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  1. #1
    Just Say No to 26" Wheels
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    Clueless new tandem owner and rear hubs....

    I'm a new owner of a used Cannondale MT800 and am considering disc brakes. I have a question about the rear hub as this bike is spaced with a rear dropout of 145mm. Are there special hubs used for 145mm spacing, or do they just use a normal hub used for 135mm spacing on a wider axel with spacers for rear mountain bike type of disc wheels?

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    I'd not use a traditional 145mm hub. Your tandem puts a heck of a lot more stress on the hub than a single bike would. You'll be needing a tandem specific hub. I've had good luck with my HuGi's but, I hear they had problems a few years back. If you've got the money look into a set of Chris Kings as I'm learning they are top shelf but, you have to pay a premium for the kings.

  3. #3
    hors category TandemGeek's Avatar
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    You'll encounter both. However, as Brad suggests, your best bet is buying a hub that is marketed as a 145mm tandem hub. Tandem-specific hubs are designed to be built as asymetrical or dishless wheels, often time come with stainless steel axles and cassette bodies instead of aluminum, etc...

    White Industries makes an excellent, lightweight disc brake hub that's rated for tandems. Phil Wood also markets disc hubs but they are very heavy compared to most others and quite expensive. Chris King -- as mentioned by Brad -- also makes a disc compatible hub for tandems but is pricey too. I must presume the DT/Hugi hubs that come as OEM on Co-Motion tandems are also up to the task otherwise they wouldn't be using them.

    The sometimes tricky part of mounting disc brakes to tandems is getting the spacing correct for the disc brake caliper, noting that most disc brake systems are designed to be installed on mountain bikes with 135mm rear spacing or,in the case of Avid's BB road bike disc, for road bikes with 130mm rear spacing. I haven't fitted a disc to a Cannondale frame so I don't know if there would be any requirement for additional spacers to get everything lined up.

  4. #4
    Just Say No to 26" Wheels
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    Thanks to Mark and Paul. I took a closer look at the current set of wheels that came on the tandem. They are a very well built set on tandem specific hubs (with the brake drum threads on the rear hub). Maybe a brake drum kit would be a better solution on the rear. My understanding is that these drums are "switched on" to create drag on long descents to prevent excessive heat build up on the rims.

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  5. #5
    hors category TandemGeek's Avatar
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    Originally posted by BruceBrown
    Thanks to Mark and Paul. I took a closer look at the current set of wheels that came on the tandem. They are a very well built set on tandem specific hubs (with the brake drum threads on the rear hub). Maybe a brake drum kit would be a better solution on the rear. My understanding is that these drums are "switched on" to create drag on long descents to prevent excessive heat build up on the rims.
    That's the ticket.

  6. #6
    Sophomoric Member UncaStuart's Avatar
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    Disclaimer: I have never ridden a disc-equipped tandem. However, let me just throw out an anecdote about a ride we took with another couple and their disc-equipped Calfee.

    Last weekend we did the Mount Hamilton Challenge, a 126-mile ride that climbs to the Lick Observatory at the peak of Mount Hamilton in San Jose, and then goes down the back side and loops around through back country before returning to the start. The descent down the back side of Hamilton is always pretty technical, and with a somewhat recent chipseal on the roadway and a lot of damp spots from rain a few hours earlier, we took the descent fairly slow. The Calfee couple are usually fast descenders, having once hit 60+mph in the Sierra Nevada, but because of the conditions, they were cautious on this ride. After about five miles of the steep descent my wife and I (using our drum brake to keep things reasonable) started catching up with the other couple, something that never happens. Soon we had slowed to 15 mph and they signalled they were pulling over and stopping. Turns out that with the amount of braking they had been doing, the disc brake had heated to the point where the hydraulic fluid expanded and actuated the brake independently. We had to wait by the side of the road for the brake to release after it had cooled. They said this had happened to them a few times before, in similarly severe conditions. I don't know if this is symptomatic of disc brakes or if they are a special case for some reason. In any event, I have been perfectly happy with using a drum brake for a drag these last five years.

