New Bike Build

[maltena]

Hi everyone, I'm going to building a bike from a used Racelight Kinesis T2 Alloy frame with carbon forks. It's a training road bike from around 2015. Rear axle 130mm, front 100mm. Here's a link for more info: https://road.cc/content/review/137576-k ... celight-t2

I know that probably sounds like a weird frame to use but I have my reasons. I wanted something relatively lightweight that can be a day tripper/commuter, but still take a bit of weight for going on overnight trips and carrying my son. The mudguards and rack mounts were also an attractive extra. I got it for £82, so pretty happy with that as a start. My budget is £1500 and I'm pretty confident I can do it.

In terms of the groupset, I'm thinking of going a Shimano Ultegra 8000 series (rim brakes & not electronic) with Mavic Open Pro rims, carbon seat post, carbon handlebars, and anything else that can be carbon. I have a few questions that I'm struggling to find the answers to.

First question is can I fit a 12 speed cassette to an 11speed Ultegra groupset (derailleurs, chainset & freehub)? As far as I can tell I should be able to, but not 100% confident. Are there any variables that I might across that I should be prepared for?

Second, my setup will be 50/34T on the front, 11/34T (12 speed) on the back. Is 34 too much, or would I be better with a 11/30T? Remember it's a 9kg bike, potentially carrying weight, and I also live in Scotland so will likely come across some steepish hills (10%max). I like the idea of going for an 11/30 and just training for hills at the gym so I can blitz them, but maybe that's overly optimistic, I don't know?

Third, what carbon dropbars and seat posts do you all recommend for a comfortable ride (not too racey)?

Fourth, which seat is the modern lightweight version of a Brooks? Or is that just a stupid question

And lastly, have I lost my mind?

If anyone has any similar experience or input please tell

[531colin]

Interesting choice of bike to put a child seat on.

[cyclop]

Hi.I also have a used Kinesis K2,recently retired in favour of a used ex cyclo cross frame which accomodates up to 50mm tyres(currently 42mm).Before spending a shedload on your very capable Kinesis,I,d have a few doubts about the wisdom of loading up with a child seat,luggage etc.Despite the versatility of modern bike frames,you may be asking too much of this combo.With your budget, do a bit more research .It would be a shame to trick out the Kinesis for it not to be bob on for your needs.Used gravel with discs maybe ?Specialized diverge gravel/adventure....good selection on ebay.

[Manc33]

Don't get a cheap carbon seatpost, or even a carbon seatpost at all, just get a Thomson Elite. Mine is only 285g in the 410mm (27.2mm) version.

[Delidroid]

Hello. I have fitted a Brooks C17 saddle to my Bike. I originally fitted it for long distance rides but it's so comfortable I left it on

[Jupestar]

Where are you planning to put your son on that bike? Rear bike seat?

[Jdsk]

Where are you planning to put your son on that bike? Rear bike seat?

That's what I was wondering as well. And how the load will be injected into the frame.

Jonathan

[oaklec]

Interesting choice of bike to put a child seat on.

That really tickled me

[maltena]

Sounds like I've underestimated the capability of the bike to carry a child, especially as he gets older, so wont be doing that then. I have an old 501 steel frame Raleigh I can use instead so that's no biggie. To be fair, I would be using it mostly as a training bike/day tripper so it still suits me well.

[Jupestar]

Sounds like I've underestimated the capability of the bike to carry a child, especially as he gets older, so wont be doing that then. I have an old 501 steel frame Raleigh I can use instead so that's no biggie. To be fair, I would be using it mostly as a training bike/day tripper so it still suits me well.

Its the weight - the only way i think you'll get a child seat on that is hanging off the seat tube and basically beyond the rear axle. It will be a pretty misrible experience for both of you, and not a particularly safe solution particularly for loading/unloading the passenger.

If your building a bike for purpose make it work.

I;ve tried a few, and in my opinion if you want to take you child on bike rides you both enjoy, look for a Weeride seat or similar, or a MacRide depending on the age. then build/buy the bike to suit the two of you. For me thats a nice big tyred rigid MTB with wide flat bars. I have 2 sets of wheels. one with 29 x 2in slicks, one with 29 x 2.3 in MTBs tires. Mostly i go off road with them, but i use it to ship him around town hence the wheels with slicks on!

