Bosveldbaas Posted October 26, 2019 Share Hi. I have a Scott mtb with Chain set: Shimano FC-M627 2-piece Design 700 Series: 38x24 T, and rear casette: Shimano CS-HG50-10 11-36 T. I have a set of slic tyres for road riding, but want to change my cassette to different gear ratio. I run out of ratio on descents. What cassette will be more suitable for road race? Link to comment Share on other sites More sharing options...
Veebee Posted October 26, 2019 Share Change of cassette isn't going to help, you need bigger rings upfront to help with your problem, or rather just buy a road bike and leave the mtb where is belongs shaper and DieselnDust 2 Link to comment Share on other sites More sharing options...
DJR Posted October 26, 2019 Share I agree with VB, the shortcoming is too small a big chainring upfront. Not sure how big you can go and still have it work with your derailleur, but if you want to have a chance to keep up with the roadies on the fast flats and downhills, you are going to need something with at least around 50 teeth. From my experience, you will be frustrated and buy a road bike sooner or later, purely because it is the right tool for the job. You can buy real 2nd hand roadie bargains that are a few years old but still competitive, will not lose value and won't cost much to maintain. (Unlike mtbs) Edited October 26, 2019 by DJR DieselnDust and Wayne pudding Mol 2 Link to comment Share on other sites More sharing options...
NotSoBigBen Posted October 26, 2019 Share Must agree with Vb and DJR, either accept the limitations of using an MTB in a road race or beg, steel or borrow the right tool for the job ... Link to comment Share on other sites More sharing options...
Bosveldbaas Posted October 26, 2019 Share Thank you all! Link to comment Share on other sites More sharing options...
A.K.A Posted October 26, 2019 Share Hi You can change the front rings to a 40/28 set up arendoog 1 Link to comment Share on other sites More sharing options...
Bosveldbaas Posted October 27, 2019 Share How hard can I pump these slick tyres with a tube for mtb? 700x35C 28x 1 5/8x 1 3/8 Link to comment Share on other sites More sharing options...
DJR Posted October 27, 2019 Share A quick thumb-suck? See if there is a pressure indicated on the outside of your tyres. I think 60 to 80 psi (5 bar) should be pretty efficient and comfortable for an average weight rider (70-80 kg) on large volume tyres like yours. But you can go up to 100 -120 psi (7-8 bar ) which will reduce rolling resistance but also increase harshness and reduce grip. Lighter riders will get the same effect at lower pressures, heavier riders will have to up pressures a bit. Best is to get a floor pump with a good gauge and experiment around the block. I find that I intuitively "feel" where the ride quality feels best - where the sweet spot is - and that is the pressure I use. Edited October 27, 2019 by DJR DieselnDust 1 Link to comment Share on other sites More sharing options...
bertusras Posted October 27, 2019 Share A quick thumb-suck? See if there is a pressure indicated on the outside of your tyres. I think 60 to 80 psi (5 bar) should be pretty efficient and comfortable for an average weight rider (70-80 kg) on large volume tyres like yours. But you can go up to 100 -120 psi (7-8 bar ) which will reduce rolling resistance but also increase harshness and reduce grip. Lighter riders will get the same effect at lower pressures, heavier riders will have to up pressures a bit. Best is to get a floor pump with a good gauge and experiment around the block. I find that I intuitively "feel" where the ride quality feels best - where the sweet spot is - and that is the pressure I use. Remember that MTB rims are not designed for the same pressure as road rims. DJR and DieselnDust 2 Link to comment Share on other sites More sharing options...
DJR Posted October 27, 2019 Share Remember that MTB rims are not designed for the same pressure as road rims.Where is the sensible upper limit? (Asking because I don't know and I don't want anybody to blow a rim at 40 km/h. in the middle of a bunch.) Link to comment Share on other sites More sharing options...
DieselnDust Posted October 27, 2019 Share Hi. I have a Scott mtb with Chain set: Shimano FC-M627 2-piece Design 700 Series: 38x24 T, and rear casette: Shimano CS-HG50-10 11-36 T. I have a set of slic tyres for road riding, but want to change my cassette to different gear ratio. I run out of ratio on descents. What cassette will be more suitable for road race? You're pretty much maxed out on the available chainring sizes for the 104/64 BCD cranks. Your options are too; 1) fit a CX crank with 110BCD 2) fit a 10T cassette (very limited gearing upgrade) 3) get a road/CX/gravel bike Link to comment Share on other sites More sharing options...
DieselnDust Posted October 27, 2019 Share Where is the sensible upper limit? (Asking because I don't know and I don't want anybody to blow a rim at 40 km/h. in the middle of a bunch.) most are rated 65psi max as the tyres are max 55psi. DJR 1 Link to comment Share on other sites More sharing options...
jdwet1980 Posted October 27, 2019 Share I have never owned mtb rims that was rated for more than 4 bar. DJR 1 Link to comment Share on other sites More sharing options...
DJR Posted October 27, 2019 Share So, please ignore my high pressure advice above. Just buy a road bike! Link to comment Share on other sites More sharing options...
arendoog Posted October 27, 2019 Share Hi You can change the front rings to a 40/28 set upI did exactly that with a hardtail mtb and pumped my tyres to 2.5 bar .It was my first road bike .On a 100km race you will lose about 6-8 min because of the bike Link to comment Share on other sites More sharing options...
A.K.A Posted October 27, 2019 Share I did exactly that with a hardtail mtb and pumped my tyres to 2.5 bar .It was my first road bike .On a 100km race you will lose about 6-8 min because of the bike Pump youre tyres 3bar + all depending what the rim &tyre allows ,my buddy did a 3h28 on his mtb in his first argus on this ratio Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now