Going from 120 to modern hubs?
 

I have decided to modernize my Falcon San Remo - however, I have measured the rear dropouts and it seems to be 120mm. I am a little nervous about spreading the frame for modern hubs - it seems a long way to spread.

Is there a best way to spread this? I have read Sheldon's article, and looked at the Park website, but they are talking about spreading the frame by 4mm - I am looking at 10. That seems a looooong way to spread. Should I attempt this myself, should I take it to someone?

Guide me, here.

Yes, but you're only speading each side by 5mm. It can be done, however you're obviously hestitant, so take it to an LBS. That way, if they overcook it, they have to come good for the damage.

The amount dropout realignment needed going from 120 to 126 isnt much. If you spread the dropouts by hand to 126mm this is how much the dropout faces are out of alignment:

http://i495.photobucket.com/albums/r...7/DSC02748.jpg

I don't think so. The entire increase in spacing on the hub is on the right side to make room for a wider cassette. So, you need to spread the right chainstay 10mm. Also, cold setting a frame means that you have to yield the material, and I think that is a very bad practice.

I'm talking about going from 120 to 130, not from 120 - 126. My LBS says they can do it, so off it goes.

off it goes then .
good luck .
:)
/T

No, that's not right. You redish the wheel to center it, not unevenly bend the frame. If you just bent one side, it would be out of true on several planes - not just skewed in one.

Instead of this:
/
\

You would have this:

/
_

And then, when you straightened the drop out, you would eityher have this:

x-
x -

Or, if you realigned both sides, then they would not be parallel to the frame any more.

Not true. When Shimano went to 130mm hubs they added spacing to left side as well as the right to help balance the dish. Shimanos 135mm rear hubs are identicle in every ways to their similar 130mm hubs with the exception of a 5mm spacer on the left side. The 5mm spacer is their to minimize dish.

Every frame manufactuere 'cold sets' thier frames. They dont come out of the jig in perfect alignment. The picture i posted shows the misalignment from 120 to 126. Any misalignment going to 130 wouldnt be any more than what most new out the jig frames may need for alignment. Its certainly less than what most of our 'can my dropout be straightened' threads need.


Shouldnt be a problem....

I again disagree. Let's deal with hard facts here. I happen to have frames with 120mm, 126mm, 130mm, 135mm and 140mm rear dropout spacing. I also have unmodified wheels that fit in these frames. I know for a fact that there is no difference in the distance from the left (non-pulling) flange to the dropout face on my 120mm and 130mm wheels (~30mm), but that there is approximately a 10mm difference between the distance from the right flange to the dropout face (~37mm vs ~47mm). So what this tells me that if I wanted to stuff my 130mm rear wheel into my 120mm frame without further dishing the wheel I would have to spread the right chain/seat stays 10mm at the dropout. When I visually compare the frames, it is apparent that the left side stays are angled out about the same, however, the right side on the 130mm frame is significantly more. Mind you, these are both road frames and road wheels, and MTB frames are a
little different, however, the OP's question relates to spreading a road frame from 120mm to 130mm.

As far as your assertion that frames are routinely cold set, I'd say that this applies only to steel frames and only 2 or 3mm at most. Furthermore, properly made frames are heat set in the jig to minimize spring back when they are removed. This is more of a problem with TIG (hot) welding than low temperature brazed lugged construction, which is why all of my old steel frames are lugged. I will maintain my opinion that spreading a frame 10mm is not a good idea, however, you and the OP are welcome to yours as it none of my business what you choose to do with your property.

Is it your assertion that the rear triangle is asymmetric?

If that is your contention, you are wrong. The rear drop outs, when properly aligned, are the same distance from centerline of the bike. They have to be, for the bike to track and ride properly.

If that is not your assertion, then I've misunderstood your position.

The distance from the dropout to the flange is meaningless. The tires are centered on the frame. The dropouts are centered on the frame. Where the hub ends up is not relevant. Dishing corrects for that. You can have extra washers on the right, the left, or on neither side. Doesn't matter. The dishing is to return the rim to the center, whereever the hub ends up.

If one set of stays was longer than the other, then yes, one drop out would be farther out from dead center.

Your not compensating for flange to centerline dimensions. Its very possible for all the hubs you mentioned to have the same left sided flange to lock nut dimensions. If thats true it means the hubs all have different centerline to flange dimensions which is what determines dish.

