Viewing 40 posts - 1 through 40 (of 49 total)
  • Custom geometry – Marino?
  • Premier Icon joebristol
    Subscriber

    Just mulling over this idea at the moment – it’s my 40th at the end of this year and the wife keeps asking me what I’d like. Originally came up with carbon road wheels – but that doesn’t feel as special as perhaps a custom designed frame.

    My hardtail is currently a 650b Vitus Sentier – the build kit is all solid stuff – 140mm Pike / Gx 11 speed / Code front guide re rear brakes / e1900 DT Swiss wheels / 150mm dropper etc.

    It’s great for mucking about on – the only way it could really improve is being a bit more forgiving on my lower back and perhaps a touch longer on steeper tech stuff.

    So it got me thinking about starting with the base geometry for the Vitus and tweaking it a bit – then get it made in some nice steel (Sentier 2018 vrx)

    It seems 725 is the nicest steel on their website – is this likely to have some good flex in it?

    Current geometry is:

    Seat tube – 432mm
    Chainstay – 425mm
    HT – 66 degree
    Effective top tube – 620mm
    Effective seat tube angle – 73 degrees
    Head tube – 110mm
    Stack – 617mm
    BB drop – 45mm

    The above based on a2c of 532mm.

    I currently run a 60mm stem and I wouldn’t want to go shorter on the current frame as it would get a bit cramped. Would like to run a 45mm sort of size on any new frame.

    I think I’d like to increase the reach but shorten the stem – keeping the chainstays the same 425mm. Maybe the headtube could go a little longer as I run quite a few spacers under the stem at present.

    The frame is designed around plus is tyres (up to 2.8) but I’m happy running 2.5WT up front and a 2.3 at the back.

    Any thoughts as I’ve never done this before?

    qwerty
    Member

    It seems 725 is the nicest steel on their website – is this likely to have some good flex in it?

    You can’t just look at it like that, the tubeset butting, welds, bracing, bending etc will all impact upon flex.

    What about a UK builder you could visit?

    qwerty
    Member

    I looked into this a while back, get yourself set up on BikeCad and have a play.

    The best bit of geometry advice I came across online was:

    “if you adjust one measurement to improve a particular characteristic it’ll have a detrimental knock on effect to another, at the end of the day it’s all a compromise”.

    Anon.

    Premier Icon joebristol
    Subscriber

    Cost is the main driver for Marino – thinking no more than £750 ish for the frame.

    They have a few butting / bracing options – I guess the more minimalist ones will lead to a little more give?

    I’m not sure without going Marino / Far East I’ll get something at that budget unless there are any other suggestions?

    If you’re not set on Steel there’s also Mielec, based out of Poland who builds in Aluminium.

    725 is the same as 4130, it’s just the reynolds branded stuff, if the 725 is butted and the 4130 is not, which is what I would expect then I would take the upcharge and get the 725 but it’s actually the same metal.

    I have a frame from Marino (one of the sick frames to be precise) so why I did not go down the custom route i’m quite have looking and reading frame geometry. As above, a chance to one element of geometry will have an effect on another part. How tall are you and what sort of riding do you like?

    Premier Icon joebristol
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    I’m 5’9 and use the bike for local rides in the main. Mostly a mixture of easy trail centres but then some fairly difficult steep off piste stuff. I like a poppy / manually hardtail (which the Vitus is) but a little longer reach should still be ok for that as well as a touch more stable on the steep bits.

    I’d definitely like it to be a little more forgiving though – hence thinking steel rather than alloy. My budget probably doesn’t run to Ti unless I go budget Far East – I remember reading a thread about one a while back I think.

    Premier Icon acsevens
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    I went the budget Far East route and have been delighted with the frame. It was a couple of years ago when the pound was a bit stronger but you may be able to get one within budget. Check out Waltly – they were very easy to deal with and helpful.

    Premier Icon singlespeedstu
    Subscriber

    I’m waiting for Marino to build this for me in 725.

    if the 725 is butted and the 4130 is not

    Is the correct assumption.

    [url=https://flic.kr/p/2j6Ya2f]Drawings for new custom Marino frame[/url] by multispeedstu, on Flickr

    Premier Icon joebristol
    Subscriber

    That’s quite a big / long / slack hardtail. Is that a sagged or unsagged reach?

    What program have you designed that on – or did you give Marino sizes and they provided it?

    dc1988
    Member

    I love my Marino frame, if you give him numbers then he does it in bike cad and sends to you to check over.

