hope to get one of these 1-piece units sometime myself to play with, I will definitely confirm interchangeability if I do.

Hello,

I'm glad that I could be of some help.

I see at least 3 versions of the FF System on ebay and various bike sites. One is a single piece crank and I am very sure that its sprocket will not interchange with the 3 piece units because of the spline pitch, shape and hole diameter. There seem to be 2 versions of the 3 piece crank. The earlier systems such as mine have six spokes in the sprocket. The later versions have five spokes. The only detailed five spoke photo that I found on the web was from an expired (unsold) ebay listing. The spline count and shape appear the same as for the 6 spoke version, but the diameter is harder to know. The five spoke version may come as a single or double sprocket and I don't know the tooth counts. I would appreciate any additional information anyone might have.

Thanks,
Mike