Cycling UK Forum

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.

Brucey wrote: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.

"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.

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.

Haha I had a Carrera full suspension MTB and it was alright, despite "Halford's".

It was yellow, cost £600, had hydraulic disc brakes around year 2000 and they were the most powerful brakes I have ever used on any bike. More powerful than my current DA7800's with salmons. With it being a Halford's bike they had to stop a 100KG bike let's remember.

I wish I could find a pic of that yellow Carrera, I loved it but flogged it for £400 a while afterwards. It had a red spring on the suspension and said magnesium or something on the fork, please someone find a pic of it or a name!

My local politician is resigning, its worrying who we might get next because the one resigning was a good guy that would and did help people. I hope his replacement is over 50. I can't stand all these young politicians like Miliband, they are all too young these days, whereas in the past, ones so young were few and far between. Tory B Liar was too young when he took office, it just doesn't work.

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.

Brucey wrote:Fundamentally the two ('panta-servo' they used to call them) springs in the main pivots don't (and indeed can't) control the pulley movement perfectly. [This is because the spring forces vary with position too much, and this in turn is because the working travel of the spring is large in relation to the preload; a more constant force from each spring could be obtained if they were larger, heavier springs, with a lower rate and a greater preload.]

I think I know what you mean, sometimes I can shift from sprocket 1 to 4 and it lands smoothly on the 4th sprocket and runs quiet, but change from the last sprocket up to the 4th and there might be a slight tinkling on the chain. I can only guess thats because when the mech shifts down it quickly "snaps" down, whereas an upshift is a gentle push so it ends up with slightly tighter cable after shifting up.

Brucey the vintage Campag mech might fix it but I'm not that rich.

Here's a question... if my chainline is right (45mm) and I unscrew the front mech inner limit screw all the way out, even then I can't "make it" drop the chain off the granny ring, what does that mean? I mean in the lowest gear, I can set the front mech so its only just not rubbing the FD cage, but I can unscrew the inner limit screw more than this and not have the chain drop. This helps take up some of the slack cable on the shifter, but I don't actually need to do it (other than to take up that slack).

The way I set it, I did it so it can just about shift off the middle onto the granny, surely thats the right way?! I have got a chain catcher on (because of the range on the chainrings) but I have never made the chain drop, not once, ever on this setup. I don't think therefore, it could, so I might just whack that limit screw out more.

That depends on the tourist.

Here's a question, if a 6600 rear mech handles up to 27t and a 6700 mech handles up to 30t (both are 10 speed) and the smallest low sprocket across both 6600/6700 is a 23t, does that mean the 6600 rear mech with its 27t max low sprocket will shift better on a cassette that only goes up to 23t?

I guess what I am asking is aside from what the b-tension screw does, does the parallelogram need to be slightly shorter on the 6600 just because its rated at 27t as opposed to 30t like the 6700? I want snappy shifting.

It annoys me that they now make 11sp road mechs that handle up to 32t, doesn't this mean they run sloppy on cassettes that only go up to 23t? The 5701 (10sp) I tried was sloppy with the b-tension screw removed altogether on a 23t and not much better on a 26t even though 25t is the smallest low sprocket in the 5700 groupset.

Maybe I should just use a mech where the smallest low sprocket was a 21t and it will give snappy shifting. Thing is I'm on a 75mm long cage now and I think a newer GS (like the 6600) has it at around 82mm allowing slightly more overall capacity. This would fix the rubbing I get on the sprockets around the middle of the cassette when on the granny, I think.

Taking a link out of the chain erm... won't that just have the same effect as having a slightly longer cage? Then big to big is probably going to be a drivetrain breaker. A 24t granny is really finicky to setup. On my other long cage mech (XT/100mm/SGS) I never got the 4th and 5th sprockets on the granny making the chain rub on the middle ring so it must be the jockey wheel isn't low enough on this 75mm cage.

Its a laugh.

EDIT: Useful... http://www.celebrazio.net/bicycling/shi ... ables.html

OK sorry I just didn't know you could file the heads off.

andrewjoseph wrote:i have trouble going up steep hills with 26/36 combo when fully loaded.

I never will be.

Tonyf33 wrote:Have you thought about combining two cassettes to get your desired combinations, an HG 30/40/41 AND an HG 50 would give you exactly what you wanted?

No because the biggest 6 sprockets are a solid block.

The ratios I want never exist. People say get a Miche Primato but others say they don't shift as well as Shimano.

For example 8-speed, I would want: 13.14.15.16.17.18.20.23

The point is you have a 16t and a 18t. A 16t is not usually found on most 8-speed cassettes, the 12-23 doesn't have a 16t, but the 13-26t does. None of them have an 18t and could have if the above ratios were used.

Around 16t, 17t and 18t it is vital to me to have them close.

Its changed since the first post, I chopped 3t off the low sprocket and gained 2 gears. Most importantly, it now has a 16t on it whereas the 13-26t doesn't. I miss having a 16t more than I will need to be on a 26t sprocket. With a 24t granny ring and 23t low sprocket, you've basically got touring bike gearing of around a 1:1 lowest gear (27.5 gear inches).

Figures in black are overlapping gears...



All the 13-26t gives over this is the 26t which in the granny ring is arguably not needed. Also with the 13-26t you will "lose" two gears compared to the 13-23t.

I'll know soon enough when I am going up a 5 mile long hill if the gearing isn't low enough, many a time I have pushed the gear lever for a lower gear and I am already in the lowest gear, sigh, but I have got a lot fitter the last few years and reckon about 1:1 aka about 27 gear inches is my safe limit.

They want it so when it gets repaired it all comes up again.

In their boardroom they will just call this "repeat sales".

"But its the Government, they don't do that"

Nope, but they will just shroud it all in legalese so the end result is... they are doing that.

Apply to all, the pharmaceutical industry for starters. Develop two pills side by side, one causes a side effect and gets released, the other alleviates the side effect of the first but is released 6 months later. Why sell one if you can sell two. Gwen Olsen was the one that came out with this. It figures, anyone making money is doing just that, making money. Not much use actually fixing anything properly like roads, or curing anyone, when you can perpetually treat them. There's a reason its called "practicing" medicine. Meanwhile the Chinese have had roots and herbs that cure everything for centuries. No money in it though if you can just grow it yourself.

We're living in the dark ages folks, take a look around. We have for some reason handed our minds over to "experts" and they exploiting that fact.

Folks this hub actually had a "UniGlide" on it, sorry.

I thought it was one that screwed off but it isn't.

I used to go to Halford's for bikes and accessories... before I got into biking.

Same as "I used to go to PC World before I got into computers".