8 Speed Cassette Question

S.Giles

Guest
Hello,

I normally just use the smallest three cogs on my current 8-speed cassette (I haven't checked, but I think it's probably an 11-34 or 11-32 type). I'm deciding what to replace it with, and would like to go with closer gear ratios.

The problem is that although 11-28 cassettes are readily available, those with a smaller than 28 large cog tend to be 12-XX rather than 11-XX. Why is this?

Also, cassettes with closer gear ratios tend to be more expensive for some reason. Is anyone able to shed any light on this?

I have found this cassette, which seems to fit the bill, but I'm wondering why it's such a rarity (and almost double the price of the common 11-28 ones )

I appreciate your help.
 
Spa Cycles always have a good selection of cassettes http://www.spacycles.co.uk/products.php?plid=m2b0s150p0
 
Location
Pontefract
It is possible with 8sp cassettes to split them, shimano ones you remove the rivet pin and carefully separate them the spacers can brake but as you are splitting two chances are there will be plenty (9sp are more prone to this), make sure you have one starting at 11 for the locknut. So you could take an 11th from either a HG41 or HG51 and couple that with a HG50 12-25, drop the 25 and make an 11-12-13-15-17-19-21-23 or 11-12-13-15-17-20-23-26 or any combo you want.

@raleighnut are 8sp still available in dura-ace or ultegra
 
Last edited:

cyberknight

As long as I breathe, I attack.
It is possible with 8sp cassettes to split them, shimano ones you remove the rivet pin and carefully separate them the spacers can brake but as you are splitting two chances are there will be plenty (9sp are more prone to this), make sure you have one starting at 11 for the locknut. So you could take an 11th from either a HG41 or HG51 and couple that with a HG50 12-25, drop the 25 and make an 11-12-13-15-17-19-21-23 or 11-12-13-15-17-20-23-26 or any combo you want.

@raleighnut are 8sp still available in dura-ace or ultegra
afaik every 8 speed i have bought lately the last 2 sprockets are loose anyway .
 

raleighnut

Legendary Member
Location
On 3 Wheels
It is possible with 8sp cassettes to split them, shimano ones you remove the rivet pin and carefully separate them the spacers can brake but as you are splitting two chances are there will be plenty (9sp are more prone to this), make sure you have one starting at 11 for the locknut. So you could take an 11th from either a HG41 or HG51 and couple that with a HG50 12-25, drop the 25 and make an 11-12-13-15-17-19-21-23 or 11-12-13-15-17-20-23-26 or any combo you want.

@raleighnut are 8sp still available in dura-ace or ultegra
They are getting thin on the ground, the last set I bought were to match up with a pair of 8-9 speed bar ends shifters about 3 years ago and they are all separate cogs and spacers. The same spacing is used on standard 8 speed now (or it is very close as the winter wheels for that bike index correctly)
 
Location
Pontefract
@raleighnut there is only 0.02mm difference between 9 and 8sp cogs but 0.44mm between spacers, so you can use 9sp cogs with 8sp spacers, shifting might not be 100% but works as I have mixed and matched, even 7sp at a pinch there being only 0.05mm difference between cog widths, I used to start with a 7sp 13th, and then make up what ratios I wanted.
 

raleighnut

Legendary Member
Location
On 3 Wheels
The shifters I have are SL-BS77 which are Dura-ace 9 speed or 8 speed compatible (The spacers/cogs are identical) simply needing an extra spacing on a 9 speed hub, at the time they could not be used with anything other than Dura-ace mech's but later on 105 9 speed used the same cable pull ratio so they work with a 105 rear mech.
They were used in Friction mode originally simply because I wanted to have bar end shifters on my touring bike and until I could afford the Dura-ace rear mech by which time that had been superceded by 10 speed but they had relegated that spacing down to a lower group.
Originally they were specific to the RD 7700 rear mech.
 
Location
Pontefract
@raleighnut 8sp cassettes are easy enough to get though. Three types at wiggle HG41, HG50 and an Sram PG850, HG50 £11.49 12-23, 12-25 13-25, 13-26, http://www.wiggle.co.uk/cycle/cassettes-freewheels/?ea=429472005, HG41 £6.95, but really for a MTB as its a 11-30 or 34, SRAM £14.99 in 11-28, 11-32 12-26.

@S.Giles the reason for the wider range cassette is because of the move away from road triples, the 11th is needed on smaller chainset 50th usual on 50/34 chainsets or on M.T.B. so they have a biggish gear, a 50x11 on a standard 700x23c wheel is 120", a proper double i.e 52/39 for example would be on a 52x12 114.8" or on a 53x12 117", however the move towards compact doubles means more people are looking for a low gear, so you have to have something like a 34x30 to get a low gear in this case 30", you now have the problem of having to have a big gear and a low gear fitted Hence the reason for an 11-28+ gear range. This is the reason I like my triple, I ride a pretty normal double, though it is only a 50/38 with currently an inner ring of 26th, my current range is 30-110" the same as many 50/34's on a 12-30 but on a 12-23 cassette, however after one ride I think the drop from 38 to 26th on the front is a little much, as I have to go back down the cassette quite a distance, almost the same as a compact, so I am looking to change the 26th to a 28th but it does mean me losing my low end gearing, but I think it is sufficient round here as I very rarely go lower than 37" and the 28x23 is 32.3"
 
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