miamijim

The question of 10-speed compatibilty with a 126mm is often asked in C&V. For a variety of reasons including, but not limited to, frame design and frame material, its notalways feasable or a good idea to cold set a frame to 130mm or 'jam' a 130mm into 126mm frame. The objective of this thread is to show that 10-speeds with 126mm spacing can be achieved with acceptable wheel dish that doesnt compromise the integrity of the wheel.To properly understand the setup an understanding of hub design, cassette design and wheel dish is neccesary.

Hub design: Not all hubs are designed the same with a primary design difference being the distance from the back of the low gear cog to the centrline of the right flange. The closer the distance the easier it is to convert to 10-speed gearing with 126mm spacing. A sampling of hubs in my parts bin finds almost a 1.4mm difference amongst hubs. Approximate measurements using an 8-speed cog are:

8-speed Dura-Ace: 5.77mm
8-speed Ultegra:....5.75mm
8-speed Deore LX...7.0mm
7-speed 105SC.......7.17mm

In reality the Dura-Ace and Ultegra hubs are probably the same. The following pictures illustrates the dimension I'm referring to:








Cassette design comes into play as well. Using a Dura-Ace hub the distance from the back of the low gear cog to the right flange center line is as follows:

8-speed cassette: 5.77mm
9-speed cassette: 5.26mm
10-speed cassette: 4.59mm






Wheel dish can be a tough concept to understand. In simple terms its the distance from the wheel/rims centerline to the centerline of the right hub flange. Smaller numbers (a lot of dish) are bad while bigger numbers (not so much dish) are good. So, how small is too small? A sampling of various manufacturers hub dimensions finds that 16-18mm from the wheel/rim centerline to right hub flange centerline is about average. The following picture will give you an idea of 'dish' as indicated by the shaded green area.





Some individuals choose to simply remove a 4mm spacer from the left side of the axle. Several problems can occur. If the wheel isn't re-dished tire rubbing on the chain stay and off centering of the rear brake will be needed. Simply removing a 4mm from the left side will result in a wheel that's not properly dished but at the same time will NOT compromise the wheels integrity. If the wheel is re-dished so the rims properly centered the rim will be too close to the right hub flange which compromises the wheels integrity because there's too much dish. The following picture illustrate the difference between a hub with a 4mm spacer removed (top drawing) and a hub with proper spacing.

As you can see a hub with a 4mm spacer removed (top illustration) has 13mm of dish which is too much. Remember, a smaller number means more dish.

miamijim

Running 10-speeds with 126mm spacing is actualy easy to do. I did my conversion with an 8-speed Shimano 600 Ultegra hub. The conversion when using a Dura-Ace hub is very similar. The most difficult aspect is finding the proper .5mm spacers..yes, I said .5mm!!

130mm 600/Ultegra conversion:

1. Remove all spacers from the left side of the axle. There should only be the axle cone and locknut.
2. Remove the ~2.5mm washer from the right side and install ~1.5mm of washers.
3. Cut axle length down as needed.
4. Install 10-speed cassette.


130mm Dura Ace conversion:

1. Remove 2.5mm washer from right side of axle. Install .5mm washer washer of appropriate thickness to prevent chain rub on dropout.
2. Remove lock nut and washer from from left side of axle. Install thinner locknut and appropriate washers the achieve 126mm spacing. Dura-Ace's left sided lock nut us extremely thick and the washer is extremely thin. To remove spacing from the left side an alternative lock nut and washers must be used.
3. Cut axle length down as needed.
4. Install 10-speed cassette.


That it. Done. The trick is finding .5mm of washers. 1mm washers are easy enough to find but the .5mm washers are almost non-existent. I used chainring washers from an old Shimano crankset.

The following picture confirms 126mm spacing:





The following picture confirms 16mm of dish. 47+16 = a rim centerline of 63mm which is half of 126mm.






The final product:

miamijim

I'd like to thank Robbietunes for loaning me the 10-speed cassette.

squirtdad

Clarification: Did you mean to say..... it is not ALWAYS feasible to cold set? In general all the info I have on steel frames indicate this is not a problem...and I had no problems going 126 to 135.

miamijim

Good catch.....I'll edit.

XR2

Thanks.My wallet hates you.

reverborama

Excellent! My 126mm 9-speed setup has been working just fine -- I had 9-speed DA downtube shifters which is why I didn't go to 10-speed.

delicious

that's really cool, thanks for sharing!

RobbieTunes

I only have one question, and it may be a dumb one. When I put a 10-sp cassette with the deep splines on an 8/9/10 freehub (shallow splines), I have to use the thin washer behind it, or the cassette stays loose. Does that factor in?

And those are my favorite hubs.

ParaWK4

This is a timely post - I have been pondering the same problem for a 126mm alum frame - and I am tired of fooling with freewheels. My thought is to get a 130 mm Ultegra hub - do the simple removal of the 4mm spacer on the left side - then use an offset rim like a Velocity Synergy OC to get back the 4mm. Seems like the dish would be no worse than a regular rim on a 130mm hub. Would this also work ??

big_heineken

Are you able to tighten the QR skewer enough? Seems like you might have to shorten the length of the axle.

JakcBeNimble

So if I'm reading you right, you're using a 130mm hub that has better dish than most, and then taking out spacers so that its narrower than it started as?

miamijim

Robbie, that is correct. The setup pictured uses a thin Shimano spacer behind the cassette.



