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  1. #1
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    Preston Bottom-out Issues

    I have a 2006 large preston with Swinger 4-way coil that I have been riding for the past 6 months. Fun bike, but I have had issues with the bike bottoming out in the 5" mode on even the most meager 2-5 drops. I took some advice from this forum and went to the 4" mode in an attempt to stop the bottom out as the loud clank I hear is annoying and probably really bad for the frame and/ or shock. I weight about 205lbs and have the chock setup with the 650# spring. Anyone else have these issues? Any advice? I thought about taking the shock in to get custom tuned but before I spend the money I am trying to find out if it is just an issue due to the frame design, etc. Appreciate any help.

  2. #2
    Chillin the Most
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    Sadly this was the big issue with the 06/earlier Prestons. Judging by my calculations you'd need a 700lbs spring if you where to run 30% sag. To get 25% you'd need an 850lb.

    With your 650, your using about 35% sag which is alot for such a short stroke shock and your weight.

    So what I would recommend is to have your LBS order you a 750lb (largest spring Manitou makes for the 1.5 stroke) spring from Manitou, BTI is currently out of stock.

  3. #3
    Deadhead
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    I would assume you are running the piggyback adjustment all the way in. This will give you the most bottom out resistance. When I spoke with Manitou, they did't recommend running a super stiff spring on the Swinger shocks as it hampers the function of the SPV. I'm about 200lb with gear and run a 600lb spring and haven't had any problems, even when hitting some sizeable jumps/drops. I have yet to put my bike in 120mm mode though and probably never will. If its tuned properly in 100mm mode, you shouldn't ever need that extra 5/8" anyway. Good Luck
    "If you can get both wheels sliding with no brakes, that's when you really know that you're cookin." Nathan Rennie

  4. #4
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    If it makes you feel any better I can bottom out my preston at 135lbs in the 5inch mode. I run 4inch always since pretty much everywhere I go we are bound to encounter drops. Do try setting the piggy back nut in if you haven't already.

  5. #5
    Gringo the magnificent
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    What would you call a loud clank?

    I cant tell If my preston is bottoming when I go off jumps but I know I can almost bottom it out just by throwing my weight down and back, yet the sag is set at or most likely below the recommended level. will bottoming out have a derogatory effect?

  6. #6
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    Preston Bottom Out issues

    Hey guys
    I had a Preston for a while till someone royally screwed me for money and I had to sell it - but anyways - I weight about 200lbs and I had the frame bottoming out on me on ride 1 ** my post is different because I was on a romic instead of a Manitou! and that was with the a 700lb spring that was supposedly specced for me - so I ended up ordering an 850lb spring to have it hold up in 5" mode. It did work, and worked better after I finally......um....finally got a hold of ROMIC and had them retune it up for me. The frame rides great in 4" mode and I really don't think it was engineered right to have the 5" mode option....even though they sold it as a HOP UP kit from Dangerboy for a while before they made their own plates. The leverage ratio of the rear suspension is super high and linear - thus giving you the "bottomless travel" feel .....until the damn think clanks out on you....and unless you are just super smooth 100% of the time - you will bottom out the frame...Often. This was the first frame where I have been able to blow a rear shock out in such a short amount of time. And it was not until I really did more research about it that it had to do with the rear suspension design...so to speak. So now that I sold it, I haven't really missed the frame at all in fact.....and now that I don't have it, I have started looking elsewhere at other companies.....and in particular ATTENTION TO DETAIL - such as things like "suspension design - leverage ratios - Pivot locations - and most importantly what is going on with the pivots - type of bearings etc....and
    .....I was actually rather shocked to see that my Preston didn't seat the bearings on both sides on the dropouts as well as the seatstay yoke...this will eventually put quite a bit of stress on ONE side of the bearings rather than have an even distribution - so the rest - you can figure out for yourselves!

    I have really noticed that some other smaller companies have some killer things to offer such as "non off the shelf" Needle bearings (which are super bombproof) that you can grease yourself a - la - greasegun which I thought was pretty killer - Props to Versus Cycles, and things like a 10yr warranty props to Banshee bikes and the list goes on!

    Now that the new Preston resembles the Banshee Pyre minus the BB linkage, it ought to ride better but I probably won't be the first one to get in line to try it out!

    Kev and Kyle are awesome guys and damn good riders but really keep in mind that you get what you pay for with the older frames - at the pricepoint they have their bikes out now? you can get a whole lot more for your money for only a couple beers more!

    Good luck with that guys!

  7. #7
    Gringo the magnificent
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    Ok

    well...
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  8. #8
    Designated Bleeder
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    Bottoming out the Preston

    I had a similar problem with my Preston in terms of bottoming it out in 5" mode. I run a Manitou Swinger Air shock in the rear so I just cranked down the screw on the piggyback reservoir and it seems to solve the problem. However, I only weigh 180 lbs.

    That said I think I like running the bike in 4" mode better anyway. It seems to be a lot more responsive for trail riding and really just hammers in 4" mode. I really only use the 5" if I am doing resort riding.

    A couple things to keep in mind about bottoming out. Its not a bad thing. So you reach the end of the shock travel, so what. As long as you are not clanking the thing on every huck or drop, its not a huge deal. If you bottom out a couple times on a ride, I wouldn't worry about it. In addition, remember that the Preston is not a 8" travel downhill bike. If you hit a 5 foot drop to flat and you weight 200+ lbs. 5" of travel might just not be enough. Its just physics.

    My Preston, with its limited travel has really helped me ride smoother and try to hit transitions rather than land flat. Think of it this way, if landing flat blows through 5" of travel, imagine what its doing to your knees and your back. Jumps and drops to transition will help you live longer, or at least walk upright.

    My advice, go with a stiffer spring if its bottoming out all the time. Otherwise don't sweat it. Bottoming is not always bad...

    SpK

  9. #9
    DLd
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    bottoming out is not all bad

    Most shock setup guides recommend you set up the shock such that it bottoms out a couple times on your typical ride. If you set it up so it never bottoms out, then you're never getting full use of the travel. With that said, the 06 preston was really designed as a 4" bike. For FR use, the 4" setting is recommended. The 5" setting is more of a ultra-plush setting that can be nice for trail riding, but because of the higher leverage ratio it will blow through the travel more. Also, the leverage ratio is so much higher that you should really be running a different (heavier) spring in the 5" mode compared to the spring that would be correct for the 4" mode. It's a big enough difference that there really isn't enough preload adjustment to correct for the change to 5" mode. Basically, there's nothing to be bummed out about with this bike. It is a 4" travel FR bike, and really works best in that setting, the 5" was added mostly because of customer demand, and everyone wants that extra inch, but really the whole design philosophy of the preston is about doing more with less. It's about having enough travel to get the job done, but not having all of the disadvantages of excessive travel. With that said, the move to a longer stroke shaft on the 07 is nice, especially for the bigger riders, but also because it opens up a lot more shock choices, I would have been fine with them sticking with 4" of travel though, but I think they wanted to maintain the similar leverage ratio to the 06 4" travel setting. So, to sum this up, switch to the 4" mode, crank in the bottom out adjustment (not too much), and you will probably be way stoked. I'm loving my preston.

    happly MLK day, get out and ride,

    d
    "Great things are not accomplished by those who yield to trends and fads and popular opinion."-Jack Kerouac

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