    I think I paid about £450 all in but that was standard 4130 tubing. Mine isn’t especially forgiving but has a seat tube brace like above. If you had a standard silhouette frame I imagine it would be a bit more forgiving.

    You can get the fancier tubing and go for internal cable routing if you want something a bit more unique.

    Premier Icon singlespeedstu
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    That’s quite a big / long / slack hardtail.

    I’m 6′ and like to ride steep trails.
    I also own a Geometron so was aiming for something similarly slack to replace my current hardtail (Last Fastforwards).
    Design is tweeked from the production frames Marino UK have in stock.

    SSStu’s design is virtually identical to what I’d go for (Also 6ft). As it is I ride a production Pole Taival that is quite similar.

    The Taival has loads of subtle tube manipulation all over it, as well as the butting, does Marino manipulate their tubing too?

    I’d go for a taller stack, slightly longer reach and slightly less slack fork, but we’re well into personsl preferences.

    Premier Icon mick_r
    Subscriber

    You’ll get more comfort / flex by using a 27.2mm seatpost than any frame tube manipulation. Similarly the 73 seat angle will help a little compared to current steep fashions.

    I use a curved seat tube for tyre clearance as I run short chainstays (410 ish). A by-product of this is that the 67 deg top part of the tube again adds a bit more flex from seatpost bending (effective sta is 72deg).

    Premier Icon joebristol
    Subscriber

    Lots of food for thought. I know I want to run at least a 150mm dropper – if I could fit in a 180mm Oneup dropper that would be even better. Having seen more much a dropper flexes backwards and forwards I wonder if a longer one = more comfortable?

    I think I need to play with a bit of software that lets me put in certain things I think I want in a frame – and then shows what the rest of the angles / distances come out at. Is that what BikeCAD does or am I hoping for something that doesn’t exist?

    I’m not set on steepening the seat angle necessarily if that could make the bike less comfortable – the 76 or 77 degree on the fs works well but you’ve got 130mm of cushioning on that.

    If I were you I’d put a Works -2 deg headset into the Vitus before you commit to such a steep head angle for that kind of hardtail. That’s particularly true if you’d like to run a shorter stem as it’s likely to feel nervy.

    You’ve mentioned liking your new Aether 7. I’d consider if you want a hardtail with similar geometry to that (at sag).

    Also, I’d ride some fancy steel hardtails to see if you can feel an improvement in ride quality vs your bike. I went from a 853 frame to an alloy one and if the latter was harsher it was cancelled out by going from 26” to 27.5 wheels.

    Premier Icon joebristol
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    So are you saying if I keep the same headangle but slightly lengthen the reach / shorten the stem it’s going to be twitchy?

    The next size up Sentier has a 449mm reach and the same seat and head angles + chainstays / bb drop. Just the seat tube goes up 50mm in length which would be less comfortable for me / limit a larger dropper.

    So if I effectively used the geometry from that but shortened the seat tube surely I wouldn’t end up with something really twitchy? Pretty sure the Sentier doesn’t ship with a 60mm stem – it just happens that’s what I had and I thought it felt great.

    I’m going to just be swapping frame for frame with all the same bits (except potentially the headset where the Waltby definitely has a 44mm headtube so would need to run an external one – not sure about the Marino).

    The only thing is I don’t want to turn this into a full hardcore hardtail – I’d still like it to be more playful than the Aether as that’s the sort of rides I use the hardtail for.

    Lengthening the reach won’t make it more twitchy but stem length really affects steering feel if you keep the bar width and head angle the same. It’s most extreme as you head from 60 to 35mm because bars have backsweep which tends to make a 35mm stem closer to zero mm long (hands in line with steerer tube).

    Personally I don’t think a slack head angle makes a hardtail less playful. Going very long on the reach and/or chainstays does, but a slack head angle on a reasonably short bike with no rear suspension just keeps it safe when the back end is going crazy!

    What’s the reach? Have you checked what the sagged geometry is?

    Premier Icon joebristol
    Subscriber

    My current reach according to the Vitus chart is 432mm – I’m assuming this is unsagged – a2c quoted as 524 on that chart but according to another chart I found my 140mm Pike is 517mm. So I guess that marginally increases the reach. I don’t think a 45mm stem is that short – I have one that size on my Aether and has running a 32mm one on my Aeris 145.

    “I don’t think a 45mm stem is that short – I have one that size on my Aether and has running a 32mm one on my Aeris 145.“

    Yes but those bikes have head angles of less than 65 deg which calms the steering feel, and they’ll get slacker still when riding. Your Vitus has a head angle of 67.2 deg with a Pike 140 and 25% sag which will get steeper when riding.

