Not happy with my new bike

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J1234 10 Aug 2018

I bought two of these https://www.decathlon.co.uk/triban-500-road-bike-black-id_8379069.html after reading all the good reviews and not having much to base things on. One for me and one for my wife.

My wife thinks hers is OK, maybe a bit noisy. I think mine is bob. Its really noisy with the chain slapping the front derailleur and it seems to keeping jumping a gear or dropping a gear. Not pleseant to ride at all.

I suspect a problem I have is I have one of these https://www.evanscycles.com/trek-6300-d-2012-mountain-bike-EV148955 or very similiar and the gear change and the whole drive is soo much better and more pleseant.

Am I expecting too much.

I know in bike world £349 is inexpensive, but I am a bit surprised with the drive train issues, I would have thought that basic stuff.

In reply to J1234:

Sounds like an indexing issue, easily missed but also easily remedied. If you're still in-period for the after-shave check-up then take it in and get he shop to do it. Otherwise, the park tool website has a really solid guidance page - you can do it yourself but just need to be aware that:

A) the front derailleur can be notorious ously fiddly and,

B) the response of the rear derailleur can be very different under load, so ride it around a bit and play with the barrel adjusters to get it just so.

 

While it may be poor set up, it's just as likely that the cables etc. have bedded in. Should be no biggy.

Post edited at 10:01
In reply to J1234:

*After sales

 LastBoyScout 10 Aug 2018
In reply to J1234:

You should be able to sort those issues with just a bit of fiddling with the cable tensions.

It's possible the front mech is slightly out of alignment, also easily fixed.

The rear mech hanger might not be quite accurate, either - easy to fix, but you need a specialist tool, so that's usually a job for a competent bike shop.

J1234 10 Aug 2018
In reply to J1234:

I tried to adjust the front mech but made a hash of it.
I took it back and the lad said he knew nothing and the mechanic was out, so swapped the bike.
I had the same thing again on the new bike, and took it back, the mechanic was in and fettled it, kind of.
The issue returned. At the weekend my mate who builds bukes for people and knows his stuff, fettled it at the weekend , and its back again.

TBH if I had bought £7k of fine tuned racing bike, I would expect I might have to keep adjusting, but this is not one of those.

At the moment I am only riding 30 - 50 miles a week. IMHO its not even fit to commute on

 the sheep 10 Aug 2018
In reply to J1234:

Cheaper bikes have cheaper components, these will include the cables. Its quite likely that your have stretched causing the issues with the gear jumping. I have had it on more expensive bikes and its not uncommon. 

If its still under warranty etc. just take it back and get them to re index the gears. It will save you a lot of faff!

J1234 10 Aug 2018
In reply to the sheep:

The shop is 22 mile round trip

 FinrodFelagund 10 Aug 2018
In reply to J1234:

Bit off topic, but I'm just looking at the specs for that triban 500.

The largest cassette cog is 25. This is strange, no, on a beginner road bike? 

Admittedly it comes with a triple chainring. The smallest chainring is 30, which gives a ratio of 30/25=1.2. This is roughly equivalent to a standard 50-34 double and a 28 cassette, with 34/28=1.2. 

But you can get plenty of beginner road bikes with 32 cassettes, giving 34/32 = 1.06. And the whole point of having a triple is to give you an even wider gearing range. Why negate the benefit of the triple by fitting a small cassette? 

If they want the bike to be beginner friendly, why haven't decathlon gone for a triple with a (pretty standard) 28 cassette, giving 30/28=1.07?

To summarise, beginner priced road bike doesn't have particularly beginner friendly gearing. 

Rigid Raider 10 Aug 2018
In reply to J1234:

Decathlon bikes look like fantastic value but the wheels are cheap as chips and don't last very long and components are not great either. That said, the bike should at least work. I have found Decathlon mechanics to be friendly and happy to make adjustments so why don't you take it back again? If you're still unhappy, demand your money back and go to a proper bike shop, not a supermarket, and ask what they've got at your budget. Many will have trade-ins of quite nice bikes they want to sell on.  I found a superb Peugeot road bike for £250 at Bicycle Doctor, low mileage and over-oiled so in great condition once I had cleaned it up and removed all the commuting paraphernalia. 

1
Rigid Raider 10 Aug 2018
In reply to FinrodFelagund:

A wide-ratio cassette on a triple would give you far too many overlapping gears. Have a look at some gear charts to see what I mean.

 Neil Williams 10 Aug 2018
In reply to J1234:

Just keep riding it and fiddling with the barrel adjusters (the turny things which are either on the gear changer, on the derailleurs or both).  Eventually you'll get it spot on, you may need to fiddle with them repeatedly as the cables stretch and it all beds in.  I tend to buy bikes in this sort of price range and I've never had one where I *haven't* had to do that.

Note that on a lot of bikes if you use "opposite" gears i.e. high rear, low front or low rear, high front you will get some noise.  This isn't really avoidable, and I don't think I've ever had a bike where it wasn't the case.

FWIW Decathlon are a box shifter - but of incredibly good quality stuff for the price.  I've not long bought a Hoprider 500 and it is without doubt the best city bike I have ever had in that sort of price range (not least because they do it in a size that fits me at 6' 4" with long legs properly!)  If you're not happy with doing it yourself, spend the money to take it to a proper local bike shop and have it fettled there.  It won't cost much and they'll get it as good as it's going to get.

