Currently have a 48mm offset fork and looking @ a fork with 51mm. Does anyone know if this amount of change would actually be noticeable? Thanks.
48 to 51mm fork offset?
keen
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I've done a bigger change -- back and forth from 45 to 50 mmm offset -- and not felt an handling change that was appreciable. I've also done a switch of fork offset on a road bike -- 43 to 45 mm -- with no adverse handling effects. In my experience, offset and head angle changes are more noticeable on the road than off. It's my opinion and experience that you won't notice the change. In principle, your trail measurement will decrease and quicken your handling, but it's not going to be noticeable on a non-paved surface.
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Generally, a 5% change should significantly noticable. But if you think about it another way, since the trail figure on your bike could be from 75-110, decreasing that by 3mm (by increasing offset by 3mm) would be closer to 3%, which is borderline noticable. What difference you should potentially notice, besides the difference in the fork's performance is...
The offset amount, as simply put as possible, mainly offsets the negative steering effects of slacker head angles and bigger wheels at low speed.
It may play a significant role in getting a bike to steer/turn in a manner that's more comfortable for certain riding styles and certain circumstances, regarding how it fits into the big geometry puzzle, but I don't think anyone knows so much that they can calculate how much offset you precisely need to work with certain other geometry figures to reach that sweet spot that happens to work for a specific turn radius, speed, riding style, bike setup and geo. For example, I hear that shorter offsets may corner with more stability at moderate to high speeds with short chainstay bikes, yet is still manageable at low speeds. I'd give some trust to the brands to decide and recommend what goes well with their bike, as they are ride testing all the different options during development (and also afterwards, to refresh yearly build kit specs). The difference shouldn't be something that your body can't adapt to.
==================
The more technical answer as to what offset does:
![Image]()
Summary of points:
- The tire contact point is directly under the axle when pointed forward
- When the tire is pointed either 90 degrees to the left or right, the tire contact point shifts to where the steering axis touches the tire, rather than directly under the axle
- The difference in height between when the tire is pointed straight and when it's turned, creates an effect called wheel flop, since the weight put onto it wants to take it to its lower position and settle there. The greater the height distance, and the greater the weight on it, the stronger the wheel flop effect. Generally an unwanted effect.
- The difference in distance that the contact point is behind the steering axle creates a "trailer" effect. When you pull an object from behind, it automatically straightens out as you move forward. I call this effect auto-centering. Like walking a dog, the longer the leash is, the more it's allowed to do whatever it wants. The shorter the leash, the more direct and responsive your inputs are to it, following close behind. The faster you go, the more the object in tow straightens out behind it. A longer distance allows for a bit more forgiveness in wobbliness from what's in the lead, also vice versa affecting what's pulling less if it wanders around. The rear wheel more vividly follows this effect, since it has a greater distance from the head tube to the rear tire contact point (the shorter the distance, the more flickable it is). This is an useful effect, allowing you to have stable ride while being lazy with control inputs. Things can be more predictable with less of it, though requiring slightly more attention without it; to quote a friend, it's like going from hip shooting to proper aiming to shoot.
- Having more offset pushes the axle forward, in effect making things more direct and responsive. It doesn't necessarily create a twitchy feeling... that could be more of a muscle memory thing where you might be used to fighting/controlling wheel-flop and expecting the auto-centering to do some of the work for you. Such as if you're expecting to fight against wheel flop and auto centering and overcorrect, needing to overcorrect your overcorrections, until your muscles find a balance. Same goes if you gain more trail, not used to the higher levels of auto-centering and wheel flop, and find yourself riding poorly since you're not yet adapted. Should adapt within a few rides, if not within a few hours...
In summary, the resulting "trail" measurement from the HA and offset, is the one geo figure that best portrays front wheel steering characteristics of the bike. Going from one bike with 100 trail should feel similar to another (in terms of front wheel steering feel) that has 100 trail, even if it has head angle difference of over 3 degrees, not considering differences to geo as it goes through suspension travel.
The offset amount, as simply put as possible, mainly offsets the negative steering effects of slacker head angles and bigger wheels at low speed.
It may play a significant role in getting a bike to steer/turn in a manner that's more comfortable for certain riding styles and certain circumstances, regarding how it fits into the big geometry puzzle, but I don't think anyone knows so much that they can calculate how much offset you precisely need to work with certain other geometry figures to reach that sweet spot that happens to work for a specific turn radius, speed, riding style, bike setup and geo. For example, I hear that shorter offsets may corner with more stability at moderate to high speeds with short chainstay bikes, yet is still manageable at low speeds. I'd give some trust to the brands to decide and recommend what goes well with their bike, as they are ride testing all the different options during development (and also afterwards, to refresh yearly build kit specs). The difference shouldn't be something that your body can't adapt to.
==================
The more technical answer as to what offset does:
Summary of points:
- The tire contact point is directly under the axle when pointed forward
- When the tire is pointed either 90 degrees to the left or right, the tire contact point shifts to where the steering axis touches the tire, rather than directly under the axle
- The difference in height between when the tire is pointed straight and when it's turned, creates an effect called wheel flop, since the weight put onto it wants to take it to its lower position and settle there. The greater the height distance, and the greater the weight on it, the stronger the wheel flop effect. Generally an unwanted effect.
