7 and 8 cassettes compatibility.
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Let me introduce myself I am a 44 year old teacher -who loves biking. writing from Buenos Aires, Argentina.
I own a 21 speed bicycle (raleigh mtb). It has a 7 speed shifter (Shimano EF-29-7). Crankset is a Shimano FC-TX71 (28, 38, 48 teeth). Rear derailleur is a RD-M340 -Acera- and the hub -cassette- is a Shimano HB-M495 (Alivio). Cassette is a Shimano CS-HG30i. It is a 7 speed cassette with a spacer. This because the hub is for 8 speed cassettes.
Right now, I have to change the cassette and chain. Some people recommend installing an 8 speed cassette such as the CS-HG50 8i (Alivio). They say the only limitation would be that I wont be able to access Cog #1 (the biggest). If that is the only problem, I never use that cog anyway. I use mostly cogs # 4, 5 and 6. So I don't care. But...
I am not sure (some people says yes and some others say no) if the space among cogs is the same for both cassettes (7 and 8 speed respectively). Is the space really the same? Will my shifter work ok. If true, I would like to install both CS-HG50 cassette and CN-HG50 chain.
So, let's go to the point: What would you recommend to me?
Note: I am always talking about Shimano products since here is almost impossible to get Sram articles.
Thanks in advance. I will be expecting your answer.
Best regards,
Glore2002.-
I suggest getting 8 speed Cassettes, there are more to choose from, a 12-25 for example.
You could change your shifter/lever set to an EF-50 8 speed, they retail in the (AUD)$50 range.
I have used 8 and 7 speed componets on the same bike.
See: http://www.cyclingforums.com/t363004.html
If you keep the 7 speed shifters and use an 8 speed cassette, then you can choose the range, by using the upper or lower limit screws, which sprocket to lock out, the biggest one or the smallest one.
I suggest getting 8 soeed Cassettes, there are more to choose from, a 12-25 for example.
You could change your shifter/lever set to an EF-50 8 speed, they retail in the $50 range.
I have used 8 and 7 speed componets on the same bike.
See: http://www.cyclingforums.com/t363004.html
If you keep the 7 speed shifters and use an 8 speed cassette, then you can choose the range, by using the upper or lower limit screws, which sprocket to lock out, the biggest one or the smallest one.
Thank you George!
Very clear explanation.
I will then go for an eight speed cassette locking out -most probably- the biggest sprocket (which I never use).
Thanks again,
German.-
In order to add more data to the discussion...
I finally found the difference. An eight speed cogset has a space of 4.8mm between two cogs while a seven speed cogset has a space of 5mm. Almost the same but not the same.
Source of information: Mr. Sheldon Brown.-
In order to add more data to the discussion...
I finally found the difference. An eight speed cogset has a space of 4.8mm between two cogs while a seven speed cogset has a space of 5mm. Almost the same but not the same.
Source of information: Mr. Sheldon Brown.-Can you post the link. I think you will find that is for spin-on Freewheel, not freehub.
When I buy 7/8 speed Cassettes Sunrace (for Shimano) the fixed sprockets are all the same, just the loose ones change.
Hello Again George and thanks again for your valuable cooperation!
It was not a link, it was an email I've sent to Sheldon Brown that he answered Let me copy and paste the lines of the mail that matter (what he answered is in bold):
...
I own a 21 speed bicycle (raleigh mtb). It has a 7 speed shifter (Shimano EF-29-7). Crankset is a Shimano FC-TX71 (28, 38, 48 teeth). Rear derailleur is a RD-M340 -Acera- and the hub -cassette- is a Shimano HB-M495 (Alivio). Cassette is a Shimano CS-HG30i. It is a 7 speed cassette with a spacer. This because the hub is for 8 speed cassettes.
I have to change the cassette and chain. Some people recommend installing an 8 speed cassette such as the CS-HG50 8i (Alivio). They say the only limitation would be that I wont be able to access Cog #1 (the biggest). If that is the only problem, I never use that cog anyway. I use mostly cogs # 4, 5 and 6. So I don't care. But... I am not sure (some people says yes and some others say no) if the space among cogs is the same for both cassettes (7 and 8 speed respectively).
Is the space really the same?
Not the same, but fairly close. 7-speed is 5 mm, 8-speed is 4.8 mm.
Will my shifter work ok?
It can probably be made to work, but why buy a more expensive cassette that won't shift as well as the cheaper one?
If true, I would like to install both CS-HG50 cassette and CN-HG50 chain.
I recommend the Sram PC-58 chain
So, let's go to the point: What would you recommend to me?
Shimano 7-speed.
--------------- End ---------------------
George, In order to tell you the truth, I am getting a little confused now. Should I go for the 7 speed cogset or for the 8 speed one? :-)
Thanks.
