The new F6

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  • 09-01-2009
    funkydrummer
    The new F6
    I'm sure some of you guys will know about plenty of this stuff already throught the grapevine - but the new developments for the F6 look pretty cool!




    I'm pretty sure this isn't anything too secret as it was on YouTube!

    As you can see though, lower BB, slacker HA, fixed brake, ISCG etc are all on the checklist as well as some snazzy new tubing! I can live without the tubing...but I've basically got the the first four done on my F5 already :D

    Good work Chumba!
  • 09-01-2009
    Flystagg
    I like the new front triangle a lot.
  • 09-01-2009
    rollertoaster
    Not digging the new front triangle. I think the F5 looks better.
  • 09-02-2009
    funkydrummer
    Aesthetically at least, I'm with you. I do prefer the F5 - somehow it's nice to see straight frame tubing these days when everything is hydroformed or curved or whatever. At least Chumba seem to be taking the other ideas about the frame on board :)
  • 09-02-2009
    nigulet
    2 Attachment(s)
    :thumbsup: :thumbsup:
  • 09-02-2009
    NCETRY
    I like the bottom one better.
  • 09-02-2009
    rollertoaster
    me too.
  • 09-02-2009
    Flystagg
    Top one better, although the bottom does look more classic chumba
  • 09-03-2009
    hairygut
    please change that 1.5 od 1 1/8 id headset thing. Internal 1.5 is the only way to go. It helps make the stack more adjustable. the board mentions adjustable head angle and the cad one looks like an adjustable head angle setup which could be a very awesome improvement. My biggest complaint with the f5 is the chain guide mount setup. If they keep the clamp concept then moving the clamp point to some other place than between the bolts would be great. the fact that the distance changes as the bolt gets torqued makes mounting it a super pain.
  • 09-04-2009
    funkydrummer
    I hear ya on the headtube! I've been thinking on tinkering with my F5 as it is, but I think what I had planned was a bit too much heavy engineering! I run a bb mounted chain guide which gives no problems, so I can't say that the iscg mounts (or lack of) bother me but I agree, it would be daft not to include a better thought out solution in a new revised model.
  • 09-04-2009
    hairygut
    bb mounted...briliant!
  • 09-10-2009
    mrpercussive
    that looks sick... should i start saving money? haha
  • 06-08-2010
    TryFour
    I hear we're going to be seeing a whole lot more about this in the relatively near future!! :thumbsup: :thumbsup: :thumbsup:

    Anybody have newer info on the new F6?
  • 06-11-2010
    Banffster
    I like the 1.5 HT, adjustable is even better but with all the offset cups coming out it might not be all that necessary. The straight 1.5 HT offers the most flexibility for angles and bar height plus it would be much simpler.

    Please no maxel though, just a better pinch bolt than the current setup.

    Larger suspension bolts is mandatory, and standard sizing would be nice. 7mm reducer? Who thought that was a good idea?

    The BB should be lower, it's what the people want. 14" with a stock dog bone with a 64* HA would be great out of the box numbers. Offer a long bone for the dudes who want to run a super low & slack setup(13.5bb, 63*ha), Considering the price of a dog bone having the option of including both with the frame would be divine, call it the world cup edition :-)
  • 06-11-2010
    funkydrummer
    Yo Banffster!

    I'd rather the frame was kept simple, just 1.5 headtube, which like you say, offers a lot of flexibility anyway. The linkage area in general needs a look at - larger than 6mm bolts aren't 100% necessary IMO, if you remove the stiction from the bushings by adding proper bearings, you relieve the bolts of a lot of strain. This needn't be really expensive, or heavy, plus since doing this I haven't snapped or even bent one bolt, whereas even for me (a lardy, unskilled rider) it was every 3-6 months before.

    I've got mine at 14" BB now, with a very slack head angle (63 ish) and I wouldn't want it any lower. I think your 'stock' numbers sound fine! I think the travel could be reduced slightly, perhaps to 8 or 7.75" and then a 13.5" BB would be feasible, but I wouldn't go that low at 8.5" travel!
  • 06-14-2010
    Banffster
    Quote:

    Originally Posted by funkydrummer
    Yo Banffster!

