Rear shock stroke length/travel adjustment?

[Amber Valley Guy]

My bike takes a 210 x 50mm rear shock, but I've seen some bargains at the more common 210 x 55mm. What I've managed to learn is most rear shocks manufacturers use spacers to reduce the stroke, so a 55mm is the same as a 52.5mm and a 50mm or a 65mm is the same 62.5mm or a 60mm, the only difference being a travel/stroke spacer for less than a tenner (usually of 2.5 or 5mm).
Does anyone know if it's true....the reason being the two I've been looking at are £150 less in the 55mm size than 50mm stroke (but both still 210mm eye to eye).

 

[John_likes_bikes]

Correct, a single eye to eye shock can be set up with multiple stroke lengths. This is achieved by limiting the stroke inside the shock, different manufacturers do that in slightly different ways with the same result. Not all shocks can do this and some are easier to change than others.

The real question is can your frame handle more wheel rear travel? Depending on compression curve 5mm in stroke can add 10mm or more in travel, leading to the tire contacting frame, over rotating pivot points, etc. And any damage this causes isn't going to be covered under warranty bc you when outside of spec.

 

[Amber Valley Guy]

Other way, I'm wanting to reduce the travel in a 55mm shock to 50mm, as I said above.

 

[JP-NZ]

Other way, I'm wanting to reduce the travel in a 55mm shock to 50mm, as I said above.

What is the bike and which shock are you looking to buy?

 

[Amber Valley Guy]

It's a Cannondale Moterra 4, Marzocchi Bomber Air or DVO Topaz 3.

 

[JP-NZ]

The bomber air, you can add reducing spacers I believe they are 0.1" and you'll need two that equals 5mm. So you can buy a 55mm and convert it to 50mm.

I don't think DVO allow you to change stroke length internally.