kj
Peloton Rider
Posts: 21
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Post by kj on Mar 29, 2017 22:34:27 GMT
B'Twin Ultra 720/920 frame proportions are unusual, I am in doubt
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kj
Peloton Rider
Posts: 21
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Post by kj on Mar 29, 2017 22:40:50 GMT
Hi all, this is my introduction as well. I just reentered to cycling last summer after 20some years of break. Assembled an MTB from old parts, but rode on road, always, average 70 km per turn (calculated) but only few times over 100 km. I would like to change to road bike, and found B'Twin Ultra 720/920 AF the best buy. (Only the number has been changed from the last year.)
Now I have got the bike few days ago and I cannot relax.
I am 183 cm tall with 86 cm inseam. Ordered size L as "Chosing the Right Sized Bike" of B'Twin recommends. All sizes are OK, but unfortunatly the stand over height is slightly over 83 cm therefore it touches my testicles when I stand over. (Inseam is measured up to pubic bone of course, which is higher.) I try to calm myself that smarter guys than me, engineers intentionally designed this frame for my body size, it should be good. Hovever that standover height - relative to length of the tubes - seems at least unusual.
On the other hand size M with 548 mm top tube and 147,5 mm head tube would be unconfortably small for me when riding.
Do anybody have similar experience or advise on this?
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Post by chas on Mar 30, 2017 6:25:02 GMT
Tighter shorts? Seriously though when you say you can't relax do you mean you're uncomfortable riding or worried about stopping? If you're comfortable riding and like the bike I would carry on, you'll soon develop a technique for stopping slightly to one side. Other options would be the smaller frame and longer stem or a 540 which has a more compact design.
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Deleted
Deleted Member
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Post by Deleted on Mar 30, 2017 6:37:11 GMT
Welcome kj I'm the same height as you with slightly longer inseam. my T3 is size 60 Mach a 63. The T3 was/is spot on the Mach had to be slightly modified by cutting a bit off the seat post/shortening handlebar stem. Neither gave me any problems with the top tube. I would suggest (if you can) get to Decathlon store and give the bike a try before you buy. All the best.
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kj
Peloton Rider
Posts: 21
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Post by kj on Mar 30, 2017 17:26:00 GMT
I see it is not the best place where I created this thread, but "search" function found only one occurence of the word "Ultra" in this map, and I did ot find that adequate. Now I see there are lots of folders and also threads in which I could enter. If there is a moderator please feel free to move this wherever you think.Thanks for replies. No, I dont worry about stopping at all and I do not feel myself in danger but strange. My soul cannot relax I have already bought the bike, this is why I know the size and the situation. Unfortunately not Decathlon (B'Twin) publish stand over data. If so, then I would have been in doubt before buy I wanted this bike because of grandious specification. There were not this model at Decathlon stores in the whole country, I had to order to get one from France. I could RMA for a size M one, but I am afraid that is not my size at all, is significantly smaller than anything recommended for me. On that size only the standover fits to me, nothing else. There is a rather fair calculator at www.competitivecyclist.com/Store/catalog/fitCalculatorBike.jsp and also if I compare the length of the tubes to Bianchi, BMC, Cannondale bikes in my size, everything shows that L is my size. But the stand over! The 'big book' says that the top tube must not touch you. That might be a superstition only, I do not know. Smart guys designed this bike like this. Therefore I am interested in your user experience.
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Post by chas on Mar 30, 2017 22:08:28 GMT
The size guide on the UK website puts you at the top of the height range for a med at 6' (183cm) if you are so concerned swap for that, you will be able to acieve the same position by changing the stem and possibly the seatpost (more layback)if necessary. blog.decathlon.co.uk/guides/guides-cycling/btwin-road-bike-size-guide/Bikes with a more traditional horizontal top tube naturally offer less standover clearance, I would worry much more about your position when riding than when stationary.
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kj
Peloton Rider
Posts: 21
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Post by kj on Mar 31, 2017 1:03:20 GMT
Thank you chas, I know the chart, as I pointed out I would worry more about size M. The strange thing why B'Twin pulled the top tube as high on this bike? Size L is recommended from inseam 84 cm and (all other sizes are perfect but) the stand over height is 83.7 which makes 0.3 cm clearance. Proportions are strange, not? I restarted cycling after ca. 25 years break, I am like a reactivated dinosaur and do not understand this. However tighter shorts were a good idea, I will adapt Anyway, if you are expert I have got less theoretic questions as well. I have never seen integrated crankset before. If there is no chain on the chainring, and I jog the crank a little bit, it stops within a half or one turn. Is that normal? No noise and smooth run, but permanent force must be applied to keep it moving. (If I jog the crank on my vintage MTB it rotates for half minutes.) The other thing is the operation of fancy inline shift cable adjuster. There is a little wheel inside, which sometimes tightened, I cannot turn. Then I turn the full thing around the cable, what makes possible to turn the inside wheel. Is that normal? (I do not want to corrupt deralliur setting, a quarter turn there, a quarter turn back.) Maybe the inner wheel makes the setting and turning the whole thing locks that to avoid unintentional change? Unfortunately got no documentation and I could not find on the web, neither. I am the guy who thoroughly read the user manual of even a toaster
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Post by chas on Mar 31, 2017 7:08:51 GMT
The shorts suggestion was half in fun but do you wear bibshorts they help keep everything in place?(I sometimes have trouble with longs that aren't bibs that come down a bit and snag getting on and off the saddle) Modern cranks don't seem to spin as easily as old square taper ones when spun under no load, this is down to the seals and apparently under load there's no difference. I've never read any instructions about the inline gear adjusters and have found like you that sometimes they don't turn and rotating the whole thing helps. It never occured to me it might be a lock feature, maybe you're right? I'm sure you'll be happy with the bike once you get some miles done together, stop worrying and ride it
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Post by r0b1et on Mar 31, 2017 13:15:29 GMT
I tested my TT bike the other day and got off vertical, rather than tipped.
My danglies didn't appreciate it. But I've never noticed before, and I won't again... rding position is what matters, and as long as you can stand over it at lights etc (likely at an angle), then it's fine... might be a good excuse to learn to track stand! (I suck at it, but I'm getting better)
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kj
Peloton Rider
Posts: 21
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Post by kj on Mar 31, 2017 15:43:12 GMT
chas, thanks a lot for help i have already ordered a pair of endura shorts
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kj
Peloton Rider
Posts: 21
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Post by kj on Mar 31, 2017 15:57:11 GMT
r0b1let, thank you too, indeed I focus on riding position, this is why not RMA for size M. A CAAD12 Black Inc. in my size (58,5 cm seat tube) sports 81,2 stand over, maybe more comfortable at the red light, but not the same price. However that Ultra frame seems to go against the trends. Or is that the French charme? Track standing on a road bike (with freehub)... I am an old fat baldy guy, must not make myself more ridiculous as I am on my new bike by default
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