    I'd rather the frame was kept simple, just 1.5 headtube, which like you say, offers a lot of flexibility anyway. The linkage area in general needs a look at - larger than 6mm bolts aren't 100% necessary IMO, if you remove the stiction from the bushings by adding proper bearings, you relieve the bolts of a lot of strain. This needn't be really expensive, or heavy, plus since doing this I haven't snapped or even bent one bolt, whereas even for me (a lardy, unskilled rider) it was every 3-6 months before.

    I've got mine at 14" BB now, with a very slack head angle (63 ish) and I wouldn't want it any lower. I think your 'stock' numbers sound fine! I think the travel could be reduced slightly, perhaps to 8 or 7.75" and then a 13.5" BB would be feasible, but I wouldn't go that low at 8.5" travel!

    Sure bearings instead of bushings sounds good too, anything that improves the lifespan of those bolts. I have the latest and greatest version of the linkage with the bearings and it's pretty skookum, have you had problems there? I assume you had the old style with the bushings since you went all military grade with the ten tonne bearing :D

    So I have been running a michelin dh 24 in a 2.2 size this year on the rear. Size is just a smidge smaller than a maxxis 2.5 width wise but a fair bit shorter. With the 3.5 dogbone I measured the BB to be 14.25 and a HA 63.83* on the angle finder. I have been riding at mount seven (home of the psychosis race) which is quite a rugged venue and I have to say that I am pretty darned satisfied with the BB height. I do still plan on making an adjustable dogbone that will go as long as yours (man that sounds bad) but I fear I will need to get shorter cranks with that setup. Less travel? I 'm not sure, I seem to rail through what I have now:eekster:

    The bike is an absolute riot to ride as it sits at the moment, I would really like the F6 to be pretty similar to the current rig. Just give us more flexibility with regards to setup and fasteners that don't constantly bend or break. Part of the appeal of the F5 is it's simplicity, and bad ass moto looks.Keep it simple and easy to work on, I really like that aspect of the F5.
  • 06-14-2010
    Banffster
    Oh, and I have to add that I dislike the looks of all three protos displayed in this thread. Keep it moto boys.
  • 06-15-2010
    funkydrummer
    Quote:

    Originally Posted by Banffster
    Sure bearings instead of bushings sounds good too, anything that improves the lifespan of those bolts. I have the latest and greatest version of the linkage with the bearings and it's pretty skookum, have you had problems there? I assume you had the old style with the bushings since you went all military grade with the ten tonne bearing :D

    So I have been running a michelin dh 24 in a 2.2 size this year on the rear. Size is just a smidge smaller than a maxxis 2.5 width wise but a fair bit shorter. With the 3.5 dogbone I measured the BB to be 14.25 and a HA 63.83* on the angle finder. I have been riding at mount seven (home of the psychosis race) which is quite a rugged venue and I have to say that I am pretty darned satisfied with the BB height. I do still plan on making an adjustable dogbone that will go as long as yours (man that sounds bad) but I fear I will need to get shorter cranks with that setup. Less travel? I 'm not sure, I seem to rail through what I have now:eekster:

    The bike is an absolute riot to ride as it sits at the moment, I would really like the F6 to be pretty similar to the current rig. Just give us more flexibility with regards to setup and fasteners that don't constantly bend or break. Part of the appeal of the F5 is it's simplicity, and bad ass moto looks.Keep it simple and easy to work on, I really like that aspect of the F5.

    If I was redesigning the F5 (go on Chumba, give me a go!), I'd certainly go for bigger/stronger hardware cos I'm a belt and braces kind of guy. I think my version would cost a little more, but sometimes these things have got to be done - I totally agree it should remain as simple as possible.

