srands
Retro Guru
SUNTOUR SR email reply:
Yes it was good of KONA.
Also this is a good one from SUNTOUR SR:
"as a service technician of SR Suntour forks I can only speak for SR Suntour. I assume that our competitors forks are built similar in some points but differencies may occur in other construction details.
For our higher end forks it´s like you say. The spring (air or coil) is in one fork leg, and the damping system is in the other, so both fork legs have different duties to do. So adjustment for softness / hardness can only be done on one side, and adjustment for rebound, compression or lockout can be done on the other. However, please see not just the fork but the whole system containing the fork, the front wheel which is in both dropouts and the (hopefully stiff) skewer which is connecting both. This system altogether is pretty stiff and making the wheel always push on both fork legs together. So, having the spring in only one side is no problem for the fork. We actually have forks with springs on both sides, but these are more entry level forks without oil damping.
Regarding the fork travel some of our forks have adjustable travel, one example is our Epicon model. The travel can be adjusted from 80 to 140mm. The stanchions and the oil damping cartridge are long enough to cover all possible travel setups, and of course the fork is built strong and stiff enough, so even with the maximum travel (and more leverage to the fork crown) the fork can handle it without problems. To adjust the travel an internal setting can be changed and the built-in-height of the fork is changing by the same amount. So. if you change the travel from 100 to 140mm will change from 481mm to 521mm. When we talk about XC or Marathon forks with about 100mm of travel, then a triple crown is certainly not needed. For DH forks with like 200mm of travel, which have to take some serious beating, a triple crown might make sense to keep the necessary amount of stiffness. However, higher stiffness can also be achieved by bigger outer diameter stanchions, so you can find lots of fork with like 180mm of travel with single crown too.
Every frame designer is making his frame construction based on a certain built-in-height of the fork he wants to use. Small tolerances are no problem. Our XC forks with 100mm of travel are all in between 475 and 485mm of length (on 26 Inch versions of course). I guess that the length of our competitors are in the same area, so typically changing the fork from one brand to another is no problem when you keep the same amount of travel. A basic “rule” is that for every 10mm more in length your head- and seat angle is going down by 0.5°. So, in most cases it´s even possible to use a fork which is up to 20mm longer than the original one. If you change the height of your fork by too much, and so also your frame geometry, you will get negative effects on the handling of the bike, like some chopper-like feel of the steering if your fork is too long. This will not handle better at all, not even in steep terrain. However I don´t think it´s possible to say how much of angle might be OK or how much change of height is OK until you get negative handling effects. Since frames and forks can be different there might be situations where a 30mm longer fork will handle OK, while on other frames a 30mm longer fork will be a NO-GO. It´s true that other kinds of bikes (like DH bikes) might have different head angles too, but you won´t be able to turn a XC machine into a DH bike. DH bikes have different geometry, different rider position, different suspension setup and for sure also different handling needs.
Hope this helps,
Best regards,
Bernhard Scholz
Service & Promotion
SR Suntour Europe GmbH
Am Marschallfeld 6a
83626 Valley
Germany
Tel: +49 (0)8024-47399-0 (Ext.2)
Direct Tel: +49 (0)8024-47399-16
Fax: +49 (0)8024-4730984
e-Mail: bernhard@srsuntour-cycling.com
web: www.srsuntour-cycling.com
SKYPE: b_scholz"
Yes it was good of KONA.
Also this is a good one from SUNTOUR SR:
"as a service technician of SR Suntour forks I can only speak for SR Suntour. I assume that our competitors forks are built similar in some points but differencies may occur in other construction details.
For our higher end forks it´s like you say. The spring (air or coil) is in one fork leg, and the damping system is in the other, so both fork legs have different duties to do. So adjustment for softness / hardness can only be done on one side, and adjustment for rebound, compression or lockout can be done on the other. However, please see not just the fork but the whole system containing the fork, the front wheel which is in both dropouts and the (hopefully stiff) skewer which is connecting both. This system altogether is pretty stiff and making the wheel always push on both fork legs together. So, having the spring in only one side is no problem for the fork. We actually have forks with springs on both sides, but these are more entry level forks without oil damping.
Regarding the fork travel some of our forks have adjustable travel, one example is our Epicon model. The travel can be adjusted from 80 to 140mm. The stanchions and the oil damping cartridge are long enough to cover all possible travel setups, and of course the fork is built strong and stiff enough, so even with the maximum travel (and more leverage to the fork crown) the fork can handle it without problems. To adjust the travel an internal setting can be changed and the built-in-height of the fork is changing by the same amount. So. if you change the travel from 100 to 140mm will change from 481mm to 521mm. When we talk about XC or Marathon forks with about 100mm of travel, then a triple crown is certainly not needed. For DH forks with like 200mm of travel, which have to take some serious beating, a triple crown might make sense to keep the necessary amount of stiffness. However, higher stiffness can also be achieved by bigger outer diameter stanchions, so you can find lots of fork with like 180mm of travel with single crown too.
Every frame designer is making his frame construction based on a certain built-in-height of the fork he wants to use. Small tolerances are no problem. Our XC forks with 100mm of travel are all in between 475 and 485mm of length (on 26 Inch versions of course). I guess that the length of our competitors are in the same area, so typically changing the fork from one brand to another is no problem when you keep the same amount of travel. A basic “rule” is that for every 10mm more in length your head- and seat angle is going down by 0.5°. So, in most cases it´s even possible to use a fork which is up to 20mm longer than the original one. If you change the height of your fork by too much, and so also your frame geometry, you will get negative effects on the handling of the bike, like some chopper-like feel of the steering if your fork is too long. This will not handle better at all, not even in steep terrain. However I don´t think it´s possible to say how much of angle might be OK or how much change of height is OK until you get negative handling effects. Since frames and forks can be different there might be situations where a 30mm longer fork will handle OK, while on other frames a 30mm longer fork will be a NO-GO. It´s true that other kinds of bikes (like DH bikes) might have different head angles too, but you won´t be able to turn a XC machine into a DH bike. DH bikes have different geometry, different rider position, different suspension setup and for sure also different handling needs.
Hope this helps,
Best regards,
Bernhard Scholz
Service & Promotion
SR Suntour Europe GmbH
Am Marschallfeld 6a
83626 Valley
Germany
Tel: +49 (0)8024-47399-0 (Ext.2)
Direct Tel: +49 (0)8024-47399-16
Fax: +49 (0)8024-4730984
e-Mail: bernhard@srsuntour-cycling.com
web: www.srsuntour-cycling.com
SKYPE: b_scholz"