  7. #7
    hors category TandemGeek's Avatar
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    Originally posted by UncaStuart
    Turns out that with the amount of braking they had been doing, the disc brake had heated to the point where the hydraulic fluid expanded and actuated the brake independently. We had to wait by the side of the road for the brake to release after it had cooled. They said this had happened to them a few times before, in similarly severe conditions. I don't know if this is symptomatic of disc brakes or if they are a special case for some reason. In any event, I have been perfectly happy with using a drum brake for a drag these last five years.
    A hydraulic disc on a Calfee? What type of disc system is it: A Formula?

    I'll try not to rant here, but hydraulic disc brakes -- even open system models like the Magura Gustav M or Hope's Enduro/04DH -- are not designed to be used like a drag brake on tandems. Mechanical discs can be used as a replacement for a rim brake and/or both rim brakes but if you "need" a drag brake the only proven product is the Arai drum.

    We have mechanical disc drag brakes on both of our road tandems but they are older models of a Hope brake that's no longer produced. The disc does an adequate job of srubbing off speed for unloaded racing tandems touring in very steep mountain areas but are prone to fade, rapid pad wear and rotor problems when used for heavy teams or loaded tandems, i.e., they're better than not having a drag brake for the most severe terrain but they are still not as good of a drag brake as the Arai.

    Avid's BB road disc brake is becoming a very popular item on the high-end custom and go-fast tandems as a replacement for the rim brakes; some builders like Co-Motion are offering them as the OEM rear brake to be used in combination with a front rim brake. Todd Shusterman at daVinci tandems -- the same guy who pioneered the independent coasting system for tandems -- has been fitting his 26" road & off-road tandems (all his tandems use 26" wheels) with primary Avid BB brakes front & rear. Although he works closely with Avid whose business HQ is located just down the street from daVinci in Colorado, Avid will not officially state that it's disc brakes are suitable for use on tandems as a drag brake or as a primary brake. Glenn Erickson has also started to build road tandems with dual Avid brakes as OEM equipment.

    While Co-Motion, daVinci & Erickson's use of the Avid's is best characterized as real world "Beta" testing, I believe these folks must have a high degree of confidence in what they've experienced in their own use of these brakes on their personal tandems before offering them to their customers. However, consumers must recognize that these are still not disc "drag brakes" and, instead, are a new form of primary brake that offers superior modulation and stopping power in dry & wet conditions and offer a method of preventing heat-induced tire/tube failures. Yes, they have their own unique failure modes, but none come to mind that are as potentially hazardous as tire blow-out caused by excessive rim heating.

    Lastly, we can also speak to hydraulic brake performance as it pertains to off-road tandems. We have a F/S tandem fitted with Hope's Enduro 4 pot hydraulic discs -- an open reservoir system designed for downhill racers -- and also owned the previous model of 4 pot Hope hydaulic disc -- the DH04. These are great primary brakes for off-road tandem teams who venture onto single track, ride aggressively and/or who ride in wet or muddy conditions. However, as good as the hydraulic brakes are they are still not useable as drag brakes and if you overuse the rear brake to scrubb off downhill speed on long descents even the open reservoir models will eventually lock-up.

    Disc brakes may never replace rim brakes entirely, but I suspect you'll continue to see them on more and more higher end road and off-road tandems. Make sure your dealer or builder knows how you intend to use your tandem if you think you'd like to use discs. Some applications are perfect for the discs whereas others are best met with the very reliable Arai drum brake.

