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chrisred 04-02-14 10:53 AM

Building a cheap Tandem.
 
Hi Guys,

I'm looking at a cheap tandem frame locally to me, I'm wondering if it is feasible and safe to build a cheap bike?

My main Question is about brakes and wheels.

Will standard wheels and rim brakes be acceptable to ride on? This won't be a heavily used Tandem, no epic trips with luggage just something for my Girlfriend and I to have a bit of fun on. I understand the problem with rim brakes on tandems is the heat, will this be an issue with light usage? How much heat does it take for things to go wrong? Also wheels, will standard 36 spoke wheels be strong enough for a combined 27st?

StephenH 04-02-14 11:49 AM

There are a lot of variables involved.
Typically, a higher-grade "cheap" tandem means an older model. They may use 7-8 speed instead of 9-10-11 speed. I understand some of the older tandems tended to have the riders closer together; ie, a shorter rear cockpit. You could potentially wind up replacing quite a few parts to get it into good riding order. And, they may use parts that aren't readily available now. But, if it worked great 10 years ago, there's mostly not any reason it can't work great now.
The rim brake issue doesn't seem to be a big issue unless you have big hills or mountain descents. You might do better to check with some local riders and see what their experiences are. From the "27st", I deduce you're probably not from north Texas! One of the local high-mileage guys uses rim brakes with a rear disk drag brake (which he seldom uses on local rides.) That also assumes you have good rim brakes in the first place.

waynesulak 04-02-14 01:36 PM

These are a little dated but still a lot of good information including on components:

Tandem Bicycle articles by Sheldon Brown -- Harris Cyclery

Tandem Bike FAQ

LastKraftWagen 04-02-14 07:36 PM

Depends on your terrain and how fast you are traveling (energy = mass * speed squared), so if you're spending most of your time in the neighborhoods and bike paths rim brakes shouldn't be a problem as long as they are adjusted and in good condition. 27st [378lbs] should be okay on the 36 spoke wheels if they are of quality build, but 40 or 48 would probably be better. Also, if you are starting from scratch with the frame, you will probably need a tandem-specific wheel (the tandem rear spacings are normally wider).
Quote:

Originally Posted by chrisred (Post 16635108)
Hi Guys,

I'm looking at a cheap tandem frame locally to me, I'm wondering if it is feasible and safe to build a cheap bike?

My main Question is about brakes and wheels.

Will standard wheels and rim brakes be acceptable to ride on? This won't be a heavily used Tandem, no epic trips with luggage just something for my Girlfriend and I to have a bit of fun on. I understand the problem with rim brakes on tandems is the heat, will this be an issue with light usage? How much heat does it take for things to go wrong? Also wheels, will standard 36 spoke wheels be strong enough for a combined 27st?


swc7916 04-02-14 08:36 PM

Quote:

Originally Posted by chrisred (Post 16635108)
Hi Guys,

I'm looking at a cheap tandem frame locally to me, I'm wondering if it is feasible and safe to build a cheap bike?

Safe? Sure. Cheap? Probably not. If you want cheap and all you need is a neighborhood cruiser, I would urge you to watch Craiglist or somewhere for a cheap complete tandem.

chris ss 04-02-14 08:51 PM

Quote:

Originally Posted by chrisred (Post 16635108)
Will standard wheels and rim brakes be acceptable to ride on? This won't be a heavily used Tandem, no epic trips with luggage just something for my Girlfriend and I to have a bit of fun on.

My own views from 10,000 miles on our tandems-
1) 1980's Santana- "real tandem" for "serious rides"
2) 1960's Schwinn Twinn, but with recent mountain bike wheels (36 spoke), brakes, + gears -- we use this around town and "ice cream rides" and just bumming around and having fun.
(me + wife = ~300 lbs = 21-22 stone)

Brakes- I think you should be absolutely fine with rim brakes. Heat isn't likely to be an issue until or unless you're on LONG, STEEP downhills --- like in the range of >5% grade for >3 miles. If you want more braking power, try the new softer brake pads- KoolStop Salmon have worked amazingly well for us- TONS of stopping power- way more than we need on the "serious bike." We used to have a drum brake but we took it off cuz we have lots more stopping power than we need.

