How to Buy Replacement Parts for a Tandem

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How to Buy Replacement Parts for a Tandem

A bicycle-made-for-two was all the rage in the hard-pressed 1930’s when most folk could not afford a horseless carriage. One of the first signs of a couple’s commitment was buying a tandem to enjoy the freedom of the less crowded roads.

With cars becoming more affordable in the 1950’s tandems dwindled in popularity, but since the 1980’s the sight of a tandem is no longer quite such a novelty.

Why have a tandem?

Tandems are an ideal solution for partners of different riding abilities (and disabilities such blindness) who want to ride together, or two strong riders who want to cover ground. Twice the motive power but much less than twice the weight of a single cycle means tandems really fly on flat, rolling terrain and downhill stretches.

Climbing is thought to be more difficult but a well coordinated tandem team can climb amazingly well. Tandems are also great for loaded rides or touring because the extra weight is less noticeable than on a single.

Where from?

Mainstream cycle manufacturers such as Cannondale and Dawes are joining specialists like Santana, Helios, Orbit and Co-motion in tandem production.

If a couple takes to the tandem experience on a rented machine, there are specialists who will build a tandem to order.

This guide provides a run-down of components, easily buyable through eBay, which will help in specifying a tandem that suits a couple’s individual requirements or assist tandem owners in upgrading their existing machine, or a newly acquired pre-owned tandem.

The differences with a tandem

Tandems do not differ hugely compared with regular bikes in terms of equipment, but before annotating the anatomy of a tandem it’s important to clarify terms that are tandem specific and keep cropping up in relation to components.

  • Captain or pilot – the rider in front who controls the bike when travelling and steadies the bike when stationary.
  • Stoker – the rider in the rear who keeps on pedalling right from the start.
  • Sync., timing or cross-over chain – the chain that connects the captain’s crankset to the stoker’s crankset.
  • Sync. Timing or cross-over rings – chainrings typically found on the left side of the tandem.
  • The eccentric – the part which allows the long timing chain to be adjusted to maintain tightness.
  • Drum brake – brake threaded on to the rear hub, typically used to curb speed on long descents without overheating the rim (a tandem plus riders makes up a weighty ensemble).

Sizing

It’s important to choose components that fit both the purpose and the people.

The choice of wheel size relates to what the tandem will be used for. 26 inch wheels for tandem equates to a mountain bike and 27” for the tandem equivalent of a road bike.

Combine the appropriate wheel size with a good handlebar option (straights, drops or butterfly) and the tandem can be the perfect partnership transport.

There being two people to take into account makes frame sizing slightly more involved than sizing for a regular bike.

The front of the bike should fit the captain, so he or she can straddle the bike with both feet planted firmly. Because the stoker’s handlebars attach to the captain’s seat post, the captain’s seat cannot go all the way down. A couple of inches are needed for the stoker’s stem clamp.

The captain's reach should be the same as on his or her single bike.  Typically, the rear stem size should be adjustable to be 1 or 2 inches shorter than the front. Of course, the stoker must be able to reach the pedals when on the saddle.  

The naming of the parts

  • Frame There are lots of different frame designs and materials, and of course in lots of different sizes. Steel is still one of the most popular materials, but tandems can also be found in aluminium, carbon-fibre and titanium.Then there is the wheel size difference. You can get 26 inch wheels or 700C. Strictly for off-road, 26 inch wheels and some form of suspension are ideal. For strictly road-riding, 700C may be the obvious choice. For a mixture of road and trail, or expedition touring, 26" wheels offer great versatility and strength. Smaller captains may need to consider 26" wheels to get a good fit.
  • Hubs After the frame, good strong hubs are one of the biggest investments.

The spacing on a rear hub will most likely either be 145 mm or 160 mm.  People who already have a tandem should note that Santana and a few others prefer 160 and Co-Motion, Burley and Cannondale prefer 145.

Hubs with larger axles tend to hold up to tandem abuse better. Due to the added weight and stress, tandems may also have more spokes - 40 and 48 spokes are common.Rear hubs may have threading for a drum brake.  Shimano tandem hubs are good for the budget minded. And there are loads of others.

  • Rims Choose sturdy ones for the extra weight. Given that a wider tyre may be required the rim should be wider, too. Again because of the issue of spoke count, rims with 40 and 48 holes are available.
  • Cranks Standard cranks normally have chainrings on the right side and no chainrings on the left. As to timing cranks, the ones on the left with chainrings have reverse pedal threads, as does the captain's right crank.
  • Eccentric The eccentric goes into the front bottom bracket shell. The front bottom bracket goes inside the eccentric. As the name suggests, it has a non-round axis, and by rotating it, the timing chain can be made tighter or looser. .
  • Timing chain On tandems the chain is long. Any chains will work, roughly one and a half one joined together.
  • Stoker stem This attaches to the captain's seat post. Therefore it must match the captain's seat post in size. Some are adjustable, so the reach can be changed easily. If no adjustment is necessary get a non-adjustable stem in a specific size and save some grams.
  • Stoker handlebar The tandem issue here is being narrow enough to stay clear of the captain's hips. This is highly dependent on relative positions and varies considerably from team to team. In general, go for wider bars for the stoker. A stoker also may not need or want a full drop bar. Bullhorns, like those found on time trial and triathlon bikes are popular.
  • Wider captain's handlebar While they not tandem specific issue, a captain may choose to use a slightly wider bar than on a single, simply to gain more leverage, or control.
  • Long Cables  Tandems are much longer than single bikes, so cables need to be longer to get all the way back to derailleur and rear brakes. One can avoid the use of special long tandem cables by using a DaVinci In-Line Cable Splitter, making travel easier since one can decouple the cables and separate the handlebars from the rest of the bike, without having to readjust cables.
  • Derailleurs and shifters. Modern derailleur gears have become much better in recent years at handling the wide range of gears demanded by tandems.

