So, these old 'Dales with looooong dropouts ...

[garethrl]

as pictured in many a thread like this:

http://www.retrobike.co.uk/forum/viewtopic.php?t=30570

A friend has recently resurrected one as a singlespeed, and as a non-retro afficionado (maybe that should read not-yet-retro afficionado) he's interested in putting disks on it. He doesn't have the original 1 1/4" Pepperoni fork or headset so has used a modern jump for with disk tab and 1 1/8" steerer and reducers.

A torsion bar is one option, but looking at it the other day we were thinking that there's a heck of a lot of metal there on the dropout. He's an engineer by trade and a colleague of his has access to CNC equipment. So, would it be practical to design some kind of disk tab that would fit over the dropout and secure via the existing eyelets, probably enlarged a bit to take an eg 5mm bolt? Having said that, new holes could be drilled of course, then depending on how the tab were designed and positioned, most of the braking forces could conceivably end up more or less perpendicular to the dropout.

So, just how strong are these dropouts? Are they somehow an integral extension of the chainstays, or welded in place where the chainstays and seatstays join? Is the area in general strong enough for the braking stresses exerted by, say, a 140mm rotor? If it's a daft idea then he'll probably go for a set of Maguras, a disk on the front and a rim on the rear.

Cheers, Gareth.

 

[MikeD]

Sounds like he's about to reinvent the popular A2Z adaptor that works in just the way you describe.

 

[orange71]

they're an extension of the chainstays. The seatstays come down to meet it and are welded there. However I would say that it is not a strong area - the seatstays are particularly thin aluminium and at that point they are also pinched on the drive side so you get clearance for the chain/cogs (only about 6mm profile). I wouldn't risk it.

 

[Xesh]

The only disc that I'd consider using on this type of frame is the old Hope C2 with the torsion arm fitting (the one with the bit that bolts on to the drop-out). You also need to use a Hope hub as well but that isn't a bad thing IMO.

 

[utahdog2003]

The dropouts are the weak spot on those era Cannondales. I wouldn't modify those frames for my worst enemy. Don't do it, and think twice about mounting a disc adaptor to them too.

 

[IbocProSX]

The Magura option with disc front an HS33 rear works a treat, you can stop the rear wheel dead with two fingers. So for normal riding there's little need for a disc on the rear , but the "uncluttered" handlebar on a SS will draw attention to the different levers. Is that Character or .....

Our group of 10 weekend warriors had 8 sets of V-brakes just not too long ago. Several guys switched over to Magura's after a very muddy weekend in the Ardennes 2 years ago, and they're perfectlty happy since. By now the bunch is split 50/50 between discs and Magura's.

Enjoy!

 

[magicmistertea]

i wouldnt bother personally i would be running cantis on a bike of that age, but if you realy want, hell why not try it ? let us no how it turns out !
cheers

 

[garethrl]

Thanks for all the input so far. In fact he's been running an old Maggie HS33 on the back for a while now, a loaner from another friend who had to put an old Avid V back on the rear to use a rear wheel with a chunky wide rim. He's been very happy with the performance of the Maggie so will probably go with a hydro rim brake on the rear and disk on the front. The concerns voiced here about potential vulnerability of the dropout area were very helpful.

Which leads to another question - is there any element of inter-operability at all over the Magura hydro range? Could he in principle use a lever intended for a disk brake with a hydro rim caliper like the HS33? This is only if he decides to be a tart and insist on matching levers, though to my eye a few of the different Maggie levers look similar enough to be a decent visual match.

Cheers, Gareth.

 

[Xesh]

Which leads to another question - is there any element of inter-operability at all over the Magura hydro range? Could he in principle use a lever intended for a disk brake with a hydro rim caliper like the HS33? This is only if he decides to be a tart and insist on matching levers, though to my eye a few of the different Maggie levers look similar enough to be a decent visual match.

Cheers, Gareth.

You can but be prepared to have either really good braking or none at all. Personally I wouldn't do it as the disc systems use different hoses and piston sizes. One of my work mates has put a HS33 lever on a set of Julie disc brakes and it worked fine. Later he changed the calliper to a Louise and it didn't work at all.

It's just best to leave them as they are in the long run, especially as your well being depends upon them working correctly.