hamachi

I just acquired this Ibis tandem that was built in the late 1980s. It has 26-inch wheels and 130 mm spacing. The bike is 25-years old, but beautifully made and in excellent condition.



What, if anything, should I do to upgrade this tandem?

The brakes don't seem very powerful. The front is a Shimano cantilever and the back is a Shimano U-brake under the chain stays. Should I upgrade the front to a V-brake, add an Arai drag brake, or leave the brakes alone? Will a drag brake fit on a 130 mm hub? My stoker and I weigh a combined 260 pounds.

At 130 mm, the rear dropouts are narrow. Should I cold set the frame to widen the rear dropouts to 140 or 145?

Would you upgrade the drivetrain? The rear hub is Shimano XTR with a 7-speed Uniglide cassette. The shifters are Shimano bar end shifters.

Should I get a suspension seat post for my stoker? Do you have any brand recommendations?

zonatandem

Upgrading a 25 year old bike can be problematic and co$tly.
If it fits you two correctly then I would only replace what wears out.
In our 39 years of tandeming have used rear U-brake and have used V-brakes. Just a matter of perhaps changing the pads and better cables and setting the brake pads closer to the rims.
Steel dropouts can be cold set to widen.
Currently we are using barend shifters on our custom carbon fiber tandem. Why? Because they are nearly trouble free and will outlast STI and electronic shifting (yes, been there and done that).
Just our in our input/experience.
Pedal on!
Rudy and Kay/zonatandem
Sinking lots of dough into an older bike is not usually the wisest thing to do, unless you are a vintage bike collector.

Ritterview

Usually, the advice is to ride it, and see what upgrades come to mind.

But since you are in the SF Bay Area, and steep hills abound, you should look to get your brakes upgraded sooner rather than later. You can try a brake booster for pretty cheap.

tandem rider

I had a '95 Ibis that my wife and I rode 32 K over 7 years. During an overhaul our mechanic discovered that the tubes are all sealed. With bosses for 8 water bottles, water had accumulated in almost every tube and some rust had developed. There was no way for the water to drain out. Your Ibis may be different but keep an eye out for rust in the frame.

geronimo2000

I have a '95 Ibis and the same concern about rust - I just had S&S couplers retrofit and had vent holes drilled and rust inhibiter applied while they were at it. Luckily for me there was nothing going on inside when they cut it open, but after he repaint it sure makes the bike look pretty!

I would put in a plug for Rodriguez' "big squeeze" cantis. I trust them to stop the bike on a descent even with a load and they are infinitely adjustable.

I also put a Maddox drag brake on the back - without a lot of miles yet I can't say much about it but I like its weight better than the Arai.

hamachi

Thank you for the alert on water buildup. I found this relevant article by noted frame builder Dave Moulton and this article by S and S Machine on the topic.

The Ibis tandem has one water bottle mount on the captain's down tubes, one on the captain's mid tube (for want of a better term), two on the stoker's mid tube, one on the stoker's seat tube, and one on the bottom tube. That's a lot of holes.

Given that adding S&S couplers is too expensive ($400 to $600 or more) to consider, what's the best way to inspect frame tubes for rust? Some recommend using a fiber optic borescope to inspect a frame. There are some flexible borescopes made with diameters as small as 0.6 mm that would fit through a water bottle mount hole, but they are quite expensive. I found an eBay listing for "Smallest Diameter Borescoe on ebay! 1mm x 6" + Light" but at a Buy It Now price of $1,275 it would be cheaper to get S&S couplers installed!

My guess is the best that one can do is to insert a paper clip through a water bottle hole, twist it around inside the frame tube, then tilt and shake the frame and see if any loose rust particles fall out. Any other ideas?

I have an old steel bike where the down tube, seat tube, and chain stays only vent into the bottom bracket. This is sealed pretty well from the outside, so I would think that since I don't see water buildup or rust in there then I wouldn't expect to see rust in my Ibis frame tubes. I still might think about adding rubber gaskets or Loctite to my water bottle mounting bolts to form a better seal.

