i'm currently looking at full sus frame with a lot of comcern over pedal bob. Now a Scott Spark (alloy 40 – 60) frame has caught my attention which i'm hoping to run with some RS revelations (140mm).

Does this frame design display pedal bob?
This frame has the lots of various lock out functions in the rear shock. Is there so much pedal bob in this frame that requires all these features or does does it run generally bobless in the middle ring and these are just gimmicks? I don't want to be thinking about traction setting/lockout levers all the time.

Spark frame + 140 Revs = Epic fail

or in easier terms, the last thing you should be concerned about after putting 140mm forks on an XC frame, that only just handles 120mm forks, is "pedal bob" it will ride like a bag of spanners.

I've got a Spark, and yes pedal bob is pretty evident. You have to use the shock settings quite a lot. Putting an RS Monarch (I think it's the Monarch) is supposed to change the ride for the better.

And 140mm is a definite no-no.

What they said.

Scott's do suffer from pedal bob unless you're on the TracLoc the whole time, and 140mm forks is just daft.

Dunno about a Monarch, but a number of folk on Weight Weenies have fitted RP23s and like it.

140's are far too long for the spark, it was only designed around 100mm forks and then stepped up to 120mm later.

As for pedal bob, bring a single pivot design it does display bob but only in the smaller rings is it massively evident, I had 2×9 on mine and mainly used the outer ring and once the shock was set up properly it rode well.

I don't want to be thinking about traction setting/lockout levers all the time.

Then buy a Spesh Epic.

Spark with an RP23 worked well for me. Definately far more effecient. As others have said, no to 140mm forks. I ran mine with 120 Durin Marathons which have quite a long axel to crown and that was about the limit.

Then buy a Spesh Epic.

Good advice. Or a Top Fuel, or Anthem, or many of the other bikes which were designed to pedal well first and be light second.

Hmmmm not surpised by the spark pedal bob but i am surprised by the opinion on the forks.

My basis is the revs on my on-one 456 give HA 69, SA 72.5 combined with a long ETT of 23" (probably a bit too long so might run a 50mm stem) and a 60mm stem.

I was thinking of running the Spark (or other similar frame) with 140mm would give me similar geometry. is this lunacy?

Well the 456 was designed with 4-6" travel forks, the Spark was designed for 100mm, then upped to 120 a couple of years ago, I wouldn't go putting another inch on that, it is still an XC race frame.

I also suspect you would void the warranty.

I was thinking of running the Spark (or other similar frame) with 140mm would give me similar geometry.

I'm sure in theory that it would seem like a good idea but just because it's technically possible doesn't mean you should do it as the Spark is simply not designed and tested for the stresses of a 140mm fork