    This is the geometry of your Vitus at 25% sag:

    HA: 67.2
    SA: 74.2
    Reach: 445mm
    Stack: 608mm
    BB drop: 54mm
    ETT: 616mm

    Have you looked at the current Stanton Slackline? That seems to be the vibe you’re after.

    I wouldn’t expect a custom frame builder to be able to get a certain “feel” unless they’ve built tons of bikes in that material and in the process sussed out the right tube gauges and butting that work, through years of trial and error.

    Premier Icon thisisnotaspoon
    Subscriber

    On the subject of geometry, does anyone else switch between flat and clips on a modern steep seat-tube bike?

    With flat pedals I found my Scandal great, but as soon as I clipped in it just feels awkward. It just feels like I can’t corner as the saddles in the wrong place. On my last bike (rigid 29er with fairly classic XC geometry) and before that an On-One Fatty which was moderately long and slack by fat bike standards, I actually went back to not having a dropper so I don’t know if I’m just used to having that little bit of space in front of the saddle to move around in. But even with the saddle dropped it still feels strangely awkward.

    I did wonder if the steep seat angle is just forcing me to pedal more with the middle of my foot on the flat pedals (it does feel very inefficient being that perched forwards on flat roads) and effectively lengthening the chainstay and shortening the reach. And then SPD’s are just making the whole bike unbalanced.

    5lab
    Member

    You can’t just look at it like that, the tubeset butting, welds, bracing, bending etc will all impact upon flex.

    I don’t think butting makes any difference. What I was told ages ago was the ONLY thing impacting the flex of a given (steel – don’t think this applies across materials) tube is the outer diameter. so a bit of scaffold with the same diameter as the nicest reynolds will flex just the same. The only thing posher tubes get you is things like more butting, which strips out weight where its not needed

    Premier Icon singlespeedstu
    Subscriber

    On the subject of geometry, does anyone else switch between flat and clips on a modern steep seat-tube bike?

    Yep I switch back and forwards on my Fastworwards.
    Makes no difference to me.

    It just feels like I can’t corner as the saddles in the wrong place

    I only ever have the seat at full mast on road/fireroad sections.

    Premier Icon joebristol
    Subscriber

    Funnily enough I was looking at the slack line last night – but it comes in at £1000 ish in the top spec tubing and basic paint colour. There was something else about it that didn’t quite add up for me when I looked, but I can’t remember what it was off the top of my head.

    Tbh the next size up Sentier with a shorter seat tube and in steel or Ti would probably be perfect for what I want.

    Perhaps broadly what I’ve outlined above but slackening the head angle by a degree to 65 might be an option.

    I’ve only got a rudimentary idea about geometry and could do with a tool to play about with to see what one change makes to another part of the frame in size / angle.

    Premier Icon joebristol
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    On the pedal front I don’t find it makes too much difference if I’m on flats or clipped in to cornering. I guess I’m slippery conditions I’m more comfortable on flats as I know I can get a foot down just that bit quicker. One bike is 74 degrees seat angle – the other is either 76 or 77 I think so I guess that classes as quite steep these days.

    docrobster
    Member

    Interesting thread this. I’ve just acquired a last fast forward frame for very little to replace a pinnacle ramin I got for even less. Even with a 2 degree slackset the Ramin steeper than I would like at 67
    I’ve used This site To compare geometries and see how different forks will affect the numbers. Thinking of running the FF with a 120mm fork (at least initially as that’s all I have) which will give a good bit longer reach than the quoted figures for my frame (which I think are unsagged) at the expense of slightly steeper head and seat angles and lower bb.
    Having been looking at the usual suspects for steel 29ers (OO, cotic, Stanton, etc) the idea of getting one custom for around the same money from Marino certainly appeals. What’s the buying experience like?

    Premier Icon thisisnotaspoon
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    On the pedal front I don’t find it makes too much difference if I’m on flats or clipped in to cornering. I guess I’m slippery conditions I’m more comfortable on flats as I know I can get a foot down just that bit quicker.

    Maybe it was just a bad day then, Swinley isn’t renowned for confidence-inspiring grip in the wet, lots of cobbles and roots polished by hundreds of thousands of tyres! it would go round the sort of neutral corners that are never a problem just fine, but as soon as “laser cock” was deployed it was more like “Poundland halogen penis”, rather than tightening up and exiting the corner quickly the whole bike just wobbled and skittered sideways.