Surly Bikes recommends applying JP Weigle Frame Saver, or motor fogging oil, or boiled linseed oil to the inside of the frame. I guess one could spray it through the water bottle mount holes if internal frame rust were a concern.

tandem rider

To find the rust on my Ibis my LBS mechanic took both screws out of the water bottle bosses and blew air from a compressor in one opening and rusty water came out of the other hole. I rode the tandem in the rain a few times but most of the water probably came from washing the frame with too much water. If I had not used so much water it might not of been a problem. A friend also had a 96 or 97 Ibis that he had Waterford repaint when the bike was a few years old. Waterford called him and recommended they drill a hole in the bottom bracket shell to allow water to escape.

JanMM

Keep in mind that the Arai brake is no longer in production.

hamachi

As I overhauled my new/old tandem, a couple of issues came up.

The first is regarding the captain's eccentric bottom bracket. The eccentric is held in position by two bolts that squeeze the bottom bracket shell. When the eccentric is secured, the two halves of the bottom bracket shell look like they are completely bottomed out. When I removed the two securing bolts I found that they were bent at the point where the Allen head joins the bolt shaft. Does this sound normal? Should I attempt to shim the eccentric so that the securing bolts don't bottom out? The eccentric appears to fit rather snugly in the bottom bracket, even when the securing bolts are loose.

The second issue is that the 7-speed Uniglide drive train shifts very slowly and noisily. The shift lever is a Shimano bar end shifter. Are slow shifts a consequence of the long cabling, or is it simply that Uniglide is that much inferior to Hyperglide? The shifts are so slow that I'm thinking I would be better off switching to friction shifting, because I can overshoot to get into the next cog more quickly, and then back off until it stops making noise.

nfmisso

Hi;

Let me weigh in as the owner of an upgraded 20 year old tandem (1994 Trek T50).

Modern shifters, rear derailleurs and cassettes shift much faster and smoother than almost all older stuff. Our T50 currently has a SRAM X.9 long cage RD with a 9 speed SRAM 11-34 cassette. It shifts quickly and smoothly. It did require some minor tweaks during the first week after installation with new cables. Cables stretch - the pre-stretched ones stretch a little bit, non-pre-streched alot. With the long cable run, cable ends, top notch housing, a bit of lubricant and good cable routing are EXTREMELY important.

Definitely change to Hyperglide or equivalent.

Regarding your eccentric - not normal. Bent bolts are SCARY, and need to be replaced. The system should not be bottoming out when it is properly tightened. There should be a slight visible gap where the shell is split.

Once you take care of the eccentric issue - if it can be taken care of; I would re-space the rear dropouts to 135mm (133 to 136), which allows you to use a large variety of very good and low cost MTB hubs.

If you are not flying down long hills, you can get away without the drum brake. And there are alternatives such as a front drum (there are several manufacturers), Phil Wood offers (used to ?) one. Phil's stuff is the best, and priced that way. Here is a 90mm Sturmey Archer: https://www.amazon.com/Sturmey-Archer...im_sbs_sg_cy_2

fietsbob

Gates center-track Belt on the crossover drive is a straightforward upgrade.

DT has a thread on to 6 bolt adapter , but how you will add the Disc caliper , is probably a braze and repaint project./


another drum brake?
Been using a Drum Brake hub on my snow bike for 2 decades , 36 hole (I laced 4X)7 speed F/W.
Now I see drum - cassette hub, from S-A,
a clever shop may be able to re axle it to match wider rear dropout spreads ..
i'd consider taking the 130 to 145 (Shimano's tandem hubs are that) ,
and you can take dish out of the rear wheel
https://www.sturmey-archer.com/produc...d/1/id/54.html

nfmisso

fietsbob;

Had not thought of that one; but it has only a 70mm brake, and 9mm rear axle. And this guy had major issues:
https://www.amazon.com/Sturmey-Archer.../dp/B005H40R1G

For a light team, a 9mm axle might be okay; for my heavy team, I really like the 14mm rear axle on the Wheelmaster hubs.

