A question about Cassette's

Quoted post said:

Originally posted by Walrus
I want to change the cassette on my bike, but I don't really know what I'm doing. I'd appreciate your thoughts?

I have a Shimano 7 speed 11-19 cassette. My chainstays have "Hyperglide" markings on them. The guy who had the bike previously set it up for time trails, and I find that 11-19 just doesn't allow me to climb comfortably.

I found an item on ebay which is a brand new HG90 13-23 Shimano Hyperglide cassette. I reckon that would help me whole lot. cgi.ebay.comeBayISAPI.dllOpen ↗

My questions are:

• Is this the right product?
  
• I can also source a HG70 12-28 cassette. Considering my smaller chainring is 42 rather than the standard 39, should I opt for this ratio to give me easier gears on hills?
  

Cheers
Walrus

chainstays(chainrings ?) Tell you nothing about what's on the back. You could have a hyperglide casette,a uniglide casette or a 7 speed freewheel.None of which are interchangable.And all that assumes what you have on the back is even shimano. Take the rear wheel off and if the casette lockring says hyperglide, or HG,then your job is easy. The 23 will help a little .A 28 will help alot more but there will be bigger jumps between gears. A switch to a 38 or 39 tooth BCD small ring is a inexpepensive option. too. If what you have is 7 speed, then you have to buy a 7 speed.

Thanks I'll have a look tonight. I have also considered changing to a 39 chainring, but will do the cassette first.

Quoted post said:

Originally posted by boudreaux
Take the rear wheel off and if the casette lockring says hyperglide, or HG,then your job is easy. The 23 will help a little .A 28 will help alot more but there will be bigger jumps between gears. A switch to a 38 or 39 tooth BCD small ring is a inexpepensive option. too. If what you have is 7 speed, then you have to buy a 7 speed. [/B]

BCD is the mm measurement of how far the mounting bolts are apart. A 39T c/ring will fit on a 130mm BCD crank. A 36T ring will fit on a 110mm BCD crank.

You may have to pull your old cassette apart to put in the new cogs (you can use 8, or 9 spd cogs in a pinch). You may have to grind the heads off the 3 rivets holding it together, and punch them out, or unscrew 3 little bolts. Re-use the old spacers, as 7 spd is a big difference to everything else. If it is Uniglide (all even splines with a threaded small cog), you are in a little trouble. You can file the odd spline off HG cogs on the inside and re-use the locking cog, or get your wheel retrofitted with an 8/9 spd freehub body/axle kit, your wheel redished, new shifter and frame respaced. Aaagh!

BTW, cassettes (plural), not cassette's (possessive).

Good luck
mh

Quoted post said:

Originally posted by mfhor
BCD is the mm measurement of how far the mounting bolts are apart. A 39T c/ring will fit on a 130mm BCD crank. A 36T ring will fit on a 110mm BCD crank.

You may have to pull your old cassette apart to put in the new cogs (you can use 8, or 9 spd cogs in a pinch). You may have to grind the heads off the 3 rivets holding it together, and punch them out, or unscrew 3 little bolts. Re-use the old spacers, as 7 spd is a big difference to everything else. If it is Uniglide (all even splines with a threaded small cog), you are in a little trouble. You can file the odd spline off HG cogs on the inside and re-use the locking cog, or get your wheel retrofitted with an 8/9 spd freehub body/axle kit, your wheel redished, new shifter and frame respaced. Aaagh!

BTW, cassettes (plural), not cassette's (possessive).

Good luck
mh

Thanks MH, though your middle paragraph made absolutely no sense to me, as I'm a newbie to this stuff 😉 . I think I'll check for the HG marking, then head in to my local shop and chat to them about fitting it for me. I appreciate your time in explaining things to me.

Cheers
Walrus

Quoted post said:

Originally posted by Walrus
Thanks MH, though your middle paragraph made absolutely no sense to me, as I'm a newbie to this stuff 😉 . I appreciate your time in explaining things to me.

Cheers
Walrus

Actually it was just a brain dump,and of no value to a newbie,and of little use to anyone else unless they have boxes full of miscellaneous junk lying about. Easier and probably even cheaper to just buy a suitable 7 speed casette and be done with it.

Quoted post said:

Originally posted by boudreaux
Actually it was just a brain dump,and of no value to a newbie,and of little use to anyone else unless they have boxes full of miscellaneous junk lying about. Easier and probably even cheaper to just buy a suitable 7 speed casette and be done with it.

