schristi69

Is there any difference in cassettes between the HG50 and the HG70 models? I am looking to get a 12-28 cassette for my 7spd road bike (42/52 chanirings). Is the only difference the color? Is this a good replacement for my 13-26 6 spd setup?

MrCjolsen

If you currently have a 6 speed setup, then you are probably running a freewheel, not a cassette. Unless you are getting a new wheel, you will need something that threads rather than slides on. Cassettes slide onto a freehub which turns. Freewheels thread onto a sold hub and the turning is in the freewheel. They are not interchangeable.

MrCjolsen

A 7 speed might be either a freewheel or a cassette.

MrCjolsen

This will work if it's a freewheel and as long as you don't have index shifting.

schristi69

Thank you for the replies, but I do know the difference between a freewheel and a cassette. Funny how nobody actually answered the question. The question pertains to the difference between the HG50 and HG70 lines and if the 12-28 7 is a good replacement for the 13-26 6

The current group is Exage Sport 6 sp SIS. Hub is cassette. Yes, building new wheels out of 105SC hubs. Yes I know I wiill need new shifters and derailleurs, bla bla bla. Now, can some one offer an answer tot he original question? Thanks

Torchy McFlux

With 7-spd cassettes:
HG50 = non-plated (brown finish)
HG70 = nickel-plated (dull silver finish)
HG90 = chrome-plated (bright silver finish)

That's the only difference, if I recall correctly.

HillRider

OK, point taken but a great number of new posters do not know the difference and post questions about replacement cassetts for their freewheel hubs so it's understandable that your post was misinterpreted.

JiveTurkey

How does your "7spd road bike" have a "6spd setup?"

Staggerwing

I love 7speed. Can go with a freewheel, on a classic hub, like a Phils, or a cassette with a spacer, on a modern wheel, and it all works fine. I've run both in the same day, and not had to touch the RD adjuster.

Cheap Shimano 7sp freewheels, a Nashbar 7speed cassette, and and now a Shimano HG50 cassette, and have never had any issues. Back up, I did have an issue with an IRD 7 speed freewheel, that needed frequent kerosene flushing, and a dab of 20wt.

I've run down tube and bar end SIS shifters only, with vintage and current Shimano SIS capable derailleurs, with no issue whatsoever.

Some of the more modern stuff gets complicated, 7 speed is not. Only wish it was easier to come by shift levers.

Just do it.

schristi69

It doesn't. The bike has a 6sp Exage Sport group. I am upgrading it to an early 105 (1051) 7 sp group because I do not want to spread the frame.

schristi69

I hear that. I was lucky and found a NOS set of 7sp shifters on Ebay. Found a rear hub that is both Uniglide and Hyperglide compatible and a front hub. Need to find out if a new series double crankset/bottom bracket will work with the 7 sp derailleurs. If not, then that might be the tricky part. I have or can get pretty much get the rest of the parts.

schristi69

Well price. hahahaha Must be the plating that makes them cost more. Thanks

bigdaddy10028

looks like a great replacement. More top end speed and more low end climbing power with nice spacing in between. I assume the 12-28 is 12-14-16-18-21-24-28

HillRider

I suppose 7-speed STIs are rare these days but around me 7-speed downtube and barend shifters are reasonably available while 8-speed is very hard to find.

Tunnelrat81

I agree that it's a nice direction to go. I've got a 7 spd freewheel wheelset, and really wish I could have a 12t cog back there. alas, I'll someday just put a new wheelset on it and get some 9 spd DT shifters and be done with it. Combining the spacer with a 7 spd cassette is also a nice idea in the mean time though...hmm..

-Jeremy

mechanicmatt

9 and 10 speed front cranksets may not be compatible, but 8 and 7 speed cranksets and down should be fine. Most of the older style square taper mount cranks should work up front.

schristi69

One big difference is that the HG-50 cassette is all one unit except for the 12T cog. The HG-70 11-28 I have is one group of 3 cogs and then separate cogs after that. The HG-50 is painted black. It looks so.....cheap. Oh well. You take what you can get. Bought the 11-28 before I realized it was for compact cranks only. Oh well. Up on Ebay it goes. Did find a set of NOS 105 175mm cranks. Think I can use my current chain rings. Having issues finding new ones for 7 speed and 130mm spacing. Bottom brackets do seem plentiful so should be set to start rebuilding this sucker. Need to buy rims and find a wheel builder.

schristi69

Yea. Last time I rode the El Tour de Tucson I ws left wanting on some of the hills. Had to get off and walk. That extra low gear would have really helped.