12 speed cassettes on direct drive trainers

@Ricky_John: Did you watch the video and follow the instructions? Using a seven speed cassette with the additional, required spacer, requires a little mechanical work with a file to get the cassette to line up with the hub.

Yeah followed that. In fact I found a 4mm spacer online that was made due 7 speed cassette and came with the rivet gaps already in place.

The only thing I can think of is that either the spacing between the cogs on the freehub cassette that is on the trainer is slightly different from the freewheel cassette on he bike, or, the teeth difference 12-28T vs 14-28T is more of an issue than I thought it might be

I suspect spacing is not the problem. According to Sheldon Brown’s site, Shimano 7 speed cassettes and 7 speed freewheels both have 5 mm spacing:

I disagree somewhat. Yes, steel frames can crack when you widen the dropouts. However you can successfully cold set them, which is what I did on a 1980 Windsor Pro. I expanded the dropouts from 126-130 mm, as you mentioned, and have now ridden the bike for two years with an 11-speed cassette. And I can use that bike on a smart trainer. So, there are other options for SteveK.

Kickr core
Sram gx eagle 12 speed with spacer, works like a charm.
No clearance issues.
This is on the standard hub, not the XDR type.

yeah came here to say this, I bought the XDR/XD freehub but forgot the SRAM NX Eagle cassette fits on Shimano. I already had the cassette from the original wheelset that came with my mountain bike. It fit on the trainer freehub just fine and shifts smoothly.

@Robert_Graawe_V and @Gregory_Fordham
I updated the original post and noted that the SRAM 12 speed mountain bike cassette models that fit a Shimano/SRAM freehub body will be distinguished by an 11 tooth smallest cog.

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I realize I’m zombie replying a little, but a quick note to say I did exactly this with a “not-from-this-century” GT Palomar mountain bike that has a six-speed freewheel.

My Elite Suito came with an 11-speed cassette, and though it said it fits “most bikes”, I’m guessing that’s for bikes made in the last 5 years :rage::wink:. Though my bike’s chain bit when I spun backwards, it wouldn’t bite reliably, slipping frequently, going forward. After some googling, I got a chain whip and a cassette removal tool, then swapped out the eleven- with a seven-speed Shimano cassette from Harris Cyclery (from a link on Sheldon’s old site).

I had also replaced my 6-speed rear shifter, which blew up, with a 7-speed shifter (accidentally) a few years back, which wasn’t particularly difficult. The shifter works surprisingly well with the original wheel, but works perfectly with the cassette. Better lucky than good.

And that’s it. I’m Zwifting. No other changes were needed. Same old chain works. Rear was wide enough for the trainer. Lots cheaper than bagging a new road bike. Check your local thrift stores, folk. If it’s wide enough in the back to fit around your trainer, you’re probably in luck.

For the sake of those who may not be familiar with the difference, Sheldon Brown illustrates the difference between a freewheel and a cassette:

All modern, direct-drive trainers require a cassette. Older bicycles with 5, 6 or 7 speed rear gearing came with wheels that required a freewheel. The transition point from freewheel to cassette was 7 speed; some wheels with 7 speed rear gearing use a freewheel, and some use a cassette. But the same chain and derailleur works on either. @Ruffin_Bailey’s trainer bike illustrates that.

Thanks Steve, others, great thread.

I also want to use an '80 bike with 6 speed uniglide, shimano 600, on one of the current direct drive indoor trainers (Wahoo, Elite, Tracx). Out in the open it still is a terrific bike, a stiff frame, tubeless tires, low resistance, and running smooth: a Koga Myiata '83 (I think) RoadWinner, 13-23 freewheel.

  • from the still available online brochure, it has a High-Manga steel fork for rear, would that be bendable from 126 > 130 mm as well?
  • would the quick release system still be compatible, when bended to 130mm there is less space?
  • If i get the Shimano CS-HG200 Cassette 7-speed, and spacers, will it work with the same chain (spacing) as on the 6 speed (600 EX)
  • is it correct to asume that because it is uniglide, you can shift gears without problems of rattling. Although the good thing of uniglide is it will jump on next gear automatically, now a bit more difficult to shift but doable?
  • do you put the spacers on the inside, so there is no adjustment of the derailleur.

