GB 531 Underslung Vintage 100 mm 1" Quill Stem

✓ Original part - in production from the 1950s to the 1960s
✓ Suitable for historic cycling events such as L'Eroica
✓ Professionally checked & cleaned
✓ Worldwide shipping

GB 531 stem, hailing from Great Britain and in production from the 1950s to the 1960s. Made from steel and weighing in at 408 grams. A fine choice for keeping your vintage bike authentic, but also great for any other compatible bike too.

If you're taking part in L'Eroica or a similar vintage event, this is fully compliant - so rest assured, the pre-1987 police won't lock you up for having the wrong stem!

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

OVERVIEW


Condition - OK
Production Era - 1950s & 1960s
Country - British
Material - Steel
Weight - 408 g
Stock Code - U-ST74V

TECHNICAL INFO


Extension Length (ctc) - 100 mm
Quill Size - 1"
Steerer Size (ID) - 22.2 mm (Standard)
Total Shaft Height - 155 mm
Clamp Size - 25.4 mm

SHIPPING, TAXES & RETURNS

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.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

HELP SECTION

Extension Length (ctc) - this is measured from the centre of the handlebar clamp to the centre of the shaft, to the point where the stem bolt passes through. We always take this measurement in a straight line through middle of the extension, not along the top.

Quill Size - the most common size for classic and vintage road bikes is 1", this should be the same as the outside diameter of your fork's steerer column. Oversized steerers found on mountain bikes and later road bikes will be either 1 1/8" or 1 1/4".

Steerer Size (ID) - this is the most important measurement when checking the stem fits your bike. This should match the measurement of the inside of your fork's steerer column, where the stem will be inserted. The standard size for road quill stems was 22.2 mm, or 22.0 mm in France until the 1980s.

Total Shaft Height - measured from the top where the expander bolt head sits, to the bottom of the stem's shaft. To give you an idea of how high the stem can be set, there should be an absolute minimum of 50 mm inserted into the fork steerer, although most stems come with a 'minimum insertion line' to help with this.

Clamp Size - this should match the outside diameter of your handlebars and should be as close as possible to ensure a good and safe fit.