Tandem Cycling - Rolf Prima Tandem disc wheels

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




View Full Version : Rolf Prima Tandem disc wheels


sweetnsourbkr
05-20-08, 05:39 PM
My question relates to the disc brake mounting system.

Because the 6-bolt rotor adapter is a thread-on piece, how can one be sure it won't get overtorqued, and thus strip the threads during hard braking?


TandemGeek
05-21-08, 06:24 AM
My question relates to the disc brake mounting system.

Because the 6-bolt rotor adapter is a thread-on piece, how can one be sure it won't get overtorqued, and thus strip the threads during hard braking?

Since the earliest days of chain-drive bicycles, the single-speed rear cogs have been screwed onto the rear hub and continue to be that way on most current track bikes, either directly or via a thread-on quick-change cog carrier. This method of fixing individual cogs and, later with multiple cogs when the rear derailleur was introduced, was eventually replaced by thread-on freewheels (http://www.sheldonbrown.com/freewheels.html)that were used for decades before the introduction of the splined cassette hub and cassettes in the 70's that you may be more familiar with.

Although I haven't asked, I strongly suspect basic engineering data regarding the load carrying capacity of different thread types and materials coupled with the vast history and experience gained with these thread-on drive-side cogs and freewheels -- to include the very high torque-generating touring-range freewheels -- was the basis for determining rear-wheel braking forces could also be handled by rear-wheel mounted thread-on drum brakes and disc rotors.

The bigger issue with these thread-on disc rotor adapters can be getting them back off if they are not installed using waterproof grease or anti-seize compound on the threads or routinely removed as part of a periodic maintenance regime.

sweetnsourbkr
05-21-08, 05:16 PM
Thanks for the insight, TG. I was wondering if any Rolf wheel owners had any issues with them.


mikeybikey101
05-22-08, 01:35 PM
hi, We have been using a disc brake with our Rolf wheels with no trouble whats so ever, as far as braking. As already noted, the problem is trying to get it off. The hub recently broke at a spoke hole, and is now at Rolf to replace. The first thing I will do when it comes back will to put some anti-seize on the threads and get rid of the set screw.

sweetnsourbkr
05-22-08, 06:03 PM
So there's a set screw? That's probably the mechanical means to keep it in place. I wonder if Rolf requires/recommends a specific type of Loctite to be used on those threads. How many miles do you have on those wheels, mikeybikey101?

mikeybikey101
05-22-08, 09:37 PM
There is a set screw, but to me it is superfluous. It will just mash the fine threads, and make removal even harder. Believe me, you don't need loctite. You need anti-seize. This thing will lock up on its own. I had around 6600 miles before I sent it in. I didn't have an industrial vise mounted to a heavy bench, therefore my efforts to get it off with a large wrench were ineffectual. If my thinking is correct, applying the brake just makes this thing tighter.

justcrankn
05-22-08, 10:23 PM
To get mine off I used a very large pipe wrench. I wrapped a several layers of rag around the adapter to keep the wrench's teeth from mauling it. I never did understand why there is a set screw.

sweetnsourbkr
05-23-08, 08:49 PM
Thanks for the insight, guys. :)