Post edited at 10:23
J1234 10 Aug 2018
In reply to J1234:

Hmmm, is this user error then?

 FinrodFelagund 10 Aug 2018
In reply to Rigid Raider:

> A wide-ratio cassette on a triple would give you far too many overlapping gears. Have a look at some gear charts to see what I mean.

I see what you're saying. 

But if you swap a double and wide cassette for a triple and narrow cassette, you get lots more gears but no increase in range. I'd have thought an increase in overall range is the most important thing on a beginner bike?

Post edited at 10:56
 JLS 10 Aug 2018
In reply to J1234:

I'd have thought this was just a new cable stretching issue that will settle down in due course.  Replacing the cables with higher quality versions MAY truncate the process but I'd stick with it for now.

Rigid Raider 10 Aug 2018
In reply to J1234:

It's not cable-stretching; cables don't stretch. What happens is that the cable ends settle into the ferrules especially if they haven't been cut square and ground flat before fitting, effectively lenghtening the inner cable. A turn of the barrel adjuster unscrewing will usually take out the slack.

Another reason for dodgy shifting is a misaligned rear derailleur hanger, caused by clumsy handling or the bike falling on its right side, entirely possible in a supermarket. The mechanic should have an alignment gauge for checking and minor corrections though big corrections need a new hanger as they are made deliberately brittle so as to be sacrificial and they will work-harden and snap.  

 

 nniff 10 Aug 2018
In reply to J1234:

It's not unusual - I have a bike with dura-ace on it and it doesn't like operating big/big or little/little.  It also has midway positions on the front shifter because the tolerances are so close - it effectively has 'big ring left' and 'big ring right' positions.  Having said that, it shifts quickly up and down with a swift click, until it gets out of tolerance at the front and the front derailleur needs a nudge.

Shimano advise against big/big or little/little.  SRAM say it doesn't matter and I forget Campagnolo's position.

Either way, with a widish chain (i'm guessing 8 speed for your bike) and three rings, one extreme to the other isn't going to be good.  The middle ring should cope OK though.  

As a guide - big ring to smallest sprocket - chain should just clear the front derailleur and rear DR should be in line with the smallest sprocket.  IF you pull the cables by hand, neither DR should move further out.

Little ring to biggest sprocket - chain should just clear front DR.  Rear DR should be in line with largest sprocket.  Tension should be out of the cable but not loose.   The DRs will have two screws - one marked H and one L.  The L one adjusts the position of the rear DR in relation to the largest sprocket (Low gear) and H the position in relation to the smallest sprocket (High gear).  Front DR is opposite way round.  Screwing the screw in extends the protrusion into the mechanism, and restricts the movement - It's easy to feel with a finger.  Adjust the cable with the barrel adjuster (see a website - shimano, park tools or sheldon brown)

Adjusting is easier with a bike stand, or hang the bike by the saddle on a broom handle resting on two wheelie bins 

Post edited at 11:58
Rigid Raider 10 Aug 2018
In reply to J1234:

Yes, I forgot to mention that it's bad practice to cross the chain too abruptly across the transmission because you are forcing it to change direction twice under tension, which will wear it fast, not to mention exceeding the capacity of the front derailleur cage causing clattering. 

Small ring should do the inside half of the cassette. 

Middle ring can do all of the cassette.

Big ring should do the outside half of the cassette.

In reply to J1234:

Your problems will only ever be solved on a temporary basis. If you're lucky you'll get a few hundred miles between adjustments. 

Make yourself really competent in adjusting the derailleurs.  There isn't a huge amount to it and once you've done it a few times you'll start to get the hang of it. There's plenty of good resources out there showing you how to do it. I found the shimano product leaflets invaluable. 

Like you I have a front triple. It's a bhatch. My model is a tiagra and there are actually 4 positions( inner, outer and two middle). When I sussed that things became slightly easier to adjust. 

Buying a bike stand will make working on your bike so much easier.

I'd never buy another bike with a front  triple but I'm stuck with it for now. 

 chiroshi 10 Aug 2018
In reply to FinrodFelagund:

You also have to consider derailleur capacity. If you start putting big cassettes on a triple, then you'd need an extremely long cage on the rear derailleur, and it'd be bouncing around all over the place.

 gethin_allen 10 Aug 2018
In reply to Rigid Raider:

> Decathlon bikes look like fantastic value but the wheels are cheap as chips and don't last very long and components are not great either. My £670 triban 540 came with mavic aksiums and mostly 105 drive train which is pretty good as the wheels are about £150 and the 105 brifters and mechs are around £230. Pretty good if you ask me and if you look down the range you can get the sora version for £500.

J1234 10 Aug 2018
In reply to J1234:

I have dropped it off and left it with them. As always the staff at Decathlon where nice.

The chap I spoke to rode the bike around the store and replicated the fault. Hopefully they will resolve the issue.

I will pick it up tomoz.

I think I will have to get proficent at adjusting, but not every 30 or 40 miles as we want to be riding 50 or 60 a day.

 


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