Wheels- I scavenged regular 36-spoke mountain bike wheels from somebody's else trash on the curb, to upgrade our old Schwinn Twinn from its original single-speed wheels. Granted you have a bit more weight on the bike than we do, but if you're just cruising around town or on bike paths or canal towpaths or something like that, they will likely do fine. I think it's very unlikely you'd suffer catastrophic failure that'd mean significant risk of injury. If a wheel like this isn't enough for you, I think the most likely failure mode be more broken spokes than you care to deal with -- rather than a wheel just collapsing underneath you and putting you in danger.

The rear spacing of the frame might be wider than regular mountain bike wheels. One way to deal with this is to "cold form" the frame to narrower spacing. Cold forming = bending. If you're comfortable with that. You have to make sure you bend both sides in parallel, not one side more and one side less. You can do this with strings from the head tube to the dropouts- keep it symmetrical. Another option is to put a longer axle into the hub, and stack nuts to widen it. This is of course not ideal but it's often adequate for "around the town" and keeping the cash outlay low.

More than anything else, I'd say figure something out, and get out and TRY it out. Get out and have fun. You can always invest more $$ (or pounds sterling) into it later, if you're so inclined and finances allow. But I'd say whatever you do, you don't have to spend a whole lot of time getting things perfect (tho there's nothing wrong with that if that's fun). When you were a kid, you might have put a friend on the back or front of your bike and rode around with that 2nd person... most likely nothing terrible happened.

Have fun!

chrisred 04-03-14 03:35 AM

Quote:

Originally Posted by chris ss (Post 16636968)
My own views from 10,000 miles on our tandems-
1) 1980's Santana- "real tandem" for "serious rides"
2) 1960's Schwinn Twinn, but with recent mountain bike wheels (36 spoke), brakes, + gears -- we use this around town and "ice cream rides" and just bumming around and having fun.
(me + wife = ~300 lbs = 21-22 stone)

Brakes- I think you should be absolutely fine with rim brakes. Heat isn't likely to be an issue until or unless you're on LONG, STEEP downhills --- like in the range of >5% grade for >3 miles. If you want more braking power, try the new softer brake pads- KoolStop Salmon have worked amazingly well for us- TONS of stopping power- way more than we need on the "serious bike." We used to have a drum brake but we took it off cuz we have lots more stopping power than we need.

Wheels- I scavenged regular 36-spoke mountain bike wheels from somebody's else trash on the curb, to upgrade our old Schwinn Twinn from its original single-speed wheels. Granted you have a bit more weight on the bike than we do, but if you're just cruising around town or on bike paths or canal towpaths or something like that, they will likely do fine. I think it's very unlikely you'd suffer catastrophic failure that'd mean significant risk of injury. If a wheel like this isn't enough for you, I think the most likely failure mode be more broken spokes than you care to deal with -- rather than a wheel just collapsing underneath you and putting you in danger.

The rear spacing of the frame might be wider than regular mountain bike wheels. One way to deal with this is to "cold form" the frame to narrower spacing. Cold forming = bending. If you're comfortable with that. You have to make sure you bend both sides in parallel, not one side more and one side less. You can do this with strings from the head tube to the dropouts- keep it symmetrical. Another option is to put a longer axle into the hub, and stack nuts to widen it. This is of course not ideal but it's often adequate for "around the town" and keeping the cash outlay low.

More than anything else, I'd say figure something out, and get out and TRY it out. Get out and have fun. You can always invest more $$ (or pounds sterling) into it later, if you're so inclined and finances allow. But I'd say whatever you do, you don't have to spend a whole lot of time getting things perfect (tho there's nothing wrong with that if that's fun). When you were a kid, you might have put a friend on the back or front of your bike and rode around with that 2nd person... most likely nothing terrible happened.

Have fun!

Great thanks exactly what I was after. I'll let you know how it goes!

nfmisso 04-03-14 08:28 AM

We're a 500+lbs team; and do fine with 40 spoke Velocity Dyad rims. A well built set of wheels with 36 spokes per should be fine for you, especially with wider moderate pressure tires. Smaller diameter wheels are stronger than larger - and generally a bit less expensive. We have Avid SD5 "V-brakes" (rim) on our T50 - they are very effective.

oddjob2 06-20-15 08:08 PM

Quote:

Originally Posted by chris ss (Post 16636968)
My own views from 10,000 miles on our tandems-
1) 1980's Santana- "real tandem" for "serious rides"
2) 1960's Schwinn Twinn, but with recent mountain bike wheels (36 spoke), brakes, + gears -- we use this around town and "ice cream rides" and just bumming around and having fun.
(me + wife = ~300 lbs = 21-22 stone)

Brakes- I think you should be absolutely fine with rim brakes. Heat isn't likely to be an issue until or unless you're on LONG, STEEP downhills --- like in the range of >5% grade for >3 miles. If you want more braking power, try the new softer brake pads- KoolStop Salmon have worked amazingly well for us- TONS of stopping power- way more than we need on the "serious bike." We used to have a drum brake but we took it off cuz we have lots more stopping power than we need.

