Carrera TDF Limited Edition 2013 (I think!) - The Wrong Gear?

[Mongoose]

Got my SRAM 11/28 cassette through which is now fitted to the Carrera TDF with 52/38T chainset at the front. I used the original 52T outer ring and changed the 42T inner ring for a 38T obtained from Ribble. I did a brief 15 mile test run tonight and first impressions are that I have now found the correct set-up for me for the moment. I don't appear to have lost anything on the hills and find the change up and down at the front much smoother and more comfortable than with the 50/34T chainset previously fitted. Planning to do 50 miles in the morning to be sure.

 

[Mongoose]

I can now confirm that I'm delighted with the new set-up of my Carrera TDF 2013 with 52/38T up front and the 11/28 cassette at the back. I enjoyed a very comfortable 50 miles today. I found the gear ratios ideal for me across the full range, high and low, and the transition between the front rings is now much more comfortable and manageable. At no point did I feel I hadn't got the right gear. It's taken a while to get to the right configuration but it has been great fun reading, learning, fitting and testing. I've learnt a huge amount about all aspects of cycling in the process.

For all Carrera TDF owners who inadvertently bought the model with the 52/42T front chainset (Pro Wheel silver chain rings) and find the hills a struggle, don't despair. This bike, 8 speed with paddle gear shifters, is a much better bike than the current 2014 model (and it's immediate predecessor). Don't be put off cycling or feel you have to trade in your bike because, at a small cost, you can have a fun and faithful runner.

To summarise, after 3 months of my owning the bike, I would recommend these simple changes in the following order until you find your most comfortable configuration.

1. Change the 42T inner ring to a 38T. This is cheaply and easily done. You don't need to be a bike mechanic to do this. You can get a 38T ring for around £10. I got mine from ribblecycles.co.uk. Fitting the chain ring requires a crank removal tool to take the pedals off and a hex key to swap the inner chain ring. You don't need a new chain and no adjustments should be necessary to the front or rear derailleurs. If you do it yourself, do take a good look at how the rings and crank spider all fit together before you dismantle them.

2. If you don't find this improves your experience enough then I would recommend changing the rear cassette from the 12/26 to 11/28. This is very simple to do as well. I managed this easily enough with a chain whip and cassette removal socket. I got a SRAM 11/28 cassette from Wiggle for £12.50. I have read that you don't need to change the chain but, having added two teeth to the biggest ring at the back, I fitted a new chain with one extra link (55 links). Once you have done this you have a similar gearing to a compact double (50/34T) with a 12/28 cassette in the lowest gear but a significantly higher gearing (13.5%) at the top end.

By tomorrow I will have completed 2000 miles on my Carrera TDF since the middle June. I'm looking forward to the next 2000 being a more enjoyable experience with The Right Gear!

 

[johnpenn81]

@Mongoose A complete novice here who wants to make the change to the 38T chainring. Could you provide the exact details for the 38T front ring please as i have looked on the website you provided but there seems to be different sizes.

Out of interest how do you measure the size?

 

[Big_Dave]

I agree, altering the gearing to suit your own style of riding is a must on any bike regardless of its price tag, you have found your "Ideal set up", my gearing 3x10 30/42/52 11/32 is ideal for me, Nigel (Viking bike) has his own 3x10 ideal set up, 3 different people with 3 different set ups, it's what works for us as individuals to improve our cycling experience.

 

[Nigelnaturist]

@Mongoose I might have gone with a 12-28 cassette, it is als possible to easily mix and match the rear cogs, I believe the sram have screws holding the cassettes together (shimano use rivets), undo these the cassette will come apart and you can use what cogs you want (providing of course they are not worn). Not sure on your ratios but I would have started with the original 12th and work fro there. 52x11 is a really big gear. I actually never went below a 52x13 on a 52 ring or 48x12 on a 48, both being the same gear of 105".

 

[Big_Dave]

I do use the 52 11gear on the long faster descents just to keep the legs spinning with some resistance even at 43 mph its a comfortable cadence. I tried the 12 27 yesterday and it was about 5mph slower on the descents so can probably live with that. On the flat it was great having a 1 tooth jump between 12 17 gears.

 

[Nigelnaturist]

I do use the 52 11gear on the long faster descents just to keep the legs spinning with some resistance even at 43 mph its a comfortable cadence. I tried the 12 27 yesterday and it was about 5mph slower on the descents so can probably live with that. On the flat it was great having a 1 tooth jump between 12 17 gears.

No doubt Dave, but it is the only time most of us would use such a combination, and as you just quoted its good having the closer grouping, you wouldn't have that option on an 8sp starting at 11, I spin out on a 52x13 (105") at just over 34mph 110rpm 52x12 just over 37mph even I struggle pushing that gear downhill more due to speed and cadence rather than the length so I just tuck in after that, mind you round here I have probably got to the bottom by then
I did set up on a 48/38/26 chainset a 12/13/15/17/19/21/24 which gave a good range of 28.5-105" a bit short on both ends than mu current set 29.2-114" swapping the 12 to an 11 would have given it 28.5-114.8, the same pretty much as my current set up.

 

[cyberknight]

On a slightly different angle i found the standard compact 50/34 to much a drop so i changed to a 36 inner ring running a 12-25 cassette which gives me a good spread of gears and i dont spin like a madman when i drop onto the small ring which is what i used to do before .
The weekender has the same 50/36 with an 11-28 because if i go on a club run they seem to know where all the meaty hills are and of course down hills.....

