I think I found the perfect gearing at last...

[Manc33]

Sometimes a tiny adjustment to the cage, EG slightly angled, but it could be 1mm that fixes it. To the naked eye nothing looks changed. Yep, it can be something as innocuous as a new chain that fixes it just because it is a different brand.

At the moment the FD cage is parallel, from looking at it. I don't think I'd dare undo the bolt holding the mech on after all the messing setting it up.

I am going to just undo that inner limit screw and see if the chain ever drops off towards the BB shell. It has got a chain catcher on, but still I don't want it to hit that every shift. Maybe the fact that I cannot get the chain to drop is just a sign of how good the components (FD-R443) are these days. I suppose if the outer plate of the cage cannot go past the inner chainring then how can it knock it off, the force might knock it off but if the plate stops before the inner ring then maybe its nearly impossible to make the chain drop?

Maybe it would hit the chain catcher (if I had the limit screw out) but I wouldn't even feel/hear it if the shift was smooth.

I did have a weird shifter where it had a trim on the granny ring to take up any excess cable, but I gave up with trim since it causes chain rub. In other words it forces you to have to trim whereas on a triple without trim I can get away with it better. I have seriously contemplated just putting a friction shifter on it but that's cheating.

One thing is I have a 127mm BB on and thats the longest spindle/axle size of that BB. The chainline is pretty much what it should be. Its just that I am using old triple crank arms (FC-B124 aka Biopace) that always did need a wide BB.

EDIT: Unscrewed the inner limit but that meant chain rub on granny and the third sprocket down so I put it back.

Once I get it so changing something means having to change it back how it was, its considered fixed.

[Manc33]

Did one of my best average speeds ever tonight and I am sure its because I can now get all those in between gears, or maybe its because I am taking on every single hill on 38x23t Yeah, its tiring on this cassette I won't say it isn't but I think I can adapt and that tiny granny is available if things get that tough.

Averaged 13.7 MPH

Its slow, but my usual is 12.3 MPH or 12.5 MPH if I pushed more.

When you get into the efficiency of it, a 11-32t eight speed cassette on 700x25c tyres with 100psi gives jumps so bad, yes you'll be doing 12.5 MPH when you should be doing 13.5+. It does seem to have made a difference and it makes riding the bike a lot better.

As long as my indescribably minuscule granny ring is covered up by my leg at traffic lights, people will think I'm as hard as nails with a 23t. Hopefully the lights will change before they notice the mech has a long cage, or they won't twig.

[Manc33]

"Just file the rivet heads off" they reckon.

Just?

I have been filing these three rivets for about 40 minutes now, the rivet heads were filed flush with the sprocket after about 10 minutes, nothing is coming out.

STOP... hammer time.

In fact, drill time because I haven't got a dremel and wouldn't trust myself with one anyway. One false move and you need a new sprocket.

EDIT 3mm drill bit worked a treat, just make a small "cone" in the top of the rivet exactly in the middle (after filing the head flat this is) then put a nail in and gently tap with the plastic end of a screwdriver, with the cassette on a soft surface and the rivets come straight out.

Here's what I am combining for anyone interested:

Three 8-speed cassettes, two road, one MTB:

Sora 13-23t (to obtain the 16t)
Sora 13-26t (to obtain the 26t)
Alivio 11-32t (to obtain the 18t)

To end up with 13.14.15.16.17.18.21.26

So this custom cassette will provide at least three benefits over any of those other Shimano configurations:

1. It will have an 18t sprocket. None of the Sora cassettes have this (not even the 13-23t)
2. It will have a 26t low sprocket. The 13-23t doesn't have this.
3. It will have the 16t not available on the 13-26t (but is on the 13-23t) while having a 26t.

So this to me gives me that 18t I thought I would have to go to 9-speed to get and the 16t is on it at the same time it has a 26t low sprocket.

I have to thank the guys in this thread that advised removing the rivets because I have never heard of doing that before (never looked into it) and I would probably be messing about with a Miche Primato or something to do it.

No, at first I didn't believe it was as simple as removing the rivets and did think it "had to be" trolling just because most people on the internet aren't that helpful (on at least one other bike forum I won't mention) and I am more used to being told the wrong advice than the right advice.

A bit like a new employee being told to go ask for a long stand.

I just haven't been on CTC very long and didn't realize people here are actually helpful.

[Brucey]

grinding or drilling are the Brucey-preferred methods for this job... and now you know why!

cheers

[Manc33]

grinding or drilling are the Brucey-preferred methods for this job... and now you know why!

cheers

I didn't want to use a drill because of how thin the metal gets next to the hole but I think I managed to only create a shallow "inverted cone" in the head and the holes remain intact. Angling the drill around a bit gets the rest of any spare metal still on the edges of the rivet head and it almost falls out then.