Tandem dynamics are such that it is easy to spin out of a top gear, or bog down in a low gear in the absence of a really wide range.

The new Dura Ace front derailleur is designed for a 14 tooth difference in outer chainrings. This is great for tandems, which often require a really big outer ring, combined with a more moderate middle ring. If a larger than 27 tooth cog is required in the back, go for the off-road bike type of rear derailleur. Otherwise, the road models will work quite well.

  • Wheels 26" wheels do offer great versatility. There are a variety of tyres available from 1" narrow slicks to wide knobblies. Typically the clearance on frames built for 26" wheels is good enough to use any tyre. While wide and knobbly 700C tyres are available, most frames (for 700C) do not have the clearance for really wide tyres. Tandems tend to be better than singles in this regard, and many production models will take a 32mm tyre.
  • Brakes Good brakes are essential. Many tandems are now fitted with linear pull (v-brakes). When combined with an appropriate brake lever, these brakes are very good on a tandem, and their levers can be mated with bar-end gear shifters. Old fashioned wide cantilever brakes are designed to work with the cable pull of standard drop bar levers.
  • A drum brake threaded on to the rear hub is not an emergency brake; it is not really designed to stop the bike. It does perform quite well keeping speed under control on long descents. It is not advisable to have both rim brakes on one lever and the drum on the other. Independent modulation of rim brakes is crucial, especially in the wet.
  • Two of many things. Everything else is pretty standard, but doubled-bars, saddles, pedals. Just choose according to your own preferences. Captains and stokers may use different pedal systems, saddles and so on.

How to Buy Tandem Parts on eBay

Now that you've worked out which Tandem Bike Parts you want, find them quickly on eBay. While you shop, don't forget Tyres & Wheels, Handlebars & Stems, Headsets, Drive, Brake Components and Saddles & Seatposts. To start shopping, go to the Sports and Leisure category. Click the Sporting Goods portal and click Cycling.

Categories

The Categories list on the left side of each page will help you narrow down your listings by item type. You'll find links for Bikes, Bike Parts, Clothing, Footwear & Helmets, Cycling Accessories, Trophies and Other Cycling.  As you refine your search you'll be able to narrow down your choice by subcategory.

Product Finder

Use the Tandem Bike Parts Finder to quickly narrow down item listings by brand, model and condition. (new or used)

Keyword search

Search eBay listing titles for specific words. For example, if you want to find new tandem bike parts, type the keywords "tandem bike parts new" (without quotation marks) into the Search box. Click "Search title and description" to expand your results. Visit eBay's Search Tips page for more tips on searching with keywords.

If you can't find exactly what you want, try browsing eBay Stores or tell the eBay Community what you’re looking for by creating a post on Want It Now, or save a search on My eBay and eBay will email you when a matching item becomes available.

Buy Tandem Parts with Confidence

Make sure that you know exactly what you’re buying and understand how eBay and PayPal protect you.

Know your item

Read the details in the item listing carefully.

Remember to add delivery costs to your final price.

If you’re buying a high value item, check that the seller will insure it until it is delivered to you.

If you want more information, click the “Ask seller a question” button on the seller’s profile or the “Ask a question” link at the bottom of the item listing page.

Always complete your transaction on eBay (with a bid, Buy it Now or Best Offer) otherwise you will not be covered by eBay Buyer Protection.

Never pay for your eBay item using an instant cash wire transfer service like Western Union or MoneyGram. These are not safe ways of paying someone you do not know.

Know your seller

Research your seller so that you feel safe and positive about every transaction.

  • What is the seller’s Feedback rating? 
  • How many transactions have they completed?
  • How many positive responses do they have?
  • What do buyers say in their Feedback? 
  • Are they positive about the seller?

Most top eBay sellers operate like retail shops and have a returns policy.

  • Do they offer a money-back guarantee? 
  • What are their terms and conditions?

Buyer protection

In the very unlikely event that you do not receive your item or it is not as described, eBay Buyer Protection your purchase price plus original delivery cost.

Conclusion

Buying a new tandem can typically cost from £1,500 to £2,500 - and over £5,000 for a high-end carbon fibre model.  But it’s possible to find a good new frame for under £700 and build up from there, buying parts separately. The investment in time and money is worth it.  What else could revitalise health, relationships and sense of well being, open up new worlds and a lifetime of fun, closeness and shared memories? 

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