German.-
7
I won't argue with "The Captain" ;)
Well I'll be... I had always thought that 7 and 8spd have the same spacing. The chain is the same width for either. Sounds like the answer is: use a 7spd cassette if you can get it easily, or use an 8spd if not.
George, I was thinking about it and -for me- your first reply sounds the best. I better change cogset and shifters too. Today I will see how much a shifter is here (Buenos Aires) and let you know what happened.
Thank you very much,
German.-
Well I'll be... I had always thought that 7 and 8spd have the same spacing. The chain is the same width for either. Sounds like the answer is: use a 7spd cassette if you can get it easily, or use an 8spd if not.
You're right! Thanks. :-)
German.-
Your current EF29-7 direct replacement would be:
ESTEF50P8AL ST-EF50 EZ-FIRE STI SET ALTUS 8-SPEED BLACK $
ESTEF50P8AS ST-EF50 EZ-FIRE STI SET ALTUS 8-SPEED SILVER $
I have a spare set of the silver here at the moment. :)
Your current EF29-7 direct replacement would be:
I have a spare set of the silver here at the moment. :)
That would be a good opportunity to visit Australia!!!! :D
Those are the shifters I was looking for. I guess they should work ok with the crankset (FC-TX71); rear derailleur (RD-M340 Acera) and the Cogset I am planning to get (Alivio HG 50). My hub is an Alivio M495.
Here those shifters are around u$s 20.- Acera ones are around u$s 27.- and Alivio ST-M405 are around u$s 35.- (American Dollars) but I am not sure if they are much better than EF50. What do you think? :confused:
After work, I will go for the things I need: Shifters, Cogset (around u$s 15.- and chain (HG-50) which is about u$s 8.-
Thanks again George for your support!
German.-
Hello again!
This is what I did:
I installed a new 8 speed Cogset (HG 50), a new pair of 8 speed shifters (Alivio), new chain (HG 50) and I also replaced cables and housing. I made it myself and I feel proud of that :) !
Now I have a 24 speed bicycle. I have to test it but I hope it will go fine.
I want to thank you friends for the help I received from you.
Have a nice week,
German.-
Well done!! ;)
Next, look at the tyres if most of your riding is on paved roads and paths. Continental Sport Contact 26x1.3 are an excellent choice. We have a MTB slicks topic here in Aus:
http://www.cyclingforums.com/t291662.html
Hello again!
This is what I did:
I installed a new 8 speed Cogset (HG 50), a new pair of 8 speed shifters (Alivio), new chain (HG 50) and I also replaced cables and housing. I made it myself and I feel proud of that :) !
Now I have a 24 speed bicycle. I have to test it but I hope it will go fine.
I want to thank you friends for the help I received from you.
Have a nice week,
German.-
I don't want to be a bastard, but, given that you were replacing chain, cassette and shifters with new, and you already had an 8/9 spd hub, you could have gone 9spd.
I don't want to be a bastard :D , but, given that you were replacing chain, cassette and shifters with new, and you already had an 8/9 spd hub, you could have gone 9spd.Not so, TX71 cranks won't take a 9 speed chain, so, he would need a complete Deore Group Set. :eek:
Not so, TX71 cranks won't take a 9 speed chain, so, he would need a complete Deore Group Set. :eek:
Are you sure, George? My 1990-era Deore DX triple crankset (7spd) takes a 9spd chain just fine. Are there fundamental differences between various 7spd cranksets?
Are you sure, George? My 1990-era Deore DX triple crankset (7spd) takes a 9spd chain just fine. Are there fundamental differences between various 7spd cranksets?Yes! Next time you see a CRX4 Giant, have a look at the TX71 Crankset. No way you would put a 9 speed super narrow chain on that. :eek: A HG 50 chain is the narrowest I would recomend.
Your old Deore will be alloy and built up to a much higher price.
Yes! Next time you see a CRX4 Giant, have a look at the TX71 Crankset. No way you would put a 9 speed super narrow chain on that. :eek: A HG 50 chain is the narrowest I would recomend.
Your old Deore will be alloy and built up to a much higher price.
The Deore DX big chainring has no steps, pins or plates to assist passage of the chain onto its teeth, and is of a standard 7spd width, and yet I have no problems with the 9spd chain upshift onto the big ring, even using a 7/8spd front derailleur. I suspect that you could get a 9spd chain working with most 7/8spd chainsets.
Well done!! ;)
Next, look at the tyres if most of your riding is on paved roads and paths. Continental Sport Contact 26x1.3 are an excellent choice. We have a MTB slicks topic here in Aus:
http://www.cyclingforums.com/t291662.html
Thanks for the advice on the tires. Now, I am using a pair of Hutchinson Acrobat (1.35). Nice tyres. I will try to find those Continental here. They sound as a good choice. Thanks again.-
German.-
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