For a given shoe area; a 90mm brake will have roughly 2/3s more braking capacity.

hamachi

Following Sheldon Brown's simple instructions, I transplanted a Hyperglide free hub onto my existing hub. Changing to Hyperglide made an enormous improvement in shifting. Who knew Uniglide was so terrible?

Unfortunately, this change introduced a spacing issue. The Hyperglide free hub body is exactly the same height as the Uniglide body it replaced; however, the bearing surface are 3 mm shorter. Now I need to hunt for the appropriate spacer to correct this. If I put the spacer on the non-drive side then I'm also going to have to redish my wheel, but this will reduce the dish and make the wheel stronger.

More and more, I'm seeing the value of purchasing a new tandem.

waynesulak

1mm spacer on each side?

SJX426 

My 94 Burley Duet also has closed tubes. Upon disassembly, about a 1/4 cup of water came out of the captains seat tube! My frame is stripped now and I plan on drilling a couple of holes in the bottom of the tubes where possible. To attack the rust, you can fill the tubes with OA and let sit for 24 hours. Neutralize with baking soda and then treat with boiled linseed oil or frame saver of your choice.
Even if you vent the tubes, I would use anti seize on the water bottle screws to seal the threads against water incursion. It will also help prevent rust and some level of lubrication, although that is not what it is for. I would replace all my water bottle mounting screws with stainless steel ones from your HW store. Use Allen heads for ease of installation and to prevent using a Phillips head screw.
Looks like a steel frame so spreading the rear DO’s is OK. Be sure the RD hanger is adjusted too so the shifting will be optimal.
New pads will make a huge difference. Do that before changing brakes around. General cable and housing replacement with more modern parts would be in order if it hasn’t already been done.
Bent screws on the captain’s BB is an indication that they were over tightened. As a result the bosses may have been deformed causing the appearances of closure. If you have calipers, check the diameter of the eccentric OD and the BB ID without the eccentric installed. With the gap closed and see if the difference equates to a clamp.
Shim stock is not a bad idea if there isn’t enough difference, or if you want, cut the slot wider on the threaded boss side. If there isn’t enough thread material, you can use a nut and a longer screw. Be sure there is enough boss material around the fasteners that they don’t pull off when tightening the screws. Keep in mind that the bosses are likely brazed on. Here is another thought. Have a boss brazed on to use a set screw in addition to the clamping configuration.
I would use anti seize on the od of the eccentric (AL?) to prevent corrosion and lock up while not making it so slippery that you can’t clamp it tight enough.

fietsbob

My old S-A elite freewheel drum hub is a 9mm solid , it's a single .. should issues arise

Knocking out the 9mmID bearing cartridge and replacing it with a 10 would be a straight forward thing ..

then a bit thicker axle can be done ..


Seems Bike Friday for their tandem/Triple uses a Drum drag brake on the front + V brakes .

rear, normal 20" wheel build ..

hamachi

Thank you for the suggestions. I have attached a close-up photo of the offending bottom bracket shell. The stuff that appears to be in the gap is just grease that was squeezed out.

I'm thinking that the bosses are deformed, but not too much because the bolts still thread into the bosses pretty easily. I like the idea of filing off a little material so there's still a gap when tight.

Does anyone know the recommended torque for the bolts on the bottom bracket shell? Is there a good reference book for tandem bike repair? My Park Tool Big Blue Book has an appendix with recommended torque values for various bolts on bikes, but it doesn't have any tandem-specific information.

SJX426 

It is based on the size of the screw. Google it. https://www.williamtools.com/STANDARD...G-TORQUE.shtml

Good to know it was not closed! I would not make any adjustments but replace the bent screws and torque them appropriately.

