Bontrager Frame/RS Fork Geometry question

[Anthony]

No, as your bike will almost certainly have had suspension forks (I don't know if they were made then with the Comp). You'll steepen all the angles, and the front will be pretty twitchy - they are already "light" on the std geo.
Fit your fork, check the seat angle is the easiest way to to validate if it's a Suspension adjusted frame or not.

Also answered here, useful reading (see the last comment).

http://forums.mtbr.com/archive/index.php/t-5545.html

Straight from the horse's mouth can't be bad, but I think KB was overly pessimistic about finding a suitable rigid fork. Steve might be able to find a later-model Pace that would be close to the ideal 42cm length and have a 1" steerer. OK, it wouldn't have a 1.25 offset, but I question whether that's truly necessary. In any case, no frame is 'designed for a 1.25 offset' - the frame is just designed for a certain length of fork, and whether you like a 1.25 offset is just a matter of taste. If it's such a great thing, how come nobody else builds forks with 1.25 offset?

 

[scant]

No, as your bike will almost certainly have had suspension forks (I don't know if they were made then with the Comp). You'll steepen all the angles, and the front will be pretty twitchy - they are already "light" on the std geo.
Fit your fork, check the seat angle is the easiest way to to validate if it's a Suspension adjusted frame or not.

Also answered here, useful reading (see the last comment).

http://forums.mtbr.com/archive/index.php/t-5545.html

Straight from the horse's mouth can't be bad, but I think KB was overly pessimistic about finding a suitable rigid fork. Steve might be able to find a later-model Pace that would be close to the ideal 42cm length and have a 1" steerer. OK, it wouldn't have a 1.25 offset, but I question whether that's truly necessary. In any case, no frame is 'designed for a 1.25 offset' - the frame is just designed for a certain length of fork, and whether you like a 1.25 offset is just a matter of taste. If it's such a great thing, how come nobody else builds forks with 1.25 offset?

yeh thats a good point

its funny how in the modern suspension fork world fork rake is hardly discussed any more.. maybe only on the 08 trek fuel ex9 with trek specific fox forks.. but even so a fairly small proportion.. so in the modern suspension fork world at least theres less of a concern for fork rake.
I guess this all relates back to the "whats actually best for me Vs, what do you thinks best for you" conversation.

 

[Anthony]

its funny how in the modern suspension fork world fork rake is hardly discussed any more.. maybe only on the 08 trek fuel ex9 with trek specific fox forks.. but even so a fairly small proportion.. so in the modern suspension fork world at least theres less of a concern for fork rake.
I guess this all relates back to the "whats actually best for me Vs, what do you thinks best for you" conversation.

The really retro touch there is where KB says "the right sized rigid fork is equal to the old judy or mag 21 fork's length minus 1/4 to 3/8 of an inch" - i.e., he was thinking in terms of 6-9mm sag. Now that 30-40mm sag is commonplace, all the numbers are so much higher that the old niceties about offset and trail seem to have gone out of the window.

 

[sjaeger]

I only could tell you from my experience: I am riding a Bontrager L (same time) with a PACE RC36 Stealth Hollowform (reduced to 80 mm). This works pretty good!
Compare to modern frames, the angles seem to be still very steep. But it is a matter of taste.

 

[Crell]

The really retro touch there is where KB says "the right sized rigid fork is equal to the old judy or mag 21 fork's length minus 1/4 to 3/8 of an inch" - i.e., he was thinking in terms of 6-9mm sag. Now that 30-40mm sag is commonplace, all the numbers are so much higher that the old niceties about offset and trail seem to have gone out of the window.

He was. Personally I'd put a custom rigid fork on it : )

To add fuel to the fire, I switch between a set of Comp forks and a set of RC36 proclass Evos on a NON - suspension adjusted frame.

 

[No Longer Registered]

There is some very useful info there are on the MTBR fourm. Many thanks for digging that infomation out. The head angle does feel steep. At first I put the extra quick response down to being used to riding a suspention fork for the last few years and the RC30's having little flex in comparison. Then I realised that the gap between the front wheel and down tube looks like a front suspention bike under compression. The Stem length is currently a 140mm Syncros and the steering is super quick, I've a shorter 130mm steel stem to fit to give my back an easy life but fear unless I do something about the head angle I'm gonna have a super twitchie Bike.
The ride is not too bad, but I would really like to experience the bike with the the setup as OE as possible.

 

[Crell]

No problem, it's a fairly common question. I really would consider sticking a rigid fork, and go to the 3/8 reduction over the MAG21 length if you can't come up with an appropriate sus fork.

A shorter stem does help on the handling front if you find it too twitchy with the shorter fork. Having said that, we all are used to different things. I actually like narrow bars and a long stem because of the "twitchy" handling. It makes a crap downhill bike but that's not what I spen most of my time doing.

Try a few different things and work out what you like