Cycling UK Forum

Sorry if I'm doing this wrong - until the last couple of days I'd never been on any sort of forum so I don't know the form. This isn't a new topic but I didn't want people to have to wade through all the stuff on my post and I now just have one last question so I thought I'd put it separately. I feel drawn to the 7.5 FX Trek - Evans have a 2011 man's that has triple chainset 48-36-26 and 11-26 cassette with 700 x 32 tyres. There's also a 2013 WSD which has 50/34 (compact) and 11-35 cassette with 700 x 28 tyres. My present bike is a 17" 7300 multrack Trek (not WSD) with 700 x 35 tyres. I am going to try both bikes out on the weekend (weather permitting) but obviously won't be able to go up hills etc. Let's say they both actually feel good to ride on the flat. The question is, even if the man's bike wasn't £150 cheaper cos of age I wonder if it would be better for me anyway? Despite helpful comments to my post I still don't fully understand the ins and outs of gears.

If you’re going to test ride a bike or two, you really need to take a keen eye with you to see if the bike can be adjusted to you without too many components being changed.
The staff at Evans might stand in the car park and watch you ride round, but their recommendations may be spoiled by a ringing sound from the cash register.

Without the keen eye, the other method is to ride the bike round and glance down at the front spindle. Assess whether through adjustment, the front spindle can be made to disappear behind the handlebars. If this looks possible, that’s a good start.
If it is that the gent’s bike’s reach is too long and even with a short stem, the front spindle can’t be brought to hide behind the handlebars, it’s NOT the bike for you.
Everything else on a bike can be changed. The toptube length can't. Hence Women Specific bikes.

A PS. Most Caucasian women can get away with a gent's bike because their Sitting Height Ratio ( body length vs total height is 52% ) is similar to the caucasian male. Negro ladies have longer legs than their males, resulting in a 50% SHR. To satisfy this, North American makers designed WS bikes but couldn't call them Negro Specific bikes.

re the ins and outs of gears; The range of gears with the compact double is about the same as the triple.

However;

1) when you use the front derailleur, there is very big jump downwards or upwards in comparison to the triple setup, requiring a messy 'double shift' where you need to use both front and rear mechs. Trying to do this on a steep hill means that you may grind to a halt at the least convenient moment.

2) if you took a straw poll of CTC members and other (experienced, non racing) cyclists as to what size gear they would be using on a flat road for (say) a 50-mile ride, most would answer between 55 and 70 inches. Any slight incline or headwind will reduce the chosen gear substantially. On the triple this means various gears in the middle chainring, mostly with a fairly straight chain run. However, on the double setup you are thinking of this means 50/22 or thereabouts (50/22 is a ~61" gear) on the flat and lower gears than this is soon as you encounter a hill. This means that for touring, anyway, you will mostly be using the leftmost sprockets with the rightmost chainring (giving a badly angled chain run), and when you meet a moderately steep hill you will have to choose your moment to do the double shift.

3) Because the gear range in with the outer chainring of the double isn't large enough (or at least doesn't go low enough), you will need to do the double shift more often than you might like.

Badly angled chain runs (running cross-chained) cannot entirely be avoided with a derailleur system; however the trick is to set the gearing up so that you don't need to use such gears very much of the time.

In fairness if you have not learned to pedal as others do (which most might find easier on the knees than pedalling slowing in a higher gear) you may not find the same problems, and in addition the triple setup on the other bike isn't brilliant either; for touring, I'd look to have them change the 11-26 cassette for a 12-32 or something, giving a more useful range in the middle ring plus some lower gears, leaving the big chainring for when the going is good e.g. downhill, or with a brisk tailwind.

Tourists, if they choose a double chainset, often might go for (say) 46 or 44 outer and ~28 tooth inner (or smaller) chainrings or something. You can't fit chainrings that size to the currently available 'compact double' chainsets.

hth

cheers

littlegreyrabbit wrote:Despite helpful comments to my post I still don't fully understand the ins and outs of gears.

Tried reading Sheldon Brown?

My advice is unequivocal, and unchanged from your previous thread.
Save your money....buy some Premium Bonds.
By about September, 2013 bikes will be reduced.
Use the time between now and September to learn to pedal with a high cadence, and play with your riding position.

Of the 2 bikes in question, I could find no data for the old model...not surprising.
Treks website tells me there are slight differences between the current "womens" and "mens" bikes.
The womens bikes have slightly shorter top tube, and slightly higher head tube. So far so good, but you could make a bigger difference fitting a different type of handlebar. (riser/swept bar)
So IF THESE WERE THE ONLY TWO BIKES IN THE WORLD, I would buy the one with the triple chainset.
But they aren't the only 2 bikes in the world, and they aren't really TOURERS.
Even the mans bike has a steep seat tube angle....the womens version is even steeper....this pushes the saddle forward, and puts more weight on your hands.
Thats OK if you are 20 years old, and going hell- for -leather all the time, but I'm at the age I like to take my time, and I need the saddle well back.
Also my knees need the saddle well back.....you need to use your current bike as a test bed to investigate your riding position.
http://www.trekbikes.com/us/en/bikes/road/fitness/fx/7_5_fx#/us/en/model/fit_sizing?url=us/en/bikes/road/fitness/fx/7_5_fx

Thanks for advice everyone. Colin I understand what you are saying about waiting until September and the reasons for doing so, which seem sound. However I think I really want to stick with a triple chainset, simply because it's what I'm used to. Even if I can get a 2013 reduced it will still be a compact (that is if I stick with the 7.5 Trek). It seems the longer I leave buying a secondhand Trek the less chance I have of getting a triple.