If the right side goes unchanged the difference needs to be made up in dish. Spread one side of your frame....you'll end up with and off centered rim or a wheel thats not in alignment with the front wheel.

Agreed.....

There's relevance to the extent that you need triangulation for a strong wheel which is why there is difference is flange width.

I agree, and retract my statement. I should know this because I have built plenty of wheels and used a centering tool. I still think it's not a good idea to cold set a frame 5mm, but that is just my opinion, and clearly no one else here agrees with it.

I don't think it's a great idea either. I cold set one of my first 3 speeds when I wanted to try out an 8 speed hub on it. Didn't like the hub at all, had to bend it back. Bending a frame back and forth is going to ruin it. Who knows, ten years down the road, someone might want your frame back to original and do the same. So yes, I agree with you.

Besides, it's trivial to flex the frame to fit a wider wheel in. All my 120mm spaced bikes have 6 and 7 speeds. If anything, it makes it easier to get the wheel in - the frame holds it steady while you tighten down.

Taking a 2x4 to a bicycle frame is not a good idea, in any circumstances.

I'm not doing that - and I'm not looking to bend it back and forth all over the place. If someone else ends up with this bike and wants to change it back, that's their decision; for me, this frame is going to wear modern running gear until one of us goes.

Is this a really bad idea - I see that two of you seem to be very against it. I have decided to take it to a shop where they have liability insurance, a frame jig, etc. Is this way bad? This is a nice lugged Reynolds 531 frame that I love, and do not want to ruin.

You can get a couple little trivial bends like this in steel before metal fatigue does any damage. My point is, I like to fiddle with bikes, and I don't like to mess with old things - when they are worth saving.

Likely as not, I or - after I get bored with this bike and move on - someone else may want to bend it back. I can get by without altering the frame, so I do. In fact, my 69 Competition I just outfitted with an indexed Ergo set up this weekend and I've had to jump thru hoops to not bend the frame. I am currently working on a custom 7 speed freewheel so I can keep the old wheels.

I wouldn't worry about nuts like me, if I were you. I'd just bend the bike.

What is wrong with 120? Learn to love 5 speed gogs/FW. If you want more, buy anewbike... If you want more gear options, go with a triple up front.

I don't like downtube shifters, never have. I like this frame, and want modernize the running gear. I already have an old 10 speed - I also have a modern bike that I don't care to ride because I don't like the frame.

If I could afford a new bike, I would - but they seem awfully overpriced, especially when I already have a nice frame that I like and can hang this stuff on.

There are a lot of possibilities for indexing, even if you decide to not bend the frame. My wife's bike indexes with Shimano 6 speed shifters and a 6 speed freewheel. Mine indexes with 8 speed shifters and a 7 speed freewheel. Hers was easy. Mine was hard.

I like downtube shifting, but I do agree that the drive train on old ten speeds sucks. It sucked when I was a kid, and it sucks now. This new stuff works as nice as my trusty old 3 speeds work. Even with downtube shifters, my bike shifts like a dream.

No - do it. I have 4 vintage Italian steel frames, all with modern Campy 10 speed drive trains. Once you ride such a bike, you'll never look back. And trust me on this - there are far more folks that desire a vintage frame with a 130mm spread than there are folks that want a vintage frame at 120mm. Re-sale will not be an issue. Unless it it something rare and/or uncommonly unusual or collectible, have it done. You will not regret it.

A 120mm bike with only 5 rear gears is not comparable to a modern drive train - it is night and day. And, you cannot buy a new bike that even remotely approximates the ride and feel of a top-tier vintage steel frame with modern components - unless you go with a custom build. $$$$$$$$$$$$

Do It Do It Do It

Do it.

I went 126 to 130 on a 87 Taiwanese Allez to put in 9 speed Campy Veloce drivetrain. The bike flys - even with this clyde astride.

I just converted a Nishiki Riviera GT into a cyclocross bike. I had never cold set a frame that far so I took it to the local co-op and they charged me $10 to go from 120 to 130. Well worth it IMO in case something happens such as the brake bridge popping off.

For those you against cold setting of steel, I suggest you stop riding vintage, steel frames, as it was SOP in the industry.

I never expected this many responses. I will do a before and after thread - I'm getting the bike painted as well.