Kojaks on a Brompton

[Gerry Attrick]

Has anyone changed from the standard Brompton "green label" tyres to Kojaks? If so, is it a worthwhile swap in terms of speed?

 

[dellzeqq]

speed over the road, or speed while fixing punctures? It's a half serious question - I see punctures on Kojak-shod Brommes a lot, but I've only had the one on my Marathon Pluses in getting on for four years

 

[smutchin]

I tried Stelvios on my Brompton, which were the precursors to Kojaks. I didn't find they offered any significant speed advantage (over the road) over the M+, and they were far more prone to punctures. I don't know how Kojaks compare to Stelvios but after my experience with Stelvios, I've never been tempted to try them.

d.

 

[Gerry Attrick]

I'm not too concerned about punctures. Firstly because there is nothing more difficult in repairing a puncture on a Brompton than on a conventional bike. It is just different. Secondly, I live in a rural area and have very few problems, even with a tubular shod vintage BSA and my old pub bike with tyres some say are puncture prone.

I was more interested in whether the Kojaks are a significant improvement over the Bromptons in reducing the vague "pedalling through treacle" sensation they have.

 

[GrumpyGregry]

I like the Kojaks on my B. Fast rolling. Don't have any recent stock tyre experience to compare with though.

 

[Pottsy]

As above, I have Kojaks on mine but no experience of other tyres on the Brompton.. Certainly pumped up to 100+ PSI they feel pretty nippy though. Don't forget they'll save a bit of weight too - it all helps when you're carrying the thing up stairs somewhere.

Personally I don't worry too much about punctures as I don't use mine for commuting or any urgent trips and since I live in London, I can just fold it up and get a bus/train/tube or taxi if I'm stuck.

 

[Gerry Attrick]

Thanks for the observations. I may have to resort to the wallet!

 

[RecordAceFromNew]

As a matter of interest, has anybody tried Conti Grand Prix 20" x 1-1/8 ( otherwise known as 28-406 )? It seems both lighter and takes higher pressure ( 120psi vs 95psi ) than the Kojak.

 

[Crankarm]

I was thinking of fitting slick tyres to mine but don't know which to go for.

I keep the brompton kevlar tyres on it at the moment near max recommended pressure which makes a difference in reducing rolling resistance. It can still bimble along at 20-25mph with minimal effort although I would like to exert slightly less effort than minimal.

 

[steveindenmark]

Do the new Kojaks have the pucture resistant strip inside them or have they always had that?

Steve

 

[RecordAceFromNew]

Do the new Kojaks have the pucture resistant strip inside them or have they always had that?

Steve

I think the question is not whether there is a puncture resistance strip, but what puncture resistance strip. Afaik they changed over the years, but currently have Raceguard (with emphasis on lightness and low rolling resistance), and which is described and compared here. There is also a huge technical doc somewhere with further info.

 

[ufkacbln]

speed over the road, or speed while fixing punctures? It's a half serious question - I see punctures on Kojak-shod Brommes a lot, but I've only had the one on my Marathon Pluses in getting on for four years

That is my take on this... Puncture repair times are significant on a rear Brompton wheel.

I really don't think that the speed gain would weigh up over a long period of commoting

 

[Rohloff_Brompton_Rider]

i have had kojaks on my brommie for long time now and had no issues. i ride everywhere, roads, bridleways, canal towpaths and manchester/salford roads full of glass. i've not had a single puncture yet. i rode approx 2000 miles on green's, 6000 miles on marathon+, 1000 miles on marathons (horrid tyres) and have done about 2000 miles on kojaks.

in my opinion and experience the kojaks are a superior tyre and mine only cost a tenner each from sjs (wire bead). as with all brommie tyres they're easy to install / remove with the right tyre levers (skinny metal ones).

repairing a rear puncture is no big deal and takes about 3 mins longer (to remove the gubbins) than the front.

edit: superior grip as well (on hard surfaces), more rubber in contact with the surface (see sheldon brown, if you don't get it).

 

[threebikesmcginty]

Saw this picture the other day and I guess it's relevant to the thread in that there's Kojak and bikes, back when kids had racers

 

[smutchin]

repairing a rear puncture is no big deal and takes about 3 mins longer (to remove the gubbins) than the front.

Repairing a puncture on either wheel takes longer than not having a puncture to repair.

d.