  8. #8
    Just Say No to 26" Wheels
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    Good post, Mark. I am a big fan of my Avid disc brakes on my Trek 8000. I was "forced" to make the switch from Avid rim brakes due to rim wear through problems of riding in mud, grit and wet conditions year round on the trails here in Austria. I guess once you have a rim explode the fear never quite leaves you that it could happen again. (Nor does the ringing in the ear ever seem to subside...) So I switched to the Avid disc brakes and am sold on these brakes. They have hydraulics coming out this summer as well. I use the middle sized rotors 185mm and imagine that the large rotors of 203mm would be the proper application for a tandem off road. I've been riding for a year in the Alps on the Avids and have never had overheating problems or been at a loss for stopping power using these brakes.

    Anyway, back to this 1999 Cannondale MT800 that I have purchased.

    http://www.cannondale.com/bikes/99/model-95MT8.html

    It has the Shimano tandem specific hubs. The rear hub (Shimano FH-HF07) has the threads for the drum brake. And the frame has rear disc brake mounts as well as the drum brake mount with a 145mm rear drop out spacing. I have to assume that Cannondale has this bike set up properly to accept the drum brake with the way it came in terms of spacing. However, although it sure looks to me that this Shimano FH-HF07 tandem rear hub could be a 135mm hub that is simply on a 145mm axle with spacers, the Shimano parts table lists that hub as only coming in 140/145/160mm. But I simply cannot tell as I have never looked at tandem hubs before and perhaps having 20 or 21mm of spacers between the hub and the dropout on the non drive side is normal. Does anyone know anything about this particular Shimano tandem hub (in terms of spacing) and what the normal amount of spacers on the non drive side is in mm? As I mentioned, according to the Shimano parts list, this tandem hub comes in 140/145/160mm. It comes from the 19998/99 Shimano parts group:

    http://www.bikepro.com/products/shim...b98_table.html

    http://www.fa-technik.adfc.de/Herste...o/Gruppen.html

    There is a 6 hole disc brake rotor adapter part available ($25) that threads on to the drum brake threads on the hub which allows you to use a disc brake on drum brake threaded hubs. If the spacing all checks out, perhaps this is an option. I would simply need the part and I could try my rear Avid from my Trek on the bike to see if the spacing all works out. If not, I'm only out $25.

    If that doesn't work, then it looks like I either go with the drum brake and keep the Avid Single Digit 5's that came on the bike - or I invest in a new wheelset with tandem specific disc brake hubs (145mm in the rear). The latter would of course be about $1000 investment, but the bike would then be properly set up for both road and off road descents.

    BB

  9. #9
    hors category TandemGeek's Avatar
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    Originally posted by BruceBrown
    The latter would of course be about $1000 investment, but the bike would then be properly set up for both road and off road descents.
    To get the skinny on that hub, drop a note to: tandemwiz@aol.com. This is the Email address for Mel Kornbluh at TandemsEast in NJ [http://www.tandemseast.com] and he is very knowledgeable regarding the Shimano tandem hubs and sells Cannondale tandems. So, he'll be able to tell you what will and won't work on your rig as well as being able to supply any odd bits you might need to make it work.

    Ultimately, unless you're going to get into some serious off-road riding the Arai drum is going to be a good investment since you can carry it over to just about any other tandem you might upgrade to in the future for use as a drag brake.

    --------------------------------------

    Something else to consider: This is going to sound snobbish, but if you really want to get serious about off-road tandem riding to the point where you'd want and/or need disc brakes (vs using the drag brake to control speed on long descents) you might want to consider saving your pennies for a full-suspension tandem (Ventana, Ellsworth, Boulder Bikes, or Chumba Wumba) and spec it with discs from the git-go and/or keep your eyes open for a used Ventana or Ellsworth F/S rig.

