A twitchy moots - fork rake q

[jimoots]

Originally Posted by happycampyer

One more point to consider: the headtube angle on the Moots of that era was based on the assumed fork span of the Ouzo Pro, which had a span of 372mm. The Enve has a span of 368mm, so when you put an Enve fork on the bike, the hta steepens ever so slightly.

When I owned Moots road bikes from that era, I didn’t follow Moots’ recommendations for fork rakes, but I had figured out that I prefer bikes with slacker htas and more trail. I would use an Enve fork with a 40mm offset on a frame with a hta of 73°+. Ymmv.

Interesting point on fork length, the 5mm difference (I have seen 367mm listed as crown to axle for Enve) would steepen by approx 0.25deg. Which is likely why a 43 Enve was suggested.

73.5 deg + 45mm rake fork + 700C/25mm tyre = 54mm trail
73.75 deg + 43mm + 700C/25mm tyre = 54mm trail

[chismog]

I think Moots changed their geometry at some point around there? Pretty sure they used to spec a 40mm rake for Vamoots on >55 frames. I remember this since it struck me as different from other makers. I had a late 90s 57 Vamoots that came with a 40mm and a steep HTA, and I thought it was a sharp ride. Too quick for me but helped me figure out I like longer trail bikes.

Certainly I think you should try it out, if you can. 3mm has been enough to noticeably affect handling in my experience. Or maybe it was just the new/different fork...

Anyway if you try and like the new setup, there ya go.

[tuscanyswe]

I think my 59 compact had a 74 degree ht angle and it was perfect with a 43 rake enve fork, imo ofcourse. But then again i like "twitchy" bikes. A bike to stable sucks in the city

[jimoots]

Just bringing this one back, I went out and sourced a 40mm Enve fork (thanks PL classifieds!) and have put it on the bike.

I've only taken it on a couple of rides so far but have tried to put it through its paces - it tracks well descending and I can still rail corners. Riding no handed felt more confident too.

Ultimately it is difficult to tell if I've fixed the issue but it certainly hasn't led to a degradation in handling, so I can at least be confident in trimming the steerer to size.

[oldpotatoe]

Originally Posted by jimmy-moots

I've had my Moots for a number of years now - it's an '09 Compact with an Enve Fork, 43 rake.

I've always felt the handling was a little twitchy and when I had carbon bars (Enve) severe speed wobbles were induced if you hit an unexpected bump or pothole. My hypothesis was that the 'flex' in the Enve bars (they noticably flexed if you pushed on the drops) created some movement that threw the bike into a wobble.

I've since built and ridden a few other bikes that have a slacker front end and more trail. And they feel better, maybe more natural, to me.

On my calcs the Moots currently has 47mm 'ground trail' while the other bikes are 55-57mm.

The question here is, is putting a 40 rake fork on the Moots a sensible idea? The calcs suggest that trail will increase to 51mm, a bit closer to the other bikes... maybe a bit more stable?

Feel free to school me here!

For that size and model, what does Moots recommend? Did you buy it new from Moots? I wouldn't change the fork based on the numbers of the other bikes unless they are identical in terms of head tube length, angle, etc...

[runbike8]

I have a 2009 Compact, with an Ouzo Pro, 40mm rake, handles great...

I vaguely remember Moots recommending a 40 rake at the time, but also remember a change to a 43 or 44 rake recommendation a year or 2 later

[jimoots]

Originally Posted by oldpotatoe

For that size and model, what does Moots recommend? Did you buy it new from Moots? I wouldn't change the fork based on the numbers of the other bikes unless they are identical in terms of head tube length, angle, etc...

This has all kind of been unpacked in the thread but key points:

- 09 they supplied with a Reynolds fork, with 45 rake
- Literature that I have sourced say this fork was either 372 or 375mm in length
- Previous owner used an Enve fork. Moots said to use a 43 rake fork.
- Enve fork is 367mm.
- In theory the 45 to 43 rake step may not have been enough to correct for a 8mm decrease in fork length.

Either way I've gone ahead and changed the fork, feels pretty good.