Frame geometry help needed…………….

Currently riding a Inbred 456 with 130mm Magura Menja forks.

Possibly looking at swapping the frame for a Kinesis Decade Virsa.

The head and seat angle for the 456 with a 5″ fork is 69.5 and 73 respectively. For a Virsa with a 460mm axle to crown length fork, the head/seat angles are 70.5 and 73.5 respectively.

Eff. top tube lengths are the same (23″).

How would this make the handling of the virsa feel like compared to the 456?

Cheers in advance.

P.S. I’ve read the bikeradar review – some of it sounds a bit odd re geometry quoting 68.5 deg and 70deg head angle on the bike for the same fork. Strange – are they talking tosh?

Well angles very as the fork compresses so it’s all slightly vague anyway, particularly if you set different sag or have a more/less progressive stroke.

As for changing the angles a little, you’ll get a bit more weight up front and slightly more lively steering. But it’s not a huge difference.

Steering will be a bit quicker with the decade and the bike will feel a bit less stable at speed. but to be honest those are both pretty steep HA’s so it may suit your style. My xc bike is running 66 HA!

Depends how its measured really. Some are with the rider on the bike so with about 25-30% sag on the forks, whilst others are measured with no weight on.

A steeper head angle will make the steering quicker which is good for technical uphills and twisty stuff, but it may feel a bit twitch and a bit less stable when your going fast.

70.5 is quite steep I think, I generally prefer something a bit slacker than that.

Its too easy to get caught up in numbers though, its best just to ride the two and see which you prefer

72 head is where it’s at, baby. Ride like Tron 🙂

On the 456 I’m running a 70mm stem. If I go for the virsa, I may up this to 80-90mm, but then I think I’d like a bit snappier handling.

Just fyi brant once suggested to me that the published geometry of his frames isn’t always what they actually are because people wouldn’t buy them because they’d sound funny…

Just measured my Menja’s – the axle to crown length is 450mm. This would then create a head angle steepr than the 70.5 deg quoted on the decade website wouldn’t it?

If my 130mm travel forks are only 450mm, what forks have a 460mm length but are less than 130mm travel – something weird going on here?

OK – just checked on the Magura website – the axle to crown length of my fork should be 498mm. Maybe I measured wrong.

Correct me if I’m wrong, but isn’t the axle to crown length between the wheel axle point and where the headset crown race goes?

geometry = emperor’s new clothes.

well maybe not quite but 5 degrees either way wont make a bike unridable so who really cares. we all get used to what we have

“Just fyi brant once suggested to me that the published geometry of his frames isn’t always what they actually are because people wouldn’t buy them because they’d sound funny… “

same for most brands! i was suprised at how openly a known suspension designer told me this about a number of brands. here we just express a geometry at a certain point in the travel, but that can be said to be another way of doing the same thing. too many people judge bikes on numbers without fully understanding them, or just riding them and judging on the ride only.

..And the numbers printed in some mags, don’t get me started!!

Ok, but when buying a frame only – the chances of getting a test ride with my set-up is pretty slim, so geometry and reviews is all I have.

I have ridden a Cotic Soul with 130 Menja’s and a 80mm stem and that rode lovely – prob better feeling than my 456.

So, if thats the case – how do I judge what the frame will ride like?

I think you’ll like a Cotic Soul with 130 Menja’s and a 80mm stem. why not buy one of them?

Cos they’re £470 vs £320 for a virsa! Virsa is at the mo a bit more niche also – which is obviously important!

Well what are you trying to achieve by replacing the frame? If “lovely” is “prob better” than your existing one then logically your current one is possibly either lovely or better, so what actual flaws are you trying to address?

Sorry, seem some confusion reigns.

I ride a 456 with 130mm Menja’s
I have test ridden (but not owned) a Soul with 130mm Menja’s
I’m interested in buying a Virsa and putting 130mm Menja’s on it.

Just fancy something with a bit more finesse to it (in terms of workmanship) and something that you lot don’t ride!!

if you know the HA and fork length, you can make a comparisison of sorts, but you need those 2 measurements.

then you can consider bb height and f-c length as well as tube diameter, it’ll give you an idea.

also depends on what fork you want to use and where / how you ride. ultimately you’ll find pros and cons in any frame and even if you don’t like it, you’ll not lose more than £100 and the experience may be worth it in getting the next frame more ‘right’.

i may be wrong, but the decade isn’t meant for 130mm anyway? it’s more a 100m trail / SS bike, and that’s no bad thing.

I’ve a DMR switchback, who are upgrade, who also do kinesis. I suspect the frames may well be similar. Angles cerainly sound familiar.

Its steeper than other frames, but doesnt seem to pitch over the front with 130mm menjas (how good are they, they fekin rock! soooooooo buttery smooth) I’m 6ft with short legs/long torso, and ride with a 90mm 8deg stem and about 10mm of spacers.

Worst geometry for being inacurately quoted seems to be TT length, I tested a load of bikes with supposedly identical reaches, theres no way they were! The spesh felt like i was trying to do a superman impression!