[Closed] 29er frame design, what would you have

On-one are having some 2.4" 29er tyres made (I think) so you might want to consider tyre clearance if you're looking at a chunky build.

From an engineering point of view, a straight tube will be stronger than a curved one if everything else is equal, except in the special case of a load in the centre of the tube, eg. a bridge.

I want room for 3" tyres at back, for when Charlie seduces surly into making a 2.9

420mm chainstays with clearance for 3" tyres is going to be interesting. Are you looking at a curved seat tube? Might help if you design it around a single chainring (no clearance for front mech required).

Dropper post bosses

Tapered headtube as it gives the option of integrated/traditional lower headset cup to raise lower the front end.

Will only ever be ran 1x9 or ss, and yes seat tube will be curved

Was thinking about dropper posts have never used one before though

If you want (genuine) 420mm stays you basically can't have a front derailleur unless you do something really odd with the ST, so you might as well give it ISCG tabs. Unless you really need the standover, I would recommend not bending the top tube.

26" wheels

Tapered headtube as it gives the option of integrated/traditional lower headset cup to raise lower the front end.

Depends on the taper, but I'd look at a straight 44mm ID headtube for maximum flexibility.

Cheers Sam i was thinking the straight 44mm route as well, the bend in the top tube this builder sometimes uses is more the cruiser look, I was thinking more of the bends in seat stays as it gives the bike a curvy look

I'd look at a straight 44mm ID headtube for maximum flexibility

I'd look at 1.5" for maximum flexibility

[url= http://www.blackcatbicycles.com/2012/01/new-year-new-bike.html ]example of the curves[/url]

God damn thats nice!

I'd consider the ISCG for 1x9, more chainguide options.

Sounds very much like the Kona Honzo 29er frame which is due to arrive to me this week. That has ISCG tabs, sliding dropouts, 16.3" chainstays, good tyre clearance, dropper post guides, 44mm headtube and based around 120mm travel.

No room for a front mech so ss or 1x9 or 10 only (mine will be 1x10).

You can have a look on the Kona world website to get an idea of how the frame looks. Top tube is straight as well which i prefer to bendy ones (purely for looks) and standover is never an issue for me anyway.

Well, they look cool (and Black Cat do a good job of getting the curve radii lined up correctly between the TT and stays) but I'd have thought that for this style of bike that if you want it curved any way it'd be the other way.

I'd look at 1.5" for maximum flexibility

What, so you can use all those 1.5 standard 29er forks out there?

I know what your saying on the curves Sam and I'm going to go straight toptube, would having the seatstays bent that way weaken them though? The stays on my Jones are bent like that and it feels solid

Have looked at the honzo and it is similar to what I'm after, have been on waiting list for this a year and need to get it right :D,

What, so you can use all those 1.5 standard 29er forks out there?

No, so you can get maximum headset flexibility for traditional/integrated/anglesets

I'm jealous, nice frame, don't forget to post up pics of full build.
So couple of questions
A: what height are you?
B: when are you selling it?
C: is postage included?

Well, any MTB stays are going to be bent somewhere, and many are bent in the way you are suggesting, so I'm sure they will be fine.

No, so you can get maximum headset flexibility for traditional/integrated/anglesets

44mm ID does exactly that. 49.6 ID headsets are less readily available, and the size of headtube required for one looks even more weird on a steel frame. In fact I'm not even certain I've seen 49.6ID headtubes in steel.

I like that!

My ideal 29er;

Sized between a medium and a large Singular Swift (top tube length) and the same geometry but with no suspension correction so the head tube can be ~2" lower, and a shorter seat tube by 2" so the top tube can be well out the way.

44mm ID does exactly that.

I have yet to see a 44mm angleset for tapered forks, likely be one along soon though.

I think this ticks most of the boxes sorry chainsaty is 407 to 427
[img][URL= http://inlinethumb45.webshots.com/24300/2889888620036898833S600x600Q85.jp g" target="_blank">http://inlinethumb45.webshots.com/24300/2889888620036898833S600x600Q85.jp g"/> [/IMG][/URL][/img]

that ticks a few too many boxes in the rear triangle aesthetic department, IMO at least!

