22mm chain stay disc brake adapter

[nanoseth]

Hi all you Klein lovers! My name is Seth and I work with a laser and fabrication shop in Denver, CO. We we tired of not being able to disc brakes on our Kleins so we made an adapter that converts the old 22mm chain stay mount pattern to the 74mm IS pattern. It works by getting the caliper above the seat stay there by avoiding any clearance issues. I am attaching some photos so people can see the functionality of the adapter. If anyone is interested or has questions they can contact me via e-mail or this site at nanoseth@yahoo.com. Thanks!

[Tycho]

Nice work Seth. One of the other posters in the thread made one very similar to this for his bike. Looks like a good solution.

Welcome to the Forums by the way!

[nanoseth]

Thanks!

Seth Clayton

[L84THSKY]

Hello

I currently use the Brake Therapy adapter, since my 1998 Mantra doesn't have the mount welded to the frame. I have a 1999 URT that I will be switching to. Can you tell me if my Magura Louise post mount brakes will adapt to this mounting? I know I need some adapter(s), but what will work properly?

Thanks
Eric

[nanoseth]

well, I can piont you in the right direction. Contact Tom at torontocycles.com and I imagine he will have what you need or know where you can get it. Good luck!

[L84THSKY]

“You MUST use Hayes 22 mm mount rear calipers. If you use adaptors for an IS or post mount caliper and the pistons are elevated much higher than the chainstay, the rear brake will eject the wheel from the micro dropouts”

The above comment was posted by the moderator. Isn't your adapter violating the rule he stated? I understand that the wheel could slip, but can't see how your solution is bad or not. My brake therapy adapter elevates the caliper even higher than yours, and I haven't had the wheel fall off yet.

So far TorontoCycles has not responded to me.

[Tycho]

Quick release mechanisms, especially on front forks, tend to "walk". As the dropouts move around due to frame or fork flex the QR skewer stretches and rebounds like a spring and the hub outer locknuts can walk around in the dropout. If you keep your QRs tight and have hubs with knurled outer locknuts, rear wheel ejection shouldn't be a problem, but it is something to keep in mind. On flexy QR disc forks you often find that the caliper will begin to rub now and then, and you have to loosen the QR and re-seat the wheel in the dropout. I haven't found this to be a problem on the rear wheel, probably because frames (especially the Mantra rear triangle) are much more dimensionally stable than telescopic forks.

There are two forces acting on the rear wheel under braking, the force of the caliper or brake pads (and the reaction of the wheel to that force) and the force of the rider's momentum wanting to carry the bike forward (and the reaction of the tire/ground interface to that force).

The wheel will want to move in the opposite direction from which the brake is grabbing it. In the case of the hayes mount caliper location, the wheel would want to travel upwards (or roughly into the dropout). In the case of a higher mount adaptor, the wheel is going to want to travel backwards, or straight out of the dropout.

The natural tendency of the wheel is to want to pull out of the dropout (assuming rear loading dropouts) under braking because the rider inertia wants to carry the frame forward and the rear wheel is opposing the rider momentum, but with the OE caliper location some of the braking force (namely the torsional force reaction) opposes this. However, with a high mount caliper these forces add, which may or may not be problematic as stated above. Seems not to be a problem based on the posts here and on the main page posts, but something to consider.