I'll do that, then maybe even look at replacing the smaller chainring.

🙂

Quoted post said:

Originally posted by boudreaux
Actually it was just a brain dump,and of no value to a newbie,and of little use to anyone else unless they have boxes full of miscellaneous junk lying about. Easier and probably even cheaper to just buy a suitable 7 speed casette and be done with it.

This is where all the abusive technically-challenged home mechanics lurk, is it?

You can do all the above with any 8 speed cassette.

Have you tried getting hold of a 7 spd cassette in a particular cog combination lately? Just hold back your incredulity a little, and take the advice in the spirit it was given, i.e., free of any egotistical impulse to stake a claim for technical superiority.

When someone corrects your technical error, get over it, get on with it, and learn where you went wrong. Don't spend time venting spleen at the people who pick you up for making an error, and confusing "newbies" with inaccurate information (BTW, you were the one who brought up Uniglide). If newbies want to have a go, good on them, but they should know what they're getting themselves in for. Take it or leave it, at least my advice was accurate.

MH

Quoted post said:

Originally posted by mfhor
BCD is the mm measurement of how far the mounting bolts are apart. A 39T c/ring will fit on a 130mm BCD crank. A 36T ring will fit on a 110mm BCD crank.

You may have to pull your old cassette apart to put in the new cogs (you can use 8, or 9 spd cogs in a pinch). You may have to grind the heads off the 3 rivets holding it together, and punch them out, or unscrew 3 little bolts. Re-use the old spacers, as 7 spd is a big difference to everything else. If it is Uniglide (all even splines with a threaded small cog), you are in a little trouble. You can file the odd spline off HG cogs on the inside and re-use the locking cog, or get your wheel retrofitted with an 8/9 spd freehub body/axle kit, your wheel redished, new shifter and frame respaced. Aaagh!

BTW, cassettes (plural), not cassette's (possessive).

Good luck
mh

I looked at the cassette last night and it has Hyperglide written on it nice and clearly. I'll have a chat to a local dealer and book the old girl in for upgrade.

Thanks for the advice everyone.🙂

Quoted post said:

Originally posted by mfhor
.........at least my advice was accurate.

........and the posters resoponse was: D'oh? Simple answer is always easiest. There are plenty of 7 speed casettes around.

Quoted post said:

Originally posted by boudreaux
........and the posters resoponse was: D'oh? Simple answer is always easiest. There are plenty of 7 speed casettes around.

You're right about the availability of 7 speed cassettes. I found heaps on eBay and my local dealer can get any combination of ratios for me.

Quoted post said:

Originally posted by Walrus
You're right about the availability of 7 speed cassettes. I found heaps on eBay and my local dealer can get any combination of ratios for me.

Yep....and a new chain would probably be a good idea to go with it,since depending on how your old chain was sized,you might need more length for the bigger cogs. An inexpensive sram 8 speed chain works well.

Quoted post said:

Originally posted by boudreaux
Yep....and a new chain would probably be a good idea to go with it,since depending on how your old chain was sized,you might need more length for the bigger cogs. An inexpensive sram 8 speed chain works well.

One thing I thought about was the size of the derailleur. If I'm increasing the size of the cogs, could there be a problem with that?

Quoted post said:

Originally posted by Walrus
One thing I thought about was the size of the derailleur. If I'm increasing the size of the cogs, could there be a problem with that?

7 speed Shimano RD except Dura Ace were speced for a max cog of 28 I think and usually handle more.

Quoted post said:

Originally posted by boudreaux
7 speed Shimano RD except Dura Ace were speced for a max cog of 28 I think and usually handle more.

Thanks boudreaux 😉

Quoted post said:

Originally posted by boudreaux
7 speed Shimano RD except Dura Ace were speced for a max cog of 28 I think and usually handle more.

It can only handle 28 in all the instances I've tried. Why would you want more than 28 on a double ring setup anyway?

A chain would be a good idea.

MH

Quoted post said:

Originally posted by mfhor
Why would you want more than 28 on a double ring setup anyway?

I wouldn't😕. I just thought given I'm going from 19-28, it mightn't fit, but it appears I should be fine.

I just ordered a 12-28 cassette, should have it fitted in the next few days. Thanks for your assistance everyone.