I thnink, I need to check, that both Cyril and Whafe were running, and happy with 2.25 tyres, although some 2.25/2.35 can be within 1mm width of a 2.4 Ardent BUT a Nevegal for instance has HUGE knobs and is a much taller tyre. I definitely have clearance, though not with, a front mech for a 2.4 with slightly shorter stays, but its the seat tube thing.
My seat tube is the same as Cyrils was at 74 deg, I would expect that a 75deg STA could well give the necessary clearance at 150mm (Actually 148mm) although whether it would with say a big Nevagal or not I'm not sure. I could try using a shorter shock and deflating it with my current mount which is 8mm forward to see what kind of ST clearance you could expect.
Personally I don't want a crazy short ETT as I race Enduro so I have to climb too.
The Ion does have a more offset Seat tube (Like Whafes) so it may be that the extra STA is not needed with a shorter CS.
If Max will have a look at creating some drawings we will get an idea if we can get down to 450mm CS. It would be good as I want at least a 610mm ETT so at 66.7deg mine is getting pretty long.
Here is the thread with my final geo.
Colour is sometimes the easiest decision...
and here Helius AC29e Experience
Mine is slightly differnt now with a Sram crank/28t bling ring and MRP Micro G2 SL chain guide along with Easton 35 800mm bars and Easton 35mm stem.
I should do a write up on what I've learned in that second thread really and what I am basing my desire for the Ion15 on, but its mostly more of the same. better sealed bearings, the eccentric link, the 44/56 headtube, 142mm rear spacing complete with Post mount brake. A tidied up BB area is the icing on the cake really.
I think the head angle needs to be for what you want to do but with an angleset and a deg on the eccentric link I think something like 67deg with a 150mm fork would be spot on.
I am at a loss as to why there was the agreement to shorten my CS up more than they have said you can the_pilot...
The setup on mine of which is taken from the first AFR type setup is mint, I would do it again if in fact it could shorten the CS even more...
At present I cant fit a 2.35 Hans D tyre and that is a problem for me... Lack of suitable tyres at Whistler hurt me some days, try 4 punctures during a lesson !
The_Lecht_Rocks: whafe - cheeers - may i offer an official apology for the wagon wheeler "dis-belief"
The Hans Dampf is definitely the reference point for AM/DH/FR 29er tires. I ran 2.35 HD's front and rear tubeless at Whistler and Winter Park all summer with zero issues. It's a tall and wide tire though, so there definitely needs to be a fair amount of room reserved. But, I think it's worth it to jump through hoops to get a shorter rear and longer front for a gravity oriented 29'er.
The 2.4 Ardent is 1mm wider than the HD And it fits in my CS with room to spare. I also have to keep clearance in mind living in the UK!
Whafe your seat offset is definitely bigger than mine, yours having the Ion style BB area box section. Mine is only offset by a single seat tube width the same as the original AFR. You also have a steeper seat tube by 0.5 deg so you will have more seat tube clearance, although clearly less tyre clearance.
The front/rear ratio is surely relative too, the front of the 29 is longer too don't forget. I think there might be 4mm that could be taken out of the CS and still fit a HD or Ardent without compromising seat tube or mud clearance too much. Realistically when it gets really muddy the 2.0s go in.
I suspect a STA of 74 would still work with the Ion style BB as again it is bigger than my design. It is clear that the swingarm has been carried over from mine/Cyril's setup web though a tidier offset BB area has been developed. (I asked for that too but they also wouldn't do that for me at the time..)
Last edited by the_pilot; 11-13-2012 at 12:11 PM.
I guess I'm not clear if the HD is contacting Whafe's swingarm or seat tube. I had assumed the latter. Either way, it sounds promising that a fairly short rear, long front based on the Ion 16 could be built if Nicolai had the appetite to do it.
Just seen how bad my typing was in that last post. Ill get that cleaned up! Phones eh.
@Err, I would bet, and I'm sure Whafe will chime in that its the CS clearance not the seat tube clearance that's the problem with the HD. The 2.4 Ardent has clearance in my CS BUT you couldn't take 7-8mm off it and fit a taller tyre (which I am pretty sure the HD is ( like the Kenda Nevagal, not quite as wide as an Ardent but bigger knobs(sic)
I'll have to do some more checking but I've got the beaver mud tyres on at the moment!
I think I saw that the Knoa Satori had super short stays did read it could take a big tyre on a forum. Haven't checked that. But there is also more than one way of measuring/quoting CS length I have noted too!
I would tend to also assume that it's a seat tube clearance issue, just hadn't confirmed. Whafe's effective seat tube angle is 74.5º. Bumping that .5º to 1.0º steeper seems to be the solution to shorter CS.
The Satori claims 17.3" (439.4 mm) CS and 130 mm travel. That's the shortest out there of the long travel 29'ers, even shorter than the Lenz.