SJX426 

That is interesting and makes good sense given how light the rear wheel can be. What hub do they use for that configuration?

Butcher

I once did the same thing, bought a Kuwahara tandem and upgraded it. By the time I got done, the only thing left was the metal steel frame. Even the paint was removed [and a few braze on items].

I had a lot of fun building/researching this tandem for my autistic son. It went from a 7sp 48lb to a 35lb 10sp Campy Record tandem. Fun build, but it was a lot of wasted money. I would still do it again.

fietsbob

the nature of Bike Friday's Build to Order, Just in Time manufacturing, they have options..
the customer can choose their preference .

hamachi

Here is some new information regarding my tandem's bottom bracket problems.

First, I went to my local hardware store to replace the bent bottom bracket shell bolts. The store owner said that the bent bolts were stainless steel. He recommended replacing these with hardened steel bolts, because they wouldn't bend. These were black in color, similar to what one might find on a seat post clamp. He also suggested that since there wasn't enough room to file open the gap between the shell bolt sleeves, and I couldn't insert a screwdriver to widen the gap, I could use a thin hacksaw blade to cut a gap. Price: $1 per bolt, and a free hacksaw blade thrown in.

Next, I visited my local bike shop. The shop owner said they'd chase the threads to see if that helped. The mechanic at first was unable to remove the fixed cup because the eccentric kept turning. He fixed this by removing the eccentric and applying some friction paste inside the shell. After that, he was able to remove the fixed cup and chase the threads. Interestingly, the shop owner said that in a pinch, an abrasive tooth paste may be used in place of friction paste.

The hope was that chasing the threads on the eccentric would allow the adjustable cup to turn more easily. Also, perhaps the threads originally had not been cut deeply enough. The mechanic cut the threads as far as his tool would go, but I later determined that they still weren't deep enough: it still takes a ridiculous amount of force for the last turn of the adjustable cup. Price: $45 to remove the fixed cup, chase the threads, and get the eccentric to stop turning.

Since the threads in the eccentric were not deep enough for the adjustable cup, my third plan was to file 2 mm off of the inside edge of the cup. In theory this would solve my problem because the cup would no longer bottom out on the threads. In practice, the cup is made out of hardened steel so several minutes of vigorous filing provided no measurable change to the cup thickness.

My fourth plan was to look carefully at the bottom bracket spindles. The rear spindle fits well. It is marked 127-68. I figured out that the first number is the total length. When I measured the width of both bottom bracket shells as 68 mm, I deduced that the second number is the width of the bottom bracket shell for which the spindle is intended.

Here's where it gets interesting. The front spindle is marked 120-68. It is long enough for the crank arms, but the distance between the bearing shoulders (the "B" distance in the diagram below) is slightly too small at 50 mm. To compensate for this, the adjustable cup has to be inserted so far that it is flush with the lock ring, and at this point the cup threads are hitting the bottom of the eccentric threads with great force.



I found another spindle to try. This one is marked 122.5-68, and the "B" distance is 3 or 4 mm larger. When using this new spindle, the adjustable cup no longer bottoms out on the thread, and the bearings in the eccentric can be adjusted properly. The problem is that it looks wrong because the adjustable cup now sticks out about 3 mm beyond the top of the lock ring. My other bikes are all showing about 1 mm of threads.

Here are some new questions for your consideration:

- the old spindle is marked 120-68 F8, while the new one is 122.5-68 CK. Does the 2-letter code indicate the "B" distance?
- is there a source for replacement square taper bottom bracket spindles where one might find a 120-68 spindle with a 52 mm "B" distance?
- is it feasible to shim the fixed cup to reduce the distance that the adjustable cup sticks out?
- is 3 mm of adjustable cup threads acceptable?

