Ti Frame Geometry - Lend me your skills

komdotkom

Likes Bikes and Dirt
After reading the threads from some other members who have purchased from Waltly Ti I've decided to take the plunge and purchase one of these frames. This is also partly because I couldn't find the bike I was looking for at a price I was willing to pay, particularly since this is an N+1 purchase I already have a perfectly good bike which I've spent far too much on. Now I'm going to embark on the false economy of building a bike from scratch which in the long term will be more expensive, but if I never add up the numbers it won't seem like much....
I'm looking to build a hard tail 29er on 2.35 tyres, about 130-140mm Pike up front, I want it to be playful and poppy - the kind of bike that makes you want to manual off every gutter and pump off every tiny undulation in the trail. I am old and would like it to be compliant(ish) and not so harsh it rattles your fillings out like some aluminium hard tails.
I'd be the first to admit that I don't know much about the detail and 'science' of geometry, hence this post because I need the input of smarter people than me to get this sorted.

Here are my numbers so far
Head Tube 66
Seat Tube Actual 75
Reach 455mm
ETT 610MM
Stack 635
CSL 420mm ish, but short as possible
BB height 315mm

Thoughts and input would be appreciated.
 

The Reverend

Likes Bikes and Dirt
I'm riding a Banshee Paradox and heavily recommend it. The chainstays are 425mm and it's set for 130mm to 150mm fork travel.

Take a look at the geo for your size.
 

Calvin27

Eats Squid
I'd be the first to admit that I don't know much about the detail and 'science' of geometry, hence this post because I need the input of smarter people than me to get this sorted.
Two options, start with a bike you own and go from there slowly adding/reducing to get what you want, or find an existing bike and start with that geometry.

I used this to figure our geometry. It is more for road bikes but workswith MTB as well. https://www.bikegeocalc.com/#7Unnam...40v6w2x10y280z40A0B150C25D370E45F172.5G30H30Z

Literally sent Waltly the link and they drafted off that.
 

Beaker74

Likes Dirt
Kona Honzo, they are a fun to ride hardtail that is surprisingly capable. If I was going to have a frame custom made I would base it off one of these.
 

Labcanary

One potato, two potato, click
@komdotkom that geo looks similar to the 2018 Dartmoor Hornet. My husband rides a medium and loves how fun it is. His dream is to get a Ti frame built to the specs of his Dartmoor.
 

komdotkom

Likes Bikes and Dirt
Kona Honzo, they are a fun to ride hardtail that is surprisingly capable. If I was going to have a frame custom made I would base it off one of these.
Yep, that's part of my spreadsheet and very similar to the numbers I've listed.

I'm riding a Banshee Paradox and heavily recommend it. The chainstays are 425mm and it's set for 130mm to 150mm fork travel.
Take a look at the geo for your size.
Interesting, is Rushys the only distributer in Australia? I'm sure I saw them on the MTB Direct website. I will add that to my spreadsheet for geo

Two options, start with a bike you own and go from there slowly adding/reducing to get what you want, or find an existing bike and start with that geometry.

I used this to figure our geometry. It is more for road bikes but workswith MTB as well. https://www.bikegeocalc.com/#7Unnam...40v6w2x10y280z40A0B150C25D370E45F172.5G30H30Z

Literally sent Waltly the link and they drafted off that.
Awesome link, thanks mate! I've got a spreadsheet going that lists all the bikes I like with their key measurements so I'm looking at numbers that they all have in common.

@komdotkom that geo looks similar to the 2018 Dartmoor Hornet. My husband rides a medium and loves how fun it is. His dream is to get a Ti frame built to the specs of his Dartmoor.
I had a look at the Dartmoor Primal 29 and it looks pretty good, but 30.9 seatpost dammit and the seat post is 73.5
 

Calvin27

Eats Squid
Awesome link, thanks mate! I've got a spreadsheet going that lists all the bikes I like with their key measurements so I'm looking at numbers that they all have in common.
Yep I did that too. With the link I sent you, you, all the specs are contained in the url so you can hyperlink those to your spreadsheet.

Also helpful is this site (there are others, but I've found these work the best)
https://bikeinsights.com/compare?geometries=5d4cb106a58ea4001797baae,5e17ade952f9ab0017bba783
https://99spokes.com/compare?bikes=kona-honzo-st-2020,ragley-marley-2.0-2020

I think you can add custom or new bikes to the library as well.
 

beeb

Dr. Beebenson, PhD HA, ST, Offset (hons)
First up, don't worry about frame compliance being an issue. The Waltly I have is great in terms of that. One of my mates loves hardtails but has only had alloy ones, and he loved the amount of "spring" and compliance in mine. He'd recently changed to a dual susp as his 27.5+ ally hardtail had just been beating him up too much, but I could see the Ti hardtail temptation in his eyes as soon as he got on it and started mucking around doing bunny hops and riding up and down gutters (it's a bit big for him for proper trail riding). If he didn't already have a project car on the go I'm sure he would've gone home and started designing one then and there! Haha.

This will vary for every rider, but for me - going shorter than 425mm on the chainstay could make for a pretty twitchy bike when riding at high(ish) trail speeds. If your trails are flatter it probably won't be an issue though. I do like a bike that's happy to have the front lifted up on demand, but I also want to know it's going to hold a line when the pace picks up - and on the other extreme, not want to wheelie constantly when climbing (most of my climbs are steep but dull fireroads so I appreciate the wheel staying down without having to wrestle myself forward over the bars). A dodgy back and being (I'm guessing) a bit taller than you makes me a bit fussier than the average about this though, so you might get on fine with the shorter stays. Just if you're coming off something with longish stay and thinking "the shorter the better", there may be a limit to it. Reviews of the Pipedream Moxie V1 tend to suggest this too as it had ultra-short stays.

And you may have already considered this - but one other thing worth mentioning is don't underestimate the importance of stack height. Because running a lot more or less spacers to match bar height between different bikes also effects reach (lots of spacer means smaller reach), or if you're going the other way and reducing spacers by increasing stack - if reach remains the same number you will end up with more front centre.
 

komdotkom

Likes Bikes and Dirt
Yep I did that too. With the link I sent you, you, all the specs are contained in the url so you can hyperlink those to your spreadsheet.

Also helpful is this site (there are others, but I've found these work the best)
https://bikeinsights.com/compare?geometries=5d4cb106a58ea4001797baae,5e17ade952f9ab0017bba783
https://99spokes.com/compare?bikes=kona-honzo-st-2020,ragley-marley-2.0-2020

I think you can add custom or new bikes to the library as well.
Thanks mate, more great info!
 

The Reverend

Likes Bikes and Dirt
Mtbdirect sell the Paradox, at least that's where I bought mine from. And I've the XL and usually prefer longer stays but it works very well on the hardtail.

Granted if I were building an XL they'd be 10mm or 15mm longer but I'm certainly loving riding it as it is. Perhaps the longer stays only really matters on FS bikes?
 

Isildur

The Real Pedant
I had a look at the Dartmoor Primal 29 and it looks pretty good, but 30.9 seatpost dammit and the seat post is 73.5
I've got a Primal 29 in Medium, shod with a 140mm fork and 2.35" rubber (Minion DHF & SS) on 27mm internal rims. Compliant is not a word I would use to describe it's ride. Super fun bike, very playful, but I generally have to remember to rein myself in a bit when I get on it after my daily driver (Ripmo). Alas this usually happens halfway down the first run after I've shaken myself up a bit and forgotten to actually pick lines! ;)
 
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