Hi Ringo (I was in the T5 at SSUK)

I have been having very similar thoughts to you recently (and coveting every new frame that appears on the Black Cat website!!), Not quite yet put the cash togther but I might have to get my name on the list if you have been waiting that long!
My wish list:

- 120mm forks
- swinging or [url= http://www.2soulscycles.com/index.php?option=com_content&view=article&id=21&Itemid=117&lang=en ]twosouls[/url] sliders
- short stays/curved seat tube
- Straight downtube (with extended (19" ish forward facing seat tube)
- 44mm head tube (Eighteen bikes have made [url= http://shop.18bikes.co.uk/products.php?plid=m21b0s525p1397 ]one[/url])
- ISCG mount (to run 1x6/9/10/11 if needed)
- Slackish front
- Room for 2.3 tyres, so prob 73mm BB, no chainstay yolk

When the Honzo details were released it seemed to tick a lot of boxes, although I think 27.2mm seat tube would give me a bit more comfort. I'm also 11 stone-ish so I would probably be carrying unnecesary weight.

Hi oxy, how's it going, my son still reminds me how I lost to you in the rollapalooza 😀 $500 secures you a place on the waiting list giving plenty of time to save have looked at other frame builders and spoke to a fair few, I love the look of these cats though

Ah yes, the rolla 😛

Yeah - the Hand Made Bike Show in Bristol was really informative last year. Hoping to go this year too, as it looks like being a bit bigger too.

Lots of frame builders out there, but not many pics of recent work. I'm really interested in 18Bikes too, but you're right, the cats are a work of art.

It's also finding someone who is confident doing something a bit different - lots of "custom" builders seem to be custom within certain narrow parameters.

Now $500 does not sound too bad - I've just raised that selling Transformers!

Black Cats are lovely bikes. Too nice for a gnar-build though ) Rigid-specific, light, SS-orientated.. that'd be my kind of Cat. Very nearly was 18 months ago but something else came along.

1. Tapered Headtube
2. Full Length Gear cable Outers
3. Geared or Gears, sliding do, swapouts or ec bb dont care.
4. No rack mounts.
5. Simple graphics, preferably anodised.
6. 100mm to 120mm fork but could also run rigid.
7. Available in Alu, Steel or Carbon
8. Decent warranty / support.
9. make my mates go wow.
10.make me a better rider.

Well 9 and 10 were made up to make up numbers, I could also have costs less than £400 otherwise a yeti big top would probably do the job.

points im uncertain of.....
ISCG mounts, do i need them on this sort of frame or are they not needed
headtube would i be best of having oversized or tapered again not sure which will be most useful

If it's for playing on and has 420mm stays, get ISCG tabs. You'll not get an FD on it anyway so you may as well have the chain device options.
Headtube - 44mm ID / XX44 std for steel bikes is a good idea, for a longer-forked 29er I'd say it should be a standard feature. Stiff forks are good.

Curved tubes tend to be straight-wall so I'd go for straight, butted tubes in the main frame if you want it light. Curved is nice if style is more important and the straight wall tubes may be a bit more ding resistant too.

However the big question for a Black Cat custom is - what paint...? )

I'm pretty sure Black Cat is (rightly) rather smug about being able to to put curves into butted tubes on most of his bikes. Also love his head lug / gusset thingy.

And it HAS to have his swinger dropouts.

Head tube has to be 44mm - don't think anyone makes a short (for a 29er) tapered steel head tube. And anyone talking 1.5" and anglesets for a custom steel 29er isn't really getting the point.

I'm riding 405mm chainstays and loving them - 420mm will still feel very agile compared to long vehicles like Trek 29ers.

I have yet to see a 44mm angleset for tapered forks, likely be one along soon though.

Curious why you'd need/want an angleset on a custom frame?

why not use an E-type FD?

Will the cage cause problems as well as any clamp?

Depends on the taper, but I'd look at a straight 44mm ID headtube for maximum flexibility.

You were the one that said that 44mm gave 'maximum flexibility' Sam, I was merely pointing out that taper or 1.5" offers more flexibility 🙄

yep the lugs are lovely, i already have another nice 29er that can be run rigid and ridden for long distances,This is why this frame will be gnar,
Todd has never built aframe with iscg but he says it shouldnt be a problem. Hes been building short stayed 29ers for quite a while now though 😀

I'd have a wolfhound 😀

looked at them and bistickel etc, something about the blackcat 😀
just done 20 mile on my pikey jones, god its a fun bike

something about the blackcat

yeh they look like they were made for halfords 😉

bigdugsbaws - Member
You were the one that said that 44mm gave 'maximum flexibility' Sam, I was merely pointing out that taper or 1.5" offers more flexibility

My meaning was that it would give maximum flexibility with regard to ability to use different forks, not to change head angle. In any case, the whole point is moot, because you can't even get 1.5" or tapered head tubes in steel. So there's not much point in rolling your eyes at me when you've made a suggestion which is as unfeasible as it is unnecessary.

1.5in headtube in steel. OUCH. HEAVY.

I'd have this.

