Bike dilemma

Discussion in 'Touring and recreational cycling' started by Gotte, Sep 10, 2006.

  1. Gotte

    Gotte New Member

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    I have this dilemma - I have two servicable bike on which to complete a 750 mile tour next May, one a £200 Decathlon road bike, the other an old tange 1000 chromo MTB frame made up to a tourer with 700 x35 wheels, brooks saddle, and butterfly bars.
    I ride my road bike, and really enjoy the sensation of the bike actually wanting to go. It's fun, and much as it's more difficlt to ride in that I have to anticipate the road surface more, and is more uncomfortable in that it's got an aluminium frame and my hands tend to numb quicker on the bars, I just enjoy it.
    WHen I get on my dedicated tourer, however, it just seems like hard work. I never get that sensation of the bike wanting to go. I always seems to be plodding on it. It absically feels like harder work.
    The tourer is heavier _ I recon by 5 lbs, and the tyres will drag more, just by being bigger, but I still feel there's something else that's making it such hard work.
    My last concern is gearing. Now I have to say, I know nothing about ratios etc and how they affect riding except that a big cog on the back combined with a small one on the front, and visa versa, will make life easier or more difficult.

    My highest gearing is - 38 x 14 (that is, the biggest chainring is 38, and the smallest gear is 14). I have a feeling that because I've got a MTB chainring and a more of a road freewheel, things are getting messed up. Could that be the case?
     
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  2. alfeng

    alfeng Well-Known Member

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    The weight difference of the two bikes is incidental ... or should be incidental in your consideration ... particularly, AFTER you add additional weight by packing gear onto the bike.

    How much gear, if any, can you pack onto your Decathlon? Or, is this a tour-by-wallet or one supported by a SAG wagon?

    The highest gear on your MTB is awfully low ... even for touring.

    What is your LOW gearing?

    If you were to set your chain on the inner (presumably, 39t) chainring on your Decathlon & the 14t cog in the rear, you wouldn't be able to zip around the countryside very quickly ...

    I would think that minimally you would want a 42-34-24 "standard" MTB crank + 11(or,12)-32 gearing in the rear. A 44t, 46t, or 48t large ring would probably be MUCH BETTER.

    What size tires do you have on the Decathlon? 700x25? 700x23?

    Since you have a steel framed MTB -- 700c wheels suggests that it is actually an old touring frame from the mid-80s to early-90s which you are referring to as a MTB because it probably has cantilever brake calipers -- even if the frame has 135mm rear spacing, the stays can be squeezed (when tightening the rear skewer) onto a 130mm spaced rear wheel, why don't you (temporarily) swap your ROAD wheel onto the MTB? THAT should give you a sense of how the frame feels with a lighter wheel & tire. YOU WILL PROBABLY HAVE TO ADJUST THE REAR DERAILLEUR's STOPS for this test ride since it sounds as though you've got a 7-speed freewheel on the MTB & probably a 9-speed wheel (if you have an 8-speed wheel, so much the better) on your Decathlon ... go to friction mode on the shifters ... ignore the chain rub (if any) as this is only a 10-minute test ride.

    NB: Since the wheel off your Decathlon has narrower rims, you would normally need to adjust the brake calipers, but since you will only be replacing the rear wheel AND you should be relying on your front brake to stop, you can probably skip the rear brake adjustment.

    If THAT all sounds too tedious to do, then you have to rethink this entire tour unless there is a going to be a reliable mechanic going along with you ... you could have a trouble free tour OR ...

    Well, let's just say you want to have as intimate a knowledge of your bike as possible.

    Your current MTB wheels could simply need service OR to be replaced ... at least the HUB should be replaced with one that uses a cassette instead of a freewheel ... or, consider having a "new" Shimano-compatible freehub laced to the rim.

    A 700x32 tyre is actually a lot smaller than a 700x35, and should possibly on you shopping list. I think that a 700x30 or 700x32 cyclocross TRAINING tyre is pretty close, dimensionally, to a 27x1 1/4 tyre which would be considered pretty beefy and will possibly be more-than-adequate for your trek. I think a 700x35 is the size you would use for a really heavy, loaded touring experience ...

    How is the bottom bracket on your touring frame? Does that need servicing?

    Heck, your brakes could be dragging on the rims ...

