dura ace cogset question
 

1. Weird item came my way on a mid-late 80's columbus slx frame. It is a dura ace corncob freewheel (not a cassette), Date code is LL (87) and it is a seven speed?

On Sheldon Brown site it says seven speed was introduced in 1986 as 7401, but this freewheel is 7400. Also on the bike was a dura ace 7400 LL bottom bracket. The rest of the bike was a first generation 6400 group. The 600 tri-color stuff with similar date code of 1987. pre dual pivot. I am not sure if the parts are original to the frame or not, but there seems to be the possibility that it is not given the campy drops and the specialized wheelset that was on there. BTW I got two specialized wheelsets this weekend, both very nice and I think the hubs look made by sansin / suntour...

Have any of you seen a dura ace seven speed cog matching this?

2. I also have a set of dura ace STI brifters that were sold to me as seven speed. They seem to have seven clicks (8 speed). Any one know if dura ace was ever seven speed brifters? I recall it being an 8 speed only for the dura ace.



Thanks

STI started with 8 speeds...That's a fact.

I'm lost on your cog question. I had a set of wheels with Mavic hubs & seven speed threaded Dura-Ace cogs...couldn't tell you what the model number was (dat wuz a long time ago!)

I have (and still ride) Dura Ace 7 speed from the early 80's. It is a cassette, though.

The MF-7400 was a 6 speed, SIS freewheel. The MF-7401 was the 7 speed version, as stated by Sheldon. There should be a date code on the outer cone/cover of the freewheel body, though it may not prove much as the two freewheels were manufactured concurrently for a while. It sounds like someone tried some creative mxing of cogs, spacers and freewheels bodies.

As stated by the previous poster, the original Dura-Ace STI Levers were 8 speed. The levers are designated ST-7400 and if you peel back the outside of the hood, at the handlebar end, you will see the marking. The date code is on the opposite side of the lever body and a bit higher up, so you will have to peel back the hood a bit more to see it.

I have in my hands right now, labeled "Dura Ace Shimano MF-7400 7S Japan VIA", a 7 speed freewheel with 12/13/15/17/18/19/21 cogs.

Based on the link provided by OFG, it appears that the outer cog may thread onto a special cog, to convert a 6 speed to a 7 speed? So maybe Shimano re-engineeried the MF-7400, 6 speed into a 7 speed and dropped the MF-7401, 7 speed? Just speculating, as my literature shows a MF-7400, 6 speed and a MF-7401 7 speed.

The ratios still appears customized. Shimano's standard 12-21T, 7 speed product was 12-13-14-15-17-19-21T. The replacement of the 14T by an 18T is a new to me.

I have exactly what vpuiva has, except mine is what T-Mar says, 12/13/14/15/17/19/21. But I can't find a date code anywhere.
This is getting interesting.

I just re-visited my literature and noted that the original MF-7400 freewheels had a minimum 13T. Based on the body diameter, it doesn't look like they could handle a 12T. Given that the 12T cog appears to sit outboard of the freewheel body and appears to be screwed onto the position 6 cog, it really does look like Shimano adapted the old MF-7400 body to a 7 speed capable of handling a 12T.

I vividly remember those freewheels. The secong cog was very very expensive.

the first cog says 7400 date code LL and MF (Multi freewheel) and 7s for seven speed.

I found one on evil bay with what looks like a 7401 code. Thanks for the clarification. It's in great shape from a wall queen. Can't decide if I am going to evil bay it or keep it yet!

I dont why people trash Ebay. If it wasnt for them we wouldnt be able to find or sell a fraction of the parts we need or have. Its not cool or trendy....and it may be against forum rules

lighten up, I love evil bay! What the hell else does it stand for... no one ever told me. Honestly some will get there underwear in a bunch over anything.

I never get my underwear in a bunch......I dont wear any.