Tapping a nail into the middle to make a tiny dent for the drill bit is also probably the best bet, centering a full sized drill over it without doing that first is tricky, sliding is guaranteed.

Even if it is done off center you can sort of drill it angled and away from the edge of the hole, into the center, just to take off the shavings around the rivet head.

Another issue is on 38x14t (middle ring and 2nd to smallest sprocket) its spinning out a bit much on the flats (a point already raised by someone earlier in this thread) meaning its causing more swapping to the big ring, so I am going to make the middle chainring a 40t instead of 38t. Now, on a 23t low sprocket this would be slightly too high a gear to get up most hills without using the granny ring (40x23t), but with the custom cassette it will be a 26t sprocket which gives 40.6 gear inches. On 38x23t it is 43.6". On 38x26t is is 38.6". With the 40x26 gearing being slightly closer to 38x26 than 38x23 I know from this it will probably just - JUST - be alright. I have been going up hills on 38x23t and with the last 10% of the hill to go its getting near granny time, but having just 3" chopped off it I think will solve it.

At the other end of the cassette it will give 75.4 gear inches on 40x14t which is probably about enough to stop me using the outer, plus avoids using the last sprocket on the middle ring, although it is there if needed and will give 81.2 gear inches. I think cross chaining it like that is alright if you don't do it for long. Most times I get to a more flat bit and have to get back on 38x15/16/17 etc. Originally it was 39x25 and that is pretty much the same gear as a 40x26. Because its now a 40t it solves spinning out on flats at the other end.

Then after that it could have a 53t outer but its only 1t more than I have now and would create a 29t front difference. I don't know but I think I read somewhere only one certain Campag front mech can cope with that so, its not really worth it but if making the middle a 40t (from 38t) it is cancelling out a gear on the outer (and adding a gear on the granny).

Honestly, you should be able to order any sprocket combo from Shimano and have them send it out in bits. I think they are really crafty for making sure none of those Sora cassettes have a 18t or 20t on them. I would probably prefer a 20t where the 21t will be but its not that important. The ratios are good as they are IMO. Its a corn cob for the first six sprockets, then the 7th jumps up 3 teeth and the last jumps up 5 teeth. I don't care about having a 17% jump then a 24% jump there, those sprockets can jump more because on a 24t granny ring you're getting something like 2" of gearing on a 1t sprocket difference. I don't want cadence in those situations I want to get up the hill without having to stop.

I did think about putting the 24t on from the Alivio to make the biggest sprocket a 24t but I think I would have regretted it and yearned to have a 26t there. I got up a really steep hill on 24x23t but its not easy.

[Brucey]

I don't think you need to worry about whacking a large hole through...(if you even could, the sprockets are hard)... you can lose three of the splines completely and it will still work OK; shimano used to supply cogs like that....

cheers

[Manc33]

Just split three 8-speed Shimano cassettes (all new) and it won't work properly on the one 18t Alivio sprocket.

Its got 13.14.15.16.17.18.21.26 (18t is Alivio, the rest are Sora).

I tried with the road spacers and this gave bad shifting on the 18t Alivio, the metal of the sprocket is thinner.

With all the other sprockets shifting well, on the 18t it was making the chain slightly touch and catch on the 17t.

If I tightened the cable to stop that, of course, all the other sprockets were out.

I changed it and put the Alivio "3.16mm" MTB cassette spacers either side of the 18t. This half alleviated the problem but the chain still catches on the 17t, when on the 18t.

The road spacers have no size stamped on them.
The MTB spacers have 3.16mm stamped on them.

If Sheldon Brown is right then the road spacers are 3.0mm.

I don't know what to do, the point of this was to have a 18t sprocket, more than any other changes.

I have not tried it with one spacer (strategically placed lol) but I guess if I added one thin sprocket, then I add one thicker spacer, not "no thicker spacers", not "two thicker spacers". Both will end up shifting wrong.

It got to midnight and I gave up.

So if it doesn't work with all road spacers and doesn't work with a 3.16mm spacer either side... does a MTB spacer only need to go on one side of the Alivio sprocket?

My plan is to put one MTB spacer after the 18t only, I have not tried this. It will make the gap to shift up from 17-18 slightly more compared to using a road spacer between those two. This means the chain is then put slightly towards the "low" end of the cassette when on the 18t, which sounds like the fix.

Its obvious the metal is thinner on the Alivio sprockets, I can feel it. Also the Alivio despite being a 11-32t feels quite a bit lighter in my hand than the 13-26t Sora.

Shimano sure do have a sense of humor.

Sheldon Brown says 7 speed spacers are generally 3.15mm (sounds ominously close to my Alivio spacers at 3.16mm) and 8 speed are 3.0mm.