[Will]

First question is can I fit a 12 speed cassette to an 11speed Ultegra groupset (derailleurs, chainset & freehub)? As far as I can tell I should be able to, but not 100% confident. Are there any variables that I might across that I should be prepared for?

A 12-speed cassette should physically fit on a 11-speed hub (as they are both 41.2mm), but it won't index properly with 11-speed shifters. An 11-speed shifter will allow you to shift between 11 sprockets on the rear - the derailleur will shift the chain the correct distance for an 11-speed cassette. The sprockets on a 12-speed cassette are closer than on a 11-speed cassette (since you have 12 sprockets in the same space as 11) and so the indexing will not work.

Will

[maltena]

Sounds like I've underestimated the capability of the bike to carry a child, especially as he gets older, so wont be doing that then. I have an old 501 steel frame Raleigh I can use instead so that's no biggie. To be fair, I would be using it mostly as a training bike/day tripper so it still suits me well.

Its the weight - the only way i think you'll get a child seat on that is hanging off the seat tube and basically beyond the rear axle. It will be a pretty misrible experience for both of you, and not a particularly safe solution particularly for loading/unloading the passenger.

If your building a bike for purpose make it work.

I;ve tried a few, and in my opinion if you want to take you child on bike rides you both enjoy, look for a Weeride seat or similar, or a MacRide depending on the age. then build/buy the bike to suit the two of you. For me thats a nice big tyred rigid MTB with wide flat bars. I have 2 sets of wheels. one with 29 x 2in slicks, one with 29 x 2.3 in MTBs tires. Mostly i go off road with them, but i use it to ship him around town hence the wheels with slicks on!

Thanks. I've ditched the child seat idea for now. I'll use my old steel frame for that

[maltena]

First question is can I fit a 12 speed cassette to an 11speed Ultegra groupset (derailleurs, chainset & freehub)? As far as I can tell I should be able to, but not 100% confident. Are there any variables that I might across that I should be prepared for?

A 12-speed cassette should physically fit on a 11-speed hub (as they are both 41.2mm), but it won't index properly with 11-speed shifters. An 11-speed shifter will allow you to shift between 11 sprockets on the rear - the derailleur will shift the chain the correct distance for an 11-speed cassette. The sprockets on a 12-speed cassette are closer than on a 11-speed cassette (since you have 12 sprockets in the same space as 11) and so the indexing will not work.

Will

Thanks for that, really helpful. I've actually gone for a Shimano 105 groupset now. Got it for £300 with shipping on Ali Express all genuine parts . Just have to wait for it to arrive

The freehub is the same for Ultegra & 105 so I can still get a 12 speed on if I want. Like you say I might need to update the shifters though.

[Will]

First question is can I fit a 12 speed cassette to an 11speed Ultegra groupset (derailleurs, chainset & freehub)? As far as I can tell I should be able to, but not 100% confident. Are there any variables that I might across that I should be prepared for?

A 12-speed cassette should physically fit on a 11-speed hub (as they are both 41.2mm), but it won't index properly with 11-speed shifters. An 11-speed shifter will allow you to shift between 11 sprockets on the rear - the derailleur will shift the chain the correct distance for an 11-speed cassette. The sprockets on a 12-speed cassette are closer than on a 11-speed cassette (since you have 12 sprockets in the same space as 11) and so the indexing will not work.

Will

Thanks for that, really helpful. I've actually gone for a Shimano 105 groupset now. Got it for £300 with shipping on Ali Express all genuine parts . Just have to wait for it to arrive

The freehub is the same for Ultegra & 105 so I can still get a 12 speed on if I want. Like you say I might need to update the shifters though.

As far as I am aware, the only way you could get 12-speed with rim brakes is to use an Ultegra ST-R8150 shifter and Ultegra ST-R8150 Di2 rear derailleur. I don't think there is a 12-speed combination with both mechanical shifting and rim brakes. 105 12-speed came later than Ultegra 12-speed and by the time it came out, Shimano had settled on disk brakes for road bikes (so the 105 12-speed mechanical shifting is hydraulic disk brakes).

A Ultegra ST-R8150 right shifter and Ultegra ST-R8150 Di2 rear derailleur + cassette would cost around £550. That is a lot of money to pay for 1 more sprocket on the rear.

Will