TA Carmina Chainset review.
Back in the good old days (sorry, couldn’t resist saying that), when derailleur-geared bikes only had five freewheel sprockets on the back, it was common to choose exactly what ratio you wanted. Freewheel manufacturers made a variety of custom options to cater for the demand, all be it from a choice of only five sprockets! To achieve the desired gear ratio it was also normal to choose which size chain rings you used on the front. Back then, normally only two rings were used, since triple chainsets were vary rare. Manufacturers like Stronglight and the more up market TA enabled this to be done; both had a large share of the market as a result; Shimano back then were far less popular than they are today.
As sprockets increased and triple chain sets became commonplace, the variety of gears naturally increased to the extent that it is now less of a problem to achieve the desired gear ratio ‘off the peg’. However, many still prefer to choose a specific set of chain ring sizes. Tourists especially often desire slightly lower all round gearing than the faster set up usually found on road bike specific chainsets, triples included, most of which are 30/39/50; for many this is just larger than they actually desiree.
Stronglight and TA still offer a full custom built set up, with an extensive variety of options to help you achieve your personal choice of gear ratios. TA is still the more upmarket of the two, their Carmina range is indeed a very well made and finished piece of kit. Many buy their quality chain sets on merit as apposed simply to achieve custom chainring sizes; I personally have four I like them that much! The most popular is the ‘Carmina’ as used here with chain ring sizes from as low as 24t up to 60t and with crank lengths from 150 to 180mm. This flexibility is achievable through the use of a replaceable CNC-machined spider. Simply choose the spider that suits your chainring selection and match it with your preferred crank length. There are spiders available for various BCDs and for both double and triple setups, in effect you use the same crank arms for each and simply build that into either a double or a triple as desired.
Front mech line can be difficult when using unusual size rings, look how the mech follows the radius of a larger chainring.
A triple setup to achieve lower overall gearing is why the majority chose TA for. I have chosen 26/36/46 with a 13-29 cassette as it gave me a reasonably high top gear as well as a set of useable low gears that should get even an unfit me up most climbs (mid 90” top with most wheel tyre combinations and high 20” low). It was not just about how low and high the extremes were, just as important is that the most often used gear ratios are available where chain line is as straight and therefore as smooth as possible, making the whole transmission also last longer as a result.
Note care is needed when choosing chain ring sizes, in my case by using chain rings smaller than the front mech’ was designed for does mean I have compromised on how well the front shifting works. Nearly all road bike mech’s are designed for larger overall rings, as you can see the ’mech line does not follow the chain ring’ so the mech’ pushes the chain too far away from where the chain disengages the chain ring. This can and in this case does mean that you don't get such good gear change, more noticeably when changing into the smallest ring. I have got it working just good well enough for me, but it is definitely a compromise, I try not to change down under full pressure and if possible not when in the largest rear sprocket, I get a better shift if I am in 3-4th sprocket down as the mech' engages the chain nearer where it was designed to do, as a precaution I have also fitted an ’Overshift Protector’. Worth bearing in mind that each individuals perception as to what is and what isn't acceptable interms of the compromises that need to be made will naturally vary. My own conclusion is that I am prepared to 'fettle' some of the gear changes and sacrifice efficient shifting to achieve the ratios I want, justifiably others conclude that they would rather have the gears work as they should, at the expense of not having quite the ratios they desire.
Interms of the bottom bracket TA offers a tapered unit, available with either a steel or Titanium axle. Both are arguably less impressive than the chainset as the bearings are not in their own protective housing. This leaves them more exposed inside the frame and easy to damage/crush when fitting should the cups be over tightened. Be warned this is easily done as you tighten the LH cup against the bearing, where as with most tapered BB units the bearings are inside a protective housing which not only offers greater protection from the elements, but in comparison to the TA unit also stops the bearing being crushed by the LH cup. I've attached a picture below that may help to illustrate.
TA Axix BB on left, Shimano JIS taper on right.
I have used this chain set for nine years and almost immediately I swapped the BB unit for something cheaper due to problems, I tried several over a variety of bikes and after far too little time the units all developed a knocking noise. Care is needed when choosing to use another brand of tapered BB as there are two popular choices. One is called 'ISO', as used by Campagnolo, the second far more popular has a 'JIS' taper (Japanese Industrial Standard) used by many including Shimano. Both JIS and ISO use the same two degree taper, the main difference is in the actual length of the taper, the JIS version being slightly longer. If you try and put a crank designed for a longer JIS BB onto the shorter ISO BB (like a Shimano Chainset onto a Campagnolo BB), then the crank arm may bottom out on the axle/spindle as shown below.