- The difference in distance that the contact point is behind the steering axle creates a "trailer" effect. When you pull an object from behind, it automatically straightens out as you move forward. I call this effect auto-centering. Like walking a dog, the longer the leash is, the more it's allowed to do whatever it wants. The shorter the leash, the more direct and responsive your inputs are to it, following close behind. The faster you go, the more the object in tow straightens out behind it. A longer distance allows for a bit more forgiveness in wobbliness from what's in the lead, also vice versa affecting what's pulling less if it wanders around. The rear wheel more vividly follows this effect, since it has a greater distance from the head tube to the rear tire contact point (the shorter the distance, the more flickable it is). This is an useful effect, allowing you to have stable ride while being lazy with control inputs. Things can be more predictable with less of it, though requiring slightly more attention without it; to quote a friend, it's like going from hip shooting to proper aiming to shoot.
- Having more offset pushes the axle forward, in effect making things more direct and responsive. It doesn't necessarily create a twitchy feeling... that could be more of a muscle memory thing where you might be used to fighting/controlling wheel-flop and expecting the auto-centering to do some of the work for you. Such as if you're expecting to fight against wheel flop and auto centering and overcorrect, needing to overcorrect your overcorrections, until your muscles find a balance. Same goes if you gain more trail, not used to the higher levels of auto-centering and wheel flop, and find yourself riding poorly since you're not yet adapted. Should adapt within a few rides, if not within a few hours...
In summary, the resulting "trail" measurement from the HA and offset, is the one geo figure that best portrays front wheel steering characteristics of the bike. Going from one bike with 100 trail should feel similar to another (in terms of front wheel steering feel) that has 100 trail, even if it has head angle difference of over 3 degrees, not considering differences to geo as it goes through suspension travel.
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I like a little more rake and a little slacker head tube angle. Do not turn to sharp, lean the bike into the turns. Maybe I will quote this guy so I can find this again. Maybe if I read this 5 more times I will figure out what it all means. Naw, I am to dumb to understand all that, just know I like more rake better. Maybe I will listen to youtube instead of attempting ot understand my bicycle.
Generally, a 5% change should significantly noticable. But if you think about it another way, since the trail figure on your bike could be from 75-110, decreasing that by 3mm (by increasing offset by 3mm) would be closer to 3%, which is borderline noticable. What difference you should potentially notice, besides the difference in the fork's performance is...
The offset amount, as simply put as possible, mainly offsets the negative steering effects of slacker head angles and bigger wheels at low speed.
It may play a significant role in getting a bike to steer/turn in a manner that's more comfortable for certain riding styles and certain circumstances, regarding how it fits into the big geometry puzzle, but I don't think anyone knows so much that they can calculate how much offset you precisely need to work with certain other geometry figures to reach that sweet spot that happens to work for a specific turn radius, speed, riding style, bike setup and geo. For example, I hear that shorter offsets may corner with more stability at moderate to high speeds with short chainstay bikes, yet is still manageable at low speeds. I'd give some trust to the brands to decide and recommend what goes well with their bike, as they are ride testing all the different options during development (and also afterwards, to refresh yearly build kit specs). The difference shouldn't be something that your body can't adapt to.
==================
The more technical answer as to what offset does:
![Image]()
Summary of points:
- The tire contact point is directly under the axle when pointed forward
- When the tire is pointed either 90 degrees to the left or right, the tire contact point shifts to where the steering axis touches the tire, rather than directly under the axle
- The difference in height between when the tire is pointed straight and when it's turned, creates an effect called wheel flop, since the weight put onto it wants to take it to its lower position and settle there. The greater the height distance, and the greater the weight on it, the stronger the wheel flop effect. Generally an unwanted effect.
- The difference in distance that the contact point is behind the steering axle creates a "trailer" effect. When you pull an object from behind, it automatically straightens out as you move forward. I call this effect auto-centering. Like walking a dog, the longer the leash is, the more it's allowed to do whatever it wants. The shorter the leash, the more direct and responsive your inputs are to it, following close behind. The faster you go, the more the object in tow straightens out behind it. A longer distance allows for a bit more forgiveness in wobbliness from what's in the lead, also vice versa affecting what's pulling less if it wanders around. The rear wheel more vividly follows this effect, since it has a greater distance from the head tube to the rear tire contact point (the shorter the distance, the more flickable it is). This is an useful effect, allowing you to have stable ride while being lazy with control inputs. Things can be more predictable with less of it, though requiring slightly more attention without it; to quote a friend, it's like going from hip shooting to proper aiming to shoot.
- Having more offset pushes the axle forward, in effect making things more direct and responsive. It doesn't necessarily create a twitchy feeling... that could be more of a muscle memory thing where you might be used to fighting/controlling wheel-flop and expecting the auto-centering to do some of the work for you. Such as if you're expecting to fight against wheel flop and auto centering and overcorrect, needing to overcorrect your overcorrections, until your muscles find a balance. Same goes if you gain more trail, not used to the higher levels of auto-centering and wheel flop, and find yourself riding poorly since you're not yet adapted. Should adapt within a few rides, if not within a few hours...
In summary, the resulting "trail" measurement from the HA and offset, is the one geo figure that best portrays front wheel steering characteristics of the bike. Going from one bike with 100 trail should feel similar to another (in terms of front wheel steering feel) that has 100 trail, even if it has head angle difference of over 3 degrees, not considering differences to geo as it goes through suspension travel.
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