If it’s a steel frame, it should be cold-settable from 126 to 130 mm. Remember to check alignment of the dropouts (that they are in parallel) with the appropriate tool afterwards. QRs are often “too long” to begin with and anyway you get a new one with the trainer in most cases. If you still want to use the bike on the road as well, things will get a bit more complicated as you need to add a 4 mm spacer to the axle on the left side (may need a longer axle as well) and recenter the rim. A new (or “new”) rear wheel may be an easier option.

Spacing-wise there should be no problems, Hyperglide is more or less the same as Uniglide. You may need a new chain (because of the new cassette and anyway) if the biggest sprocket is bigger than before (Sunrace makes a 12–24 7sp cassette if you want something more similar to what you have now, I think the smallest you can get from Shimano is 12–28) and the old chain isn’t long enough. If there is no indexing and/or you are willing to forego it, you could probably use your existing setup with all 7 cogs or even a full 8-speed cassette. (I have sometimes used unindexed downtube shifters for a while with a 9-speed cassette while waiting for spare parts and it starts to get a bit finicky with the tighter spacing…)

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Don’t do it. There’s so many layers of incompatibilty there that it’s not worth it IMO.

I was considering buying an old steel frame for a trainer-dedicated bike, spreading the rear dropouts to 130mm and hanging all modern parts (8/9/10/11 speed would all work) on it. That’s what it would take for it to work well.

Sorry - no. UG’s twist-tooth shape and HG’s ramped cogs are very different, and put different loads on a chain that would cause the chain to break under load.

If you were thinking of transferring the cogs on your wheel to the trainer - they will not fit onto any modern freehub system. 6/7 speed Uniglide cogs and modern Hyperglide cogs are completely incompatible in that way.

Bottom line - It’s going to take way too much time & money to try to hack together what you’re proposing, and it’s going to be metal-on-metal noisy and not shift worth a damn.

Ok. The last time I had fishing gear in my drivetrain was in the 80s so I’m not exactly an expert… Anyway, I presume with a new chain and a new cassette you should be in the clear, even if you stay with 7-speed.

Hi everybody, I’ve recently changed to a 12speed mtb groupset, so I wanted to do the same with my elite suito cassette, to match my gear. I’ve purchased the microspline freehub for shimano, so I could install the new cassette. The problem is that while all switch perfectly on my bike, when I’m in the trainer I have issues switching , it’s not adjusted at all. How is this possible? With my old 2x10 groupset all was working fine in both, bike and trainer.

Thanks for your help

You also changed your shifters and rear mech to 12speed right? Edit: I think I asked a dumb question.

You’ll have to adjust your rear mech. The B-screw adjustment is very critical to get right on 12-speed but its likely that the new free-hub tolerance isnt quite matching that of the old on your bike so adjust at the barrel is all it will take after the B adjustment.

A post was split to a new topic: 7 speed cassette question

Hi! I’ve been searching as well as contacting Zwift and Saris about this. And i continue to hear conflicting answers. I have a SRAM SX-PG1210 / 11-50 T cassette. Are you saying this will work flawlessly? I’ve been told i wouldn’t be able to use the largest cog as it would run into the trainer. I’m also trying to get a Saris Hammer trainer. Thanks!

Not sure about the cog but the RD might be an issue. I have 28 and small cassette RD and it seems close on my H3. I can take a close look but it will be a couple days as my bike is in the shop.

I think I’m at the point where i simply want to know if it’s physically possible to fit the cassette on the trainer and ride without it being a problem, and just not shift to the largest.

Well it works with Kickr: Smart Trainer Tip: SRAM Eagle NX Cassette for MTB/Gravel Bikes // Shimano HG Compatible // Save :moneybag: - YouTube

You could try asking Shane if he has tried on the H3.