Should I add disc brake tab to Yo Eddy?

[jonsonneborn]

My 1990 Yo Eddy is due for a powdercoat. Since the frame has already been repaired and I don't have alot invested in it, I was thinking about having a local frame builder (Bernie Mikkesen) custom make and weld on a disc brake tab (he quoted me $200).

Some questions and potential downsides are:


The cable routing is not correct for a rear disc brake; perhaps i'd have Bernie add some braze-on cable guides? Anyone have a good solution here?

I would still have cantilever spots although i could remove the posts

Would the rear drop-out spacing support a hub with disc?

For the front fork i'd convert my Judy to a Sid fork with discs

Obviously this frame was never designed to have the stress of a disc brake in this location; any forseeable problem here?

If i end up going through with this I will photograph and post the results.

[clockworkgazz]

pm Dr S on here as he did this with a Yo last year, very nice job to so see no problem in doing this.

http://www.retrobike.co.uk/forum/viewtopic.php?t=125004

[jonsonneborn]

Originally Posted by clockworkgazz

pm Dr S on here as he did this with a Yo last year, very nice job to so see no problem in doing this.

http://www.retrobike.co.uk/forum/viewtopic.php?t=125004

Wow, he did a nice job on this! Removed the Canti mounts, removed 1 of the 3 cable guides from the right side of the top tube and added some braz-ons to the left side to route the hydraulic lines. It looks like he also beefed up the drop out to support the additional stress of the brakes in this area. This is exactly what I want to do with mine. Thanks for the link. I have IM'd Dr S for more info. Cheers, Jon

[chainline]

also look at the yo's i have in my albums We have had disc tabs done on both with the studs removed

[terrafirma]

Chris Igleheart welded a tab on my Kona P2 1" threadless steel fork for $50. The fork went on my early IF.

[Dr S]

No problems with my Yo after 9 months of use. It has just been stipped and rebuilt after a seasons riding and there is no sign of any structural problems around the disc mount or stays. It is a pretty straightforward procedure that any good frame builder can do. One thing though- due to the bullet stays and the way they sit outboard of the line of the dropout, not all 'off the shelf' disc mounts will work. Mine was custom cut on a water jet cutter to my own spec. It needs to be longer, and tapered, to be able to braze onto the rear side of the tube, thus providing a larger joining area one fitted.
If using a SID, i would recommend using a later 100mm fork as they only work well when sagged by around 30%. if you dial that much sag into a 80mm SID you will end up with very little usable travel. Using a sagged 100mm fork on a Yo is fine as long as it is a later suss corrected frame, using one on an earlier frame might affect low speed handling and turn in.
When selecting a fork I looked into several differing fork options and concluded that the 2000-2001 100mm SID Hydra-Air would be the better option for this project. Finding a one inch steerer SID is not easy though. But this is another advantage. By removing the crown and steerer on a SID and replacing it with the bolt on crown and steerer from a mid 90's Judy DH you lessen the rake and offset of the fork. Coupled with a shorter stem, you quickly regain the low to mid handling characteristics that Yos are celebrated for.
With a little basic engineering and math you can easily overcome the negatives associated with fitting a longer fork to a frame that was designed around a shorter item. I love the handling of my Yo now as much as i did before the modifications. It is much more comfortable and there is a vast improvement in front end grip over rougher surfaces.

As a final note, i would never condone defacing a good Fat Chance frame by adding discs and guides etc. But as my frame was just about fit for the trash can, I feel I was justified in making the mods, trying out the theory and giving it a new lease of life.

[jonsonneborn]

Originally Posted by Dr S

Using a sagged 100mm fork on a Yo is fine as long as it is a later suss corrected frame, using one on an earlier frame might affect low speed handling and turn in.
that

Since my frame is a 1990 and not suspension corrected I decided to bail on the whole disc brake project. Thanks for your nice write-up Dr. S I really enjoyed seeing pictures of your '94 Yo with Discs. I am going to stick with Cantilever brakes and send my frame and Judy lowers off for powedercoat. I did a little research on brakes and decided to order a set of the Avid Ultimate Black Ops V-brake calipers with sealed cartridge bearing and revearsable cable loop. Ideally I would have liked to go disc but the cost would have been alot considering the cost of brakes, new wheels, a SID donor fork & at least $200-$300 to have the frame modified. My Judy with England Air seems perfect right now and I didn't want to add to the front end height with a SID. Will post pics as I have them. Jon

[ameybrook]

My 98 with disc addition is currently my main hardtail. Such a great riding bike. I think you made the right choice passing on adding a disc to your 90. Some bikes were meant to be kept as is.

[yo-Nate-y]

Your Yo's a very nice way to update. Nice cranks too!

I agree about passing on disc'ing the '90, unless you were going to stay rigid, it seems like the wrong platform.

[fat66]

Originally Posted by ameybrook

My 98 with disc addition is currently my main hardtail. Such a great riding bike. I think you made the right choice passing on adding a disc to your 90. Some bikes were meant to be kept as is.

That is a beautiful bike, did 3D do the work on the disc retro-fit? Or Norse Cycles? Paint or powder? Well Played Sir!

[misterdangerpants]

Originally Posted by ameybrook

My 98 with disc addition is currently my main hardtail. Such a great riding bike. I think you made the right choice passing on adding a disc to your 90. Some bikes were meant to be kept as is.

Nice bike! You too, Dr S.! My 1994 Rhygin Ra is in queue to get disc tabs this spring (at Circle A Cycles). It was a difficult decision considering I've logged thousands of miles on this beauty and I recently had it repainted by Toby Stanton. Will it destroy such a fine example (and it is stunning if I might say so myself)? I don't think so. I think it's a testament of how well the bike was made to keep up with the times!

[WVEddy]

Originally Posted by ameybrook

My 98 with disc addition is currently my main hardtail. Such a great riding bike. I think you made the right choice passing on adding a disc to your 90. Some bikes were meant to be kept as is.

This bike motivated my current rebuild (on month 9). I did not go disc though. I have way more problems with discs than i ever did with my magura rim brakes. all the dragging and bs it just not worth it. I have never had a rim brake try to cut off the end of my finger while tuning (keep your fingers away from a spinning disc!!!). plus brakes slow you down. going fast is way more fun. I went with the cane creek direct 5 brakes. lots of power, without the destruction of the historical value of my fat.