    I had a Last Fastforward prior to the Taival.

    It was may gateway bike into new skool LLS, but as I learned about this ‘new’ geometry I found it’s reach too short for it’s slack headtube angle.

    Seat tube was less than 74° too and with the front axle so far forwards my weight distribution was too far rearward to be intuitive.

    Sure I could move forwards and load the front, but I wasn’t in the right position naturally, which often resulted in a tiny delay to steering inputs, which got tiresome and a bit crashy when I was tired.

    Premier Icon joebristol
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    Yeah I’m quite keen not to end up with a bike with a reach that’s too long for it’s use / what I like and the same on the slack head angle. I’m really happy with my fs bike right now – I just want my hardtail to be a touch more playful again from the fs.

    docrobster
    Member

    @scienceofficer that’s what I’m thinking regarding running shorter forks- would bring the numbers into the same ball park as frames like the on ones. (Unsagged…)

    I reckon your logic is sound. Watch that BB though. Its low anyway, possibly annoyingly low if you are running 650b with those 120 forks.

    docrobster
    Member

    Yeah I think I might need to invest in some 165mm cranks!
    Running 29 though

    https://geometrygeeks.bike/bike/sick-wulf-2018/

    So I have a large wulf OG 64 degrees head angle set up with 29×2.6 tyres and am 5.9” is size. I would say after a years worth of use I would happy go slacker for a hardtail to 63 or even 62. The reach is spot on with a 40mm stem (have a geomatron with a 500 reach and have to run a 32mm stem). I would say it would be worth talking with Stanton as they do do the custom route as well

    Premier Icon joebristol
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    Stanton unfortunately are £999 for an 853 Slackline with the cheapest paint – so they’re over budget already. Al Ty Pugh they are very very nice.

    I have a full suss that’s 457mm reach / 65 degree headangle and 140mmf / 130mm r travel. This hardtail is to be more mellow than that.

    I’ve been down the 64 degree HA / 481mm reach with 170mm / 160mm travel and after 3 years I decided it’s just too long for my little short Dino arms (even with a 32mm stem) and too much bike for 80% of my riding.

    Hence I sized down in both reach and travel on my current bike and I’m really really happy with how that rides and fits. I haven’t done an uplift day on it yet but I expect it to be pretty decent still for that, it rides better on steep / slow ish tech (for me anyway) and for general riding it’s more fun.

    The hardtail is really for messing about on locally, or if I’m out joining up bridleways with road sections. Also some steeper tech stuff fairly local.

    Premier Icon singlespeedstu
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    Just been sent this.
    Looks like it’ll be here quicker than I thought.
    Just the small matter of actually welding the tubes together now.😄
    [url=https://flic.kr/p/2jhyass]Merino Build[/url] by multispeedstu, on Flickr

    justaname
    Member

    @singlespeedstu Out of curiosity what was the waiting time between confirming your geo and paying a deposit and then seeing the frame getting built?

    I’m wondering how long the build queue is at the moment

    Premier Icon joebristol
    Subscriber

    That looks good – I wouldn’t mind something that has that line from the top tube down into the seat stays – just without that seat tube brace. Mine wouldn’t be so slack / wouldn’t be getting ridden so hard so if there could be a more subtle brace there that would work.

    I’ve dropped Waltly an email too to get a ball park cost for one of their frames but I’m expecting it to be too expensive.

    Someone suggested Curtis – their 853 frame for £1150 with custom geometry at no extra cost looks good but a fair chunk over budget unfortunately.

    Premier Icon mick_r
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    Looks like a powered up TIG plant in the background of Stu’s photo so probably finished by now (or at least tacked together and on the welding bench).

    Paint over there or in UK?

    Premier Icon dovebiker
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    I’ve bought a couple of frames of Waltly Titanium – prices start from about $600, my totally custom fat bike with curved tubes, polished logos was $1000 – it’s the one with orange wheels on their gallery. Quite a few of the ‘UK’ titanium frame builders buy from them.

    Premier Icon singlespeedstu
    Subscriber

    what was the waiting time between confirming your geo and paying a deposit and then seeing the frame getting built?

    Paid a deposit at the end of May.
    There’s a delivery to the UK of production frames due in three weeks time.
    It should be on that delivery.
    Not bad considering he’s been working on his own and moved his unit because of the current situation.

    I wouldn’t mind something that has that line from the top tube down into the seat stays

    That’s something that I asked specifically for.

    Paint over there or in UK?

    No paint, going for a raw finish with clearcoat.
    That’s being done over there.

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