FlyingFranco

I have a single shock suspension (RST SS-A7) with 35 mm of travel
RST
on a bike with 700c wheel with disk brake.

I look at the web page info like this
- STEERER 28.6 mm 7050 Aluminum (Min. length: 200mm)
- LOWER 9mm open dropout
And I am lost :-)


I am looking for a Double Shock suspension with at least twice the travel.

What parameter I need to know to select one that will fit my bike.


Thank you

dabac

Strictly speaking you need a fork that has:
- the same steerer tube diameter
(Smaller steerer in bigger head tube is doable, but let's not go there)
- the same steerer tube length - or longer - than what's already on there. If threadless, and you want the bar higher, you must search for a longer steerer than what's on THE BIKE. The spec sheet value isn't important. If you have a threaded headset, fork needs to have threads enough to do up the headset.
- the right dropouts if you want to keep using the wheel. In this case a 9 mm q/r axle.
- it needs to be able o use the right kind of brake system.
- if rim brakes, it needs to be made for the right wheel size
- AND to keep the bike handling as it should, and avoid overstressing fork and frame you need to stick as close as possible to the axle-to-crown measurement of the old fork.
This will obviously be impossible since your express wish is to increase travel. Which will mean that while still rideable, the bike will handle differently.
There's rake that should be matched too. But no point if you're going to a longer fork.
The really big thing to consider is this:
A bike only fitted for 35 mm travel is obviously not meant for rough riding. If you want to fit a longer travel fork you probably WANT to ride it harder. There are NO guarantees that the rest f the bike will survive that.

cny-bikeman

Somebody familiar with suspension forks can correct me, but it seems to me that 2x longer travel is not a good solution, but rather stiffer springs.

AlexCyclistRoch

From an engineering standpoint, doubling your travel is going to cause havoc with your steering dynamics. I'm trying to imagine what such a setup would even LOOK like. From a bike mechanic standpoint, I'd say that you don't know what you are doing, and you should take it to a bike shop.

FlyingFranco

Well, it seem my idea of changing the fork was not a very good one.

I have been riding all my life but with very basic bikes. I had an opportunity for this one, and I took it :-)

After reading all your answer i think you are right about the fact that bike does not fit my riding style but I guess it will have to do for my first travel plan. I have another project after that definitely will need better suspension. Next winter I will find another bike after I sell this one.

I will read again the post by dabac to begin my knowledge about bike and fork in this case. I might add a question or two because I still dont understand all the tech word in your reply.

Thank you all for the time you took to answer my question