I'm trying to save costs so I want to upgrade to 7 speed 11-28 Cassette to keep the same shifters, dealer says I need a new Freehub, new 7 Speed Cassette, new chain AND NEW DISC BRAKES, why do I need new Disc Brakes? I already have them.

UPDATE: researching I've found it is a 6 Bolt Disc Brake (I added a new photo) so I think seller was trying to sell me what he had (Centerlock hub I think), not what I need (36H 6-Bolt rear hub).

enter image description here enter image description here enter image description here

  • 1
    Did you ask them why the disk brake replacement was required when you were given the quote? You appear to have an ISO hub, so I doubt it's a fitment issue. Maybe there is additional damage to the brake? Either way, asking them to explain the quote seems like a logical first step. – zenbike May 12 '16 at 22:52
  • So to clarify, you're changing the cassette from a MZ-TZ21 14-28T 7speed to a new 11-28 cassette? You only need a new chain. Consider a second opinion from a trustable LBS. – Criggie May 12 '16 at 23:39
  • MF-TZ21 is a Freewheel, I would like to upgrade to 7 Speed Cassette so I will need a new Freehub, new 7 speed 11-28 Cassette, new chain, what makes me feel confused is why do I need a new Disc Brake? – Ivanzinho May 13 '16 at 3:38

Pretty sure that the MF series has the freewheel integrated with the cassette, so if you are going to a "pure" cassette, you will need to replace the freewheel and possibly the hub. You would need to replace the hub if you can't find a conversion to a non-integrated freewheel for your current hub. If the hub gets replaced, that could affect the disk as well. Does your current disk have an ISO 6 bolt pattern, or something else like Shimano's centerlock? If it's an ISO 6 bolt, you should not need a new disk with a new hub, assuming you get a hub with an ISO 6 bolt pattern.

| improve this answer | |
  • Excellent point. If its some integrated nightmare, a whole new wheel might work out cheaper, and transfer the rotor/tyre/tube over. – Criggie May 12 '16 at 23:44
  • 1
    It's hard to tell from your pictures, but you might not need one. As said above, if you have an ISO 6 bolt pattern on your current disk brake rotor, it should bolt right up to a new hub. – Scott Lundberg May 13 '16 at 3:41
  • Looking at the first picture I think I can see a bolt head at the back of the dropout, suggesting 6 bolt ISO. But you never know, with bike bits, it might be a new, cheaper 5 bolt one :) – Móż May 13 '16 at 4:07

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.