Folding Bikes - Tikit upgrades

Monday night I upgraded my Tikit with:

SRAM Rival double crankset (I only use the 53t chainring) with a GXP bottom bracket
SRAM X.9 short cage rear derailleur
SRAM X.0 twist shifters
SRAM 9 spd cassette
SRAM 9 spd chain

The combination is great! The bottom bracket removal and installation was painless, the rear derailleur was super easy to setup, and the shifter has a much more solid click and feel. Whenever I get home, I'll post some pictures.

The only issue I have now is the chain keeps falling off the outside of the chainring. For now I mount the chainring guard on the inside because the outside position seems to line up the best with the middle of the rear cogs, and because the chainring has a metal thing sticking out that interferes with placing the chainring guard on the outside. I'll need to figure out how to solve the chain derailing issue; it popped off three times on my 19 mile commute this morning. It only seems to do this when shifting to the high gears (probably when it's bumpy). I tried reducing the chain length by one inch, but that prevented access to the lowest gear, so I added it back.

Any suggestions on how to solve the chain issue? I tried searching for solutions, and all of them either revolve around a front derailleur or changing the rear derailleur. Is there a place I can find some chainring guards like the one that came with the Tikit, but that would mount on the outside of the outer chainring? Any recommendations on a chain tensioner or something similar?

Maybe I'll try cutting the pin that sticks out of the chainring and swapping the positions of the chainring and the guard and try that out for a day.

I'm no mechanic, since the chain is falling off the chainring, could it be that your crank is differently spaced than the old one? I at first thought about the chain length, but re-reading your post, I see you already thought about that.

Finally what about changing things one at a time... what would happen if you put the original crankarm (with or without the old chainring) back on and tried it with the SRAM shifters...would that be compatible?

I have some questions though: What are the gearing ratios for your cassette? (sprocket numbers). I'm too lazy to go count my tikit, what are the old ones? Did you change the ratios to go faster, or just to get some more quality shifts? How is chain clearance? Does the new derailleur drop lower?

Can't wait to see pics... PS I hope this doesn't void your warranty.

I'm no mechanic, since the chain is falling off the chainring, could it be that your crank is differently spaced than the old one? I at first thought about the chain length, but re-reading your post, I see you already thought about that.

Finally what about changing things one at a time... what would happen if you put the original crankarm (with or without the old chainring) back on and tried it with the SRAM shifters...would that be compatible?

I have some questions though: What are the gearing ratios for your cassette? (sprocket numbers). I'm too lazy to go count my tikit, what are the old ones? Did you change the ratios to go faster, or just to get some more quality shifts? How is chain clearance? Does the new derailleur drop lower?

Can't wait to see pics... PS I hope this doesn't void your warranty.

I don't think it's the shifters or the derailleur, and putting the old crankset would require that I remove and reinstall the old bottom bracket. From what I've read, having one chainring on the front tends to create more dropped chains because there's no derailleur to prevent it from dropping. I'll probably just figure out a way to mount a chainring guard like the original crankset had.

I think the old cassette was 11-28 but was an 8spd. The new derailleur, shifter, and cassette are for 9spd. The new cassette is 11-32. I could have gotten an 11-34, but the extra two teeth would have costed me more. I mainly did it for quality shifts, but I also wanted lower gears. The shifting is more deliberate and quicker, and the shifter itself has a nicer firm click when switching gears.

Since I got the short cage derailleur, it doesn't seem any lower than the original microshift. Also, as long as Bike Friday honors the warranty on the frame, I'm happy. I don't expect them to honor the warranty on the parts I've replaced.

http://www.iamstuffed.com/photos/zp-core/i.php?a=tikit-upgrades&i=IMGP3387.JPG&w=400&h=300 (http://www.iamstuffed.com/photos/tikit-upgrades/IMGP3387.JPG)
SRAM Rival Crankset. I had to keep the chain guard on because I don't have crank bolts for a single chainring.

http://www.iamstuffed.com/photos/zp-core/i.php?a=tikit-upgrades&i=IMGP3388.JPG&w=400&h=300 (http://www.iamstuffed.com/photos/tikit-upgrades/IMGP3388.JPG)
SRAM PG-970 9spd cassette, and SRAM X.9 short cage derailleur

http://www.iamstuffed.com/photos/zp-core/i.php?a=tikit-upgrades&i=IMGP3391.JPG&w=400&h=300 (http://www.iamstuffed.com/photos/tikit-upgrades/IMGP3391.JPG)
SRAM X.0 twist shifters. I still need to replace the grips I put on the bike to replace the foam grips, but they work well enough for now.