This is where it gets confusing as TA on their own website quote the shorter ''ISO square taper', where as the UK distributor Chickencyclekit.co.uk advised they were the longer JIS! I was asked to clarify this quite often back when I was running the CTC Shop, the answer is infact that the taper is not only longer than the shorter ISO taper, it's actually longer than the JIS as well! To clarify this can be easily seen if you click on this link where I have measured all three, you will see the TA Axix BB is clearly the longest of the three, I used a vernier gauge to measure the TA then offered that upto the other two to compare. I now use the JIS Shimano BB unit's on all four bikes that have this chain set as the taper is long enough, I've used them for nine years and all have worked perfectly.
In conclusion, BB unit aside this is a well-made chainset, not cheap, but to many, myself included, worth the investment. With such a variety if options available it can get a bit confusing working out exactly what you need; my chain set was made up of the following, links and text from the UK Distributors site www.chickencycles.co.uk with additional edits from me:
Specially designed with pure, traditional lines and a smooth shape with road clearance to keep a low Q-factor. Highly polished with satin finish
6061 T6 Aluminium Alloy
ISO Square taper
Chainring range 22 - 61T
Requires C.N.C spider/lockring (not supplied with cranks)
Detachable spiders (double/single or triple) (94,104,110,130pcd)
113/116mm Bottom bracket required with triple use.
Edit from me: I used a 116mm BB, my Van Nicholas Yukon has a front mech' clamp size of 31.8mm. if I fitted a narrower BB the chainset fitted with clearance between small ring and chainstay, although the front mech' would not shift far enough inwards, it simply hit the seat tube before dropping the chain onto the small ring
For Fitting RH crank to spider
Spider CNC 6082 T6 aluminium alloy.
Triple chainring fitting.
130 - 110 - 104 and 94mm pattern circle diameter.
Carmina and Vega crank compatible.
Edit from me: You need to chose the correct spider to suit the pcd of the chainrings, my chainset had quite small chain rings and and I used the 'Triple 5-Arm Spider Black 110/74pcd' size, where as if you wanted larger rings you would use 'Triple 5-Arm Spider Silver 130/74pcd'
74 PCD mine fitted with 26t, available 24t through to 36t
110pcd mine was fitted with 36 middle 46t outer, available 34t through to 53t (note you can go to 60t with a 130mm pcd ring and spider)
Middle rings can be used as inners on a double chainset.
To fit middle and outer to spider
This bottom bracket offers great lightness, two ball bearings.
Compatible with frame shell of 68 and 73 mm.
AXIX Light steel axle
lengths 103 to 131 mm - weight 220g (L103mm).
I used a 116mm BB, my Van Nicholas Yukon has a front mech' clamp size of 31.8mm. if I fitted a narrower BB the chainset fitted with clearance between small ring and chainstay, although the front mech' would not shift far enough inwards, it simply hit the seat tube before dropping the chain onto the small ring
Aluminium Self extracting dust cap set 2030 T4 anodised alloy.
2 Brass washers
Lightweight only 18g per set
Black, Blue, Red, Silver.
When I stopped using the TA Axix BB I also stopped using the self extracting bolts, I now use the bolts with built in plastic covers that came with my Shimano JIS BB, so that I can use a standard Park CWP-7 - Crank Wrench & Puller. I come from a generation when cranks were fitted with normal bolts, unlike the bolts shown below they were covered by a separate dust cap to not only cover the bolt, but protect the crank puller threads in the crank arm from the elements. The trouble is that often over time the dust caps would fuse in to the crank arms. Many an hour wasted delicately trying to remove a stubborn dust cap, attempting not to damage the threads so that the crank puller could still be used; I feared the same may happen with the self extracting rings so was more than happy to revert to a bolt with plastic cap that did not use the crank arm thread. As with the old fashioned dust caps the two small pin holes are easily damaged especially if you are having to use a bit of torque to remove a fused dust cap or in this case 'ring'. In reality that maybe a hang up I should dismiss, although if you do like the self extracting bolts I would recommend removing the two rings on a regular basis with a 'pin spanner' and use 'anti-seize'; at least annually!
Prices 2nd January 2017 from www.chickencyclekit.co.uk
Written and reviewed by Paul Smith for roadcyclinguk.com and continually updated since