I just checked a Kona thread here Kona Satori - rear tyre size and fitment issue?, looks like 2.4 ardents fit at full compression
Also in this post, someone claims the Hans Dampf 2.35 fits without issue on the Satori but no pic.
It bears repeating that the Prime has CS as short as 443 mm and reportedly fits Hans Dampfs without issue. It appears that they, in part, accomplished this through using 75º to 76º seat tube angles.
It's all quite encouraging for a 140-150 mm travel setup with CS somewhere between 440-447 mm. And yes, I recognize 7 mm is quite a range, but I'm armchair engineering here, no Solid Works loaded up on this laptop
Must have misread my post. I think it's more of a CS issue Not ST. CS length obviously includes up to the pivot point. The Yoke on a Nicolai is quite forward of the pivot, which may not be the case to the same degree on other designs, I'll have a look. Bear in mind that 150mm is a ful 15% more travel so it would be reasonable to assume an increase in CS length for ST clearance.
However for me, I can't stress enough how much of a non issue I think getting the CS shorter than 450mm-454mm is.
If you read Cyril's comparison of his Prime compare to his Nicolai you will seen
he says the Nicolai was more agile and Cyril rides tight rocky technical terrain.
It sounds to me Err like you are looking for more of a feeling that perhaps 650b might give? (You may verbally lash me for that!!)
But again, I find my 150mm AC29 playful, fast, stable, grippy...did I mention fast...66.7deg HA...and fast...
i agree phil. without riding one id also say shorter is better but in reality its been a non issue as you say.
Originally Posted by the_pilot
Getting the BB height righ and the dynamic CofG on the bike definitely as important and a nice 'poppy' shock/linkage.
I stressed sooo much about CS length (as Dipper and Nicolai know!! How many emails...) before getting this and pushed and pushed Nicolai to reduce it further but they wouldn't at this travel. I do wonder a little if that was something to do with designing for a direct mount front mech also.
I tried to design in so much flexibility into the geo as I really want sure what I would prefer. I'm glad I did as it has enabled me to find that out and be pretty sure about the next one.
My biggest fear was it would be too long, too slack and slow steering and be a pig to manual, I was completely wrong!
Yeap, sorry, misread your post. And now that we're talking about it, I do recall that my old Helius-ST had really tight CS and was a pain to put a big tire in without partially deflating first. I could very well see that issue popping up in Whafe's ride.
On the debate of longer CS being quite rideable, I totally hear ya. I have 2 bikes in my stable at 455 mm and I've ridden a host of others I spent some time on one recently that measured up at 450 mm that wasn't too shabby. I've also done quite a bit with anglesets and offset bushings to tweak HTA, BBH, etc. I've held some nice long manuals with 455 mm CS. There are however, certain attributes that I'm hoping to improve on with tighter CS, for instance, I like to rear-wheel steer in steep tech and that gets to be much better with shorter CS. Rolling into manuals under fatigue is also improved with a shorter rear as is popping off of small trail features to gap over roots and rocks. But like you said, and I totally agree, balance in geometry at all points must be correct.
No worries on the 650b, I'm always opent to alternatives. I've ridden a few 650b so far, nothing that's really blown me away but each have had their strong points. I'd almost be keen to build a 650b and a 29 version of this bike and see which one I like best! Now that would be a fun project.
Last edited by Err; 11-14-2012 at 07:05 AM.
Doing some noodling the KonaSatori has approx 12mm clearance between the back tyre and seat tube at full compression with 130mm travel with a2.4 ardent.
The ardent fits and lots of guys saying loads of clearance and you don't use a big tyre in the mud...well maybe not where they live but you never know when a ride might turn muddy and we ride big rocks and big mud in the same ride! The clearance to me in 444 stays looked pretty tight, wouldn't need much flex in a wheel, out of true to cause rub, let alone another 30mm of travel. the HD is a taller tyre still.
This is with a 74deg ST so maybe the steeper tube would sort it.
For me it looks like 450mm could be the limit with 150mm AND a 2.35 tyre like the Dampf but whether Nicolai would build one I don't know.
And yes comparing 650b and 29er would be ideal. Perhaps this recent comparison posted in the forum is the answer, a lot of them though the 650b was the best of both rather than the worst of both.
Me, I manual out of necessity to get over obstacles, jump, usually, to maintain speed and want a bike that is fast and grippy and takes out the small stuff, I can ride a long way and uphill for big ascents, the 29er ticks that box.
If I'm really just playing, that's what the fatbike is for :-)
I'll get on to Max and see what he says about CS but I think the answer will be if you want it to guarantee to fit all tyres then 454mm might be min.
It's incredibly rare that I ride in mud living in UT. Even when I travel to Oregon, Whistler, Washington, it's usually during mid summer with little mud.