    In terms of versions, my bike's had the older bushing style throughout, then moved to bearing 'rocker' linkage (as this was the worst place for bushing wear and bolt snapping). That replacement part cost me a fortune because of shipping/import duty/úvs$ at the time etc. That's when I decided I would stop buy original Chumba parts and make my own. I don't think it saved me any money but everything came out just how I wanted it each time. There are other mods on my frame that you can't see - on my frame, the lower dog bone mount was ovalising, causing some play (this is one of the problem of using smaller hardware, IMO). So I enlarged the hole and turned some steel tube to the right size and press fitted it to keep it strong. When I was taking the frame apart to do the last mods, I noticed that the bearings in the new rocker link which I had spent so much $$ on were already crapped out (less than a year). So I thought F**k it, I'm going to sort that too - hence overkill bearings. The bonus of that is that the rocker is now very easy to remove (no press fit parts to drift out), should I ever need to.

    My kind of riding terrain is generally not deserving of an F5 if I'm honest, I just was sick of having bikes that were unreliable. I do ride in Scotland, Wales etc which can be rough places but in general my local trails in England are pretty slow/technical. The Chumba is amazing for the Alps/Morzine etc.

    I was considering asking cane creek (I'm on 1st gen double barrel) if it's possible to slightly decrease shock travel, then I would slightly shorten the dog bone so that my static geometry remains the same but bottom out is 0.5-0.75" higher. I'm already running 165mm cranks and it's sketchy for me as it is! Cornering is good low, but we have some flattish rock gardens at my local trails which you have to pedal/pump through to maintain speed.
    What shock are you running Banffster? I find the progression on the F5 is such that I almost never feel a harsh bottom out...I'm 13st and running a 325lb spring :yikes:
  • 06-16-2010
    Banffster
    I am running a DHX 5 that has been custom tuned. I weigh 185lb (13 stone according to google!) and I run a 350lb spring. Prior to the shock being tuned I was contemplating a 400lb spring to give the bike a poppier more responsive feel, but this is no longer necessary. The rear feels much more supportive and responsive to my inputs while maintaining a very plush ride. It's my first experience working with a suspension tuner and I am blown away by the results, I highly recommend James at suspensionwerx to anyone contemplating this sort of service, for less than the price of a set of tires no less.
  • 06-16-2010
    hairygut
    I just wish i could ride my f5
  • 06-16-2010
    Banffster
    Quote:

    Originally Posted by hairygut
    I just wish i could ride my f5

    Yes, much funner when ridden.
  • 10-20-2011
    jeffleishman
    Quote:

    Originally Posted by Banffster View Post
    Yes, much funner when ridden.

    mines been out of commission for 2 months since i ve been waiting on bolts from chumba!
    :nonod:
  • 10-22-2011
    Phazz470
    Have you tried looking in your local hardware store for bolts?
    I replaced all of my bolts on my EVO with grade 5 and 8 hex head bolts that are much stronger than the bolts chumba gives.
  • 10-28-2011
    laxman2001
    Quote:

    Originally Posted by jeffleishman View Post
    mines been out of commission for 2 months since i ve been waiting on bolts from chumba!
    :nonod:

    ...what a surprise.
  • 10-28-2011
    Dibbs_
    Cash flow must really be bad. Or Daddy is refusing to bail it out.
  • 10-28-2011
    kavika
    Well, I had intended to give the F5 a rebuild this season, but after getting partial replies to enquiries, I finally managed to get enough details to place an order for parts.
    A week after placing the order, there was still nothing taken from my C/Card, and no email stating what the hold up was, so I cancelled the order, and have now sold the Chumpa.

    Thanks for the great customer support. I ordered a new linkage for the mates Demo8, and it arrived within 7 days! I would say try to learn from this, but I won't bother, it would just be more lame excuses.

    So I now have to find a new bike in the next 2 weeks for my DHing holiday, but at least I know if I break something, I'll be able to get parts!
  • 10-28-2011
    Dibbs_
    Oscar probably doesn't know what the F5 is. Would have to google it.
  • 10-28-2011
    huckit
    Quote:

    Originally Posted by Dibbs_ View Post
    Oscar probably doesn't know what the F5 is. Would have to google it.

    hehehehe:D