[img] [/img]

Lefty head tube
454mm chainstay and split seat stay to take 50x28 or 50x20 belt drive.
Rohloff cable guides.

Should be here in a couple of weeks. 😀

did Porter say a couple of weeks? it did take a little longer for mine

For thoose of you with facebook.

Check out aricycles. I have a steel frame he made for me. I know him in person. But he makes the coolest frames.

Latest a TI 29 beltdrive with super short chainstays, 2.5 tyre clearence and assymetrical chainstays.

Midlands graham, my other frame is belt drive with 440mm stays which I love

Sam the OP asked an opinion on 44 or tapered headtube, and for your future reference:

[url= http://www.18bikes.co.uk/content/head_tube.php ]18 Bikes Tapered steel headtube[/url]

[url= http://groovycycleworks.blogspot.com/2010/11/tapered-headtubes.html ]Another[/url]

Ade, he quoted about 8 weeks from placing the order, only two weeks to go.

Ringo, I currently run 32x13 Rohloff and 32x18 SS.
The nearest I could get to those ratios, both using the same chain stay length, was 50x28 and 50x20, which both work out at 454mm.
I've had to buy two rear pulleys and two belts, but luckily only one front pulley.

The 18 bikes tube says it is a 1 off machined from billet - there was some talk but not sure if they got round to doing a batch sufficient for sale to other builders.

And both the tapered tubes you mention look far too long for a 29er with 120mm travel fork. So neither is of much practical use for this situation (unless the OP is immensely tall - in which case I figure he isn't going to enjoy ultra short chainstays).

Thanks for the link though - I've been trying to find a 44 tube in the UK and 18 Bikes have some Reynolds stuff.

So back to 44mm being the only practical option.

And back to the OP instead of pedantic headset comments - have you seen MTBR 29er forum? - there was a post last week with a homebuild lightweight gnar frame that might have some good geo tips - titled something like "West Coast AM hardtail"

My estay bike is belt ready, just need to get the cash together to place the order it's not cheap,

I am looking at a 50 t front and 28 rear and a 115 belt or a 24 and 113 belt with alfine hub , to run a 417 ish chainstay length

Sam the OP asked an opinion on 44 or tapered headtube, and for your future reference.....

The 18 bikes HT is external tapered, so would not take a 1.5 fork anyhow. The Deda one appears to be the same, and may or may not be available - I've certainly not seen it in their product listings.

You're right, he asked an opinion, I gave mine and I gave the reasons for it. Not quite sure why you've then suggested less practical, verging on unavailable, options then tried to shoot me down for disagreeing with you...

Anyhow, enough of this pissing about, I'm sure Black Cat would have told you all this anyway... I'm sure you'll end up with a lovely bike and look forward to seeing it (although they [i]did[/i] steal my [url= http://www.flickr.com/photos/69163524@N00/2262555961/ ]pivoting drop idea[/url] 😉

Todd at black cat does indeed agree with you Sam , ade I have a 38 front with 22 or 20 rear, the centre track is far better than the old design

Sam, are you going ssec and will you be bringing a buzzard would love to have a play on one 😀

Ringo - No SSEC I'm afraid, and even if I were, couldn't really bring a Buzzard as they are geared 😀

MidlandTrailquestsGraham

just been looking at your drawing , 25.4 for the chainstays they are a bit chunky
mine are 22 on my estay bike and i am tempted to go smaller if i get another done would also help your tyre and front ring clearance

I've been trying to find a 44 tube in the UK

Mickr, Reynolds made a 631 44mm ID headtube for me when I was at Genesis, it's a stock part in the catalogue now. It's 48.3 OD I think rather than 50mm as it's from 631 stock tube. Looks fine with the FSA xx44 headset though.

MidlandTrailquestsGraham - Member
I'd have this.

Lot of crimping on that chain stay, and a very short slot on the front of the seat tube. I predict a fatigue failure 🙁

The 18 bikes tube says it is a 1 off machined from billet

Shame there is not a simple SS option on the Buzzard - it looks lush in the Privateer advert

Terry - I recently found Ari on FB - look like some nice, simple designs - another one on the list...

Great if 18 are doing the tube for general release - not sure how much cut down it will accept - a 29er wheel and big fork can end up with some awfully high bars. I guess nothing that couldn't be solved with a re-program of the CNC machine.......

Now the 44mm tube exists and is being rapidly accepted as a "standard", I'm not quite sure what the benefit of tapered head tubes are for steel mtbs?

Thanks Jameso - I've already emailed Matt at 18 to see if he could sell me a tube - all my stuff comes from Ceeway - never investigated if Reynolds will deal with hobbyists.