Mavic MA40 compatible tyre size?

GaryGkn

Can Mavic MA40's (700c) take 23c tyres or 25c?
I have put some 28c on as they were lying around but they look too big for the bike.
The width of the rims looks like 18-19 mm. I have some Open 4CD rims which are skinnier and they had 23c tyres mounted.

I have some 23c on a BJ Vigorelli and was thinking of putting some 25's on this bike to soften the ride a bit. The 23's could be used on the MA40's which I have just put on an old road bike.

Any info much appreciated.

Anonymous

Apparently they are the old 27 1/4" tyres. Panaracer do a decent set set on the paselas. Kevlar and everything for puncture resistance.

http://www.ukbikesdepot.com/products.php?plid=m2b0s121p353

Dickie

MA40s may come in 27" (I have a set of MA2 in 27"), but they are far more common in 700c. Gary you can fit 28c on MA40, MA3, G40, MA2 etc

GaryGkn

My MA40's are 700c but 28's look too bulbous for the frame they actually fit but look very heavy and over sized was hopping to fit 23c?

Thanks everyone.

Dickie do you have any Raleigh Twenty tips?

Dickie

Gary, 23s on MA40s will be fine.

The twenty is next on the list. The mods I have settled on are.

It has 451s and the gold mafacs I have will cope with the drop from 451 to 406, but from a fixed point of view that puts the b/b very close to the ground, about 9.5" from a rough calculation. I would prefer at least 10" ground to b/b-cntr. So it may end up single speed.

Mill b/bkt shell to 68mm and fill threads with silver solder. Bore b/b shell to size and re tap 24 tpi.

Remove all braze ons. Put new ones on for r/brake. Pump pegs are staying.

Set rear triangle to 120mm. 410mm seat pin just does it.

Silver solder ring round the top of the head tube for strength, ream and face h/tube. Bottle fittings behind head tube and front of seat tube. S/S bolt for the hinge.

The fork, what a piece of sh-t. Remove or extend steerer tube to give around 6-7" of steerer showing above the aheaset. Turn long spacer! Make a jig to restrain the fork to reset the oln to 100mm. File the fork ends paralell, instead of the keyhole slot. Mine is a green stowaway, my unc suggested it be renamed the throwaway. Im inclined to agree. Way too much work and never worth the time invested. I've started so I will finish...
F-kin thing.

GaryGkn

I am in the same boat. Didn't want a Brompton. Did want a fixed folder. Saw Sheldons. Read up on it bought a Stowaway. Jammed a cotter pin. It just goes on...got 406 wheels ...will now need a 160 crank or less. Now I have started will have to finish! Agree that it seems too much work. Thanks for the feedback it has inspired me to complete. Wished I had stuck with the original wheel size.

Dickie

Gary, just spoke to Chris Grange at bakers bikes 01279 758718. 451 rims £11, lots of 27" and obscure tyres as well, loads of clssic stuff. He does campag lookalike b/b cups in 26tpi and is having a coterless spindle made for the 77mm b/b later in the year. The rims are wheel chair rims so have 4 extra holes for the hand rim.

GaryGkn

Thanks Dickie. I have not got to the BB yet do you think it is better to stay with 26 tpi I would be glad to rid of it but could work out cheaper. I have not tackled the the bb shell yet as the cotter pin is still jammed. This will be the status for the next fortnight as got to work late to meet deadlines etc. My bb is still 77mm 26 tpi. I will have to think of which way to go.

Dickie

You would save a lot of time machining/fitting etc by leaving it 77mm/26 tpi. I dont like doing anything non reversable but I still prefer the idea of fitting a cartridge as it is a better idea and does not rely on the b/b faces being dead square to each other.

Forgot to add the stand is not long for this world. It will be known henceforth as the F-kin Raleigh throwaway. I really should buy a Dahon, I'm just to tight.

GaryGkn

I like/prefer the idea of using a sealed bb. Although the stand has been useful while I was stripping the bike I was tempted to grind it off but the cotter pin is my mine job for now. Will probably have the 4.5mm faced off each side of the bb and get it re tapped to 24 tpi. It would probably be cheaper to buy a new Dahon!