Brake

I received a reply from Yuba (below) regarding the problem with my rear disc brake. It seems a weird idea that only one brand of brake has a problem with these mounts but Ok I guess thats life building bikes. It does make the idea of IS or international standard mounting point a bit obsolete.

“Hello Mark,

For the BB7 there’s a need for a special caliper adapter, something that helps position the caliper in the proper position. We have some here at the warehouse shop we would be happy to send you a pair ($30).
We are still looking for a courier to Australia, however we could try to send the Utility Deck with the caliper adapters.

I will let you know later today.

Benjamin”

**** EDIT UPDATE: it seems it is not that uncommon for forks and frames to have trouble with larger disk sizes.  So apologies to Yuba. – thanks Dave for the research on this*****

BTW the utility deck has been on the way for 2 months so I’m thinking of just making my own.

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10 Responses to “Brake”

  1. Dave Says:

    I’m looking forward to hearing about your build! The V3 certainly seems to have some new quirks.

    That sucks about the rear disc mount! It’s a real shame to hear that doesn’t actually subscribe to the IS spec. Can’t say I’m surprised though. I requested a second frame after the first one I was sent had lopsidedly arched chainstays and one of the rack stays had one of it’s end sockets welded on backwards. The second one had stays that could all bolt on, but the chainstay issue was still there, albeit less severely. I ended up shimming the H-racks at the bolts in front of the rear wheel for them to come out level.

    So yeah, if Ben says he has an adapter to fix the “problem”, take lots of pictures of your setup before you pay for shipping for it. You shouldn’t have to pay extra for manufacturing defects. I can’t think of any reason why the BB7 would have this issue and not any other makes/models. And hey this guy got them on his: http://monumentallyafflicted.blogspot.com/2009/12/yuba-mundoscwhing.html

    I think the rear axle adapters Yuba sells are a little sketchy for exactly the same reason you do. I’d use a bolt-on hub and some big serrated washers on the outside of the dropouts. Or if your hub doesn’t have a bolt-on axle available you can at least get a non-quick-release skewer and do something similar.

    You’ll find a way to get past these little issues, it will all come together!

  2. mark Says:

    Hey Dave thanks for the encouragement. Your blog has been very helpful and many a night I hovered over the buy button for a Halo hub and adaptors. I went the end for very light (1.6Kg a set) but no doubt unsuitable Spinegy downhill wheels. They have their own problems which I may blog about later.

    BTW congrats on the bub and very nice work on the neonate transport buckets!

  3. baker Says:

    I’m the guy mentioned above using BB7’s. 185mm worked fine in the front. I could only get 160mm to work in the rear, and that was after man-handling the disc mount to straighten it out. I received an email from Ben saying that the 185mm would work on the rear if I used a 203mm mount. I just ordered some other junk and threw the 203mm adapter in just out of curiosity. Gets here tomorrow, we’ll see if it works.

    I’m very interested in the electric conversion and will be following this blog to see how it goes. I’d really like some type of assist for picking up my kids and bringing them up the 12% hill to my house.

    baker

  4. mark Says:

    Baker, yeah I’m keen to hear how the brake adapter thing goes for you. I might end up getting the tab mount moved to fit the 203mm disc I’ve got. Worst case I could probably find someone willing to swap a 160mm or 185mm for my 203mm.

  5. Dave Says:

    That’s just so odd that Ben would use a mount that wasn’t within the IS spec. If the mount was located properly you’ be able to run any IS-compatible setup without all this silly mismatching of adapters. In any of your correspondence with Ben about this have either of you been given a reason why he decided to make it this way?

    If it comes down it to, I’d say just run the 160mm disc. You’ll be able to lock up the rear wheel, and emergency stops are still going to use the front break too.

    About your Spinergys (sexy, by the way, your wheelset probably weighs about as much as my rear wheel…) word has it that the hubs (at least the freehubs) are made by Hadley. Hadley makes a 10mm bolt-on axle conversion kit for their hubs and I’s say there’s a reasonable chance it would fit your hubs too. If so you can grab some big serrated washers meant for a BMX bike and get some real grip on the rear dropouts. Your local DH/FR-heavy bike shop will probably be familiar with Hadley parts (might even have them in stock) they’d be a good resource to answer that question without having to buy the part first.

  6. baker Says:

    It looks like the 185mm rotor, 203mm rear adapter works fine, although I have only spun it around in the garage for now.

    http://monumentallyafflicted.blogspot.com/2010/01/yuba-mundo-v3-upgrades.html

    I believe the spacing on the disc mount is normal (although the alignment is terrible). The problem lies in the complicated frame design, where the built in rack introduces interference…

    baker

  7. Mark Says:

    I have not really got an explaination from Yuba. I’ve not really asked. I imagine the explaination word be pretty boring with slot of ums an ahhs involved. It’s ok I’ll go with the 160 or 185. Just would have been good to know about this limitation before.

    So Baker the converter is really just the 203mm adapter to allow me to run the 185 disc? (this is starting to sound like a Monty Python sketch!). Of course I have the 203 mm adaptor. So who wants to swap a 203mm disc for a 185? I can even provide an adaptor!

  8. Dave Says:

    I’m feeling a little sheepish after looking at SRAMs compatibility documentation: http://www.sram.com/_media/techdocs/disc-brake-compat.pdf . Regarding the medium and large size rotors:

    “May be compatible with your frame with the use of a different caliper mounting bracket. Check with the frame manufacturer to ensure proper
    clearance for an oversized rotor. Avid offers these brackets and they are available through your local bike shop.”

    So, if the 160mm works as intended, it’s not out of spec. And really, even fully loaded, we don’t need big rotors. How fast do you really intend to go with hundreds of pounds of cargo? Yuba just needs to put in the specifications that you can’t use big rotors, nothing wrong with that, it just needs to be said up front so their customers buying a frameset know what parts they can use.

  9. keller74 Says:

    Good call and good research Dave. Yeah it’s easy to go negative on manufacturers, I in particular get a bit trigger happy, but I have never found the communication from Yuba to be all that great either and I think poor communication inspires mistrust.

    It’s true that 203mm is just bling not performance so I’ll say it loud and and proud Yuba I did you wrong! Seems like it does at least largely conform to the IS spec (i’ll edit my post a bit)

  10. keller74 Says:

    I just had a better read of that SRAM link and really it seems to say just watch out for clearance issues with larger discs, not so much caliper positioning. I guess as Baker said the unusual shape of the Yuba frame makes finding a good mounting point difficult.

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