[Gilzean]

I’m new to cycling especially folders, I purchased a Downtube 8FS and have been commuting for 2 weeks now. I like the downtube but already feel the need to upgrade some components. My ride is between 8-10 miles a day and a little hilly. The gearing is useless (slips and is cheap)

Not knowing much about bikes I was wondering if anyone could help me out…

I want to upgrade the gears and was thinking of getting the following:

1. SRAM PG-950 9-Speed Cassette (11-34)
2. SRAM X.5 Rear Derailleur
3. SRAM X.5 Trigger Shifters - 9-Speed
4. SRAM PC971 Chain - 9 Speed

I can get all this for around $150. Will this all fit a downtube FS? What else would I need to get?

Can anyone recommend anything else? Should I upgrade with a crank crank set as well?

Thanks

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[Sammyboy]

You could probably fit all of that, but a tune-up should solve the slipping. I'll make my apologies if you've already done this, but a bit of tweaking on the adjusters should get it shifting just right.

[Fat Boy]

Your changes will make a _huge_ difference in the shifting and overall happyness of your bike. No amount of tweaking would help my bike to shift, ghost shift, skip, throw chains, etc. I would say that a crankset change will probably help life a little as well. The stock crankset is really crap. The stamped spider deflects like crazy if you try to put any torque on it. 175mm is your max on crank arm length, and that's a little too long, IMO.

On my bike I changed the crankset to an FMF BMX crankset with a 53 tooth chainring. That gearing is actually a little tall, and I'm a reasonably good climber. A 50 would be about perfect. Everything else you have spec'd out is good stuff. While you're there, you might think about changing the derailler cable housing to something that is nicer. The stock stuff is pretty flexy.

If you do these changes, you'll have a really nice folder. I know it seems like a lot of stuff to change over, but it makes the bike _so_ much nicer that you'll wonder why you didn't do it soon. Been there, done that.

Once more I'll say for any Downtube prospective customers. The components are crap. Plan on replacing them as soon as you buy the bike. Sad, but true. When you put the rear derailler on, make sure the hanger isn't tweaked. If it is, bend it back straight.

[mdweezer]

I'm no bike pro but I just got my Downtube 8H with the SA 8-speed hub and I have a similar distance commute and it's a dream. Being able to come to almost a complete stop while in 4/5th gear and to be able to shift down to first gear and pick right back up in an instant is such a nice benefit.

I know they make a 3-speed SA hub, though I don't know if that would be enough gearing for you but I've found I barely ever go 4th gear on my flat route.

I would highly recommend the SA on the Downtube.

Aside from that I can't contribute much else, this is the first bike I've owned in many, many years :) So I'm not very knowledgeable with the gear mechanism.

[Gilzean]

[QUOTE=Fat Boy;6641410]On my bike I changed the crankset to an FMF BMX crankset with a 53 tooth chainring. QUOTE]

Fat Boy can you direct me to any sites that supply the FMF crankset or simular at reasonable prices? What bottom bracket are you using?

I'm thinking the SRAM x.7 now cause the x.5 looks a big long.

I like my downtube and expected the parts to be not so great, i didn't expect them to this bad. I tried tuning it myself (didn't work) sent it to my local shop for a tune up and with in 2 days it was back to normal. No i don't want to waste my time anymore I want to upgrade to some decent parts sink maybe $250 into the bike and have something thats going to last.

Another thing I dont understand why downtube don't add to their product line is some sort of guard to stop the bike scratching where it meets on the fold!? Mine is now covered in electrical tape... And another thing why not include a magnet or nice looking strap to hold the fold?

Don't get me wrong for the money compared to other folders the downtube is a nice bike, I had the chance to get a Birdy White 9 Speed for $750 wish I went with that now.

Thanks for your replies!

[psykoocycle]

GIZ: A lot of people have changed the drivetrains on their DT's...

If you have already done a tune up and it went back to slipping in 2 days, then it could be the bolt attaching your derailleur hanger to the frame has loosened... tighten it, retune, and if the problem persist or you are still unsatisfied, then proceed with the drivetrain change...

ESSENTIAL: Derailleur, chain (or adding more chain, depending on the chain ring you mount on), and chain ring.

IF YOU WANT: Triggers (you can only do 1:1 with the xo, x9, x7... so if you are going with one of these... you definitely need SRAM triggers), if you are going with a shimano derailleur then your twister is fine... changing the cassette (unless you have bent or chipped teeth) won't do much to change things, and is cost prohibitive... the BB if you have =/< FS 2007 may be necessary (I forgot which one had the sealed bearings)...

try this... for parts...

www.bestbikebuys.com (http://www.bestbikebuys.com)

happy modding!

[Fat Boy]

Here's the cranks.

http://fmfbmx.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=C

They are square taper cranks, so you can use your present bottom bracket. At $25 they don't break the bank, either. I recommend greasing the BB, though, because it could have come from the factory dry. The bolt pattern lets you use any 'compact' chainrings. I recommend a 50 tooth.

I used a short cage X.9 derailler and a the X.0 twist shift. Because of the clearance issue, I would only use a short or medium cage derailler, a long cage (like X.5) would be very close to the ground. Like someone else said, if you use a Shimano derailler, you can stick with your shifter, but only if you want to keep it to 8 speeds. If you want to get nine speeds you have to change shifters, chain, and cassette (which is what I figured you were interested in). The good news is that once these parts are dialed in, you can forget about it and you'll have a much more reliable bike.

I used 'heli-tape' on the frame to keep it from chipping. Electrical tape should work just as well. It should be this way from the factory....a common statement about the Downtube.

If you have any more questions, let me know.

[Gilzean]

Thanks for your help guys, gonna order the SRAM x.7 RD and shifter tomorrow!!!