Shimano Exage 400LX (RD-M400-GS) c.1990 Classic Rear Mech

Shimano Exage 400LX (RD-M400-GS) c.1990 Classic Rear MechOriginal part produced in the 1990s Professionally checked & cleaned Worldwide shipping Shimano Exage 400LX rear mech, hailing from Japan and dating back to 1990. Made from aluminium steel and weighing in at 321 grams. A fine choice for keeping your classic bike authentic, but also great for any other compatible bike too. The mech's been carefully cleaned, thoroughly checked by one of our mechanics and graded as good condition, but do take a good look

✓ Original part - produced in the 1990s
✓ Professionally checked & cleaned
✓ Worldwide shipping

Shimano Exage 400LX rear mech, hailing from Japan and dating back to 1990. Made from aluminium/steel and weighing in at 321 grams. A fine choice for keeping your classic bike authentic, but also great for any other compatible bike too.

The mech's been carefully cleaned, thoroughly checked by one of our mechanics and graded as good condition, but do take a good look at the detailed photos so you can see the cosmetic condition before you buy.

OVERVIEW

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Body Condition - Good
Jockey Wheel Condition - Very Good
Model ID - RD-M400-GS
Production Era - 1990s
Country - Japanese
Material - Aluminium/Steel
Weight - 321 g
Stock Code - U-RM78C

TECHNICAL INFO

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Shifting System - Shimano SIS, Friction
Speed* - 7 Speed
Max Sprocket Size - 30 Teeth
Max Chain Wrap - 36
Chain Width - 3/32" (Standard)

*See help section.

▼SHIPPING, TAXES & RETURNS

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We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

EU Customers – for orders under €150 (excluding shipping), VAT will be collected at checkout, but from 1st July 2026, due to new EU import regulations, there may also be a customs duty payable to the carrier. For orders over €150, all import fees will be payable to the carrier, with nothing collected at checkout.

USA Customers – import fees are now collected at checkout for all orders to the US, so there won’t be any surprise charges when your order arrives.

Other International Customers – local import fees may still apply, charged by your customs office or courier before delivery. These are not collected by us, so please check your local rates before purchasing.

Any applicable fees will appear at checkout.

▼HELP SECTION

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Shifting system - friction means your gear levers don't click when you change gear, when they do click it's referred to as indexed shifting. If you have indexed gear levers they must use the same system as the rear derailleur, if you're using friction levers you can mix and match.

*Speed - the number of cogs at the back the derailleur was designed to be used with. This is important with indexed shifting, but with friction shifters you can in theory run any rear mech with any number of cogs, but you are more likely to have issues running high numbers of cogs with mechs from earlier eras.

Max cog size - the amount of teeth on the largest cog of your freewheel/cassette can be no greater than this to work with this derailleur.

Chain wrap - subtract the size of your smallest rear cog from your biggest, then do the same with your chainrings, add the 2 numbers together and you have your chain wrap.

Chain width - generally speaking, derailleurs designed for more than 3 speed use will fit a standard 3/32'' chain, the exception being some Cyclo & Simplex models from around the mid 1900s.