    I say this only because I was considering similar upgrades, e.g., selling our '98 MT3000 and moving up to a used '99 model that would work with discs front & rear. While looking for the '99 C'dale MT3000 I stumbled on a NOS '98 Ventana El Conquistador frame in South Dakota and purchased it for not a lot of money. Debbie was not happy because she "loved" the '98 MT3000 and was leary of moving onto something that couldn't be better. Well, after the first ride on the Ventana (Stratos 100mm fork & Hope 04DH discs front & back) she made this profound obserservation... "I didn't realize my back and neck weren't supposed to hurt after riding! This thing is amazing. I don't feel like I'll need to go to the Chiropracter after this week's ride." I had no idea how rough her ride was out back even with a suspension seatpost. The F/S rear end was the ticket to much more enjoyable and longer off-road rides.

    Just something to consider.

    Finally, you might also want to consider subscribing to our off-road tandem enthusiasts' discussion forum hosted on YahooGroups. There are about 240 list subscribers from around the world who are all off-road tandem owners and the group's name at Yahoo is: Double_Forte. You can find out more about the forum at: http://home.att.net/~double_forte
    Last edited by livngood; 05-02-03 at 09:21 AM.

  10. #10
    Just Say No to 26" Wheels
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    Thank you for all of that information, Mark.

    I was able to chat via email with a store called Tandems Limited. They knew all about that particular Shimano rear hub and they have fitted the disc brake rotor mount on the drum brake threads of that hub many times with little, if any difficulty. The mechanic said I may need a washer, but that he has personally never had to use one on that hub/threaded rotor mount combination. So it looks like the rear could be taken care of with the $25 part if I want to go that route. I am still contemplating the drum brake.

    I probably won't be using this bike for to much "serious" off road riding, but who knows? I don't want to limit the possibilities, but I purchased it mainly due to finding a used solution for my daughter and I to tool around on. Although I love rigid, we'll both be using the Thudbuster on this aluminum frame. If I take my daughter up in the hills and woods, it would be basic single track and fire roads where mud and wet is still an issue on those trails here in Vienna due to the annual amount of rainfall. These Sun Rhyno rims don't look like they would suffer rim wear through like my Bontgrager Race Lites did in 3-4 months time and I would watch them like a hawk. Any serious stuff we do up in the Alps and Vienna Woods will be on our solo mountain bikes which are already decked out with disc brakes, suspension forks and suspension seatposts.

    In my research of choosing a bike to buy, I did look at the Ventanas on the internet. Beautiful looking bikes. If I had a partner that was as interested in off road riding as I am, I would head in that direction. We'll see if I can cultivate one of my kids or my wife into enjoying some time on the tandem for serious off road rides. We haven't even taken it out on a really decent ride yet as I just picked it up a few days ago and it has the Schwalbe Big Apple 2.35's on the rims at the moment.

    You found your used fully in South Dakota? I've ridden in the Black Hills a few times. Beautiful country in that area and some nice riding is available. Home of the Thudbuster as well. Ryan works out of Rapid City and still handles all the orders for Cane Creek even though he sold his invention to them. I know that area well as my parents retired there over a dozen years ago.

    Thanks for the suggestions and information. I am looking forward to exploring the adventures a tandem can provide.

    BB
    Last edited by BruceBrown; 05-02-03 at 02:43 PM.

  11. #11
    hors category TandemGeek's Avatar
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    Originally posted by BruceBrown
    I was able to chat via email with a store called Tandems Limited.
    That would have been Jack Goertz over in Birmingham. Jack's been selling tandems longer than Cannondale's been making them. We bought our first tandem from Jack and his wife Susan, aka. Tandems Limited about 7 years ago and they are now good friends -- I should have given you a list of the various tandem guys/gals to call: my bad. I had Mel on my mind since ParamountScapin was looking into tandems and happened to live near TandemsEast. Regardless, good that you hooked up with Jack and got your questions answered.

