Jamil.Siddiqi said:
Hi,
I changed from 26" MTB to 21" MC rims and tires. What I noticed is the huge difference in weight (~ 5kg per wheel, with rims, tubes and tires ) and also the reduced top speed. I was previously able to do about 70 kmh on a slight downhill, which is now down to 60-65kmh. I have the Shinko 244 (2.75 x 21), which are indeed quite wide. They look really cool (with a Lauf Carbonara fork).
Interestingly the average speed increased, since I can just go over small obstacles instead of going around them. With that the range has gotten less by 10-20% (1.5KW hub motor 14S8P - going to upgrade to 26S shortly). I usually ride 30-40km.
I would like to go a bit lighter and am hence considering 18" or 19" MC wheels (I build them myself). Most of the Conti tires listed above are only rated for 50 km/h, hence that will not work. The RF tires are good for 100 kmh, hence I might give them a try. I was also considering the Heidenau K40 or M3 tires. Does anyone have experience with Heidenau? Specifically the weights and rolling resistance (I presume the Shinko 244 have a horrible rolling resistance). The K40 should be fast for street use, but is only available in 18". I am not sure if I want to go from 21" to 18" (seems small).
Since I actively pedal, I would need a larger chainring when I go to smaller tires. I can do about 55kmh with my 52T. I found an 85T 130 BCD chainring for folding bikes. Does anyone have experience fitting something like that?
Best regards
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i have used heidenau m3 on the front in 19"*2.5, really nice tyre, light, low rolling resistance but feels secure.
heidenau k40, i have used 18" 2.5, on rear. solid, fairly heavy, low rolling resistance,firm grippy when new, but now the center of the grip has gone and slews sideways in wet on road.
i have a heidenau k39 on hand, 18*2.75 looks to be really solid and grippy on road with low resistance, quite heavy though. i never tried it but will soon.
im now full convert to the sr241 religion, 19 2.75 front, 17 2.75 rear. they rock!
great on road, grippy as hell, surprising low rolling resistance! they will take just about anything off road too. makes me ride in totally different style
they seem to last really well to boot.
there are some light moped tyres out there. i used hutchinsons vroom 16*2.5 they were nearly as light as mtb. i got them from treatland tv.
the one i have is still nailed to the rim of my 5404 with a large nail from the edge of the highwy...has sat there some 2y since the flat incident like that..i moved onto cromotors and qs :lol:
btw, id love to see a link to the tubeless kit you got.