Can you add a road bike cassette to a MTB?

[sefe2022]

Hello.

Is there any reason why a road cassette like this for example -> https://bike.shimano.com/en-EU/product/ ... 00-11.html would not work, or cause any incompatibility, unexpected wear etc... if used on a MTB?

At the moment I have a 2x11 ( 36T/26T at the front, and a 11 speed cassette 11T-42T ).
What I want is to replace my 26T chainring with a 22T, and the cassette with a 11T-34T.
I want to do this, because the jumps in the gears are smaller, and as a bonus I also can save about 100 grams from the rear cassette weight.

Is this possible? Thanks

[rareposter]

It'll be fine although you'll probably have to adjust the b-tension screw to move the mech "upward" (ie closer to the cassette) as it won't need the range of movement that a bigger cassette requires. The chain will need to be shorter too. Everything else will be fine.

It did make me smile slightly seeing that referred to as a "road" cassette. I remember the days when road cassettes ended at 25T and MTB cassettes went up to 30T! And both of those were only to be considered if you were climbing mountains!

[Jupestar]

I also think it's fine.

Just one thing sticks in my mind.

In that some MTB 11 speed can be slightly dished (on the inner sprocket). So it overhangs the inboard end as its typically larger it can clear the spokes?

So it's possible that the MTB Freehub may not take the road cassette. I think it's the difference between having a 35mm freehub body and 36.75mm Freehub body. Dished MTB 11 speed being able to fit on the 35mm, undished and road 11speed fitting the 36.75.

I seem to remember having this problem before. Maybe it was a one off, so unlikely to be an issue, but also should be fairly easy to check.

Also, Have you checked FD compatible with the smaller chain ring and the jump?

[sefe2022]

So it's possible that the MTB Freehub may not take the road cassette. I think it's the difference between having a 35mm freehub body and 36.75mm Freehub body. Dished MTB 11 speed being able to fit on the 35mm, undished and road 11speed fitting the 36.75.

I seem to remember having this problem before. Maybe it was a one off, so unlikely to be an issue, but also should be fairly easy to check.

Also, Have you checked FD compatible with the smaller chain ring and the jump?

I haven't checked this info yet, as I was not aware of the issue.
The front derailleur it's https://bike.shimano.com/en-EU/product/ ... -11-H.html
Do you think it's compatible?
I will also have to measure the freehub body with a Digital Caliper to make sure it will fit.

[rareposter]

I haven't checked this info yet, as I was not aware of the issue.
The front derailleur it's https://bike.shimano.com/en-EU/product/ ... -11-H.html
Do you think it's compatible?
I will also have to measure the freehub body with a Digital Caliper to make sure it will fit.

Front mech should be fine, they're normally rated up to about a 16T difference in chainrings.

Freehub - just put the cassette on. Worst case is it might need a spacer (any bike shop will be able to sort this) but you're unlikely to find this out using calipers. Just fit the thing, test the gear shifting. and the clearances at each end.

[slowster]

I haven't checked this info yet, as I was not aware of the issue.
The front derailleur it's https://bike.shimano.com/en-EU/product/ ... -11-H.html
Do you think it's compatible?

Front mech should be fine, they're normally rated up to about a 16T difference in chainrings.

According to the link that particular derailleur is designed for a 10 tooth difference between chainrings. The derailleur has a shaped inner cage, and that might result in poor shifting if used with a 14 tooth difference between chainrings.

Each extra tooth on a chainring increases its radius by approximately 2mm. Therefore the chain on a 22t inner ring will be approximately 8mm lower in relation to the derailleur than on a 26t ring. The wrong part of the inner cage might therefore press against the chain when attempting to shift from the 22t chainring to the 36t. I think deviating from Shimano's specification by a couple of teeth (4mm) is usually OK, but 8mm might be too much depending upon the design of the derailleur.

If you can raise the front derailleur on your bike, I suggest you experiment by raising it 8mm, to see if it will then shift from the 26t chainring to the 36t chainring. If it does, that would suggest that you could successfully use a 22t chainring.

As regards the cassette width, there should be no need for a spacer. Shimano 11 speed cassettes with largest sprockets of 34t and more are the same width. Cassettes with largest sprockets of 32t and fewer are wider and will only fit Shimano 11 speed road standard freehubs. The narrower cassettes with largest sprockets of 34t require a 1.85mm spacer if used on a Shimano 11 speed road standard freehub. The Shimano 11 speed MTB standard freehubs can only be used with cassettes with largest sprockets of 34t and more.

[Jupestar]

As regards the cassette width, there should be no need for a spacer. Shimano 11 speed cassettes with largest sprockets of 34t and more are the same width. Cassettes with largest sprockets of 32t and fewer are wider and will only fit Shimano 11 speed road standard freehubs. The narrower cassettes with largest sprockets of 34t require a 1.85mm spacer if used on a Shimano 11 speed road standard freehub. The Shimano 11 speed MTB standard freehubs can only be used with cassettes with largest sprockets of 34t and more.