    A lot could be happening to make the unloaded touring bike seem sluggish ...

    Sight-unseen, I would (if not inferred, already) do everything you can in the next half year to make the touring frame ride as-close-as-possible to the way you want it to feel when it is not loaded with gear.

    BTW. You will PROBABLY want to mount a set of fenders on the bike unless you are doing a trans-Saharan tour! If you can't mount fenders on the Decathlon, then ...
     
  3. Gotte

    Gotte New Member

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    Thanks for that comprehensive answer.
    I always knew the MTB chainring was much too small. I did have a road chainring fitted at one time, and much as it gave me a higher(?) gearing, I fond it almost impossible to haul my daughter about on it (as I was doing at the time) if I was starting on anything over a gentle gradient.
    The Decathlon has 700x23 tyres.
    The MTB has a small chainring of 25, and a largest rear gear of 30.
    The road chainring has max 52, and a min of 42 (only two chainrings).
    I have got another rear freewheel (screw on) which is has is more teeth on its biggest ring, I might try it.

    You're right, my Decathlon is 9 on the back, so mismatches my MTB, which is 7.

    I've checked bottom bracket and brakes, none are rubbing. I sometimes wonder whether it's just a combination of the wrong ratios, a slightly more upright position and more drag from the tyres.

    I guess my main concern is that the MTB ticks all the right boxes for touring - more relaxed, steel frame with longer stays and a long wheelbase, 700 wheels with broader tyres, a more upright position, but is less exhilirating to ride.

    I wonder whether position isn't a main factor. I'm tempted to take the drop bars off my Decathlon and fit them to the MTB, to see if a lower, more racelike position doesn;t improve things.

    Again, many thanks for the input.

    Any further comments are much appreciated.
     
  4. Gotte

    Gotte New Member

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    Just to let you know. I changed the chainset, and you know, the difference in the MTB is astounding. I put on the old road chainset I mentioned, and it really is a different bike. So there you go, one simple change.
     
  5. NuCommuter

    NuCommuter New Member

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    Alfeng,

    What an amazing, comprehensive, knowledgeable answer you gave this guy.

    In my religion, that's a lot of good karma!

    NuCommuter
     
  6. Gotte

    Gotte New Member

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    I second that.
     
  7. Velotour

    Velotour New Member

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    You might also want to check out your chain rings in the front. I have a touring bike that felt slow and unresponsive for a while, but I knew that it had felt very responsive before that. What I did was change chain rings. I changed the entire crank arm and chain ring assembly from the steel I got in China to aluminum alloy I got in the US. As soon as I pedaled with the alumunium alloy that old feeling of responsiveness and quickness returned to my ride. It might not be the gearing. It may be the chain rings themselves.
    Are they the thin aluminum alloy rings or are they the more cumbersome steel rings. These things can make a difference.



     
  8. Gotte

    Gotte New Member

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    Thanks for that. Yes the MTB chainring was steel, and I did swap it out for an alu road crankset. The difference is amazing. A different bike altogether. THanks for the input.

    Gotte
     
  9. Velotour

    Velotour New Member

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    So then it was the chain rings. That was exactly my experience. I outfitted my touring bike in China because the components were much less expensive than in the USA---Marathon touring tires for $2.50, Shimano deraileurs for $2.00, really strong touring wheels for $7.00, chain $1.50. But I made the wrong choice for chain rings. They looked really great but there was a sort of perceptible drag in the pedaling. I got to hating it after a while and could not figure anything was wrong except the chain rings. And sure enough, as soon as I switched to light weight aluminum alloy the responsiveness and quickness returned. That is a fact and that is the reason I suggested it to you.

    Good cycling.
     
  10. Gotte

    Gotte New Member

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    My ony probelm now is that the chainset I've got feels a little too narrow. It's an old Campagnolo, with straight arms down from the rings. THe pedal are nice, but old, with a kind of lip at the outside edge to keep your feet on when in the toe straps. Trouble is my shoes rub a bit on the crank arm and feel a bit too far in. I might have to change the BB for a wider one, or change the pedals. We'll see.
    Again, many thans for the input

    Phil
     
  11. Velotour

    Velotour New Member

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    You all ready have that problem solved. Get wider pedals. I too got too narrow pedals once and had the same problem. The solution is a simple one and it works quite easily and well.
     
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