    Originally posted by BruceBrown
    You found your used fully in South Dakota?
    Yup. South Dakota. The Internet is a wonderful place and www.tandemmag.com/classified is THE place to start your used tandem searches. Apparently the frame had been sold to a customer by Ventana and shipped out by UPS who promptly lost it. It was eventually found by UPS after the claim had been settled with Ventana so it was put out to auction as happens with most of the stuff UPS loses and then finds. A 2nd hand shop in SD bought the $2,800 frame probably for a few hundred bucks and eventually a mountain biker bought it. However, he never built it up and ended up selling it to me for $1k. I refurbished the frame which was pretty scuffed up after bouncing around in trucks, etc..., put on new decals, a disc brake compatible swingarm and ended up with what was essentially a brand new, never been built Ventana ECdM for $1,200. It was an awesome bike; however, we sold it to a couple in California a year ago. Interestingly enough, it was shipped in two boxes -- one with the frame and running gear and a second with the fork, wheels, seats/posts, and bars. UPS lost the second box. We're now on our 2nd Ventana ECdM which was built for us by Sherwood Gibson, the man behind Ventana.

    So, there you go... It's a small world when it comes to tandems.

  12. #12
    Just Say No to 26" Wheels
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    I just got back from my LBS here in Vienna. They have two teams that race mountain bike tandems, so I spoke with a couple of the guys about my possible upgrade to disc brakes on this Cannondale MT800. I had mentioned I was interested in getting a Hügi tandem front disc hub. They recommended using a Hügi freeride hub instead of a Tandem hub up front with 32 spokes on a disc rim and a Magura disc brake with a 200mm rotor up front for my needs. Is that bad advice as it sure seems to go against everything I have read here and other sites about tandem hubs?

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  13. #13
    hors category TandemGeek's Avatar
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    Not necessarily. There's not a whole lot of difference in front hubs with regard to tandem vs non-tandem models until you get to the spoke hole count. The bodies, bearings and axles are usually the same as the non-tandem version of the front hubs. Therefore, most hubsets that are marketed as tandem models are the heavier-duty models with a beefier rear axle, perhaps a different grade of bearings, a steel cassette body, and larger number of spoke hole drillings.

    Now, since this thread started off discussing only rear hubs and disc compatibility the introduction of the front disc option opens up a different discussion entirely.

    On the hubs, again, you can pursue a matched set of hubs marketed as "disc hubs for tandems" such as the Chris King, White Industries or Hügi model you suggested. Or, you can mix and match different hub models that offer the features needed for a tandem and that would work just as well. So, the recommendation to use a Hügi FreeRide disc hub certainly isn't a bad one.

    On spoke count, 36 has always been my preference for our off-road tandems since tandem-rated hubsets and heavy-duty rims are readily available. So, back to the recommendation; would 32h rims work? Properly built on deep-section rims, I suspect they would but long-term durability would depend on your team weight, how you use the bike and your riding style.

    Finally, to the brakes. There are only three disc brake manufacturers who have produced disc brake systems that are warrantied for use as primary brakes on tandems: Formula (Italy), Magura (Germany) and Hope (UK). Magura makes two models -- the Gustav M and the Julie hydraulic brakes. Both use an "open" reservoir and are available for use with 203mm front discs and 185mm rear discs. These brakes were designed for use on off-road DH bike applications and while approved as primary brakes on tandems, they are not warrantied for use as drag brakes. The open reservoir systems were designed to tolerate heat-induced brake fluid expansion which is a common occurance on DH bikes and tandems and the larger disc rotors are also used to manage heat. However, even these high-heat tolerant models of disc brakes aren't able to deal with the heat loads that pure drag brakes must deal with.

    But, what about Avid? Avid's BB disc brakes are being used as primary brakes on both road and off-road tandems by several builders. However, Avid will not warranty their use as the OEM. Therefore, builders who are offering them on their tandems are essentially own their own for providing customers with "warranty" coverage. Of the builders I know who are using them, I believe they understand the requirements and risks well enough to have made them available. But, all that aside, Avid still does not produce a tandem-rated disc brake.

