adiladub

Well, after a lot of reading, I think I finally understand the whole "trail" concept and its effect on bike handling. Now I've got a question regarding how it applies in the real world.

My current bike is 58cm with 73.5 head tube angle and a fork with 43mm rake which, according to Anvil Bikes' trail calculator, produces 54.7 mm of trail. I'm looking at a bike with a 74 head tube angle and 43mm fork rake which produces 51.6 mm of trail.

I understand that, in theory, the handling of the new bike will be "quicker" and "less stable" because of the lower trail. My question, though, is will I experience a noticeable difference in real world riding? I'm not a "princess and the pea" kind of guy so I'm wondering if I could really feel the effect of a .5 degree change in HTA. Can 3mm of trail really make a tremendous difference in the way the bike handles? Just in case it is important, the wheelbase of the new bike is .4 cm longer than the current bike. Would this moderate any change in trail?

Second, in absolute terms, is 51.6mm of trail sufficient to produce a responsive but adequately stable ride for general, all-around cycling or is it getting into twitchy, unstable territory?

AnthonyG

Well I recently went from a bike with 67 mm of trail to one with 53 mm of trail and I sure noticed that! I was concerned that the new bike would be nervous and twitchy but it wasn't and my concern was partialy based on me believing that the new bike would have a trail of 57 mm, not 53 mm. Anyway its fine although it is a lugged steel frame which are renowned for being stable. If it was an aluminium/carbon frame then who knows?

I kind of would be concerned about 51.6 mm of trail being nervous and I would be test riding the bike, not ordering it online.

Regards, Anthony

rmfnla

This is really unanswerable because it depends on the rest of the bike's characteristics. On a well-balanced frame a small change could be disasterous, whereas on one that is close to being right that same change might be exactly what is needed to make it perfect. Or, it might have no effect at all!

Looking beyond AnthonyG's ramblings, his advice about test riding is probably the best thing you can do.

Al1943

The answer is yes. I had a chance to test the difference 3mm of rake offset makes. A few years ago I upgraded my wife's 5220 Trek and my 5500 Trek with Reynolds Ouzo Pro forks, a 40mm offset in hers and a 43mm in mine. Later we sold her bike and as an experiment I put her fork in my frame. The steer tubes were the same length because she was riding with a lot of spacers. The only difference in the forks was the rake. With the 40mm I could feel difference immediately. I could not say for sure which I liked better but there was an obvious difference. After 2 or 3 rides I was adjusted to the change and felt normal and comfortable. I decided to leave the 40 on the bike because Treks have a relatively steep HTA and a short trail. I have two other road bikes with more trail and I like them better.
Was the difference in 3mm rake noticeable, definitely yes. Was it a tremendous change, no, not to me.

Al

531Aussie

yes and no. In my opinion, when you change bikes or forks, there are other variables which determine handling characteristics, so, the geometric data is too simple. Different frame & fork design and materials should make more of a difference than a few mm of rake or trail. Therefore, despite the trail diffrence, there's no telling what the bike will do until you ride it

I've experimented with several different forks in recent years, most with varying rake, and the effect of trail is minimal compared to material, shape and overall design.