Good knowledge! Very helpful.

[CyberKnight]

It'll be fine although you'll probably have to adjust the b-tension screw to move the mech "upward" (ie closer to the cassette) as it won't need the range of movement that a bigger cassette requires. The chain will need to be shorter too. Everything else will be fine.

It did make me smile slightly seeing that referred to as a "road" cassette. I remember the days when road cassettes ended at 25T and MTB cassettes went up to 30T! And both of those were only to be considered if you were climbing mountains!

my 1st road bike had a 6 speed freewheel with a 13-18 ratio and 52/42 chainrings, i wouldn't have the legs now!

[sefe2022]

my 1st road bike had a 6 speed freewheel with a 13-18 ratio and 52/42 chainrings, i wouldn't have the legs now!

Wow, this is a setup for Hulk legs

[CyberKnight]

at the time 28" waist and each thigh was about 25 "

[foxyrider]

It'll be fine although you'll probably have to adjust the b-tension screw to move the mech "upward" (ie closer to the cassette) as it won't need the range of movement that a bigger cassette requires. The chain will need to be shorter too. Everything else will be fine.

It did make me smile slightly seeing that referred to as a "road" cassette. I remember the days when road cassettes ended at 25T and MTB cassettes went up to 30T! And both of those were only to be considered if you were climbing mountains!

my 1st road bike had a 6 speed freewheel with a 13-18 ratio and 52/42 chainrings, i wouldn't have the legs now!

When i did the Eroica event based in Bakewell i did the long event on my '78 road bike with that exact gear set up, i will admit to walking a couple of the steepest climbs down Ashbourne way and the steepest bit of Mam Nick, but whilst not ideal, it wasn't so bad. BITD i actually used a 14-24 block on hilly events and the winter hack, still with the 52/42 at the front, that got me up anything in the PD. Getting soft now, a bottom of 34x27 is a bit more civilised

[Dingdong]

I don't see why not!

[zenitb]

.....

Just one thing sticks in my mind.

In that some MTB 11 speed can be slightly dished (on the inner sprocket). So it overhangs the inboard end as its typically larger it can clear the spokes?

So it's possible that the MTB Freehub may not take the road cassette. I think it's the difference between having a 35mm freehub body and 36.75mm Freehub body. Dished MTB 11 speed being able to fit on the 35mm, undished and road 11speed fitting the 36.75.

I seem to remember having this problem before. Maybe it was a one off, so unlikely to be an issue, but also should be fairly easy to check.

This post has been bugging me for a while. "Of course the thing won't fit" I thought "the blddy mtb splines aren't wide enough" (Because 11 speed road hubs have HG splines 1.8mm wider, or maybe 1.75mm wider as Jupestar correctly posits)

But then doubts crept in. "What if I'm wrong? 1.8mm isn't that much. Perhaps it fits anyway?"

Bottom line I tried it. I used a standard MTB HG hub (FH-T660 Deore LX but they all have the same HG spline length) and then got an old Shimano 105 11-28 block that I have just taken off my 11 speed road bike.

It doesn't fit.

10 cogs on. Now there is no room at the Inn!!

I can get 10 of the 11 cogs on but that extra 1.8mm really does make a difference.

10 out of eleven cogs on. 12 tooth omitted.

Now we have had this problem the other way round in that the Hope hub we made a wheel from had the wider splines by default and needed 1.8mm spacer to accept MTB cassettes without rattling. However if this is a shimano MTB hub it isn't going to work with the wider 11 speed road cassette out of the box. However if its a Hope hub you have..well...hope!!

[Jupestar]

I think Slowster explained this very well in the post above. As your 11 speed cassette has a largest sprocket less than 34t. It won't fit on the slightly smaller MTB Freehub. It needs a road Freehub which is slightly longer.

As the OP was going from a max 42t to max 34t he should not have had a problem. If he had a MTB Freehub both would fit without the spacer and a road Freehub he would have needed the spacer.

Glad some tested it. As I had a similar problem once. I sold it all and stuck with 10s.

[zenitb]

I think Slowster explained this very well in the post above. As your 11 speed cassette has a largest sprocket less than 34t. It won't fit on the slightly smaller MTB Freehub. It needs a road Freehub which is slightly longer.

As the OP was going from a max 42t to max 34t he should not have had a problem. If he had a MTB Freehub both would fit without the spacer and a road Freehub he would have needed the spacer.

Glad some tested it. As I had a similar problem once. I sold it all and stuck with 10s.

Ah OK.. so you think the 105 11 speed road series 11-34 cassette quoted by the OP has a narrower spline fit than the 11 speed 105 road series 11-28 that I have?

I can't test that unfortunately because I don't have an 11-34 105 cassette....but is it likely they would sell two different cassette widths for the same groupset?

Surely they are the same fit?