    Bottom Line: If you're building your tandem up to be an off-road machine a good set of heavy-duty wheels and one of the Magura systems or perhaps even the Hope Enduro 4 pod open brake system would work fine. If you're building a road-going tandem it begs the question -- are you looking for a drag brake to help you control your downhill speeds or a full-disc brake road tandem?
    Last edited by livngood; 05-15-03 at 12:06 PM.

  14. #14
    Just Say No to 26" Wheels
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    Mark,

    I appreciate the discussion. Especially your patience with me as I am still trying to think it all through. I have no tandem experience, but really enjoy the riding I have been doing on it with my family over the past couple of weeks.

    Based on the type of riding we have "migrated" to with the tandem since acquiring it, it looks like we are building the tandem up for a lot of paved road use with occasional fire road, easier single track and gravel road use. We haven't been up or down any serious granny gear only trails as I am having to power most of the tandem by myself (8 year old stoker doesn't provide much power) and the granny ring is only a 26T which doesn't have the altitude climbing abililties of my 22T single bikes. I have a 24T laying around in a drawer that would fit, so I might swap it to see if there is any benefit. Total weight of tandem team is 250 - 305 pounds (tandem an additional 40 pounds). Stokers include my daughter, son and wife. The wife and I max out at 305 pounds. We all have single bikes designed for single track and rougher trail riding and will most likely stick with that type of riding for the majority of our off road experience.

    One of the main reasons I went to the LBS today is that I cannot get the front Avid Single Digit 5's to stop squealing on this tandem - in spite of dialing them and cleaning the rims correctly. They stop great, but could wake the dead. They squeal even more now that I have cleaned everything up and dialed them in. Dogs from miles away are howling. I am also concerned about the longer term effects of heat build up on the front rim. Since I am the captain and weigh around 200 pounds and the majority of braking takes place up front - that is a lot of work for the front V's to take on. On a single bike, my size and weight have me right at the Clydesdale entry point (200 pounds).

    My thought was to run a disc brake with a 200mm rotor up front to see how effective that works and controls the tandem braking. If I really like it, I have the option of adding a rear disc using the Shimano HF-07 tandem hub that came on the bike by acquiring one of those $25 disc adapters that screw on. At least I think I have that option according to the discussion I had which I wrote about in an above post in this thread. And I have the option of keeping the rear Avid Single Digit 5 V brake and adding an Arai drum brake to use in its proper manifestation for those longer descents. I remain amazed at how fast one can go down a hill on a tandem - even with a stoker who only weighs 40 - 60 pounds.

    The Magura's are plentiful here in Austria due to our location. As are products from DT/Swiss. After reading your earlier post and thinking of our particular use of the tandem not being serious off road riding, but more pavement and fire road, I was considering the Avid BB's with the 203mm rotors. And I understand that they are not warrantied by Avid for tandem use and that they are not to be used as drag brakes, but rather replacement upgrade for rim brakes.

    The LBS and the tandem guys said to leave the Shimano rear hub for now and use the freeride Hügi up front with a 32 spoke count. The large rotor disc brake they showed me was a Magura (they have all the Magura models in stock), but I cannot actually recall being told which model it was and I didn't look too closely as we were just talking about options. Rim would be a heavier duty disc specific rim.

    Any additional comments or suggestions you could provide would be much appreciated. I know the Avid's since I have a pair, but the Magura's seem to get high reviews and if the brake they were planning on selling me is actually designed or warrantied for tandem use....

    BB

  15. #15
    hors category TandemGeek's Avatar
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    Still sounds like a drum brake to control your descent speeds is the most cost effective approach for right now given your intended use.

    Not sure what to tell you on the brakes; Avid's cantilever brakes have a long-standing reputation for being squealers. If toeing-in the shoes hasn't stopped the squealing there are two other minor mods that have been known to stop the noise.

    1. Install a brake-booster like the daVinci "Stiffy" or "Little Stiffy"
    2. Install "Kool Stop" brake pads -- black or the softer salmon colored compound.

