Changing bars, gears & brakes

[pubrunner]

Hi All,

I've an elderly Carlton Pro Am, which would form the basis of an excellent bike for my eldest lad. Thing is, he has an aversion to drop handlebars and downtube changers.

What I'd like to know is, where can I find a kit to change the downtube shifters ? I'd be changing to 'horizontal' bars and I'm not sure which type of gear changers would be most suitable/possible ? He likes 'grip shifters' & 'thumb shifters' on the mountain bikes that we own - would it be feasible to transfer these over ?

Would it even be possible to use bars, brakes and changers (the whole lot) from an old mountain bike ? (I have a quill - AHEAD convertor)

Has anyone done such a conversion ? Are there any pitfalls of which I need to be aware ?

Thank you for any suggestions.

 

[MacB]

you've got a few options depending on how much you want to spend, the easiest would be to get thumb mounts to allow you to move the DT shifters onto the flat bars, you'll find these under gear spares on the SJS website. For trigger shifters it depends on the mechs/No of gears but should also be feasible and probably not much difference pricewise to getting the thumb mounts. Either way you'll need new cables to cover the longer distance.

Then there's the brake lever, as it's a road bike then it's probably got caliper or canti brakes, both of which are short pull, so standard MTB/v brake levers won't work as they are long pull. You'll need to get flat bar road levers to match the brake pull required.

 

[pubrunner]

Cheers MacB ,

I think that this will be the start of an exciting new project.

I might as well have the frame powder-coated into a colour that'll suit a trendy teenager.

Ta v. much !

 

[tyred]

I might as well have the frame powder-coated into a colour that'll suit a trendy teenager.

Ta v. much !

When I was a teenager, I used to re-paint my bike on an almost weekly basis, depending on what was fashionable that week...

 

[HLaB]

I've converted a flat bar to drops and it was quite straight forward. You'd only need new cables to convert downtube shifting to flat bar shifting. Drop levers pull half as much brake cable as flat levers, I'm not sure how that effect your conversion. I used Problem solver travel agents to overcome in part the problem.
Just a general thing but I'd go with thumbshifters rather than gripshift, its more comfortable on the hands.

 

[tyred]

Surely any old school MTB lever designed for canti brakes would work fine with calipers.

 

[MacB]

Surely any old school MTB lever designed for canti brakes would work fine with calipers.

yep, it's only v-brake, or MTB mechanical disc brake, levers that won't - not all bike shops/bike mechanics seem to be aware of this....more than one story of a shop fitting mismatched brakes and brake levers

 

[Zoiders]

Surely any old school MTB lever designed for canti brakes would work fine with calipers.

Yep they work fine like McB said, shifters can be replaced with cheap thumb shifters a well, you just turn the indexing off on the front mech shifter.

Having said that there are one or two V-levers that will do the job, namely the old LX lever with the adjustable pull.

 

[RecordAceFromNew]

Flat bar combined brake-gear levers that can be adjusted to be compatible with all types of brakes are readily available, and should let anyone used to mtbs feel at home. Imho, in this world of inexplicably expensive drop bar sti's they are outstanding value for money.

A question remains in terms of gear cable pull compatibility, i.e. what rear wheel the Carlton has (and in particular whether it can take an 8* speed cassette at the back to index perfectly e.g. with the above levers), and whether the front mech will index (but you wouldn't need to worry about indexing up front if you only have a double chainset, which I suspect is the case?).

If the rear wheel can only take a freewheel then as long as it is a 7 speed one it should still index tolerably well with the above 8 speed shifter, the reason is because the sprocket pitch difference between 7 and 8 speed is only 0.2mm - so if indexing is set correctly at the 4th sprocket the worst case error at the extreme sprockets is only 0.6mm, which is hardly noticeable in the scheme of things.

Of course indexing at the back is also dependent on whether the rear mech is compatible with the current 5/6/7/8/9 speed Shimano mechs, so it is dependent on its age/make. This is no big deal either way, decent compatible ones can be bought for a few £s and up.

Perhaps the only remaining potential pitfall is related to handlebar/stem dimensions for your conversion. As usual the late great Sheldon provided excellent info.

* for the same reason as 7 speed freewheel being workable, if the wheel has a 7 speed cassette it will also index fine with an 8 speed shifter if set up as described.