Wheels- I scavenged regular 36-spoke mountain bike wheels from somebody's else trash on the curb, to upgrade our old Schwinn Twinn from its original single-speed wheels. Granted you have a bit more weight on the bike than we do, but if you're just cruising around town or on bike paths or canal towpaths or something like that, they will likely do fine. I think it's very unlikely you'd suffer catastrophic failure that'd mean significant risk of injury. If a wheel like this isn't enough for you, I think the most likely failure mode be more broken spokes than you care to deal with -- rather than a wheel just collapsing underneath you and putting you in danger.

The rear spacing of the frame might be wider than regular mountain bike wheels. One way to deal with this is to "cold form" the frame to narrower spacing. Cold forming = bending. If you're comfortable with that. You have to make sure you bend both sides in parallel, not one side more and one side less. You can do this with strings from the head tube to the dropouts- keep it symmetrical. Another option is to put a longer axle into the hub, and stack nuts to widen it. This is of course not ideal but it's often adequate for "around the town" and keeping the cash outlay low.

Have fun!

Chris, could you post or send a link of your Twinn with the MTB wheels? Interested in front and rear brake setup and rear wheel setup. I built a Twinn from frame up for my gf's two teenagers and using normal 26 X 1 3/8 rims, single speed with a coaster brake. But they getting the rear chain jammed, no matter how tight I've got it. Don't know if the axle is moving on them and thus chain is getting loose. Thanks so much.

zonatandem 06-20-15 09:03 PM

2 Attachment(s)
We are absolutely fine with rim rakes on our tandems. Live and ride in the southwest USA with lots of hills and mountains.
Have climbed/descended up to over 9,000 foot elevation. Did 7% grade for 11 miles (Kitt Peak in Arizona) with just Mafac cantilever brakes on tandem.
We are rather light tandem duo (just under 250 lbs).
Yes, at your weight an older quality tandem with 40 or 48 spoked wheels would do just fine with good quality pads for braking.
"Cheap' does not hold up as well as 'quality'.
Picture #1 is our current custom Zona tandem with over 40,000 miles on the odometer with rim brakes. Our Co-Motion tandem before that we logged 56,000 miles.
Rudy and Kay/zonatandem

chris ss 06-21-15 02:29 PM

Quote:

Originally Posted by oddjob2 (Post 17912193)
Chris, could you post or send a link of your Twinn with the MTB wheels?

Yes I will, in the next day or 2 - need to get it out from behind the car in the garage -

chris ss 06-22-15 10:32 AM

6 Attachment(s)
Quote:

Originally Posted by oddjob2 (Post 17912193)
Chris, could you post or send a link of your Twinn with the MTB wheels? Interested in front and rear brake setup and rear wheel setup.

If your drive chain is getting loose, it's almost certainly the axle slipping. I'd try putting a friction washer between the axle nut + the dropout on each side. I'd also check the chainline- make sure the chainring+sprocket are more-or-less in line; and carefully look that chain over for flaws- stiff, frozen, bent, or damaged links.

Here's a bunch of pictures from my Twinn - hopefully it helps. Notes -
First rebuild ~1980:
- put it on 27" wheels - there were no 26"/MTB wheels back then. R wheel had a 5-speed Sturmey-Archer internal hub.
- The fork you see in these pic's is for a 27" wheel, hence longer than I'd want, if I were to replace again it today.

2nd rebuild ~2005:
- put it onto MTB wheels picked off the curb. (By now, not a matched pair- R is steel, F is aluminum.)
- brazed studs onto it for cantilever brakes.
- spread the R dropouts (cold-formed = bent) to fit the wider axle for 7-speed freewheel + derailleur.
- stoker crank is a MTB triple off another trash-picked bike - by a minor miracle, it fit the bottom bracket perfectly. I removed the inner ring from the MTB, and bolted the Twinn's timing chainring on there in its place. The limit screws on the F derailleur keep the shifting chain away from the timing chain.


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