    If you do go the disc brake route the next item to attend to is your fork. Make sure it has "lawyer" lips and be sure to use an all-steel (e.g., XT) QR skewer. Disc brakes evolved so fast that the engineers didn't have time to redesign fork drop-outs and, as it turns out, most front disc brakes are mounted in such a way that the position of the calipers directs the brake torque through the front wheel axle and down, i.e., it's trying to push the front wheel out of the drop-out. Therefore, the only things holding the tire in the drop-out are the skewer and any fork-end recesses or retention lips (aka, Lawyer lips) that were put there to prevent accidental wheel loss from an improperly fastened skewer.

    As for which brake model, you really need to be sure what ever you buy is supported by your LBS if you rely on them for support. Avids -- IMHO -- would probably work just fine for you; however, I'm not you and only you know what types of conditions you'll encounter. Magura's Gustav M brakes have a great reputation for stopping power but, beware, they also have a reputation for being a bit noisy, e.g., rotor drag. The Julies are a new product and so far so good on the reports I've heard from the folks using them.

    Regards,
    Mark

  16. #16
    Just Say No to 26" Wheels
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    Thanks, Mark. Fork has the lawyer lips, althought the QR's are Dimension (F and R) and not XT. I am comfortable with the disc brakes from Avid (price, dialing in the red knobs and changing the pads). I pretty much do all of my own wrenching outside of suspension fork annual overhauls. I don't consider the Avid disc brakes that I currently have to be difficult to maintain - and of course there is no issue of having to set them with a slight drag. I have no experience dealing with hydraulics, so would have to learn about the Magura's.

    I have no squeal or squeak problems at all on single bikes with Avid's (SD 3's and SD 5's), but I am using the Rim Wranglers™ with the cartridge pads (Ritchey reds) on those bikes as well as various Mavic rims (221's, 517's, etc). The pads on the SD 5's that came on the tandem are the 20R™ Avid pads. They may be the culprit, or the circa 1998/99 silver annodized Sun Rhyno Lite smooth as glass rim braking surface may be the culprit. I've tried toeing, but it didn't stop the problem. The back is fine. Go figure. These rims look to be pretty darn durable as I see no signs of rim wear through even though they are several years old. Maybe some Kool-Stop pads would help tackle the resonance.

    Getting back to possibly the most economical and practical solution - in addition to solving the longer ascent braking problem, do you think the Arai drum brake would take enough pressure off of the front to curtail the squealing?

    BB

  17. #17
    hors category TandemGeek's Avatar
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    Originally posted by BruceBrown
    ...do you think the Arai drum brake would take enough pressure off of the front to curtail the squealing?
    Not really. If you're front brake is making noise it is, in essence, screaming for attention. You might experiment with a different 26" front wheel off of another bike to see if you can eliminate the rim as the catalyst for the noise. In other words, if you don't hear the squeal with a different rim you'll at least know that it's the combination of that rim and those brake shoes. If you still have the squeal you can dismiss the rim.

    I just finished troubleshooting a "creaking" headset/fork/wheel using parts substitution and determined that the skewer was the source of the noise instead of the headset, fork or hub. It was a welcome relief to know that instead of being the $500 fork, hub bearings or a stem it was only the $35 skewer.

  18. #18
    Just Say No to 26" Wheels
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    Thanks for the advice Mark.

    I just spent an hour this morning fiddling with the front brake and brake pads - as well as swapping out the granny chainring from a 26T to a 24T. I first swapped out the front wheel with one I use on my daily commute bike. They are the Mavic 517's and the rim braking surface is in excellent condition. I got on the tandem and headed down a hill. It squeaked and squealed, but not as much as the Sun Rhyno Lites. I swapped the wheel back to the Shimano tandem hub/Sun Rhyno Lite and decided to mess with the Avid 20R™ pads.