Nice....let us know how it rides. BTW - what was your motivation to swap out the stock 8 speed setup?

Nice....let us know how it rides. BTW - what was your motivation to swap out the stock 8 speed setup?

Since I commute such a long distance, some of the hills I encounter are more than a mile long. Mainly I wanted a larger cog for the low gear, so I replaced the rear cassette with an 11-32 and wasn't sure if the microshift could support that, so I replaced the RD with an SRAM X.9. The SRAM also requires a compatible shifter, and I wanted a nicer crankset.

Also, I wanted to see if I could do it, and it was actually fun figuring out how to replace all the components. The bottom bracket replacement was actually what I was worried about, but it went smoothly.

Eventually, I'm going to try a dual drive rear hub (I already have the hub) and I thought it needed an SRAM rear derailleur to work with it, but after I bought the parts, I found just a left shifter for the hub, so I guess you could use any derailleur and shifter you want.

http://www.iamstuffed.com/photos/zp-core/i.php?a=tikit-commute&i=elevation.png&w=400&h=300 (http://www.iamstuffed.com/photos/tikit-commute/elevation.png)
Elevation chart of my commute. Even though they probably aren't considered big hills by some people, the commute definitely is not flat.

Since I commute such a long distance, some of the hills I encounter are more than a mile long. Mainly I wanted a larger cog for the low gear, so I replaced the rear cassette with an 11-32 and wasn't sure if the microshift could support that, so I replaced the RD with an SRAM X.9. The SRAM also requires a compatible shifter, and I wanted a nicer crankset.

I swapped the drivetrain on my Tikit for the same reason when I first bought it. I also put on drop bars because I hate flat bars. I used an 11-34 8sp cassette, 8sp Shimano barend shifters, and a Sachs New Success rear derailleur that could handle the 32t cog (I already had the derailleur).

http://alexandchristine.smugmug.com/photos/181276896_9y3oo-L.jpg
http://alexandchristine.smugmug.com/photos/181276852_a2KqR-L-1.jpg

I put on a 105 crank because it was the cheapest quality 130mm BCD crank that I could find at the local used bike shops. I wanted something shorter than the stock 175mm (on a large Tikit) crank.

I like this setup, but I like my setup with the SRAM S7 hub even better. Similar wide gear range, better shifting, no low-hanging derailleur to damage.

The Tikit is sensitive to chainline. I experimented with the bottom bracket length and spacing a few times before finding a setup that worked well for me. You can mount the chainguard outside of the chainring (with the chainring mounted on the outside position) if you get some chainring spacers from a bike shop. That got me the best chainline with the lowest Q-factor.

alex

if you get some chainring spacers from a bike shop. That got me the best chainline with the lowest Q-factor.


Can I just use regular washers? Do I need specific chainring spacers?

Alex,

Where did you get the large chain ring protector?

I recently installed a slightly larger chain ring on my dual-drive NWT (46mm). I know I can get color-keyed ones from BF for $40+. Haven't seen many others out there.

I am assuming the tikit is the same bolt pattern/size as the NWT.

Thanks.

Lou

Alex,

Where did you get the large chain ring protector?

I recently installed a slightly larger chain ring on my dual-drive NWT (46mm). I know I can get color-keyed ones from BF for $40+. Haven't seen many others out there.

I am assuming the tikit is the same bolt pattern/size as the NWT.

Thanks.

Lou

Those come standard on the Tikit.

Where did you get the large chain ring protector?


That is from the stock crank on the Tikit.

I also remembered one other thing. If you replace the crank on your Tikit you should use the Tikit chainring or another chainring without shift ramps. Most chainrings made these days will drop the chain much more easily to improve shifting. The Tikit doesn't have a front derailleur, so you don't want such a ring.

alex

Can I just use regular washers? Do I need specific chainring spacers?

It is difficult to find 8mm ID washers with an appropriately small OD (around 10mm) that aren't chainring spacers.

That is from the stock crank on the Tikit.

I also remembered one other thing. If you replace the crank on your Tikit you should use the Tikit chainring or another chainring without shift ramps. Most chainrings made these days will drop the chain much more easily to improve shifting. The Tikit doesn't have a front derailleur, so you don't want such a ring.

alex

Ah... I didn't even think about using the stock chainring. I'll give it a try tonight.