So then somehow, for some reason, Shimano are making 8-speed Alivio cassettes with 7 speed spacers and all the sprockets reduced in thickness accordingly. So you end up with a correctly spaced 8-speed cassette.

Nutcases! At least they have stamped 3.16mm on them though, otherwise I would be climbing the walls by now, but the MTB spacers are just about distinguishable as being thicker, you can put the 2 spacers touching each other on a flat surface, run your finger over the spacers and sort of tell that way.

So if Shimano use 5 spacers at 3.16mm thats 15.8mm (compared to 15mm for normal 3mm spacers).

So the Alivio sprockets are 0.8mm thinner across all 8 sprockets, meaning each one is at least 0.1mm thinner than road sprockets ahem OK, "Sora HG50". This isn't taking the two smallest sprockets into account, that have no spacers. I'm not clever enough to work it out, but the bottom line is the sprockets and spacers are different thicknesses.

[Manc33]

Urgh, ignore all that, I can see now looking at it, the thick spacer behind the 18t needs to be replaced with a thinner spacer and the thicker one in front of the 18t leaving there.

So then each sprocket on the cassette has the right spacer on top of it, as a rule. Add one sprocket, add one spacer.

A thicker spacer either side won't work, all thin spacers won't, one on the behind of the offending sprocket won't, it has to be one, in front of it (between 18t and 17t).

It will be a great setup if it eventually works.

[Brucey]

when you have got the right spacing (tip, use the original matching spacer that went with each sprocket to the right of it if both cassettes were the same pitch) then you can worry about the next bit which is the HG ramp alignment.

If you look at a new HG cassette side on, all the ramps line up in a kind of coarse spiral. To ensure that that the HG alignment is always good, there is the one wide timing spline on each sprocket. There are several different versions of each sprocket, denoted by a two letter code. Some sprockets (esp small ones) often have more than one code on, because they will work with more than one set.

If you assemble a cassette with sprockets missing or added sprockets (using two different coded sets) there will HG ramp misalignments; each HG ramp should spirally align with the one to each side of it (important for multiple shifts) and also with the 'departure gate' in the neighbouring small sprocket (important on all shifts).

In fairness the shifts may not be terrible even if the HG ramps and gates don't line up perfectly but they are certainly a bit slicker if they do.

If you grind the large spline down on each sprocket you can re-time neighbouring sprockets (in 40 degree increments) so that you can improve the HG ramp alignment, even when you have mismatched sprocket sets.

cheers

[Manc33]

Cheers Brucey you always answer everything.

I tried it all four ways with the odd 18t MTB sprocket, nothing worked though as far as getting the sprockets to all run smooth at the same time.

1. All 3.0mm spacers (road spacers). Didn't work.
2. Two MTB spacers (3.16mm), one either side of the 18t. Didn't work.
3. One MTB spacer on the "high" side of the 18t. Didn't work.
4. One MTB spacer on the "low" side of the 18t. Didn't work.

The four different ways give varying results but none make it work smoothly.

I am just going to put the Sora 19t on and have done with it.

So its going to have to be:
13.14.15.16.17.19.21.26
- Instead of -
13.14.15.16.17.18.21.26

It wasn't all in vain, because I still have a custom cassette in that I have the 16t only normally found on a 13-23t but I have a 26t low sprocket only usually found on the 13-26t (that doesn't have a 16t).

Now maybe there's an old 105/Ultegra 8-speed 18t sprocket somewhere who knows, but its just not worth it to have a 18t in place of the 19t. In a way the 19t makes the jump from it to 21t less. Gotta look at the positives lol, but I can't believe that 18t is impossible to put in with the road sprockets.

For whatever reason it just can't be made to be uniform no matter how I swap the spacers around.

Now I hope you don't answer it because I am swapping it back to 8 road sprockets.

[Brucey]

3. ought to have run smoothly on the 18T but the shifting would have been poor unless you adjust the ramp timing as I described earlier.

cheers

[Manc33]

Gave up in the end and just put the 19t Sora sprocket back on.

13.14.15.16.17.19.21.26

Now its rough on the 16t a little bit, but only because that one sprocket is newer.

So all it is then is a 13-26t with the 23t taken out, the 21/19/17 moved up one and the 16t fitted in the gap. Where the 23t came out, it just jumps more to the last sprocket from 21-26 instead of 23-26. I don't care as much about that as I do about gaining a 16t sprocket.

Having the 3rd to last sprocket 1 tooth bigger than I wanted isn't that bad and it being a 19t coming from a 17t isn't ideal, but not as bad as I would have to have it on a normal cassette jumping from 15t to 17t.