ParaWK4, yes, that is an alternative solution. A little trick would be to remove 1mm from the right and 3mm from the left while adding the 4mm offset rim. The end result would be a 1mm reuction in dish. (A good thing).


Correct. Shortening of the axle is required.


Correct. I dont know what the measurement are for any other 8-speed hubs like a 105, RX100 or RSX. To be honest I'm not sure if this will work with an 8-speed freehub body bolted to an older 7-speed hub. I suppose that could be a different project.

JakcBeNimble

Alright, that makes more sense. I was confused because your thread title says "10s on a 126mm hub," but then in your writeup you talk about using a 130mm hub. Also, calling it an 8s hub is a little confusing because I always think of them as 8/9/10s hubs.

Anyway, that's an amazing little find you've made, I'll keep it in mind next time I'm upgrading a drivetrain.

Another couple question: Did you have to do any redishing of the wheel? It doesn't look like it based on your writeup.
Also, did you use a friction shifter or indexed? I suppose you could use either, but it'd be obnoxious to use friction shifters with the cogs spaced so closely.

RobbieTunes

I can address the shifter question a bit. I've gone friction 2x9 before, and have indexed DT 2x10's running the cassette Jim used above. I basically rest my thumb on the DT, and then shift. Without it being somewhat steady, you can hit a bump and go 2-3 cogs. Light touch required, friction or not.

miamijim

I understand the confusion/misunderstanding. Yes, I took and existing 130mm 8-speed hub and converted it 126mm spacing and then I added a 10 speed cassette. Newer hubs may be 8,9 and 10 speed compatible but old hubs are NOT. Its NOT possible to add a 9 or 10s cassette to a an older 8s hub. I've tried and both hit the dropout/seat stay.

126mm hub bodies are bult with more space between the hub flange and where the cassette body bolts to it. I'll tentatively say NO, its not possible to run 9 or 10s on an OEM 126mm without having to much dish. (less than 16mm from the rims center to centerling of the righ hub flange.)

Dishing....a slight 1mm change in dish may be needed dpending on the hub. Ultegra ubs use different thickness than Dura Ace hubs which means there could be a slight dish between the 2. With the Ultegra hub as pictured above I could go another .5mm or so closer to the dropout without rubbing, unfortunately I dont have supper thin washers. With an addtional 1mm of dish there'd be 16mm from the rims centerline to the center of the right hub flange. 16mm falls within the normal range.

I've never run 9 or 10 speeds in friction mode....refer to Robbietunes response. The 9 and 10s cassettes I used were 100% original and unmodified.

Monoborracho

I just purchased a 126mm Schwinn OS Paramount frame. This should be interesting.

miamijim

It should go OK. The key is finding an 8-speed with less than 6mm from the back of the low gear cog to the right flange centerline. Find a hub like that and it should go OK.

dit

I am ignorant of part interchangeability. It seems that a 10 speed cassette will fit on an 8 speed hub? I thought that only 8 speed cassettes would fit on 8 speed hubs.

miamijim you did a great job of explaining the process which is not an easy thing to do. Even a rank amatuer like me could understand it.

bikemeister

Dang! Really great explanation. What's your day job - building jet engines or what? Detailed drawings, pictures for us visual folks, digital calipers, thorough text. Great job!

When I first read the post, I figured it would be a tough sell, unless you dished the heck out of the rear wheel and cold set the frame ta boot. You've shown me it can be done safety. One things for sure - there's gonna be a run on those applicable Shimano parts!

miamijim

8, 9 and 10-speed cassettes will fit on 8-speed specific hubs and older 7-speed hubs that have been fitted with more modern 8-speed cassette bodies.

7-speed hub sheel w/ 8-speed cassette body = No, it will not work with adequete dish.
8-speed hub shell w/ 8-speed cassette body = Yes, it will work with proper dish and rearrangement of spacers.

Keep in mind that all 8-speed cassette hubs are NOT created equal. A Deore LX hub has the same dimensions as a 7-speed hub thats been fitted with an 8-speed cassette body. 10-speeds on a Deore LX hub wull NOT work.

I'll try to post pics of this later today.

miamijim

Thanks for the kind words. Aside from finding an appropriate hub there are no special parts to acquire.

cwhale27

As someone who just recently had several spokes rip out of the rim due to metal fatigue on a 20 year pair of wolbers, this is a timely find.

But there is something that I feel that I am still missing, in what are the physical differences between the existing 130mm 8 speed hub you use/mention, and a current 130mm 10 speed hub, providing you found one that used the 6mm spacing between the cassette back and the flange. Do current hubs not use the same width in spacers, and therefore cannot be pared down in the same way?

Sorry if this has been expressed in different terms, my head's been a bit thick of late. But this could give me a few more years on my old c'dale.
Kris

TejanoTrackie 

Why not split the difference? Spread the dropouts 2mm from 126mm to 128mm, which would be only 1mm on each stay, and cut the hub OLD spacing down from 130mm to 128mm. It seems to me that this would be a lot easier, and you would not have to cold set the frame because it is not all that hard to spread the dropouts that much.

miamijim

You could split the difference with a 128mm frame but if you were to do that why bother spacing the hub down? Honestly, if I had a 128mm frame I'd leave the 130mm hub as is. From what I've read in these pages Cannondale designed their early 8-speeds frames with 128mm spacing so they could be used with eith 126 or 130mm hubs.

The intent of this thread was to see if 10 speeds with 126mm and acceptable dish was feasable. Nothing more, nothing less.