With Whafe already at 150 mm travel with 448 mm CS and no assumed ST clearance issues, the question really becomes, can they accomodate a 2.35 HD in an updated CS design at 448, maybe 550 mm. I'm 100% no FD on this build which hopefully helps make this possible.
BTW, have you measured your actual BB height resulting from the 40 mm drop spec? Curious what you ended up at with 2.4 Ardents.
I'll measure the BB height, IIRC it's about 455mm with the 2.4 in 150mm. No FD definitely helps, fitting an FD to mine makes the 2.4 a no no. I never intended to use one, just my chainguide isn't in yet for the 28t front so using it to keep the chain on but I couldn't get the 2.4 past it..
I assume you meant 355 mm. 455 mm would be pretty funny. Old Skool San Andreas territory.
Looks like the Ion 16 geo adjust design allows for 1º at the HTA and 7 mm change at the BB. Something like 333 in the low and 340 in the high setting with high-volume 2.35/2.4 tires could be real nice.
I have a 140 mm bike set to 338 mm with 2.35 Hans Dampfs right now and it's lovely. In stock form it was about 350 mm which was nice for pedaling through rock gardens but not quite optimized for getting through corners.
Last edited by Err; 11-14-2012 at 10:49 AM.
Gotta love phones!! Yes 350mm, it's probably closer to 340mm now as I measured it roughly at 68.2deg HA not the current 66.7. It was designed at 340mm on the basis of Ardents. Don't think I'd want it much lower. It's about the right balance between low as but getting away without pedal strike. That's static, unsagged so 290mm give or take sagged height.
I'd plan for a 340mm basic height in the high setting.
So, Nicolai have come back to me and confirmed that they are up for an Ion15 29er as a custom beastie with Kalle's blessing, bonza.
It (or they) depending on how many are ordered will obviously be tailored for the individual but initially going to use my intial specs to work out chainstay length, seat tube angle, head angle, wheelbase etc etc. might even get some suspension curves.
The basic HA for the first draft will be 67deg using a 565mm fork reference, which is a 150mm Fox 34. There will be a 571mm 160mm 29er fork out next year, which this bike could be accomodate, but its not worked out yet whether that would require a stronger downtube and thus more weight.
We will start with a BB at 335mm-340mm at 67 deg, which would mean 66deg and 330(ish)mm if the eccentric was switched.
Also part of the initlal design brief is to try and make the chainstay 450mm or shorter and still fit a 2.35 Hans Dampf and not foul the seat tube. This does assume no front derailleur mounts, so Hammerschmidt or 1x 10/11.
For me and Dipper this is an all rounder in the manner of a Helius AM so whilst weight isn't the driver, it is a consideration. 150mm is pretty much spot on as an all rounder for me with a target weight of 29lb or under with a 1x10/11 drivetrain, 30lb with a hammerschimdt (Assuming my current other components)
If it can be designed with a 571 max fork ref in mind without adding more weight then great.
Err, obviously with the above, fitting an angleset would give you the ability to go to 64.5deg if you wanted :-O and maybe 320mm BB!!! but you might want to tweak that if this thing interests you too.
Awaiing initial drawings this week! We're going to work out the basic geo based on what's been proposed on here.
If it all looks like it will work out there is a possible production slot at the end of Feb 2013 for an end Mar/mid Apr delivery....
Interesting, sounds like a it could be quite a bike. 450 mm CS is a bit longer than I'd hoped for but also not too shabby. Could be quite a weapon. Hmmm, worth some serious consideration.
Err, 450mm OR shorter, to be determined. There is a question of what is more important, fitting a 2.35 Hans Dampf or a 4mm shorter chainstay? Based on my experience, I'd take the bigger tyre! But lets see what Max comes up with.
Excellent. Yeap, gotta have room for the Hans Dampf, no compromise there.
Originally Posted by the_pilot
Personally, I'd put the ability to take a big tyre before big travel. My order of importance would be- Big tyre(2.35 HD or 2.4 ardent), light weight, short chain stay, more travel.
Is there a reason Nicolai can't raise the main pivot, or adjust the Horst link for more rearward axle path at bottom out. This would allow shorter stays, more anti squat, but a bit more pedal kickback when bottomed out. Not to big a deal with sub 160mm travel.
If you look at my Ion29 uncut thread you will see that's what we have done to an extent. But it's not so much to head into the 150's in rear travel (too much has other detrimental effects?). However we have now optimised around a 28-32 ring, raised the pivot for better initial pedalling/anti squat.
Oh okay, cheers, I'll check it out. I noticed the Pinioned Nicolais have a slightly higher pivot. I'll be getting a Pinion for sure on my 650b wheeled one. I wonder if I can get them to raise the pivot more.