    I was previously toeing in the pads on the front simply by feel and sight. I thought I was getting a good angle, but I decided to try and follow the toeing in advice of placing a dime between the rear portion of the brake pad and the rim while leaving the front portion of the pad flush against the rim. I believe another way to do the same thing is to wrap a thick rubber band around one end of the pads, but I went with the dime technique. Tightened it all up and was surprised that a thin little dime made a much more dramatic toeing in angle than I had done by sight and feel.

    End result - I took the bike out for a spin on my own and headed down some hills. Squealing was pretty much 95% gone. I heard a faint iddy biddy squeal at the end of one of the stops, but no longer am I waking the dead. Question is - doesn't this basically just alter the relationship of how the pads will wear? Or is it really an accepted technical way of lining up the brake pads? I will keep an eye and ear on everything and be prepared to replace the pads.

    If I can get this bike properly set up to work for us with the wheelset and brakes that came with it I will indeed be happy due to the cost savings. Based on your advice about the Arai which I have made you repeat a couple of times in this thread (sorry), I think the better solution for our particular tandem cycling needs is to add the Arai drum brake. Disc brakes and a new wheelset certainly would be an upgrade that I would in the end be happy with, but since the wheelset and brakes that came with the bike are in such good shape it is probably money best spent later on for something else.

    Here is what I read on the Arai:

    http://www.precisiontandems.com/arai.htm

    The Cannondale MT800 does have cable stops and routing from the captain's position to the drum brake location, so that is not a problem. Besides, I don't imagine having a child stoker in charge of controlling the drum brake is the best option. What would be a fair price to pay for an Arai drum brake kit? I find it advertised on the internet from $98 - $145.

    BB

  19. #19
    hors category TandemGeek's Avatar
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    Originally posted by BruceBrown
    Or is it really an accepted technical way of lining up the brake pads?
    Yes, it's how it's done... .5mm to 1.5mm of toe is spec. Check Chapter 36 of Barnett's manual and you'll find Toe Alignment prominently featured.

    Originally posted by BruceBrown
    What would be a fair price to pay for an Arai drum brake kit? I find it advertised on the internet from $98 - $145.
    Precision tandems and Tandems East will have fairly competitive pricing for a complete sytem. $120 would seem to be about right unless you were getting a shaved drum from Tandems East. You might also try posting a "wanted to buy" notice at http://www.tandemmag.com/classified or on Tandem@Hobbes (Links and instructions on how to subscribe are on our Web site at www.TheTandemLink.com)

  20. #20
    Just Say No to 26" Wheels
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    Yes, it's how it's done... .5mm to 1.5mm of toe is spec. Check Chapter 36 of Barnett's manual and you'll find Toe Alignment prominently featured.

    Well, that it explains it. Barnett versus Zinn!!! I am using the "Zinn & The Art of Mountain Bike Maintenance" following instructions in chapter VII direction VII-20 PAD ADJUSTMENT where it states:

    "5. Finally, adjust the pad toe-in (e, Fig. 7.28). The pad should either be adjusted flat to the rim, or toed-in so that, when the forward end of the pad touches the rim, the rear of it is 1mm to 2mm away from the rim."

    I had always leaned heavily on the premise of the "either" portion of the sentence that reads "the pad should either be adjusted flat to the rim...." which had been working well for me with the particular bikes, brakes and rims (all Mavic) that we use. So I stand corrected and now have learned something through this squealing process and with your help. Regardless of Barnett or Zinn, I guess the toe-in method of using a dime works because a dime (measuring without calipers) looks to be just about 1mm exactly in thickness. So using Barnett's manual I could actually go another .5mm and using Zinn's manual I could go up to two full dimes if need be.

    Tidbit for those that live in Europe and deal in Euros: a 1 cent piece is 1.5mm in thickness and a ten cent piece is 2mm.

    I will look around for an Arai kit where you suggested.

    Thanks for all the help, Mark. I owe you a



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