 

[Mongoose]

@Mongoose A complete novice here who wants to make the change to the 38T chainring. Could you provide the exact details for the 38T front ring please as i have looked on the website you provided but there seems to be different sizes.

Out of interest how do you measure the size?

Here is the link http://www.ribblecycles.co.uk/sp/ro...al-130mm-shimano-8-9-10-chainring/strochri300
You will need a crank removal tool and a hex key but it is very straight forward. You shouldn't have to adjust anything else unless you are changing the rear cassette too. I should change the inner ring to 38T and give it a whirl. If you have the 12/26 rear cassette you will notice a big change. If it is still not enough then you may need to get the 28 teeth on the rear.

Good luck, enjoy and look forward to hearing how you get on.

 

[Mongoose]

@Mongoose I might have gone with a 12-28 cassette, it is als possible to easily mix and match the rear cogs, I believe the sram have screws holding the cassettes together (shimano use rivets), undo these the cassette will come apart and you can use what cogs you want (providing of course they are not worn). Not sure on your ratios but I would have started with the original 12th and work fro there. 52x11 is a really big gear. I actually never went below a 52x13 on a 52 ring or 48x12 on a 48, both being the same gear of 105".

I'm pretty sure the 11T and 12T are interchangeable as the old and new cassettes are both SRAM. The 11/28 came with the 11T & 13T detached. When I removed the 12/26 cassette the 12T was detached. I shall bear you suggestion in mind. I am finding myself using the 52T x 11 and even when I'm not I enjoy knowing there is something in reserve!

 

[Mongoose]

@Mongoose A complete novice here who wants to make the change to the 38T chainring. Could you provide the exact details for the 38T front ring please as i have looked on the website you provided but there seems to be different sizes.

Out of interest how do you measure the size?

In response to your question about the size.........

I'm not a cycle mechanic or an engineer but I enjoy tinkering so don't quote me on this but I think the size is the diameter of the chain ring measured across the ring between the holes for the hex nuts IF they were opposite each other or 'diametrically opposed'. Engineers refer to this as PCD which I think is short for Pitch Circle Diameter. Of course because there are 5 holes for the hex nuts, equally spaced around the circumference, none of them are diametrically opposite each other so it is tricky for us mere mortals to measure. I'm sure someone will put me right on this. In the case of the offending 52/42T chainset / crankset that came with the Carrera TDF 2013 (Shamano Claris paddle gear shifters and silver Pro Wheel crankset) this diameter is 130mm.

I forgot to mention that you will need a hex key to undo the crank bolts too. I don't normally like to advertise and I don't want to add to your costs but, on this occasion, I will let on that Aldi do a fairly comprehensive cycle tool kit for about £20 that contains everything you will need to make all the changes I've suggested and maintain your Carrera generally.

I hope you will let us know how you get on and be reassured that you've got a lot of bike for the money. Change that inner chain ring, get those tyres pumped up (120 psi) and get out and enjoy. You may have noted from earlier in this chat, that, as I fall into the category of the heavier cyclist, I had to upgrade my tyres after suffering numerous punctures including two on one outing. Mongoose

 

[cyberknight]

Here is the link http://www.ribblecycles.co.uk/sp/ro...al-130mm-shimano-8-9-10-chainring/strochri300
You will need a crank removal tool and a hex key but it is very straight forward. You shouldn't have to adjust anything else unless you are changing the rear cassette too. I should change the inner ring to 38T and give it a whirl. If you have the 12/26 rear cassette you will notice a big change. If it is still not enough then you may need to get the 28 teeth on the rear.

Good luck, enjoy and look forward to hearing how you get on.

Am i mis reading your reply ? a crank removal tool ?
When i changed my inner rings all i did was undo the bolts holding the spider together and slip the rings over the crank arm, no need to get a crank puller and take the crank off.

 

[Mongoose]

Am i mis reading your reply ? a crank removal tool ?
When i changed my inner rings all i did was undo the bolts holding the spider together and slip the rings over the crank arm, no need to get a crank puller and take the crank off.

Fair comment. I hadn't thought about doing it this way as, although I didn't need to, I changed my bottom bracket too, which did require removing the cranks.
No need for the crank removal tool or hex key for the crank bolts then. Just a hex key to undo the five hex bolts holding the spider and rings together.

 

[Nigelnaturist]

Am i mis reading your reply ? a crank removal tool ?
When i changed my inner rings all i did was undo the bolts holding the spider together and slip the rings over the crank arm, no need to get a crank puller and take the crank off.

It doesn't always work, depends on the rings and cranks.
@johnpenn81 as @Mongoose says the P.C.D. or B.C.D. (Bolt centre diameter), it can be worked out from measuring from centre of one hole to the centre of the next,
and then use this table to work out you B.C.D. most are pretty common 130mm normal double, 110 compact doubles (this is why they are compacts, not the chain ring sizes), you can't fit a ring of less than 38th to a 130mm its why they use the 110mm for the 34th, 74mm BCD is usually used for the inner ring, though Shimano triple use different sizes, my prowheel has a really odd size in that i cant find a size to fit. Campagnolo double is 135mm BCD so it is important to check them.

 

[Dogtrousers]

Engineers refer to this as PCD which I think is short for Pitch Circle Diameter. Of course because there are 5 holes for the hex nuts, equally spaced around the circumference, none of them are diametrically opposite each other so it is tricky for us mere mortals to measure.

SHeldon to the rescue http://www.sheldonbrown.com/cribsheet-bcd.html