Forks on me IBIS

[Sithlord]

Hi fellas

After a recent comment regarding me putting Tange Switchblades on my IBIS Steel mojo and them messing the handling up, just wanted to get any feedback about this... what do you guys think...

 

[retrobikeguy]

messing up handling as opposed to.........................what ?

I have tange switchblades on my kestrels, love em - nice and resposive steering - although I do have to say the RS1's I put on em a while back does make for a much more comfortable riding position.

 

[Anthony]

I would guess that the Switchblades will quicken up the steering if that's what you want, but as to whether it would be so much that they would ruin the handling I don't know - that depends how much shorter they are than the frame was designed for, and I've never had any. But we could work out the steering angle reasonably accurately from their length (from crown race to axle centre) and the year of the frame.

 

[Sithlord]

Hi anthony,

The forks measure approx 382mm (15") from the top of the crown to the dropouts .. The frame I think may be a 98 model..frame no 4598.any ideas...

I dont mind the handling being sharp and responsive..

 

[Wold Ranger]

Handling

Can be too twitchy and if the caster is too small, the bike will wander all over the place and not hold a line. The rake of the fork, which varies dramatically from fork to fork, will also affect the straight line handling and front wheel wash out. Kona do project two's in three differing suspension corrected length, options and would look more in keeping with the Ibis than modern Carbon jobbies.

 

[Anthony]

Hi anthony,

The forks measure approx 382mm (15") from the top of the crown to the dropouts .. The frame I think may be a 98 model..frame no 4598.any ideas...

I dont mind the handling being sharp and responsive..

OK, well my guess is a 98 frame was almost certainly designed to have a standard 71 degree head angle with Z2 Bombers or maybe 63mm SIDs, both of which are c43.5 cm long, or c42 cm assuming c1.5 cm of sag with a rider on the bike. So the 38 cm Switchblades are 4cm shorter than the bike was designed for and each cm steepens the head angle by 0.6 of a degree, so that means the head angle will be c73.5 degrees. I have to say that is pretty steep, so if you don't mind the handling being sharp and responsive then you'd certainly get your wish.... and then some. But obviously the thing to do is try it!

Incidentally, the 97 P2s that came on my humble Kilauea are 41.2cms long, which would give a 71.5 head angle, which could be just about perfect. So even if you find the Switchblades are a little bit *too* exciting, that doesn't mean rigids are no good for the frame. It's just that the Switchblades were designed for earlier frames that aren't 'suspension-corrected'.

 

[Sithlord]

Doh!! thanks for that... anyone want a tange switchblade ....

 

[Wold Ranger]

Forks

Si' got a set of Sus corrected Kona P2 V brake only 1 an 1/8 in Black which are 43.7 cms crown race to axle centre. What are the Switchblades like-colour steerer etc

 

[purplewicked]

Hi anthony,

The forks measure approx 382mm (15") from the top of the crown to the dropouts .. The frame I think may be a 98 model..frame no 4598.any ideas...

I dont mind the handling being sharp and responsive..

OK, well my guess is a 98 frame was almost certainly designed to have a standard 71 degree head angle with Z2 Bombers or maybe 63mm SIDs, both of which are c43.5 cm long, or c42 cm assuming c1.5 cm of sag with a rider on the bike. So the 38 cm Switchblades are 4cm shorter than the bike was designed for and each cm steepens the head angle by 0.6 of a degree, so that means the head angle will be c73.5 degrees. I have to say that is pretty steep, so if you don't mind the handling being sharp and responsive then you'd certainly get your wish.... and then some. But obviously the thing to do is try it!

Incidentally, the 97 P2s that came on my humble Kilauea are 41.2cms long, which would give a 71.5 head angle, which could be just about perfect. So even if you find the Switchblades are a little bit *too* exciting, that doesn't mean rigids are no good for the frame. It's just that the Switchblades were designed for earlier frames that aren't 'suspension-corrected'.

the mojo medium has a 71.5 head angle w/ a 63/70mm susp fork. it's already tight and responsive at that w/ a wheelbase of just 41.5in.
the 380mm A_C fork will make it handle like ****

 

[gump]

yeah, gotta say not a good idea really
- handling will be poo
- a newer fork would look better too..