Switching the chainring back to the original Bike Friday supplied one worked. No more dropped chains for me!

Alex, what kind of front rack is that on your tikit?
Keith

Alex, what kind of front rack is that on your tikit?
Keith

It is one that I made.

http://alexandchristine.smugmug.com/photos/201842496_LDeHn-M.jpg

http://alexandchristine.smugmug.com/gallery/3561136_BXV84

I've made many porteur racks like this for various bikes:
http://alexandchristine.smugmug.com/Bicycles/286770

alex

Very nice Alex....:thumb:

I own a Dahon Speed Pro TT

One of the first things to check if experiencing chain drops, especially if you changed the chain, chainring or cassette size, is whether the chain size is properly adjusted.

Out of three Dahons, all three came with too-long chains and drops went away after adjusting the chain to the proper length. Making sure your rear derailler is adjusted can help as well.

I swapped the drivetrain on my Tikit for the same reason when I first bought it. I also put on drop bars because I hate flat bars. I used an 11-34 8sp cassette, 8sp Shimano barend shifters, and a Sachs New Success rear derailleur that could handle the 32t cog (I already had the derailleur).

http://alexandchristine.smugmug.com/photos/181276896_9y3oo-L.jpg
http://alexandchristine.smugmug.com/photos/181276852_a2KqR-L-1.jpg

I put on a 105 crank because it was the cheapest quality 130mm BCD crank that I could find at the local used bike shops. I wanted something shorter than the stock 175mm (on a large Tikit) crank.

I like this setup, but I like my setup with the SRAM S7 hub even better. Similar wide gear range, better shifting, no low-hanging derailleur to damage.

The Tikit is sensitive to chainline. I experimented with the bottom bracket length and spacing a few times before finding a setup that worked well for me. You can mount the chainguard outside of the chainring (with the chainring mounted on the outside position) if you get some chainring spacers from a bike shop. That got me the best chainline with the lowest Q-factor.

alex

Alex -

Is that the manufacturer's name on the chainring guard? I can't quite make it out in the photo, so would appreciate it if you could pass it on.

I've been trying to track down an alloy guard for a Birdy with no success other than Japan. Unfortunately, they only sell the guard as part of a chainring set.

Thanks

CB

Change the extension on the URL to say "-O" instead of "-L" and you'll see it in full resolution. The logo says "Speedwheel".

I'd call Bike Friday and see if they'll sell it.

url]

I've made many porteur racks like this for various bikes:
http://alexandchristine.smugmug.com/Bicycles/286770

alex

Looks like you have welding experience. I've often thought of doing this, but using PVC pipe. Esp. a removable one that I can put in front of one of my full size bikes to pick up a pizza.

Change the extension on the URL to say "-O" instead of "-L" and you'll see it in full resolution. The logo says "Speedwheel".

I'd call Bike Friday and see if they'll sell it.

Only reference for "Speedwheel" in a search brought up a Japanese bike site. It may be a product name and not a manufacturer's name, or it could also be a Japanese product.

I tried Bike Friday, but they lost interest after I told them it was for another company's product.

Thanks for the attempt.

Looks like you have welding experience. I've often thought of doing this, but using PVC pipe. Esp. a removable one that I can put in front of one of my full size bikes to pick up a pizza.

The rack is brass brazed, not welded. I learned how to do this so that I could build bicycle racks and bicycle frames. I didn't have any experience two years ago.

There are various plans for racks made with aluminum or steel angle stock or u-channel stock and rivetted together. I think such a design would be a lot stiffer than PVC and wouldn't require any welding experience. Here is an example
http://www.flickr.com/photos/drwelby/2514235699/

CETMA and Pass and Stow are two companies that make front platform racks that fit most bicycles.

alex

The rack is brass brazed, not welded. I learned how to do this so that I could
alex

Alex, where do you source an 8 speed 11-34 cassette? I've only seen these in 9sp, easy to find 11-32 in 8sp, have wanted one for another bike for a long time. Thanks.

11-34 8sp cassettes were sold as part of the Shimano Nexave group in the late 90s. They have an interesting shift pattern where the second to largest cog is 26t and the largest is 34t (that is a big jump). This keeps the gearing pretty tight through most the range and gives you a bailout gear.

It looks like they are still being offered:
http://harriscyclery.net/page.cfm?PageID=49&action=details&sku=FW8091

FW8091 is the QBP part number. Most bicycle shops in the US order parts from QBP and could special order this for you.

alex