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  1. #1
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    Question re: the DT 8H gearing

    In a review of the DT 8H the writer expressed the opinion that this folder was geared too high and that Yan had indicated that he would institute changes on following shipments that would lower the gearing. The review indicated that the rear sprocket was 23T and the front sprocket was 48T. Based on these sprockets and the hills here in East Tennessee I am inclined (I am a spinner) to agree with the reviewer! My preferred choice would be to use a larger rear sprocket but if 25T is the only other available size rear sprocket, Iím guessing chaining out the front sprocket would give more options, but would likely not allow the continued use of the chain guard! Too bad!

    Now for my main question! Has the gearing been changed, if so what changes were made?

    OK one more question for DT 8H owner/riders! Have any of you guys found a need to change the gearing and if so what method did you use!

    I really like the looks of the 8H and am thinking of getting one to use while Rving! However, it would appear I am going to need lower gearing if I am gonna be able to ride it in some of the state parks that we like to stay in!

    Thanks for your replies!
    Al

  2. #2
    Senior Member Polaris43's Avatar
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    Quote Originally Posted by ahorner1946
    In a review of the DT 8H the writer expressed the opinion that this folder was geared too high and that Yan had indicated that he would institute changes on following shipments that would lower the gearing. The review indicated that the rear sprocket was 23T and the front sprocket was 48T. Based on these sprockets and the hills here in East Tennessee I am inclined (I am a spinner) to agree with the reviewer! My preferred choice would be to use a larger rear sprocket but if 25T is the only other available size rear sprocket, Iím guessing chaining out the front sprocket would give more options, but would likely not allow the continued use of the chain guard! Too bad!

    Now for my main question! Has the gearing been changed, if so what changes were made?

    OK one more question for DT 8H owner/riders! Have any of you guys found a need to change the gearing and if so what method did you use!

    I really like the looks of the 8H and am thinking of getting one to use while Rving! However, it would appear I am going to need lower gearing if I am gonna be able to ride it in some of the state parks that we like to stay in!

    Thanks for your replies!
    Al

    When I changed the bottom bracket, I also installed a 40 tooth chainring. Huge improvement.

    I'm going to check the chain line to see if that's why I have a clicking noise while peddling. The click was there before the new chainring and is still there.

    I have the same hub and the stock chainring on my Mini and it never clicks. Does anyone have any ideas on this?

    Yan said to clean the hub - I did that - no change in the click.

  3. #3
    Eschew Obfuscation SesameCrunch's Avatar
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    AHorner:

    There was a very creative solution by PineCone for this problem described on the Downtube thread. He took a standard 53/39 crank, uses the 39t as his front chainring, filed off the teeth on the 53t to form the chainguard. I thought it was ingenious! Here's the thread and pictures. It might work for you.



    Look at post #198 on this thread.
    Downtube folding bike

  4. #4
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    I believe either Gaerlan or Harris Cyclery can provide you with spacers if you would rather remove the big chainring,

    Juan

  5. #5
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    Re:the DT 8H Gearing

    Thanks for the replies! Now I have even more questions! ;-)

    Polaris43: When you changed out the bottom bracket did you also change out the crank assembly? If not, were you able to retain the chain guard when you went to a 40T chain ring? What speed to you spin-out at going down a hill? What rear sprocket did your 8H come with?

    Oh yeah, regarding the click, make sure the chain ring boltsíspacers are evenly tight, and also check the pedals! On my RANS Stratus I developed a click when climbing I checked, lubed, and re-tightened everything connected to and including the crank assembly, it turned out to be the pedals making the noise! It drove me nuts for about 2 weeks!

    SesameCrunch: Yeah, PineConeĎs solution is quite creative and I do like it! Unfortunately I donít have a 105 crank laying around, thus that would be an expensive solution for me! I think if I was gonna do something like that I would look into installing the front Der also and go for 16 speeds. Hopefully the chain line on the 8H would still function correctly!

    Oh yeah, I really do like the looks of your Folder/recumbent conversion!

    Juan162: Are you suggesting that if I used the idea of PineCone I could remove the big chain ring and use spacers to install the chain guard in itís place? Or am I misunderstanding you??

    Thanks for your Help and time guys!

    Al

  6. #6
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    Al,

    I meant that if you don't want a chainguard and just want a basic single crank without paying an exhorbitant fee for a track crank, you can get the spacers to modify a double into a single. The spacers help keep the chain line straight. I think that it is the Harris Cyclery site that carries it.

    Juan

  7. #7
    Senior Member Polaris43's Avatar
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    Quote Originally Posted by ahorner1946
    Thanks for the replies! Now I have even more questions! ;-)

    Polaris43: When you changed out the bottom bracket did you also change out the crank assembly? If not, were you able to retain the chain guard when you went to a 40T chain ring? What speed to you spin-out at going down a hill? What rear sprocket did your 8H come with?

    Al

    No, I kept the stock crank assembly. No, the chain guard wouldn't fit so now I don't have one. I do like the dual with the large ring filed down... very nice.

    There aren't many hills in Long Beach (no, I'm not going to ride up Signal Hill just to ride down) so my hills are limited to those associated with underpasses on the LA river bike trail. I've never really spun out because the hills aren't long enough and I've hit speeds in the mid 20's. I'm not a bike techno wizard so if I've misunderstood your question... please be gentle...

  8. #8
    Senior Member
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    I replaced it with a 39 tooth chainring on a used Shimano 105 crankset and bottom bracket. I posted a picture of it on the Downtube site as well as the DT megapost here. Too many hills around here for the stock chainring.

  9. #9
    Folding bike junkie! Wavshrdr's Avatar
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    There is a bigger rear sprocket which may be enough for a lot of people unless you have pretty steep hills as I mentioned in my original review. The DT Mini is geared about perfect for most people.

  10. #10
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    After reading the various post on re-gearing the DT 8H I feel I have been much enlightened! Given the hills of East Tennessee and my preference for sitting and spinning as opposed to "walking the pedals" (while climbing), I lean toward lower gearing than a 25T sprocket would provide (with an otherwise stock drivetrain)! I played around with Sheldon Brown's gear calulator (Thank you Captain) and I like a 23 x 34 gearing. I would have to go to a Crankset that accepts 110 BCD Crankrings. There is sufficient variety in that size, especially since I won't be doing any "extreme" riding with that bike, or any other bike for that matter! ;-)

    Does anybody see any problems (yeah I know the stock chain guard will not work) with my thinking as it regards my use! Thanks for all the help! Now I just have to talk the little woman into allowing me to have "just" one more bike!!!

    Al

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