SJX426 

Hamachi, Thaniks for the detailed update. IMHO the original spindle is the wronge size WRT the B dimention. A proper B dimension with a 120 may be available. Looks like intense search is needed. You may want to look on the Harris Cycle site.

Yes you can shim the fixed cup. Shims work on both a standard BB and freewheel with varing thicknesses. The down side is the chain line change that happens. If you move the fixed cup out, say 1mm, I would check the rear BB on the same side to insure proper chain line dimensions. Having said that, 1mm may not be enough to make a big difference.

I think the issue with the 3mm is more about number of threads engaged in the BB housing wrt the cup. If there is more than 3 or 4 threads engaged, then yes 3 mm is acceptable, IMHO. Another way to look at it is to determine if more than half the threads of the cup are engaged with the BB housing. I would not want less than that, with more engagement,the better.

BTW, cup thickness can vary somewhat. I am not too knowledgable on the subject but I do know that Campagnolo had both thin and thick cups. However, cups are not interchangable in all cases as the spindle diameter varies.

Asking this question on the mechanics forum might work well for you.

hamachi

Thanks for your comments and suggestions. I found a lot of interesting and relevant information in the mechanics forum.

I think that I solved the problem. I found a 2.55 mm spacer of some sort in my parts box and put it on the "drive" side of the eccentric. This, paired with the 1225-68 spindle with the wider bearing spacing, yielded a front timing chainring position that is only 0.22 mm different from the rear timing chainring.

In the course of doing this I did learn some ugly truths in addition to what I have previously mentioned:

It's quite likely that my used tandem, the way I bought it, had the wrong spindle installed. With the old spindle, it was impossible to adjust the bearings unless I used a ridiculous amount of force, with one pin tool on each side of the eccentric. I doubt that the timing chain's chain line was as close as it is now.

My eccentric is, well, eccentric. In some positions it moves easily, while in other positions my bottomed-out pinch bolts will hold it in place while removing or installing the fixed cup. This doesn't seem right to me; however, right now I'm not willing to pay the $85 that my local bike shop would charge me to order a new eccentric that might or might not fit any better.

Using a hacksaw looks like the only way to open up a gap between the pinch bolt posts on my bottom bracket shell. Fortunately, it appears that I may not have to do this after all.

Different bottom bracket spindles may not be compatible in various ways. I already have noted that the bearing distance is different on two Specialized spindles. I got my hands on a Shimano spindle that looked ideal because its bearing distance was halfway between the two Specialized spindles, but I couldn't use it because the metal ball bearing clips of my crankset would rub directly against the Shimano spindle.

It appears that the old spindles aren't made any more. It is difficult to find one that is the right size. The ones I found on eBay were generally new old stock, priced at $40, $50 or even more.

There are plenty of square taper cartridge bottom brackets on the market. One of these could be a viable substitute, especially since the part that screws into the eccentric is often made out of plastic so it could easily be filed down if there are too many threads to go into the eccentric.

Spacers can be expensive, and not all bike shops have them. One shop was asking $3.50 for a 1 mm spacer, which I passed on because I knew that I needed more spacing than that. On eBay I saw a bag of 10 spacers of assorted widths for about $10, and on Amazon a bag of 10 1-mm spacers for about the same price. In the end the spacer I found in my parts box was almost the ideal size, and it was free.

SJX426 

@hamachi, Glad you resolved you BB issues!

WRT our uneven rotation of the ecentric, something is causing a binding, maybe an out of round shell due to distortion from over tightening or the cylinder of the eccentric is not cylindrical. You can check the later with digital calipers if you want. If you can get it into the proper position, lock it down, then your good to go and who cares!

There may be a coop in your area where you could scrounge. Also, if you visit the C&V forum, you may get some help. They are a great bunch of very knowledgable people with some surprising resources!

Another resource for older parts is Yellow Jersey in Wis. Unfortunately, Loose Screws is nearly gone. They were a good source of parts too. Did you check Tandems East or the Tandem stores in Co?