frame and fork choice

jpv987

hi all

was just wandering what it is about a frame that determines the amount of travel you can have on the forks?

hope i put this in the right forum

cheers in advance

supersonic

What the designer decided - you have to check.

nockmeister

The head angle plays a big part in deciding the fork length

jpv987

the reason i was asking is because im thinking of buying a cube acid and possibly upgrading the forks in the future. however i could'nt see on the cube website the maximum travel allowed

nockmeister

The Acid uses a 100mm travel fork, i'd probo stick with that length of travel.
You could fit any length fork, BUT it affects the ride DRASTICALLY...If you increase the length of travel it will slacken the head angle off, which in turn will slow the steering down, oh and may damage ur frame!! You can get forks which work over a range (U-Turn etc) from say 85-120mm...but these are not the best option if u cannot use all the travel

Northwind

Geometry partly. Mainly strength though. The way I see it is that you might get away with fitting a substantially longer fork. But if you're riding hard enough to justify fitting a longer fork, you're probably riding too hard for the frame to survive

Still, there's a lot of balls talked on this subject, people will have you believe that a 120mm fork in a 100mm frame will turn it into a chopper... But they have no issue with frames that are designed for a range of fork lengths. What's the magic difference that makes a 130mm Rockhopper a barge but a 130mm Soul a singletrack weapon? (apart from the fact that the Hopper might fold in half)

The Northern Monkey

Northwind
Strength.

Gusseting and tubing profiles etc etc.

Northwind

Which is why I said "(apart from the fact that the Hopper might fold in half)". But I was talking geometry.

supersonic

So...

What the designer had in mind.

What's the magic difference that makes a 130mm Rockhopper a barge but a 130mm Soul a singletrack weapon?

Have you looked at the rest of the geo? BB height, SA, HA etc. And of course the weapon of choice is personal ;-) Soul I like, but too slack for me.

But mainly is a warranty issue.

Northwind

supersonic wrote:

Have you looked at the rest of the geo? BB height, SA, HA etc.

You're being a bit too literal here mate. Point I'm getting at is that people assume that bikes will only work well with the fork length they came with, won't change in either direction, tell you it'll handle all wrong if you do. But the same people have no problem with bikes that are supposed to operate at different lengths. Design obviously plays a part but, say, look at the BFe- the Soul was never designed for a 160mm fork, the BFe shares its geometry exactly so it's effectively sticking a 160mm fork into a short travel bike, design wise. But it works.

Then again you get 456s not working very well at 100mm and Inbreds not working at 130mm, both designed to do so but compromised if you do.

peter413

I think some of it is phsychological just like the bullshit about kids going hyper with sugar.

When I was riding a Chameleon I wound the travel out to 140mm and it handled like a pig on the flat but as soon as the slope went down it was great!!

Basically if the bike is not designed for it, it will do it no favours in 90% of cases but then even if the bike was designed for it, if you are using it in the wrong conditions, it can completely wreck the whole thing

supersonic

When I was riding a Chameleon I wound the travel out to 140mm and it handled like a pig on the flat but as soon as the slope went down it was great!!

Basically if the bike is not designed for it, it will do it no favours in 90% of cases but then even if the bike was designed for it, if you are using it in the wrong conditions, it can completely wreck the whole thing

Yep, I agree!

The BFe works well because you are likely to go faster and steeper on it than say a RH, which is more of an XC bike and will be used as such. I'd say the RH would slay it on singletrack. Well, at least for me ;-)