The main thing was adding the 16t, because it gives a worse jump from 15-17 than it does from 17-19. I mean if you have to go without one, its going to be the 18t, before going without the 16t.

Now I think it would be better with a 40t middle ring as opposed to 38t to help with not spinning out on 38x14t. Then it makes hills a bit harder but that's why the 26t is there. So it would go from 52-38-24 to a 52-40-24. Can't really afford to splash the cash for one yet but I will at some point, then flog the 38t for a tenner, its done under 500 miles. I am constantly changing the drivetrain around lol.

[Manc33]

Just tried 13.14.15.16.17.19.21.26 and couldn't get on with the jump on the biggest 2 sprockets.

I use them more than I realized. I suppose the 26t could be replaced with a 23t but then I just have a straight (not customized) cassette again.

I am still spinning out on flats on 38x13 and shouldn't be on the 13t (cross chaining it), so I think going to a 12-23t is the best bet. It lets me cross chain "if need be".

I never needed the 26t really, it was just a nice thought but unless you leave out the 16t its not viable with that 21-26 jump.

12-23t is some sort of compromise, that will again not be able to have a 16t on it.

12.13.14.15.17.19.21.23

Biggest jump is 13.3% but, unavoidable.

You know what the really sick part is, I have got a 12-23t cassette here but it is a PG850 and I don't want to use it.

To save buying a HG50 12-23t cassette I am going to try mixing and matching the smallest three sprockets off the 12-23t SRAM. Its needed because of the lockring, I don't have a 12t Shimano one. It appears to be the right spacing, but I have not tried it yet.



12 - SRAM
13 - SRAM
14 - SRAM
15 - Shimano
17 - Shimano
19 - Shimano
21 - Shimano
23 - Shimano

Giving up the 16t now, to have the 12t.

I did miss having that 23 on the first hill from my house.

Mixing SRAM and Shimano, wish me luck. :p

[Manc33]

Sorry about all the duplicate posts but I have cracked it I think now. With whats pictured above, but it is only a mixture of SRAM and Shimano sprockets because I don't want to buy another cassette lol. You can just get a cassette from anywhere that sells them with those ratios in a HG50 and a PG850.

12-23t

12.13.14.15.17.19.21.23t

It should have a halo around it.

No 16t, no 18t either. The biggest jump (between 15-17) is 13.3% which, while not nice, isn't so bad it has me getting shirty on the bike. Looking at the numbers more, I noticed it only does have that one jump like that and with it not being that bad its worth losing the 16t to have the 12t. One thing I couldn't cope with was spinning out on that last 13t knowing a 12t would fix it and the 16t is making the smallest need to be a 13t.

After a lot of trial and error with ratios (including chainsets months back) its like this:

http://i.imgur.com/et5Qilq.png

[Manc33]

I have had just about every combination of cassette ratios apart from going up to a 34t and down to a 19t and the funny thing is, after probably a year of trial and error, I am just about back on the same cassette that came stock on the bike.

It came with a 12-25t Sunrace cassette, now I have a "custom" 12-26t Sora cassette on. Custom because there is no such thing as a 12-26t on this cassette (13-26t/12-25t) so I thought I might as well make a custom one that gives that tiny bit more at the hilly end.

The 12t I have found is vital and a 13t just won't cut it. I am not sure how large the middle ring would need to be to stop spinning out on the flats with a 13t but it isn't really doable.

Because it starts at a 12t and not 13t, I had to lose the 14t (over a 13-26t) but, after trying that combo out tonight I found I wasn't bothered by it. 13-15 is more than a 15% jump but, when you're on 38x15 and speeding up, the 13t felt OK but I was pretty wary of leaving a gap there after all the talk of it having to be close ratio.

After messing about so many times I can say that big jumps on the cassette were more annoying than having a smaller low sprocket up the hills (that was forcing me onto the granny ring on all hills!).

It ended up the same as a cassette SRAM make but is a HG50:

12-13-15-17-19-21-23-26
52/38/24

I think I found the perfect gearing... now. Until it changes again.

I want to get an adapter to fit a 22t inner ring (74 BCD adapter > 58 BCD inner chainring). Front mech is just about able to cope now with a 28t difference (when it should be 22t ) but I am sure it would still shift from a 38 to a 22 and back up, then the middle to outer shift is just the same as it always was.

Here's a question... the throw from granny to middle is gigantic compared to the throw from middle to outer. Why aren't front mechs designed so they swing more when loose and less when tight? I mean designed so the shift lever has a 50:50 throw? It feels more like 70%/30% on my setup. An "oval" ring where the cable goes around the shifter would do it if shaped properly. I am not an engineer and I can only half imagine it. I think they are oval on a lot of shifters but it needs more surface area on the granny, or I have a screwy setup (most likely).